Nutritive value of maize silage in relation to dairy cow performance and milk quality

Influence of maize genotypes and harvest stages on in-silo fermentation quality and nutritional value of corn silage during hot summer condition of the tropics

The aim of the experiment was to evaluate the potential of promising summer maize genotypes and optimal stage of harvesting these genotypes for ensiling in terms of dry matter (DM), starch, and crude protein (CP) yields, silage fermentation quality, nutrients profile, total digestible nutrients, metabolizable energy (ME) content, Cornell Net Carbohydrate and Protein System (CNCPS) carbohydrate (CHO) subfractions composition, in vitro DM digestibility (DMD) and in situ starch degradation characteristics. Six maize genotypes were chosen for the study: DK9108 from Monsanto, P30Y87, P3939 from Pioneer, QPM-300 (quality protein maize) and W94 from the International Maize and Wheat Improvement Center (CIMMYT), and a local cultivar, Afgoii, from the Cereal Research Institute (Persabaq, KP). A total of 72 plots (8 m × 10 m) were blocked in three replicate fields, and within each field, each genotype was sown in four replicate plots according to a randomized complete block design. For the data analysis, the Proc-Mixed procedure of Statistical Analysis System with repeated measure analysis of variance was used. The DM yield was strongly influenced (P < 0.001) by maize genotypes, varying from 12.6 to 17.0 tons/ha. Except for total CHO and ammonia nitrogen (NH3-N), the contents of all measured chemical components varied (P < 0.001) among the genotypes. Further comparison revealed that, genotype P3939 had a higher (P < 0.05) content of CP (7.27 vs. 6.92%), starch (36.7 vs. 27.9%), DMD (65.4 vs. 60.0%), ME (2.51 vs. 2.30 Mcal/kg) and lactic acid (5.32 vs. 4.83%) and lowest content of NDF (37.3 vs. 43.1%), pH (3.7 vs. 4.10) compared to the local cultivar (Afgoii). Advancement of post-flowering maturity from 25 to 35% DM (23 to 41 days after flowering (DAF)) increased (P < 0.05) the DM yield (10.4 to 17.8 tons/ha), starch content (29.1 to 35.0%), DMD (65.3 to 67.3%) and ME (2.34 to 2.47 Mcal/kg), and decreased (P < 0.001) the contents of CP (7.42-6.73%), NDF (48.8-38.5%), pH (4.10 to 3.60), NH3-N (8.93-7.80%N) and effective degradability of starch (95.4 to 89.4). Results showed that for higher yields and silage nutritional and fermentation quality, maize crops should be harvested at whole crop DM content of 30-35% (34 to 41 DAF). It was further concluded that genotype P3939 is the most suitable summer maize genotype for silage production in terms of yields and silage nutritional and fermentation quality under the hot environmental conditions of the tropics.

Effect of commercial fibrolytic enzymes application to normal- and slightly lower energy diets on lactational performance, digestibility and plasma nutrients in high-producing dairy cows

The inclusion of fibrolytic enzymes in the diet is believed to have positive effects on animal production. Hence, the objective of this study was to investigate the impact of supplementing diets with a commercial fibrolytic enzyme preparation (Vistamax; mixture of xylanase and cellulase) derived from Trichoderma reesei on lactational performance, digestibility, and plasma nutrient levels in high-producing dairy cows. Two dietary energy levels were considered: a normal energy diet (metabolizable energy = 2.68 Mcal/kg) and a slightly lower energy diet (metabolizable energy = 2.55 Mcal/kg). A total of 120 lactating Holstein cows (parity = 2; Days in Milk = 113 ± 23) were randomly assigned to four treatment groups using a 2 * 2 factorial arrangement. The dietary treatments consisted of: (1) normal energy diet without enzyme supplementation (NL); (2) normal energy diet with enzyme supplementation (NLE); (3) slightly lower energy diet without enzyme supplementation (SL); and (4) slightly lower energy diet with enzyme supplementation (SLE). The amount of enzyme added to the diets was determined based on previous in vitro studies and supplier recommendations. The enzyme and premix were mixed prior to the preparation of the total mixed ration, and the trial lasted for a duration of 42 days. The results indicated that the application of the fibrolytic enzyme did not have a significant effect on dry matter intake (DMI), but it did enhance the digestibility of dry matter (DM), neutral detergent fiber (NDF), potentially digestible NDF (pdNDF), organic matter (OM), milk production, milk urea nitrogen (MUN), and blood urea nitrogen (BUN). On the other hand, the slightly lower energy diet resulted in a decrease in DMI, milk production, milk protein yield, plasma free amino acids (FAA), and an increase in plasma B-hydroxybutyrate (BHBA). In conclusion, the inclusion of the fibrolytic enzyme in the diets of dairy cows led to improvements in the digestibility of DM, NDF, pdNDF, OM, milk production, and feed efficiency. Furthermore, the application of the enzyme to the slightly lower energy diet resulted in milk production levels comparable to those observed in cows fed the untreated normal energy diet.

Cadmium negatively affects the growth and physiological status and the alleviation effects by exogenous selenium in silage maize (Zea mays L.)

Increasing soil cadmium (Cd) contamination is a serious threat to human food health and safety. In order to reduce Cd uptake and Cd toxicity in silage maize, hydroponic tests were conducted to investigate the effect of exogenous Cd on the toxicity of silage maize in this study. In the study, a combination of Cd (5, 20, 50, 80, and 10 μM) treatments was applied in a hydroponic system. With increasing Cd concentration, Cd significantly inhibited the total root length (RL), root surface area (SA), root volume (RV), root tip number (RT), and branching number (RF) of maize seedlings, which were reduced by 28.1 to 71.3%, 20.2 to 64.9%, 11.2 to 56.5%, 43.7 to 63.4%, and 38.2 to 72.6%, respectively. The excessive Cd accumulation inhibited biomass accumulation and reduced silage maize growth, photosynthesis, and chlorophyll content and activated the antioxidant systems, including increasing lipid peroxidation and stimulating catalase (CAT) and peroxidase (POD), but reduced the activity of superoxide dismutase (SOD) and ascorbate peroxidase (APX) in the root. Besides, selenium (Se) significantly decreased the Cd concentration of the shoot and root by 27.1% and 35.1% under Cd50, respectively. Our results reveal that exogenously applied Cd reduced silage maize growth and impaired photosynthesis. Whereas silage maize can tolerate Cd by increasing the concentration of ascorbate and glutathione and activating the antioxidant defense system, the application of exogenous selenium significantly reduced the content of Cd in silage maize.

Bacillus velezensis promotes the proliferation of lactic acid bacteria and influences the fermentation quality of whole-plant corn silage

Objective

This study aimed to investigate the promoting effect of a Bacillus velezensis (BV) strain on lactic acid bacteria (LAB) and determine its influence on the fermentation quality and aerobic stability of silage.

Methods

Flat colony counting method was used to evaluate the effect of BV on the growth of LAB. Freshly harvested whole-plant corn was inoculated separately with BV and L. plantarum (LP), along with an uninoculated control group (CK), and assessed at 1, 3, 5, 7, 15, and 30 days of ensiling.

Results

The results indicated that BV exhibited a proliferative effect on Weissella confusa, Lactobacillus plantarum L-2, and Pediococcus pentosaceus. And exhibited a more rapid pH reduction in BV-inoculated silage compared with that in CK and LP-inoculated silage during the initial stage of ensiling. Throughout ensiling, the BV and LP experimental groups showed enhanced silage fermentation quality over CK. Additionally, relative to LP-inoculated silage, BV-inoculated silage displayed reduced pH and propionic acid. BV also prolonged aerobic stability under aerobic conditions. The microbial community in BV-inoculated silage showed greater stability than that in LP-inoculated silage. Additionally, Firmicutes and Lactobacillus exhibited more rapid elevation initially in BV versus LP-inoculated silage, but reached comparable levels between the two inoculation groups in the later stage.

Conclusion

In summary, BV enhanced the efficacy and aerobic stability of whole-plant corn silage fermentation by stimulating LAB proliferation.

A 2-year study reveals implications of feeding management and exposure to mycotoxins on udder health, performance, and fertility in dairy herds

We recently reported the ubiquitous occurrence of mycotoxins and their secondary metabolites in dairy rations and a substantial variation in the feeding management among Austrian dairy farms. The present study aimed to characterize to which extent these factors contribute to the fertility, udder health traits, and performance of dairy herds. During 2019 and 2020, we surveyed 100 dairy farms, visiting each farm 2 times and collecting data and feed samples. Data collection involved information on the main feed ingredients, nutrient composition, and the levels of mycotoxin and other metabolites in the diet. The annual fertility and milk data of the herds were obtained from the national reporting agency. Calving interval was the target criterion for fertility performance, whereas the percentage of primiparous and multiparous cows in the herd with somatic cell counts above 200,000 cells/mL was the criterion for impaired udder health. For each criterion, herds were classified into 3 groups: high/long, mid, and low/short, with the cut-off corresponding to the <25th and >75th percentiles and the rest of the data, respectively. Accordingly, for the calving interval, the cut-offs for the long and short groups were ≥400 and ≤380 d, for the udder health in primiparous cows were ≥20% and ≤8% of the herd, and for the udder health in multiparous cows were ≥35% and ≤20% of the herd, respectively. Quantitative approaches were further performed to define potential risk factors in the herds. The high somatic cell count group had higher dietary exposure to enniatins (2.8 vs. 1.62 mg/cow per d), deoxynivalenol (4.91 vs. 2.3 mg/cow per d), culmorin (9.48 vs. 5.72 mg/cow per d), beauvericin (0.32 vs. 0.18 mg/cow per d), and siccanol (13.3 vs. 5.15 mg/cow per d), and total Fusarium metabolites (42.8 vs. 23.2 mg/cow per d) and used more corn silage in the ration (26.9% vs. 17.3% diet DM) compared with the low counterparts. Beauvericin was the most substantial contributing variable among the Fusarium metabolites, as indicated by logistic regression and modeling analyses. Logistic analysis indicated that herds with high proportions of cows with milk fat-to-protein ratio >1.5 had an increased odds for a longer calving interval, which was found to be significant for primiparous cows (odds ratio = 5.5, 95% confidence interval = 1.65-21.7). As well, herds with high proportions of multiparous cows showing levels of milk urea nitrogen >30 mg/dL had an increased odds for longer calving intervals (odds ratio = 2.96, 95% confidence interval = 1.22-7.87). In conclusion, the present findings suggest that dietary contamination of Fusarium mycotoxins (especially emerging ones), likely due to increased use of corn silage in the diet, seems to be a risk factor for impairing the udder health of primiparous cows. Mismatching dietary energy and protein supply of multiparous cows contributed to reduced herd fertility performance.

