Associative effects of ensiling mixtures of sweet sorghum and alfalfa on nutritive value, fermentation and methane characteristics

Effects of Sweet and Forge Sorghum Silages Compared to Maize Silage without Additional Grain Supplement on Lactation Performance and Digestibility of Lactating Dairy Cows

This study investigated the effects of replacing maize silage (MZS) with high-sugar sorghum silage (HSS) or forage sorghum silage (FSS) without additional grain supplement in the diets of dairy cows on nutrient digestibility, milk composition, nitrogen (N) use, and rumen fermentation. Twenty-four Chinese Holstein cows (545 ± 42.8 kg; 21.41 ± 0.62 kg milk yield; 150 ± 5.6 days in milk) were randomly assigned to three dietary treatments (n = 8 cows/treatment). The cows were fed ad libitum total mixed rations containing (dry matter basis) either 40% MZS (MZS-based diet), 40% HSS (HSS-based diet), or 40% FSS (FSS-based diet). The study lasted for 42 days, with 14 days devoted to adaptation, 21 days to daily feed intake and milk production, and 7 days to the sampling of feed, refusals, feces, urine, and rumen fluid. Milk production was measured twice daily, and digestibility was estimated using the method of acid-insoluble ash. The data were analyzed using a one-way ANOVA in SPSS 22.0 according to a completely randomized design. Dietary treatments were used as fixed effects and cows as random effects. The results indicate that MZS and HSS had greater crude protein but less neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), and a lower pH than FSS (p ≤ 0.04). High starch contents in MZS and water-soluble carbohydrate (WSC) contents in HSS were observed (p < 0.01). While the highest starch intake was observed for the MZS-based diet, the highest WSC intake was noted for the HSS-based diet, and the highest NDF, ADF, ADL intake was observed for the FSS-based diet (p ≤ 0.05). The diets, including MZS and HSS, had greater digestibility than that of FSS (p ≤ 0.03). Feeding MZS- and HSS-based diets increased the yield, fat, and protein content of the milk, as well as feed conversion efficiency (p ≤ 0.03). However, feeding the MZS- and HSS-based diets decreased the contents of milk urea N, urinary urea N, and urinary N excretion more than the FSS-based diet (p ≤ 0.05). The N use efficiency tended to increase relative to diets containing MZS and HSS compared with FSS (p = 0.06 and p = 0.09). Ruminal ammonia-N and pH were lower, but total volatile fatty acids, acetate, and propionate were higher in cows fed the HSS- and MZS-based diets compared to those fed the FSS-based diet (p ≤ 0.03). It appears as though replacing MZS with HSS in the diet of cows without additional grain supplements has no negative influence on feed intake, milk yield, N utilization, or ruminal fermentation.

The effects of native lactic acid bacteria on the microbiome, fermentation profile, and nutritive value of Napier grass silage prepared with different legume ratios

Mixing grass with legumes before ensiling is beneficial for improving dry matter and crude protein yield, but additional information is needed to balance nutrient content and fermentation quality. In this study, the microbial community, fermentation characteristics, and nutrient content of Napier grass mixed with alfalfa at different proportions were assessed. Tested proportions included: 100:0 (M0), 70:30 (M3), 50:50 (M5), 30:70 (M7), and 0:100 (MF). Treatments included: (CK) sterilized deionized water; (IN) selected lactic acid bacteria: Lactobacillus plantarum CGMCC 23166 and Lacticaseibacillus rhamnosus CGMCC 18233 (1.5 × 10⁵ cfu/g of fresh weight for each inoculant); and (CO) commercial lactic acid bacteria: L. plantarum (1 × 10⁵ cfu/g of fresh weight). All mixtures were ensiled for 60 days. Data analysis was used as a completely randomized design with a 5-by-3 factorial arrangement of treatments. The results showed that with increasing alfalfa mixing ratio, dry matter, and crude protein increased, while neutral detergent fiber and acid detergent fiber decreased both before and after ensiling (p < 0.05), which was not influenced by fermentation. Inoculation with IN and CO decreased pH and increased the lactic acid content compared to CK (p < 0.05), especially in silages M7 and MF. The highest Shannon index (6.24) and Simpson index (0.93) were observed in the MF silage CK treatment (p < 0.05). The relative abundance of Lactiplantibacillus decreased with increasing alfalfa mixing ratio, while the abundance of Lactiplantibacillus was significantly higher in the IN-treated group than in other treatment groups (p < 0.05). A higher alfalfa mixing ratio improved the nutrient value, but also made fermentation more difficult. Inoculants improved the fermentation quality by increasing the abundance of Lactiplantibacillus. In conclusion, the groups M3 and M5 achieved the optimal balance of nutrients and fermentation. If a higher proportion of alfalfa needs to be used, it is recommended to use inoculants to ensure sufficient fermentation.