Effect of growing regions on morphological characteristics, protein subfractions, rumen degradation and molecular structures of various whole-plant silage corn cultivars

Little information exists on the variation in morphological characteristics, nutritional value, ruminal degradability, and molecular structural makeup of diverse whole-plant silage corn (WPSC) cultivars among different growing regions. This study investigated the between-regions (Beijing, Urumchi, Cangzhou, Liaoyuan, Tianjin) discrepancies in five widely used WPSC cultivars in China (FKBN, YQ889, YQ23, DK301 and ZD958), in terms of 1) morphological characteristics; 2) crude protein (CP) chemical profile; 3) Cornell Net Carbohydrate and Protein System (CNCPS) CP subfractions; 4) in situ CP degradation kinetics; and 5) CP molecular structures. Our results revealed significant growing region and WPSC cultivar interaction for all estimated morphological characteristics (P < 0.001), CP chemical profile (P < 0.001), CNCPS subfractions (P < 0.001) and CP molecular structural features (P < 0.05). Except ear weight (P = 0.18), all measured morphological characteristics varied among different growing regions (P < 0.001). Besides, WPSC cultivars planted in different areas had remarkably different CP chemical profiles and CNCPS subfractions (P < 0.001). All spectral parameters of protein primary structure of WPSC differed (P < 0.05) due to the growing regions, except amide II area (P = 0.28). Finally, the area ratio of amide I to II was negatively correlated with the contents of soluble CP (δ = -0.66; P = 0.002), CP (δ = -0.61; P = 0.006), non-protein nitrogen (δ = -0.56; P = 0.004) and acid detergent insoluble CP (δ = -0.43; P = 0.008), in conjunction with a positive correlation with moderately degradable CP (PB1; δ = 0.58; P = 0.01). In conclusion, the cultivar of DK301 exhibited high and stable CP content. The WPSC planted in Beijing showed high CP, SCP and NPN. The low rumen degradable protein of WPSC was observed in Urumchi. Meanwhile, above changes in protein profiles and digestibility were strongly connected with the ratio of amide I and amide II.

The effect of biogas slurry application on biomass production and the silage quality of corn

OBJECTIVE

The objective of this study was to evaluate the effect of biogas slurry application on biomass production and the silage quality of corn.

METHODS

A field experiment was conducted in which corn was grown using different biogas slurry application rates. The effect of 25% to 500% biogas slurry nitrogen replacement (T1 to T14) on the yield and quality indices of corn were studied by field plot experiments.

RESULTS

The results revealed that biogas slurry application improved the stem diameter and relative feed value of corn silage in treatments T13 and T11. Moreover, the fermentation quality of corn silage was improved due to an increase in lactic acid content; in comparison with the chemical synthetic fertilizer (CF) group. The crude protein contents of corn silage had no obvious change with increasing biogas slurry application. However, the forage quality index of acid detergent fiber was decreased (p<0.05) in the T11 group compared with the CF group. In addition, higher (p<0.05) 30 h in vitro dry matter digestibility and 30 h in vitro neutral detergent fiber digestibility were observed in the T11 and T13 groups than in the CF group.

CONCLUSION

Based on these results, it was concluded that the optimum biogas slurry application rate for corn was approximately 350% to 450% biogas slurry nitrogen replacement under the present experimental conditions.

Effects of Vachellia mearnsii Tannin Extract as an Additive on Fermentation Quality, Aerobic Stability, and Microbial Modulation of Maize Silage

Maize silage is produced to alleviate the effects of forage shortages on ruminant animals, particularly during the dry season. Microorganisms play a significant role in silage fermentation and thus, to a large extent, determine the silage quality. The modulation of silage microorganisms may help to inhibit undesirable bacteria and improve the silage quality. Therefore, condensed tannin extract from Vachellia mearnsii bark was used as an additive in maize silage during ensiling. Hence, this study evaluated the effects of a tannin extract (condensed tannin) additive on the fermentative quality, aerobic stability, and bacterial composition of maize silage. A mini-silo experiment on maize with five treatments was conducted for 75 days. The silage treatments were as follows: (T1) maize forage with no inoculation (negative control); (T2) maize forage inoculated with LAB and 1% tannin extract; (T3) maize forage inoculated with LAB only (positive control); (T4) and maize forage inoculated with LAB and 2% tannin extract; (T5) maize forage inoculated with LAB and 3% tannin extract. The results showed that the additives modulated the silage microorganism composition. However, this was without affecting the silage's fermentative quality and aerobic stability. All the silages recorded a pH below 4.2, which indicated well-fermented silage. The tannin extract suppressed the growth of undesirable bacteria, such as Dysgonomonas, Gluconacetobacter and Clostridium genera, while promoting desirable bacteria, such as Lactobacillus and Weissella genera, which were attributed to the silage quality. It is thus concluded that tannins can be strategically used as silage additives to modulate the microbial composition of silage and improve the silage quality by promoting the dominance of the desirable bacteria in the silage.

Silage maize as a potent candidate for sustainable animal husbandry development-perspectives and strategies for genetic enhancement

Maize is recognized as the queen of cereals, with an ability to adapt to diverse agroecologies (from 58^oN to 55^oS latitude) and the highest genetic yield potential among cereals. Under contemporary conditions of global climate change, C₄ maize crops offer resilience and sustainability to ensure food, nutritional security, and farmer livelihood. In the northwestern plains of India, maize is an important alternative to paddy for crop diversification in the wake of depleting water resources, reduced farm diversity, nutrient mining, and environmental pollution due to paddy straw burning. Owing to its quick growth, high biomass, good palatability, and absence of anti-nutritional components, maize is also one of the most nutritious non-legume green fodders. It is a high-energy, low-protein forage commonly used for dairy animals like cows and buffalos, often in combination with a complementary high-protein forage such as alfalfa. Maize is also preferred for silage over other fodders due to its softness, high starch content, and sufficient soluble sugars required for proper ensiling. With a rapid population increase in developing countries like China and India, there is an upsurge in meat consumption and, hence, the requirement for animal feed, which entails high usage of maize. The global maize silage market is projected to grow at a compound annual growth rate of 7.84% from 2021 to 2030. Factors such as increasing demand for sustainable and environment-friendly food sources coupled with rising health awareness are fueling this growth. With the dairy sector growing at about 4%-5% and the increasing shortage faced for fodder, demand for silage maize is expected to increase worldwide. The progress in improved mechanization for the provision of silage maize, reduced labor demand, lack of moisture-related marketing issues as associated with grain maize, early vacancy of farms for next crops, and easy and economical form of feed to sustain household dairy sector make maize silage a profitable venture. However, sustaining the profitability of this enterprise requires the development of hybrids specific for silage production. Little attention has yet been paid to breeding for a plant ideotype for silage with specific consideration of traits such as dry matter yield, nutrient yield, energy in organic matter, genetic architecture of cell wall components determining their digestibility, stalk standability, maturity span, and losses during ensiling. This review explores the available information on the underlying genetic mechanisms and gene/gene families impacting silage yield and quality. The trade-offs between yield and nutritive value in relation to crop duration are also discussed. Based on available genetic information on inheritance and molecular aspects, breeding strategies are proposed to develop maize ideotypes for silage for the development of sustainable animal husbandry.

Assessing the impact of phyllosphere microbiota on dynamics of in-silo fermentation of Italian ryegrass harvested at heading and blooming stages

BACKGROUND

The present study aimed to investigate the relationship between the phyllosphere microbiota of Italian ryegrass (Lolium multiflorum Lam.) harvested at heading (H) [> 50% earing rate or 216 g kg^-1 fresh weight (FW)] and blooming (B) (> 50% bloom or 254 g kg^-1 FW) stages and in-silo fermentation products, and the composition, abundance, diversity and activity of bacterial community. In total, 72 (4 treatments × 6 ensiling durations × 3 replicates) laboratory scale (400 g) silages of Italian ryegrass were prepared: (i) irradiated heading stage silages (IRH) (n = 36) were inoculated with phyllosphere microbiota inoculum (2 mL) eluted from fresh Italian ryegrass at either heading (IH) (n = 18) or blooming (IB) (n = 18) stages; (ii) irradiated blooming stage silages (IRB) (n = 36) were inoculated with either IH (n = 18) or IB (n = 18). Triplicate silos of each treatment were analyzed after 1, 3, 7, 15, 30 and 60 days of ensiling.

RESULTS

In fresh forage, Enterobacter, Exiguobacterium and Pantoea were the three major genera at heading stage, and Rhizobium, Weissella and Lactococcus were the most abundant genera at blooming stage. Higher metabolic activity was found in IB. After 3 days of ensiling, the large amounts of lactic acid in IRH-IB and IRB-IB can be attributed to the higher abundances of Pediococcus and Lactobacillus, 1-phosphofructokinase, fructokinase, l-lactate dehydrogenase and glycolysis I, II and III.

CONCLUSION

The composition, abundance, diversity and functionality of the phyllosphere microbiota of Italian ryegrass at different growth stages could remarkably affect silage fermentation characteristics. © 2023 Society of Chemical Industry.

Characterization of mycotoxins and microbial community in whole-plant corn ensiled in different silo types during aerobic exposure

Silage can be contaminated with mycotoxins and accidental fungi after aerobic exposure. The study assessed the effects of bunker silos (BS), round bales (RB), and silage bags (SB) on the nutritional characteristics, fermentation quality, aerobic stability, mycotoxin levels and microbial communities of whole-plant corn silage (WPCS). After 90 days of fermentation, silages were opened and sampled at 0, 1, 3, 5, 7, and 9 days of exposure. SB group conserved higher lactic acid and dry matter contents and a lower pH value than other groups after 9 days of exposure (p &lt; 0.05). The SB group showed the longest aerobic stability (202 h) among all silages (p &lt; 0.05). The concentrations of aflatoxin B1, trichothecenes and fumonisin B1 were significantly lower in SB after 9 days of exposure (p &lt; 0.05). Acetobacter became the dominant bacteria in BS and RB groups after 5 days of exposure. However, Lactobacillus still dominated the bacterial community in SB group. Acetobacter was positively correlated with pH, acetic acid content, and ammonia-N content (p &lt; 0.05). Lactobacillus was positively correlated with Kazachstania and Candida abundances (p &lt; 0.01) but negatively correlated with Fusarium abundance (p &lt; 0.05). Considering the feed value and food safety of silage in the feeding process, silage bags are recommended for WPCS according to the observed nutritional quality, fermentation index and mycotoxin content.

Precise control of water stress in the field reveals different response thresholds for forage yield and digestibility of maize hybrids

INTRODUCTION

With dwindling global freshwater supplies and increasing water stress, agriculture is coming under increasing pressure to reduce water use. Plant breeding requires high analytical capabilities. For this reason, near-infrared spectroscopy (NIRS) has been used to develop prediction equations for whole-plant samples, particularly for predicting dry matter digestibility, which has a major impact on the energy value of forage maize hybrids and is required for inclusion in the official French catalogue. Although the historical NIRS equations have long been used routinely in seed company breeding programmes, they do not predict all variables with the same accuracy. In addition, little is known about how accurate their predictions are under different water stress-environments.

METHODS

Here, we examined the effects of water stress and stress intensity on agronomic, biochemical, and NIRS predictive values in a set of 13 modern S0-S1 forage maize hybrids under four different environmental conditions resulting from the combination of a northern and southern location and two monitored water stress levels in the south.

RESULTS

First, we compared the reliability of NIRS predictions for basic forage quality traits obtained using the historical NIRS predictive equations and the new equations we recently developed. We found that NIRS predicted values were affected to varying degrees by environmental conditions. We also showed that forage yield gradually decreased as a function of water stress, whereas both dry matter and cell wall digestibilities increased regardless of the intensity of water stress, with variability among the tested varieties decreasing under the most stressed conditions.

DISCUSSION

By combining forage yield and dry matter digestibility, we were able to quantify digestible yield and identify varieties with different strategies for coping with water stress, raising the exciting possibility that important potential selection targets still exist. Finally, from a farmer's perspective, we were able to show that late silage harvest has no effect on dry matter digestibility and that moderate water stress does not necessarily result in a loss of digestible yield.

Reticulate evolution underlies synergistic trait formation in human communities

This paper investigates how reticulate evolution contributes to a better understanding of human sociocultural evolution in general, and community formation in particular. Reticulate evolution is evolution as it occurs by means of symbiosis, symbiogenesis, lateral gene transfer, infective heredity, and hybridization. From these mechanisms and processes, we mainly zoom in on symbiosis and we investigate how it underlies the rise of (1) human, plant, animal, and machine interactions typical of agriculture, animal husbandry, farming, and industrialization; (2) diet-microbiome relationships; and (3) host-virome and other pathogen interactions that underlie human health and disease. We demonstrate that reticulate evolution necessitates an understanding of behavioral and cultural evolution at a community level, where reticulate causal processes underlie the rise of synergistic organizational traits.

In Vitro Study of the Effect of Ensiling Length and Processing on the Nutritive Value of Maize Silages

The effect of the ensiling length (3, 6, or 9 months), and the processing by dehydration (D) or dehydration and pelleting (P) with respect to the fresh silages (F) were studied in vitro on three maize cultivars in three incubation runs to study the effect of these factors on the nutritive value of maize silage. Gas production pattern, in vitro true digestibility (IVTD), methane concentration (6 and 12 h), ammonia, and volatile fatty acid concentration (VFA) at 12 h were measured. The moisture and pH of F averaged 676 g/kg and 4.09, respectively, and were not affected by the ensiling length, but moisture was reduced, and the pH increased in D and P with respect to F (p < 0.05). The ensiling length did not affect the chemical composition, but differences among the processing forms were detected in a higher acid detergent insoluble nitrogen (ADIN) proportion in P than D, and D than F (p < 0.001). Silages opened at 9 months showed the lowest gas production (p < 0.05), and those that opened after 3 months showed the highest IVTD. The effects of processing on nutrient utilisation only manifested on 3 month silages, with the volume of gas production and IVTD being lower in D than F. However, processing tended (p = 0.064) to reduce the methane proportion at 12 h, indicating both a more efficient fermentation and a lower potential of greenhouse gas emissions compared to the fresh silages. Extending the length of ensiling to 9 months reduced the fermentation of maize silage. The processing increased the dry matter and buffered the feed as well as contributed to an increase in fermentation in 3 month silages.

Effect of Spring Maize Genotypes on Fermentation and Nutritional Value of Whole Plant Maize Silage in Northern Pakistan

In the current study, we evaluated the growth, biomass yield, ensiling, and nutritional characteristics of spring maize genotypes grown under the climatic conditions of Northern Pakistan. Six promising spring maize genotypes were grown under uniform standard agronomic conditions in 72 plots (8 m × 10 m), blocked within three replicate fields. Maize crops were harvested at targeted dry matter (DM) content (33 g/100 g DM). Data were collected on plant phonological characteristics and biomass yield, and then the harvested crop of each plot was chopped, and subsamples were ensiled in three replicate 1.5 L laboratory silos (n = 12/genotype). After 90 days of ensiling, subsamples were analyzed for fermentation quality, nutrient composition, Cornell Net Carbohydrate and Protein System (CNCPS) carbohydrate subfractions, digestible nutrients, metabolizable energy (ME), and in vitro dry matter digestibility (DMD). Results revealed large differences (p < 0.001) among maize genotypes in the yields (tons/ha) of DM (13.0 to 17.9), crude protein (CP; 0.83 to 1.24), and starch (4.16 to 6.67). Except for total carbohydrates (CHO) and NH3-N, the contents of all measured chemical components varied (p < 0.001) among the spring maize genotypes. Similarly, all reported CNCPS subfractions varied (p < 0.01) among the genotypes, except for the non-digestible (CC) subfraction. Among the genotypes, there were large variations in the contents (g/100 g DM) of CP (6.60 to 8.05), starch (32.0 to 37.3), non-fiber carbohydrates (40.3 to 43.8), in vitro DMD (61.5 to 67.9), total digestible nutrients (68.1 to 70.6), digestible energy (2.80 to 3.07 Mcal/kg), and metabolizable energy (2.28 to 2.44 Mcal/kg), with genotype QPM300 having the highest values and genotype Azam having the lowest values. It was concluded that QPM300 is the most suitable spring maize genotype for silage production in terms of yields and silage nutritional and fermentation quality under the environmental condition of Northern Pakistan.

Effects of antibacterial peptide-producing Bacillus subtilis, gallic acid, and cellulase on fermentation quality and bacterial community of whole-plant corn silage

In the current study, we assessed the effects of antibacterial peptide-producing Bacillus subtilis (BS), gallic acid (GA) and cellulase (CL) on the fermentation quality and bacterial community of various varieties of whole-plant corn silage. Three different varieties of whole-plant corn (Yuqing386, Enxiai298, and Nonghe35) were treated with 0.02% BS (fresh material basis), 0.2% GA (fresh material basis) and 0.02% CL (fresh material basis), after which 45 days of anaerobic fermentation were conducted. With the exception of its low dry matter content, the results showed that Yuqing386's crude protein, water-soluble carbohydrate, and lactic acid contents were significantly higher than those of the other two corn varieties. However, its acid detergent fiber and cellulose contents were significantly lower than those of the other two corn varieties. Among the three corn variety silages, Yuqing386 had the highest relative abundance of Lactobacillus at the genus level and the biggest relative abundance of Firmicutes at the phylum level. In addition, the three additives markedly enhanced the quantity of dry matter and crude protein as compared to the control group. The application of GA considerably decreased the level of neutral detergent fiber while significantly increasing the content of lactic acid and water-soluble carbohydrates. Even though all additives enhanced the structure of the bacterial community following silage, the GA group experienced the greatest enhancement. On a phylum and genus level, the GA group contains the highest relative abundance of Firmicutes and Lactobacillus, respectively. Overall, of the three corn varieties, Yuqing386 provides the best silage qualities. GA has the biggest impact among the additions employed in this experiment to enhance the nutritional preservation and fermentation quality of whole-plant corn silage.