Influence of Lactobacillus plantarum inoculation on the silage quality of intercropped Lablab purpureus and sweet sorghum grown in saline-alkaline region

Ensiling legume with cereal is an effective method to ensure the energy rich-feed, but no information is available on the microbial fermentation mechanism of intercropped Lablab purpureus (Lablab) and sweet sorghum in the saline-alkaline region. Therefore, the present study investigated the silage quality and microbial community of intercropped Lablab and sweet sorghum silages grown in the saline-alkaline region with or without inoculation of Lactobacillus plantarum (LP). The experimental treatments were prepared according to the Lablab and sweet sorghum planting patterns: Lablab and sweet sorghum sowing seed ratios were 1:1 (L), 5:1 (M), and 9:1 (H). After harvesting, each mixture was treated with LP or sterilized water (CK), followed by 60 days of fermentation. Results showed that both LP inoculation and intercropping significantly raised the lactic acid (LA) content and decreased the pH value, acetic acid (AA), and ammonia-N in intercropped silages. The LP addition and intercropping also improved the relative feed value by reducing structural carbohydrates. Moreover, LP silages had a greater relative abundance of Lactobacillus than CK silages, and its relative abundance increased with an increased seed-sowing ratio of Lablab in intercropping. LP was the prevalent species in LP silages compared to CK silages, and its relative abundance also increased with an increased seed-sowing ratio of Lablab in intercropping. The genus Lactobacillus was negatively correlated with ammonia-N (R = -0.6, p = 0.02) and AA (R = -0.7, p < 0.01) and positively correlated with LA (R = 0.7, p < 0.01) and crude protein (R = 0.6, p = 0.04). Overall, the intercropped seeding ratios of Lablab and sweet sorghum of ≥ 5:1 with LP inoculation resulted in better fermentation quality and preservation of nutritional components providing theoretical support and guidance for future intercropped protein-rich silage production in the saline-alkaline region.

Fermentation quality, bacterial community, and predicted functional profiles in silage prepared with alfalfa, perennial ryegrass and their mixture in the karst region

There is little information regarding the dynamics of fermentation products and the bacterial community in silage prepared with alfalfa (MS), perennial ryegrass (LP), and their mixture in the karst region. In this study, we explored the effects of combining MS with LP in different ratios (100% MS, 70% MS + 30% LP, 50% MS + 50% LP, 30% MS + 70% LP and 100% LP; fresh matter basis) on silage chemical composition, fermentation quality, bacterial communities and predicted functions during the ensiling process. Each treatment was prepared in triplicate and stored at room temperature (22–25°C) for 7, 15, and 45 days. The dry matter (DM) and water-soluble carbohydrate content of the silages increased as the LP proportion in the mixed silage increased; at 45 days, the 70% MS + 30% LP, 50% MS + 50% LP and 30% MS + 70% LP silages contained higher (p &lt; 0.05) CP content than the 100% MS and 100% LP silages. The 30% MS + 70% LP and 100% LP silages exhibited lower (p &lt; 0.05) pH and higher (p &lt; 0.05) LA content than the other silages; at 45 days, none of the silages contained PA or BA. As fermentation proceeded, the abundance of harmful (Enterobacteriaceae and Sphingomonas) and beneficial (Lentilactobacillus, Lactiplantibacillus, Secundilactobacillus, and Levilactobacillus) microorganisms decreased and increased, respectively, as the LP proportion in the mixed silage increased. The predicted functional distribution of microbial communities and metabolic pathways revealed that the 30% MS + 70% LP and 100% LP silages had a stronger capacity for fermentation and a weaker capacity for nitrate reduction than the other silages. Moreover, as the fermentation proceeded, the 30% MS + 70% LP and 100% LP treatments enhanced the functions of “Metabolism,” “Genetic information processing” and “Organismal systems” at level 1, the functions of “Amino acid metabolism” and “Nucleotide metabolism” at level 2, and the functions of “Metabolic pathways,” “Biosynthesis of secondary metabolites,” “Biosynthesis of antibiotics” and “Purine metabolism” at level 3. Thus, adding LP could improve the fermentation quality of MS silage by changing the composition and metabolic function of microbes; furthermore, ensiling 30% alfalfa with 70% ryegrass can produce high-quality silage in the karst region.