A Nutritional Investigation of Major Feed Types and Feed Rations Used in Medium-Scale Dairy Production Systems in Sri Lanka

In this paper, the nutritional quality, digestibility, and chemical composition of major feed types as well as the use of those feeds in rations by medium-scale dairy farmers in the Kurunegala district of Sri Lanka were studied. Nine dairy farms were visited fortnightly over a five-month period to identify the feeds that were commonly used. All farms operated under a stall-feeding system in which a manually mixed ration (MMR) was fed 2–3 times daily. Four forages were identified: Guinea grass ecotype A (Panicum maximum), called Guinea grass; Hybrid Napier CO-3 (Pennisetum purpureum × Pennisetum americanum), called CO-3 grass; Gliricidia (Gliricidia sepium); and maize stover (Zea mays L.), along with three other supplementary feeds (maize silage, barley distillers’ by-products, and commercially formulated cattle feed). These feeds were subjected to proximate analysis and in vitro digestibility analysis. The metabolisable energy (ME) of the forages ranged from 7.5–10.0 MJ/kg dry matter (DM), with the ME of Guinea grass and CO-3 grass (7.5 and 8.0 MJ/kg DM, respectively) being lower than that of Gliricidia (10.0 MJ/kg DM). The neutral detergent fibre (NDF) concentration of both Guinea grass and CO-3 grass (both 72% DM) was much higher than that of Gliricidia (47% DM). Crude protein (CP) was higher in Gliricidia (17.5% DM) than in either Guinea grass or CO-3 grass (8.0 and 8.8% DM, respectively). The ME of the supplementary feeds varied between 11.0 and 12.8 MJ/kg DM, while CP varied between 15.0 and 24.0% DM. The daily ME intake of cows was consistently 10% lower than their calculated daily energy requirement; for dry cows, the mean intake was 90 MJ/cow/day supplied vs. 101 MJ required, while for cows in early lactation the mean intake was 126 MJ/cow/day supplied vs. 140 MJ required. The average CP intake of lactating cows (13.5% DM) was inadequate (requirements: 16 to 17.5% DM), while the average CP intake of dry cows (11.8% DM) was satisfactory (requirements: 11 to 12% DM). The current study shows that the majority of the feed types used in these medium-scale dairy farms provide insufficient ME or CP to meet the nutritional requirements of either lactating or dry cows irrespective of the quantity of feed provided.

Characterisation of landrace 'criollo' maize silage from the highlands of Mexico in terms of starch content

Maize silage is appreciated for dairy cows due to its high energy content. Mexico is a centre of origin for maize and small-scale dairy farmers use landrace 'criollo' maize silages to feed their herds. However, the characteristics of landrace 'criollo' maize silages in terms of starch content, which defines their nutritional value in terms of energy, are not known. The objective was to characterise criollo maize silages in terms of starch content. Seventy-seven silage samples from 2011 to 2015 were analysed for contents of dry matter (DM), organic matter (OM), neutral detergent fibre (NDF), acid detergent fibre (ADF), crude protein (CP), in vitro dry matter digestibility (IVDMD), and starch content. A factor analysis using principal component analysis as an extraction method was undertaken, and a hierarchical cluster analysis performed. Five factors affected the starch content of silages and five maize silage clusters identified. There was a positive association between IVDMD and metabolisable energy and between crude protein and acid detergent fibre; moreover, a positive relation was found between dry matter and maize starch contents. Significant differences were found (P < 0.001) for the contents of IVDMD, ME, ashes, OM, DM, and starch. The DM content of group 1 silage did not show any significant differences from other groups, except with group 2 silage, which had the lowest contents of DM and starch. Therefore, group 1 and 5 silage had the highest DM and starch contents, while group 3 silage had the highest IVDMD values and ME contents; finally, group 4 had the highest ash contents. Starch content in criollo maize silages was higher that reports for other maize races and is influenced by climate conditions and dry matter content.

Genotype by Environment Interaction on Tropical Maize Hybrids Under Normal Irrigation and Waterlogging Conditions

Unpredictable rainfall in the tropics often increases the risk of waterlogging or even flooding in agricultural lands, hindering the efforts to fulfill maize demands. Breeding maize for waterlogging tolerance is necessary yet challenging since performing varietal testing on a set of hybrids might be biased toward the presence of genotype and environment interaction (GEI). This study aimed to elucidate the GEI effects on yield and related agronomic traits of tropical maize hybrids under normal irrigation and waterlogging conditions and to assess the adaptability of these hybrids in such conditions using several stability models. Ten hybrids including two commercial checks were evaluated across 14 environments under normal and waterlogging conditions in Indonesia from 2018 to 2020. Waterlogging imposed at the V6 stage for ten consecutive days significantly hampered the plant height and ear height, slightly delayed flowering dates, and reduced yield and yield components. The genotype, location, and genotype by location effects were significant on yield, but the genotype by waterlogging effect was not. Stress tolerance index is highly significantly correlated (p &lt; 0.01) with yield in both normal (r = 0.90) and waterlogging (r = 0.96) conditions. The GGE biplot analysis on yield revealed five sectors, two mega-environments, and five vertex genotypes. This study indicated the possibility of breeding maize hybrids tolerant to waterlogging (G05), as well as high-yielding hybrids under both conditions (G07).

Effects of Chilling Stress on Morphological, Physiological, and Biochemical Attributes of Silage Corn Genotypes during Seedling Establishment

Chilling stress is one of the major abiotic stresses which hinder seedling emergence and growth. Herein, we investigated the effects of chilling/low temperature stress on the morphological, physiological, and biochemical attributes of two silage corn genotypes during the seedling establishment phase. The experiment was conducted in a growth chamber, and silage corn seedlings of Yukon-R and A4177G-RIB were grown at optimum temperature up to V3 stage and then subjected to five temperature regimes (25 °C as control, 20 °C, 15 °C, 10 °C, and 5 °C) for 5 days. After the temperature treatment, the morphological, physiological, and biochemical parameters were recorded. Results indicated that temperatures of 15 °C and lower significantly affected seedling growth, photosynthesis system, reactive oxygen species (ROS) accumulation, and antioxidant enzyme activities. Changes in seedlings’ growth parameters were in the order of 25 °C > 20 °C > 15 °C > 10 °C > 5 °C, irrespective of genotypes. The chlorophyll content, photosynthetic rate, and maximal photochemical efficiency of PS-II (Fv/Fm) were drastically decreased under chilling conditions. Moreover, chilling stress induced accumulation of hydrogen peroxide (H2O2)and malonaldehyde (MDA) contents. Increased proline content and enzymatic antioxidants, including superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxide (APX), were found to alleviate oxidative damage under chilling stress. However, the genotype of Yukon-R exhibited better adaption to chilling stress than A4177G3-RIB. Yukon-R showed significantly higher proline content and enzymatic antioxidant activities than A4177G3-RIB under severe chilling conditions (temperature ≤ 10 °C). Similarly, Yukon-R expressed low temperature-induced ROS accumulation. Furthermore, the interaction effects were found between temperature treatment and genotype on the ROS accumulation, proline content and antioxidant enzyme activities. In summary, the present study indicated that Yukon-R has shown better adaptation and resilience against chilling temperature stress, and therefore could be considered a potential candidate genotype to be grown in the boreal climate.

Silage Quality and Output of Different Maize–Soybean Strip Intercropping Patterns

Intercropping improves land-use efficiency under conditions of limited land and resources, but no information is currently available pertaining to land-use efficiency and silage quality based on whole-plant utilization. Therefore, a two-year field experiment was conducted with the following conditions: three maize–soybean strip intercropping patterns (SIPs), comprising two maize rows along with two, three, or four soybean rows (2M2S, 2M3S, and 2M4S, respectively); and two sole cropping patterns of maize (SM) and soybean (SS). The aim was to evaluate the biomass yield and silage quality under each condition. Our results showed that all SIPs had a land equivalent ratio (LER) of over 1.6 based on both fresh and dry matter yield, and a higher whole plant yield, compared to sole cropping. Specifically, 2M3S exhibited the highest whole crop dry matter LER (1.8–1.9) and yield (24.6–27.2 t ha−1) compared to SM and SS (20.88–21.49 and 3.48–4.79 t ha−1, respectively). Maize–soybean mixed silages also showed better fermentation quality with higher lactic acid content (1–3%) and lower ammonia-N content (2–8%) compared to SS silages, and higher crude protein content (1–1.5%) with lower ammonia-N content (1–2%) compared to SM silage. Among the intercropping patterns, 2M3S had the highest fermentation quality index V-score (92–95). Consequently, maize–soybean strip intercropping improved silage quality and biomass yield, with 2M3S being recommended, due to its highest LER and biomass yield, and most optimal silage quality.