Silage Mixtures of Alfalfa with Sweet Sorghum Alter Blood and Rumen Physiological Status and Rumen Microbiota of Karakul Lambs

The study investigated the effects of feeding mixtures of alfalfa (AF) and sweet sorghum (SS) at different ratios of silages in terms of the physiological status of blood and rumen, and rumen microbiota in lambs. A total of 30 four-month-old male Karakul lambs with 25.5 ± 1.4 kg mean initial body weight were randomly allocated to five groups, with six lambs in each group. Five experimental diets containing 40% of one of the five AF−SS mixed silages (containing 0%, 20%, 40%, 60%, and 80% AF on a fresh weight basis, respectively) and 60% of other ingredients were formulated. Overall, the results showed that the mixed silage with more AF tended to increase serum antioxidant capacity, dry matter (DM) intake, and rumen fermentation metabolites. The AF−SS mixed silages containing AF at 60% and 80% caused a significant linear increase (p < 0.05) in the activity of total antioxidant capacity. The superoxide dismutase in the Karakul lamb responded with significant linear and quadratic increases (p < 0.01) as the ratio of AF was increased in the AF−SS mixed silages. Feeding diets with AF in silage mixtures at the ratio of 60% significantly increased (p < 0.05) the concentration of ruminal total volatile fatty acids (tVFA), acetate, and ammonia-N. However, no statistical significance (p > 0.05) was found in the alpha diversity of rumen microbes among the tested groups (p > 0.05). Principal coordinates analysis could clearly discriminate the differences between the five groups (p = 0.001). The relative abundance of Firmicutes in the rumen were significantly higher with AF at 40% in the AF−SS silage-based diet than those with AF at 0%, and 20% ratios. The abundance of Ruminococcus_albus had a significant linear increase (p < 0.05), as the ratio of AF in the AF−SS mixed silages was increased. In conclusion, the best beneficial effect on the physiological status of the blood and rumen, DM intake, and rumen microbiota in lambs came from those that consumed the diet containing the AF−SS mixed silage with 60% AF.

Associative effects of ensiling mixtures of sweet sorghum and korshinsk pea shrub on fermentation quality, chemical composition, and in vitro rumen digestion characteristics

Silages processed with gramineous grass and wood feed mixtures may have positive associative effects on silage quality and animal performance when ruminants are fed those silages. The present study was conducted to evaluate the fermentation quality, chemical composition, and in vitro rumen digestion characteristics of silages produced with mixtures of sweet sorghum (SS) and korshinsk pea shrub (KP) in six different ratios of fresh weights: 100:0 (0%KP), 80:20 (20%KP), 60:40 (40%KP), 40:60 (60%KP), 20:80 (80%KP), and 0:100 (100%KP). As the proportion of KP increased in the silages, the contents of lactic acid, acetic acid, starch, total phenolics, hydrolysable tannins, and condensed tannins decreased (p < 0.05), while the pH value and the contents of neutral detergent fiber, acid detergent fiber, ether extract, crude protein, and ash increased (p < 0.05). The silages were evaluated in 48 h incubations with rumen liquor. The in vitro dry matter digestibility, in vitro neutral detergent fiber digestibility, and in vitro gas production decreased as the proportion of KP increased (p < 0.05). This study suggests that ensiling SS-KP at a ratio of 80:20 is a practical method for preserving such low-DM forages (SS) and that these silage mixtures offer an opportunity to optimize the nutrient supply for ruminant production.