Effects of Soybean Density and Sowing Time on the Yield and the Quality of Mixed Silage in Corn-Soybean Strip Intercropping System

Intercropping is a cropping strategy that makes efficient use of space, nutrients, and soil. A 2-year field trial was conducted in 2019 and 2020 to study the effects of different soybean sowing times (9 days before corn sowing (ST1), 0 days at corn sowing (ST2), and 9 days after corn sowing (ST3), respectively) and densities (120,000 plants ha−1 (PD1), 150,000 plants ha−1 (PD2), and 180,000 plants ha−1 (PD3), respectively, and the planting density of corn was 60,000 plants ha−1 constantly) on total yield and on mixed silage quality in corn-soybean strip intercropping system. The yield decreased with an increase in soybean planting density. Before ensiling, the total dry matter (DM) content increased with an increase in soybean planting density, while that of crude protein content decreased with sowing time. The interaction of planting density × sowing time was significant for neutral detergent fiber and water-soluble carbohydrate (WSC) content. After ensiling, the WSC content of PD2ST3 (4.90% DM) was the highest. The PD1 (4.51%) had a higher content of ammonia–nitrogen to total nitrogen than that of PD2 and PD3. The lactic acid content of PD2ST3 (3.14% DM) was the highest. In general, better silage quality and a higher total yield were obtained when soybean was sown at the planting density of 150,000 plants ha−1 after 9 days of corn sowing.

Effects of Cellulase and Lactobacillus plantarum on Fermentation Quality, Chemical Composition, and Microbial Community of Mixed Silage of Whole-Plant Corn and Peanut Vines

Significant anaerobic fermentation occurs in silage through the action of anaerobic bacteria. The objective of this study was to evaluate the effects of cellulase and Lactobacillus plantarum on the fermentation quality and bacterial community of whole-plant corn and peanut vine mixed silage. Mixed silage was tested with no addition (CK), addition of Lactobacillus plantarum (LP), addition of cellulase (CE), and the simultaneous addition of Lactobacillus plantarum and cellulase (LPCE). LPCE samples exhibited decreased pH; decreased content of acetic acid, propionic acid, and butyric acid; and increased content of lactic acid. LP and LPCE had better effects on chemical composition than CK and CE, especially in decreasing acid detergent fiber and neutral detergent fiber content. High-throughput sequencing identified Lactobacillus, Klebsiella, Serratia, and Weissella as the main microorganisms. LP and CE increased the abundance of Acetobacter, and LPCE decreased the abundance of Acetobacter. All additives decreased the abundance of Weissella, Leuconostoc, and Lactococcus, and increased the abundance of Pantoea. Overall, simultaneous addition of cellulase and Lactobacillus plantarum helped to improve the quality of mixed silage of whole-plant corn and peanut vines.

Yield and quality properties of silage maize and their influencing factors in China

Silage maize (Zea mays L.) is one of the most important forages in the world, and its yield and quality properties are critical parameters for livestock production and assessment of forage values. However, relationships between its yield and quality properties and the controlling factors are not well documented. In this study, we collected 5,663 observations from 196 publications across the country to identify the relationships between yield and quality properties of silage maize and to assess the impact of management practices and climatic factors on its yield and quality in China. The average dry matter yield of silage maize was (19.98±6.93) Mg ha^-1, and the average value of crude protein, ether extract, crude ash, crude fiber, acid detergent fiber, neutral detergent fiber, nitrogen-free extract, and relative feed value was 7.86%±1.71%, 2.53%±1.01%, 5.05%±1.66%, 23.97%±6.34%, 27.62%±7.12%, 51.60%±9.85%, 59.68%±7.72%, and 131.17±31.49, respectively. In general, its nutritive value decreased as its yield increased. Increasing planting density could increase the yield but inhibit the nutritive values, while increasing fertilization could benefit the nutritive values. Geographically, the yield increased and the nutritive value decreased from warm (south) to cold (north) regions. The length of growth duration was a major controlling factor for the patterns of these properties. Our findings provide insights for police-makers to make strategy for achieving high yield and good quality of silage maize and help local people to implement better management practices.

Effect of Different Regions and Ensiling Periods on Fermentation Quality and the Bacterial Community of Whole-Plant Maize Silage

This study aimed to explore the changes in the microbial community on the silage material surface and during the ensiling process of whole-plant maize in different regions. Whole-plant maize silages were sampled in Ziyun, Guanling, and Weinning counties within warm and humid climate areas in southern China. Silages were sampled at 0, 2, 5, 10, 20, and 45 days during ensiling. The nutritional components, fermentation properties, and microbiomes were examined to evaluate the influence of sampling area and fermentation time on the quality of silage. The results showed that the pH values of all silages significantly decreased (<4.2 at ensiling day 2) during fermentation and all silages achieved satisfactory fermentation at 45 days. Butyric acid was not detected during ensiling, and the contents of acetic acid and ammonia nitrogen in the final silages were below 6 g/kg DM and 50 g/kg total nitrogen, respectively. Weissella was the dominant epiphytic bacteria of raw material in Ziyun and Weinning, while Lactobacillus was prevalent in Guanling. Lactobacillus dominated the ensiling process, and its abundance significantly increased with increasing fermentation time in the three groups. Lactobacillus was negatively correlated with pH of all silages (p < 0.05) and positively correlated with lactic acid, propionic acid and acetic acid (p < 0.05). Furthermore, the bacterial community was significantly correlated with environmental factors. Altitude had a highly positive correlation with the abundance of Stenotrophomonas, Chryseobacterium, and Massilia (p < 0.01), while precipitation was negatively correlated with these bacteria. The humidity and average temperature significantly influenced the Lactobacillus and Weissella abundances of fresh whole-plant maize. During the ensiling process, the silages from three regions had similar bacterial dynamic changes, and the Lactobacillus formed and maintained good fermentation characteristics in whole-plant maize silage.

Cellular detection of the chemokine receptor CXCR4 in bovine mammary glands and its distribution and regulation on bovine leukocytes

Mastitis has a high incidence in dairy cows. Experimental infection with Escherichia coli increased the number of leukocytes in milk and the gene expression of the chemokine receptor CXCR4 in mammary gland tissues. A link between CXCR4 expression and lipopolysaccharide sensing was demonstrated in other species using in vitro models. The receptor that binds the chemokine stomal cell-derived factor 1 might be associated with the inflammatory response in bovine mammary glands. However, studies in cows are rare, and data on the localization of CXCR4 in bovine mammary glands and its distribution in bovine leukocytes are lacking. Fatty acids (FA) affect the inflammatory response. In human peripheral blood monocytes, exposure to conjugated linoleic acids (CLA) decreases the expression of CXCR4, leading to a decreased inflammatory response in these cells. In this study, we analyzed the expression of CXCR4 in the mammary glands of dairy cows by immunohistochemistry (n = 5) and laser capture microdissection followed by qualitative PCR (n = 3). We characterized the surface expression of CXCR4 on bovine leukocytes, including monocyte subpopulations, first by flow cytometry (n = 5) and then confirmed these results by Western blotting (n = 3). Rumen fistulated dairy cows (n = 4; 126 ± 4 d in milk) were fitted with abomasal infusion tubes, arranged in a 4 × 4 Latin square design, and supplemented for 6 wk twice daily with rising doses of FA followed by a 3-wk washout period. Then, CXCR4 expression on leukocytes was analyzed. The cows received a corn-based diet and were supplemented with coconut oil delivering medium-chain FA (38 g/d), linseed-safflower oil mix delivering n-3 FA (EFA, 39 g of linseed oil and 2 g of safflower oil per day), Lutalin (cis-9,trans-11 and trans-10,cis-12 CLA, 5 g/d; BASF), and EFA + CLA. In the bovine mammary gland, the epithelial cells of the lactiferous duct, but not alveolar epithelial cells, showed clear CXCR4 protein and mRNA signals. Among the leukocyte subsets, monocytes displayed the highest percentage of CXCR4-positive cells (87%), whereas circulating neutrophils showed almost no CXCR4 surface expression (3%) but stored the receptor intracellularly. The percentage of CXCR4-positive leukocytes was not affected by the different FA supplements, but FA supplementation reduced the receptor abundance per cell (40% on average). In conclusion, CXCR4 was clearly detected in the lactiferous duct cells of the mammary gland but not in the alveolar epithelial cells. Compared with other leukocytes, bovine monocytes showed the highest signal intensity of CXCR4 on their surface, whereas granulocytes stored CXCR4 intracellularly. Supplementation with all the FA reduced the surface expression of CXCR4 per leukocyte and could therefore potentially affect the inflammatory status associated with the surface expression of CXCR4. The importance of our observations should be verified in cows with mastitis in the future.

Evaluation of corn hybrids for silage grown in different locations

ABSTRACT The aim of this study was to evaluate the yield, morphometric and chemical characteristics, and the digestibility of various corn hybrids cultivated in different locations for silage production. Four corn hybrids were grown: P2866H, P3456H, P30R50VYH and P4285YHR, in four locations, defined as farm A; B; C and D. The hybrid P4285YHR presented the highest plant and ear insertion heights (2.72m, 1.52m respectively), with a minimum registered height of 2.63 m and 1.42 m, for plant and ear insertion height, and for that reason it presented the highest yield of fresh biomass (78,089kg ha-1). The TND values showed trend very close to that observed in the DISMS of the whole-plant, with hybrid P3456H presenting the highest estimated value (68.74%), and the hybrid P4285YHR the lowest among them (65.25%). In general, lower fibrous carbohydrates and lignin content, higher fibrous carbohydrates content, together with satisfactory grains participation in the plant structure led to a greater dry matter digestibility. Hybrids with lower plant heights do not necessarily have lower dry biomass yields, but hybrids of greater height and with high stem and leaf participation tend to have a higher aFDN content and less dry matter digestibility.