Effects of total mixed ration with various silage on growth performance, serum parameters, ruminal fermentation, and bacteria community profile in beef cattle

The possibilities of using high-quality forages in incorporation with total mixed ration (TMR) during the fattening period of beef cattle have been investigated. A total of 30 Simmental bulls (438.94 ± 11.45 kg) were selected and randomly divided into two groups, TMR with single corn silage (SS) and TMR with various silage (MS). The whole experiment consisted of 15 days preparation period and 69 days experimental period. Rumen fluid and blood samples were taken from six beef cattle per treatment at the end of the experiment. The results showed that the average daily gain of the MS group (1.56 kg/day) was higher than (p < .05) the SS group (1.30 kg/day), and a decrease of feed conversion ratio in the MS (10.83) group was observed compared with SS group (12.36) (p < .05). The concentration of total volatile fatty acids for MS group was greater than (p < .05) the SS group. The activities of total antioxidant capacity and superoxide dismutase from MS group were also higher than the SS group, but lower urea nitrogen was found in the MS group from serum (p < .05). In addition, the abundances of the Prevotella-1 and Verrucomicrobia were higher in the MS group than the SS group (p < .05). An increase in the flavonoid biosynthesis was detected in the MS group compared with the SS group by Kyoto Encyclopaedia of Genes and Genomes analysis. The present findings suggest that it is economical and healthy to substitute high-quality forage +low level of concentrate for a relatively low proportion forage +high level of concentrate in a finishing diet of beef cattle, which was a feasible and healthy strategy in the intensive feeding system.

Effect of Silage Diet (Sweet Sorghum vs. Whole-Crop Corn) and Breed on Growth Performance, Carcass Traits, and Meat Quality of Lambs

Diet and breed directly affect ruminant carcass traits and meat quality. Therefore, this research aimed to evaluate the effect of silage diet and breed on growth performance, carcass traits, and meat quality of lambs. A total of 28, 3-4 months old female lambs consisting of 14 Dorper lambs (DP) and 14 Thin-tailed Han lambs (TH) were allocated in a 2 × 2 factorial design and offered two experimental diets (sweet sorghum silage: SS; whole-crop corn silage: WS) for 90 days. Lambs fed the WS diet had a higher growth performance (p < 0.01), intramuscular fat content (p < 0.05), and bright meat color (p < 0.01) than lambs fed the SS diet. The lambs fed the SS diet showed a higher polyunsaturated fatty acid (PUFA) content than the lambs fed the WS diet (p < 0.01); there was no significant difference in growth performance and carcass characteristics between DP and TH lambs (p > 0.05). The meat of the DP lambs showed lower values of initial pH, shear force, lightness (L*), redness (a*), and saturated fatty acid (SFA) content (p < 0.05). The lamb breed influenced fewer variables of growth performance and carcass characteristics compared to the diet. The lambs fed the SS diet had higher nutritional quality meat than lambs fed the WS diet.

Diets varying in ratio of sweet sorghum silage to corn silage for lactating dairy cows: Feed intake, milk production, blood biochemistry, ruminal fermentation, and ruminal microbial community

The objective of this study was to investigate the effects of partial substitution of corn silage (CS) with sweet sorghum silage (SS) in the diets of lactating dairy cows on dry matter (DM) intake, milk yield and composition, blood biochemistry, and ruminal fermentation and microbial community. Thirty mid-lactation Holstein dairy cows [mean ± standard deviation; 639 ± 42.0 kg of body weight; 112 ± 24.0 d in milk (DIM)] were assigned to 3 groups (n = 10/treatment) by considering parity, milk yield, and DIM. The cows were fed ad libitum total mixed rations containing 55% forage and 45% concentrate, with only the proportion of CS and SS varying in 3 treatments (DM basis): SS0 (0% substitution of CS), 40% CS and 0% SS; SS25 (25% substitution of CS)_, 30% CS and 10% SS; and SS50 (50% substitution of CS)_, 20% CS and 20% SS. Dry matter intake and milk protein concentration tended to linearly decrease with increasing proportion of SS in the diet. Yields of milk (mean ± standard deviation, 30.9 ± 1.12 kg/d), 4% fat-corrected milk (30.0 ± 0.81 kg/d), energy-corrected milk, milk protein, lactose, and total solids, concentrations of milk fat, lactose, somatic cell counts, and milk efficiency did not differ among diets. The concentrations in blood of urea nitrogen, phosphorus, aspartate aminotransferase, and malondialdehyde linearly increased with increasing SS proportion. Blood IgA decreased with increasing SS substitution rate, but blood IgG and IgM were not different among diets. Ruminal pH did not differ among diets, whereas ruminal NH₃-N concentration quadratically changed such that it was greater for SS50 than for SS0 and SS25. Molar proportions of propionate and acetate to propionate ratio were less for SS25 than for SS0. Although the diversity and general ruminal microbial community structure were not altered by partially replacing CS with SS, the relative abundances of predominant bacteria were affected by diets at the phylum and genus levels. Firmicutes and Bacteroidetes were dominant phyla in the ruminal bacterial community for all diets, and their relative abundance linearly decreased and increased, respectively, with increasing SS substitution rate. Prevotella_1 and Ruminococcaceae_NK4A214_group were detected as the most and the second most abundant genera, with their relative abundance linearly increased and decreased, respectively, with increasing SS substitution rate. The relative abundance of Fibrobacter linearly increased with increasing dietary SS proportion, with greater abundance observed for SS25 and SS50 than for SS0. These results suggest that substitution of CS with SS altered the relative abundances of some predominant bacteria; however, these changes had little effect on ruminal fermentation and milk yield. Under the current experimental conditions, substituting up to 50% of CS with SS had no negative effects on milk yield, indicating that SS can partially replace CS in the diets of high-producing lactating dairy cows without adding extra grain, when diets are fed for a short time. As the effects of substituting CS with SS depend upon the chemical composition and digestibility of these silages and the nutrient requirements of the cows, additional grain may be required in some cases to compensate for the lower starch content of SS.

Using mixed silages of sweet sorghum and alfalfa in total mixed rations to improve growth performance, nutrient digestibility, carcass traits and meat quality of sheep

Combining sweet sorghum (SS) with alfalfa for ensiling has the potential to make a high-quality silage with relatively a better nutrient balance. However, the existing data are insufficient about how changes in ratios of SS to alfalfa in different silage mixtures affect animal performance and meat quality. Therefore, the objective of this study was to determine the effect of feeding total mixed rations containing mixed silages of SS and alfalfa on growth performance, nutrient digestibility, carcass traits and meat quality of Karakul sheep. Five total mixed rations were formulated with different SS proportions at 100%, 80%, 60%, 40%, and 20% on a fresh weight basis. Thirty 4-month old male Karakul sheep with 25.5 ± 1.4 kg BW were randomly allocated into five treatment groups, each with six lambs for this experiment. The results indicated that the Karakul sheep consuming total mixed rations containing SS-Alfalfa (SS-AF) silage mixtures with a lower proportion of SS tended to increase nutrient digestibility, growth performance, carcass traits, and meat quality. Feeding diets with SS at 40% and 20% inclusion rate showed a significant linear increase in the apparent digestibility of DM, CP and NDF, as well as subcutaneous fat thickness and water holding capacity (P < 0.5). Moreover, reduction in SS inclusion rate in these diets caused significant (P < 0.05) linear and quadratic increases in DM intake, final BW, average daily gain, carcass weight, and the amino acid contents of meat (P < 0.05). Conversely, feeding diet with lower SS inclusion rate led to decrease in feed conversion ratio and shear force significantly (P < 0.05) for these sheep. It appears that 40% inclusion of SS was the optimal rate in making the SS-AF silage mixture for lambs to achieve a superior production performance and high-quality meat products in Karakul sheep. However, further research is needed to investigate the effect of feeding SS-AF silage mixtures alongside contrasting ingredients on rumen function, ruminal microorganisms and digestive enzyme activity of sheep and other ruminant animals.

Effects of Sugar Cane Molasses Addition on the Fermentation Quality, Microbial Community, and Tastes of Alfalfa Silage

Simple Summary

It is difficult for Alfalfa alone to obtain a competitive fermentation quality due to its low content of fermentable carbohydrate and great buffering capacity. Sugar cane molasses additives provide a substrate for the rapid accumulation of lactic acid (LA) and pH reduction while increasing the nutritional quality of silage. The present work aims to study the effects of molasses additives on the fermentation quality and taste evaluation of the alfalfa silage. The microbial communities of the alfalfa silage were also described as the explanation for the changes in silages. The study could give directions on improving the fermentation quality of alfalfa silage and achieve long-term preservation.