Effect of a Low-Methane Diet on Performance and Microbiome in Lactating Dairy Cows Accounting for Individual Pre-Trial Methane Emissions

This study examined the effects of partly replacing grass silage (GS) with maize silage (MS), with or without rapeseed oil (RSO) supplementation, on methane (CH₄) emissions, production performance, and rumen microbiome in the diets of lactating dairy cows. The effect of individual pre-trial CH₄-emitting characteristics on dietary emissions mitigation was also examined. Twenty Nordic Red cows at 71 ± 37.2 (mean ± SD) days in milk were assigned to a replicated 4 × 4 Latin square design with four dietary treatments (GS, GS supplemented with RSO, GS plus MS, GS plus MS supplemented with RSO) applied in a 2 × 2 factorial arrangement. Partial replacement of GS with MS decreased the intake of dry matter (DM) and nutrients, milk production, yield of milk components, and general nutrient digestibility. Supplementation with RSO decreased the intake of DM and nutrients, energy-corrected milk yield, composition and yield of milk fat and protein, and general digestibility of nutrients, except for crude protein. Individual cow pre-trial measurements of CH₄-emitting characteristics had a significant influence on gas emissions but did not alter the magnitude of CH₄ emissions. Dietary RSO decreased daily CH₄, yield, and intensity. It also increased the relative abundance of rumen Methanosphaera and Succinivibrionaceae and decreased that of Bifidobacteriaceae. There were no effects of dietary MS on CH₄ emissions in this study, but supplementation with 41 g RSO/kg of DM reduced daily CH₄ emissions from lactating dairy cows by 22.5%.

Dynamics of Bacterial and Fungal Communities and Metabolites During Aerobic Exposure in Whole-Plant Corn Silages With Two Different Moisture Levels

The study was aimed to investigate the effect of moisture content on microbial communities, metabolites, fermentation quality, and aerobic stability during aerobic exposure in whole-plant corn silages preserved long time to improve the quality and aerobic stability of the silage during feed-out. Corn plants with two different moisture levels (high-moisture content, 680 g/kg; low-moisture content, 620 g/kg) were harvested at one-third and two-thirds milk-line stages, respectively, ensiled in laboratory-scale silos, and then sampled at 350 day after ensiling and at 2 and 5 day after opening to investigate bacterial and fungal communities, metabolites, and aerobic stability. High-moisture content increased aerobic stability and pH and decreased lactic acid and microbial counts in silages (P < 0.05). During aerobic exposure, the low-moisture silages had higher pH and lactic acid bacterial count and lower lactic acid than the high-moisture silages (P < 0.05); Acinetobacter sp. was the most main bacterial species in the silages; Candida glabrata and unclassified Candida had an increasing abundance and negatively correlation with aerobic stability of high-moisture silages (P < 0.05), while C. glabrata, Candida xylopsoci, unclassified Saccharomycetaceae, and unclassified Saccharomycetales negative correlated with aerobic stability of low-moisture silages (P < 0.05) with a rising Saccharomycetaceae; the silages had a reducing concentration of total metabolites (P < 0.05). Moreover, the high-moisture silages contained greater total metabolites, saturated fatty acids (palmitic and stearic acid), essential fatty acids (linoleic acid), essential amino acids (phenylalanine), and non-essential amino acids (alanine, beta-alanine, and asparagine) than the low-moisture silages at 5 day of opening (P < 0.05). Thus, the high-moisture content improved the aerobic stability. Acinetobacter sp. and Candida sp. dominated the bacterial and fungal communities, respectively; Candida sp. resulted in the aerobic deterioration in high-moisture silages, while the combined activities of Candida sp. and Saccharomycetaceae sp. caused the aerobic deterioration in low-moisture silages. The greater aerobic stability contributed to preserve the palmitic acid, stearic acid, linoleic acid, phenylalanine, alanine, beta-alanine, and asparagine during aerobic exposure.

Bacterial Succession Pattern during the Fermentation Process in Whole-Plant Corn Silage Processed in Different Geographical Areas of Northern China

Whole-plant corn silage is a predominant forage for livestock that is processed in Heilongjiang province (Daqing city and Longjiang county), Inner Mongolia Autonomous Region (Helin county and Tumet Left Banner) and Shanxi province (Taigu and Shanyin counties) of North China; it was sampled at 0, 5, 14, 45 and 90 days after ensiling. Bacterial community and fermentation quality were analysed. During fermentation, the pH was reduced to below 4.0, lactic acid increased to above 73 g/kg DM (p < 0.05) and Lactobacillus dominated the bacterial community and had a reducing abundance after 14 days. In the final silages, butyric acid was not detected, and the contents of acetic acid and ammonia nitrogen were below 35 g/kg DM and 100 g/kg total nitrogen, respectively. Compared with silages from Heilongjiang and Inner Mongolia, silages from Shanxi contained less Lactobacillus and more Leuconostoc (p < 0.05), and had a separating bacterial community from 14 to 90 days. Lactobacillus was negatively correlated with pH in all the silages (p < 0.05), and positively correlated with lactic and acetic acid in silages from Heilongjiang and Inner Mongolia (p < 0.05). The results show that the final silages had satisfactory fermentation quality. During the ensilage process, silages from Heilongjiang and Inner Mongolia had similar bacterial-succession patterns; the activity of Lactobacillus formed and maintained good fermentation quality in whole-plant corn silage.

Corn-Soybean Intercropping Improved the Nutritional Quality of Forage Cultivated on Podzols in Boreal Climate

Intercropping systems could be a potential source of nutrient-rich forage production in cool climates on podzolic soils common in boreal ecosystems. In this study, we evaluated the effects of corn-soybean intercropping (IC) on the nutritional quality of forage. Two silage corn varieties were cultivated as monocropping (MC) or were intercropped with three forage soybean varieties using a randomized complete block design. IC significantly increased the crude protein (22%) and decreased the acid detergent (14%) and neutral detergent (6%) fibers. Forage net energy, total digestible nutrients, ash, dry matter intake, digestible dry matter and relative feed value were also significantly increased (p ≤ 0.05) in the IC treatments compared to corn MC. The macro and micro nutrients were higher in IC than corn MC. Intercropping increased the omega 3 fatty acid (FA) contents (67%) compared to corn MC. IC also increased the active microbial community in the plant root zone, which may contribute to the improvement in forage nutritional quality because the active soil microbial community composition showed significant correlations with soluble sugars, soluble proteins and potassium contents of the forage. These results demonstrate that corn-soybean IC could be a suitable cropping system to increase the nutritional quality of forage cultivated on podzols in boreal climates. The resultant forage has the potential to be a source of high-value animal feed for livestock production in cool climate regions of the world.

Productive, economic, and environmental effects of sunflower (Helianthus annuus) silage for dairy cows in small-scale systems in central Mexico

Small-scale dairy systems (SSDS) are important source of livelihood and socio-economic wellbeing for the rearers in general. The reduction of methane emissions with the inclusion of sunflower seed or seed-meal in rations for dairy cows has been reported in several studies. However, studies pertaining to the use of sunflower silage in dairy cattle feeding are lacking. The present study was conducted to assess the productive, economic, and environmental effects of the inclusion of graded levels of sunflower silage at 0%, 20%, 40%, and 60% (SFSL) along with maize silage (MZSL) on a dry matter basis. The silage was provided to eight Holstein cows in two 4×4 Latin-squares with 14-day periods. The study encompassed the productive performance of the cows, composition of feeds, besides the feeding costs, and enteric methane emissions estimated. The study indicated that inclusion of SFSL in the diet enhanced (P<0.001) the FCM by 3.5% and milk-fat content. SFSL increased feeding costs, but income/feeding costs ratios did not differ across the treatments. The higher inclusion of SFSL reduced methane emissions/kg of DM intake, / kg of milk, and in energy lost as methane. The inclusion of sunflower silage in feeding strategies for cows may be a viable alternative by increasing their milk yields and milk fat content and reducing methane emissions without affecting the income/feeding costs ratios.

Succession of Bacterial Community During the Initial Aerobic, Intense Fermentation, and Stable Phases of Whole-Plant Corn Silages Treated With Lactic Acid Bacteria Suspensions Prepared From Other Silages

The present study was aimed at investigating the bacterial community in lactic acid bacteria (LAB) suspensions prepared from whole-plant corn silage (LAB suspension-CS) and Elymus sibiricus silage (LAB suspension-ES) and the bacterial community succession of whole-plant corn silages inoculated with LAB suspension-CS or LAB suspension-ES during initial aerobic phase, intense fermentation phase, and stable phase. The LAB suspensions were cultured in sterile Man, Rogosa, Sharpe broth at 37°C for 24 h and used as inoculants for ensiling. The chopped whole-plant corn was treated with distilled water (CK), LAB suspension-CS (CSL), or LAB suspension-ES (ESL) and then ensiled in vacuum-sealed plastic bags containing 500 g of fresh forage. Silages were sampled at 0 h, anaerobic state (A), 3 h, 5 h, 10 h, 24 h, 2 days, 3 days, 10 days, 30 days, and 60 days of ensiling with four replicates for each treatment. The results showed that Lactobacillus, Weissella, and Lachnoclostridium_5 dominated the bacterial community in LAB suspension-CS; Lactobacillus was the most predominant bacterial genus in LAB suspension-ES. During the initial aerobic phase (from 0 h to A) of whole-plant corn silage, the pH and the abundances of Pantoea, Klebsiella, Rahnella, Erwinia, and Serratia increased. During the intense fermentation phase (from A to 3 days), the pH decreased rapidly, and the microbial counts increased exponentially; the most predominant bacterial genus shifted from Pantoea to Weissella, and then to Lactobacillus; inoculating LAB suspensions promoted the bacterial succession and the fermentation process, and LAB suspension-CS was more effective than LAB suspension-ES. During the stable phase (from 3 to 60 days), the pH and the microbial counts decreased, and Lactobacillus dominated the bacterial community with a little decrease. The results also confirmed the existence of LAB fermentation relay during fermentation process, which was reflected by Weissella, Lactococcus, and Leuconostoc in the first 5 h; Weissella, Lactococcus, Leuconostoc, Lactobacillus, and Pediococcus between 5 and 24 h; and Lactobacillus from 24 h to 60 days.

Halting European Union soybean feed imports favours ruminants over pigs and poultry

The European Union (EU) livestock sector relies on imported soybean as a feed source, but feeding soybean to animals leads to a loss of macronutrients compared to direct human consumption, and soybean production is associated with deforestation. Here we show that 75-82% of current EU animal fat and protein production could be sustained without soybean imports while avoiding increased use of cropland for feed production within the EU. Reduced soybean feed exports, mainly from South America, would free up 11-14 million hectares outside the EU, but indirect land-use changes would increase demand for palm oil produced in southeast Asia. Avoiding imported soybean feeds would result in reduced EU pork and poultry production; increased plant-based food consumption would be required to maintain the supply of essential nutrients for human diets. Optimizing livestock production to overcome dependency on imported soybean feed can reduce cropland demand in deforestation-prone areas while supporting the nutritional requirements of EU diets-but will require progressive policies targeting all aspects of the food system.

Potential of Lactic Acid Bacteria Isolated From Different Forages as Silage Inoculants for Improving Fermentation Quality and Aerobic Stability

We aimed at isolating lactic acid bacteria (LAB) from different plant materials to study their crossed-fermentation capacity in silos and to find strains able to confer enhanced aerobic stability to silage. A total of 129 LAB isolates were obtained from lucerne (alfalfa), maize, sorghum, ryegrass, rice, barley, canola, Gatton panic, Melilotus albus, soy, white clover, wheat, sunflower, oat, and moha. Four Lactiplantibacillus plantarum subsp. plantarum strains (isolated from oat, lucerne, sorghum, or maize) were selected for their growth capacity. Identity (16S sequencing) and diversity (RAPD-PCR) were confirmed. Fermentative capacity (inoculated at 10⁴, 10⁵, 10⁶, 10⁷ CFU/g) was studied in maize silage and their cross-fermentation capacity was assessed in oat, lucerne, sorghum, and maize. Heterofermentative strains with the highest acetic acid production capacity conferred higher aerobic stability to maize silages. Regardless the source of isolation, L. plantarum strains, inoculated at a rate of 10⁶ CFU/g, were effective to produce silage from different plant materials. From more than 100 isolates obtained, the application of a succession of experiments allowed us to narrow down the number of potential candidates of silage inoculants to two strains. Based on the studies made, L. plantarum LpM15 and Limosilactobacillus fermentum LfM1 showed potential to be used as inoculants, however further studies are needed to determine their performance when inoculated together. The former because it positively influenced different quality parameters in oat, lucerne, sorghum, and maize silage, and the latter because of its capacity to confer enhanced aerobic stability to maize silage. The rest of the strains constitute a valuable collection of autochthonous strains that will be further studied in the future for new applications in animal or human foods.

Effect of Lactic Acid Bacteria on the Nutritive Value and In Vitro Ruminal Digestibility of Maize and Rice Straw Silage

A study was conducted to determine the effects of lactic acid bacteria (LAB) on nutritive value and in vitro rumen digestibility of maize and rice straw silages. Two identical experiments were carried out for each of the two silages. A total of five treatments were used for each experiment: (1) negative control (NC); (2) positive control (PC); (3) Lactobacillus plantarum (LPL); (4) L. paracasei (LPA); and (5) L. acidophilus (LA). Each treatment was then divided into four ensiling periods: 3, 7, 20, and 40 days with three replications. The LPL treatment had significantly higher dry matter (DM), lower ammonia-N, and a lower number of fungi on maize silage after 40 days (p < 0.05). On the other hand, the LA treatment increased DM and CP content, reduced NDF and ADF contents compared to NC, and also produced more lactic acid compared to the other LAB-treated rice straw silages. Results of the in vitro rumen fermentation of maize silages showed no significant differences in DMD after LAB inoculation. However, higher DMD and ruminal ammonia-N were shown by rice straw ensiled with L. acidophilus. In conclusion, silage additives, which could improve the ensiling process of maize and rice straw, appeared to be different and substrate specific.

Dynamic microbial diversity and fermentation quality of the mixed silage of corn and soybean grown in strip intercropping system

This study assessed the fermentation quality and microbial community of corn (Zea mays L.) and soybean (Glycine max Merr.) (CS) mixed silage in strip intercropping system. CS mixed silage increased lactic acid content and decreased ammonia-N content compared to 100% soybean (S) silage, while it decreased ammonia-N content compared to 100% corn (C) silage. The largest number of epiphytic lactic acid bacteria was detected in CS fresh materials. During ensiling, Weissella and Lactobacillus dominated silage, the relative abundance of Lactobacillus in mixed silage was higher than that in S silage with the same S variety. After aerobic exposure (AE), synergistic effect existed in low relative abundance bacteria correlating with ammonia-N content and pH at ensiling 60 days and AE 7 days. In conclusion, CS mixed silage modified microbial community and improved fermentation quality.

The Bacterial Community Associated with the Amarillo Zamorano Maize (Zea mays) Landrace Silage Process

Maize silage is used in the diet of dairy cows, with suitable results in milk yield. In this study, the composition and diversity of the bacterial communities of the silage process of Amarillo Zamorano (AZ) Mexican maize landrace with relation to the Antilope (A) commercial hybrid are described. From both types of maize, seeds were sown in experimental plots, plants harvested at the reproductive stage, chopped, and packed in laboratory micro-silos. Physicochemical parameters were evaluated, and DNA was extracted from the juice in the micro-silos. The bacterial communities were analyzed by next-generation sequencing (NGS) of seven hypervariable regions of the 16S rRNA gene. The composition of both bacterial communities was dominated by Lactobacillales and Enterobacteriales, Lactobacillales mainly in A silage and Enterobacteriales in AZ silage; as well, the core bacterial community of both silages comprises 212 operational taxonomic units (OTUs). Sugar concentration showed the highest number of significant associations with OTUs of different phyla. The structure of the bacterial communities was different in both silage fermentation processes, showing that AZ silage has a shorter fermentation process than A silage. In addition, NGS demonstrated the effect of the type of maize and local conditions on silage fermentation and contributed to potential strategies to improve the quality of AZ silage.

Effects of a combined essential fatty acid and conjugated linoleic acid abomasal infusion on metabolic and endocrine traits, including the somatotropic axis, in dairy cows

The objective of this study was to test the effects of essential fatty acids (EFA), particularly α-linolenic acid (ALA), and conjugated linoleic acid (CLA) supplementation on metabolic and endocrine traits related to energy metabolism, including the somatotropic axis, in mid-lactation dairy cows. Four cows (126 ± 4 d in milk) were used in a dose-escalation study design and were abomasally infused with coconut oil (CTRL; 38.3 g/d; providing saturated fatty acids), linseed and safflower oils (EFA; 39.1 and 1.6 g/d; n-6:n-3 FA ratio = 1:3), Lutalin (CLA; cis-9,trans-11 and trans-10,cis-12 CLA, 4.6 g/d of each), or EFA and CLA (EFA+CLA) for 6 wk. The initial dosage was doubled twice after 2 wk, resulting in 3 dosages (dosages 1, 2, and 3). Each cow received each fat treatment at different times. Cows were fed with a corn silage-based total mixed ration providing a low-fat content and a high n-6:n-3 fatty acid ratio. Plasma concentrations of metabolites and hormones (insulin-like growth factor-binding proteins only on wk 0 and 6) were analyzed at wk 0, 2, 4, and 6 of each treatment period. Liver biopsies were taken before starting the trial and at wk 6 of each treatment period to measure hepatic mRNA abundance of genes linked to glucose, cholesterol and lipid metabolism, and the somatotropic axis. The changes in the milk and blood fatty acid patterns and lactation performance of these cows have already been published in a companion paper. The plasma concentration of total cholesterol increased with dosage in all groups, except CLA, reaching the highest levels in EFA+CLA and CTRL compared with CLA. The high-density lipoprotein cholesterol plasma concentration increased in CTRL and was higher than that in EFA and CLA, whereas the concentration of low-density lipoprotein cholesterol increased in a dose-dependent manner in EFA and EFA+CLA, and was higher than that in CLA. Hepatic mRNA expression of 3-hydroxy-3-methyl-glutaryl-CoA synthase 1 was upregulated in all groups but was highest in EFA+CLA. Expression of sterol regulatory element-binding factor 1 tended to be lowest due to EFA treatment, whereas expression of long chain acyl-CoA-synthetase was lower in EFA than in CTRL. Hepatic mRNA expression of GHR1A tended to be higher in EFA+CLA than in CTRL. The plasma concentration of insulin-like growth factor I increased in CLA, and the plasma IGFBP-2 concentration was lower in EFA+CLA than in CTRL at wk 6. The plasma concentration of adiponectin decreased in EFA+CLA up to dosage 2. Plasma concentrations of albumin and urea were lower in CLA than in CTRL throughout the experimental period. Supplementation with EFA and CLA affected cholesterol and lipid metabolism and their regulation differently, indicating distinct stimulation after the combined EFA and CLA treatment. The decreased IGFBP-2 plasma concentration and upregulated hepatic mRNA abundance of GHR1A in EFA+CLA-supplemented cows indicated the beneficial effect of the combined EFA and CLA treatment on the somatotropic axis in mid-lactation dairy cows. Moreover, supplementation with CLA might affect protein metabolism in dairy cows.

Maize and Grass Silage Feeding to Dairy Cows Combined with Different Concentrate Feed Proportions with a Special Focus on Mycotoxins, Shiga Toxin (stx)-Forming Escherichia coli and Clostridium botulinum Neurotoxin (BoNT) Genes: Implications for Animal Health and Food Safety

A feeding experiment was carried out with late-lactating cows over 12 weeks to evaluate the feeding value of a basic diet with maize and grass silage (MS, GS) when combined with varying portions of concentrate in the ration (20% and 60% on a dry matter basis) and to test the effects on health and performance, the transfer of important Fusarium toxins to blood and milk, the total and Shiga toxin (stx)-forming E. coli counts, and the presence of Clostridium botulinum neurotoxin (BoNT) genes in rectal fecal samples. MS was contaminated by a broader spectrum of fungal and other metabolites compared to GS. MS contained higher concentrations of the important Fusarium toxins deoxynivalenol (DON) and zearalenone (ZEN). Blood and milk levels of DON and ZEN residues generally reflected the differences in exposure at a low level. Feeding of MS with 60% concentrate feed induced subacute ruminal acidosis (SARA) associated with a marked drop in dry matter intake, fat corrected milk yield and a fat to protein ratio in milk of lower than 1. The SARA-associated higher ruminal LPS concentration did not affect the circulating concentrations of haptoglobin as an indicator of systemic inflammation. Lower rumen pH values in both MS-fed groups were associated with lower pH values, higher absolute E. coli counts and increased proportions of stx-positive E. coli in rectal feces. BoNT genes A, B, C, D, E and F remained undetectable in any of the fecal samples suggesting that feedstuffs were virtually free of the corresponding C. botulinum strains. In conclusion, maize feedstuff (silage, grains, starch-containing byproducts)-dominated rations for dairy cows should be avoided to reduce adverse effects on health and food safety.

Fatty Acid and Stable Carbon Isotope Composition of Slovenian Milk: Year, Season, and Regional Variability

This study examined the percentage and stable isotope ratios of fatty acids in milk to study seasonal, year, and regional variability. A total of 231 raw cow milk samples were analyzed. Samples were taken twice per year in 2012, 2013, and 2014, in winter and summer, covering four distinct geographical regions in Slovenia: Mediterranean, Alpine, Dinaric, and Pannonian. A discriminant analysis model based on fatty acid composition was effective in discriminating milk according to the year/season of production (86.9%), while geographical origin discrimination was less successful (64.1%). The stable isotope composition of fatty acids also proved to be a better biomarker of metabolic transformation processes in ruminants than discriminating against the origin of milk. Further, it was observed that milk from Alpine and Mediterranean regions was healthier due to its higher percentage of ω-3 polyunsaturated fatty acid and conjugated linoleic acid.

Effects of abomasal infusion of essential fatty acids together with conjugated linoleic acid in late and early lactation on performance, milk and body composition, and plasma metabolites in dairy cows

Rations including high amounts of corn silage are currently very common in dairy production. Diets with corn silage as forage source result in a low supply of essential fatty acids, such as α-linolenic acid, and may lead to low conjugated linoleic acid (CLA) production. The present study investigated the effects of abomasal infusion of essential fatty acids, especially α-linolenic acid, and CLA in dairy cows fed a corn silage-based diet on performance, milk composition, including fatty acid (FA) pattern, and lipid metabolism from late to early lactation. Rumen-cannulated Holstein cows (n = 40) were studied from wk 9 antepartum to wk 9 postpartum and dried off 6 wk before calving. The cows were assigned to 1 of 4 treatment groups. Cows were abomasally supplemented with coconut oil (CTRL, 76 g/d), linseed and safflower oil (EFA, 78 and 4 g/d; linseed/safflower oil ratio = 19.5:1; n-6/n-3 FA ratio = 1:3), Lutalin (CLA, 38 g/d; BASF SE, Ludwigshafen, Germany; isomers cis-9,trans-11 and trans-10,cis-12 each 10 g/d) or EFA+CLA. Milk composition was analyzed weekly, and blood samples were taken several times before and after parturition to determine plasma concentrations of metabolites related to lipid metabolism. Liver samples were obtained by biopsy on d 63 and 21 antepartum and on d 1, 28, and 63 postpartum to measure triglyceride concentration. Body composition was determined after slaughter. Supplementation of CLA reduced milk fat concentration, increased body fat mass, and improved energy balance (EB) in late and early lactation, but EB was lowest during late lactation in the EFA group. Cows with CLA treatment alone showed an elevated milk citrate concentration in early lactation, whereas EFA+CLA did not reveal higher milk citrate but did have increased acetone. Milk protein was increased in late lactation but was decreased in wk 1 postpartum in CLA and EFA+CLA. Milk urea was reduced by CLA treatment during the whole period. After calving, the increase of nonesterified fatty acids in plasma was less in CLA groups; liver triglycerides were raised lowest at d 28 in CLA groups. Our data confirm an improved metabolic status with CLA but not with exclusive EFA supplementation during early lactation. Increased milk citrate concentration in CLA cows points to reduced de novo FA synthesis in the mammary gland, but milk citrate was less affected in EFA+CLA cows, indicating that EFA supplementation may influence changes in mammary gland FA metabolism achieved by CLA.

Quantifying non-fibrous carbohydrates, acid detergent fiber and cellulose of forage through an in vitro gas production technique

BACKGROUND

The in vitro gas production (GP) technique has been useful for evaluating the potential degradability of feedstuffs in ruminal environments; GP is related to the components of feedstuff ingredients.

RESULTS

Linear models were generated and validated as alternatives of quantifying neutral detergent-soluble fiber, starch (St)/hemicellulose (Hem) and cellulose (Cel) through GP. Residuals of models obtained from the peaks of GP [0-8 h (GP-8), > 8-24 h (GP-24), > 24-48 h (GP-48) and > 24-81 h (GP-81)] of 0.02, 0.04, 0.08, 0.12 and 0.20 g of glucose (Glu), St and Cel respectively. The incubations were analyzed in mixtures of Glu, St and Cel. The best fitting models (r² from 0.709 to 0.935) were tested on corn stover (CS) to quantify rapid fermentation fractions (RF; equivalent to Glu), medium fermentation fractions (MF; equivalent to St) and low fermentation fractions (LF48; equivalent to Cel); in CS, RF, MF and LF models had standardized residuals < 0.09. The analysis with Leucaena (Leucaena leucocephala Lam. de Wit) and star grass (Cynodon nlemfuensis Vanderyst) consider high-protein ingredients.

CONCLUSION

The in vitro GP of RF, MF and LF48 fractions equivalent to Glu, St and Cel are affected by maturity and harvest time even when the chemical composition remains similar, and so RF, MF and LF48 should be considered during the design of ruminant diets. In vitro GP could be used to quantify the components of some forages, although further studies are necessary. © 2020 Society of Chemical Industry.

A mixture of potassium sorbate and sodium benzoate improved fermentation quality of whole-plant corn silage by shifting bacterial communities

AIMS

To investigate the changes in fermentation quality of whole-plant corn silage ensiled with varying dosages of mixed organic acid salts (MS), and link these dosage changes to shifts in bacterial composition.

METHODS AND RESULTS

Fermentation quality and bacterial community of corn silage ensiled with MS at four application rates (0, 0·67 g kg^-1 , 1·33 g kg^-1 , and 2·00 g kg^-1 ) were investigated. The MS consisted of 40% potassium sorbate and 60% sodium benzoate. The corn silages were conserved for 42 days. Dry matter losses and ammonia nitrogen concentration were linearly declined by up to 19·10 and 33·3% with increasing dosages of MS. MS treatments significantly reduced the pH of silage vs the control group. Further analysis indicated that the improvement of fermentation quality was the result of shifts in bacterial composition, the relative abundance of Lactobacillus paralimentarius and Pediococcus spp. increased while Lactobacillus reuteri, Lactobacillus coryniformis and Klebsiella declined with increasing dosages of MS.

CONCLUSIONS

MS effectively improved the fermentation quality of whole-plant corn silage with an optimum dosage of 2·00 g kg^-1 .

SIGNIFICANCE AND IMPACT OF THE STUDY

The correlation between bacterial taxa and fermentation quality provides a potential for the development of novel silage inoculants and for the application of MS on controlling Klebsiella mastitis of livestock farms.