Abstract

The objective was to study the effects of sugar cane molasses addition on the fermentation quality and tastes of alfalfa silage. Fresh alfalfa was ensiled with no additive (Control), 1% molasses (M1), 2% molasses (M2), and 3% molasses (M3) for 206 days. The chemical composition and fermentation characteristics of the alfalfa silages were determined, the microbial communities were described by 16S rRNA sequencing, and the tastes were evaluated using an electronic tongue sensing system. With the amount of added molasses (M), most nutrition (dry matter and crude protein) was preserved and water-soluble carbohydrates (WSC) were sufficiently used to promote the fermentation, resulting in a pH reduction from 5.16 to 4.48. The lactic acid (LA) content and LA/acetic acid (AA) significantly increased, indicating that the fermentation had turned to homofermentation. After ensiling, Enterococcus and Lactobacillus were the dominant genus in all treatments and the undesirable microbes were inhibited, resulting in lower propionic acid (PA), butyric acid (BA), and NH3-N production. In addition, bitterness, astringency, and sourness reflected tastes of alfalfa silage, while umami and sourness changed with the amount of added molasses. Therefore, molasses additive had improved the fermentation quality and tastes of alfalfa silage, and the M3 group obtained the ideal pH value (below 4.5) and the best condition for long-term preservation.

Effects of Ensiling Oxytropis glabra with Whole-Plant Corn at Different Proportions on Fermentation Quality, Alkaloid Swainsonine Content, and Lactic Acid Bacteria Populations

Simple Summary

In Inner Mongolia, developing innovative forages is an indispensable way to ease the shortage of animal feed. Oxytropis glabra (OG) has become a dominant population, with a high nature yield in the degraded grassland of Inner Mongolia. As a typical legume, it is rich in amino acids and trace elements, so using OG to feed livestock is a valuable strategy. However, it contains swainsonine (SW), which hinders the utilization of OG. This study was conducted to evaluate silage fermentation and SW removal from OG ensiled with whole-plant corn at different proportions, and the result showed ensiling a mixture of OG and corn could be a valuable approach for producing livestock feed, as it had a positive effect on fermentation quality and SW detoxification; the optimal ratio was 1:1. In the silages, Lactobacillus plantarum was the most common microorganism present in all mixture silages, and Lactobacillus amylovorus and Lactobacillusbrevis were prevalent at lower ratios of corn to OG. All representative strains were able to remove SW from OG fermentation, and the strains of L. amylovorus and L. plantarum had a higher SW removal rate. These mixtures of silages could make OG useable as a feed source in ruminant production.

Abstract

Oxytropis glabra (OG) is a leguminous forage that is potentially valuable for solving the shortage of feed for livestock production, while, in large quantities, it may be toxic because of its swainsonine (SW) content. In this study, OG was ensiled with whole-plant corn (Zea mays L.) at 10:0, 9:1, 8:2, 7:3, 6:4, 5:5, 4:6, and 0:10 ratios on a fresh matter basis, and, after 60 d of ensiling, the chemical composition, fermentation characteristic, SW removal rate, lactic acid bacteria (LAB) populations, and their capabilities for SW removal were analyzed. As the proportion of corn in the silage increased, the pH, as well as the propionic acid, ammonia-N, dry matter, crude protein, and SW contents, decreased linearly, while the lactic acid, neutral detergent fiber, and residual water-soluble carbohydrate contents increased linearly. Lactobacillus plantarum was the most common microorganism present in all mixture silages. Lactobacillus amylovorus and Lactobacillusbrevis were prevalent at lower ratios of corn to OG. Meanwhile, the LAB strains belong to L. amylovorus and L. plantarum had a higher SW removal rate. Our results suggested that ensiling OG with whole-plant corn improves fermentation and decreases SW content, and that 5:5 is the optimal ratio, so this type of mixed silage could make OG useable for ruminant production.

Combining Orchardgrass and Alfalfa: Effects of Forage Ratios on In Vitro Rumen Degradation and Fermentation Characteristics of Silage Compared with Hay

Simple Summary

Forages are an essential portion of ruminant rations to maintain rumen function. Exploring how orchardgrass and alfalfa interact in the rumen is necessary to better understand their feed use potential as both hay and silage. This study evaluated in vitro rumen degradation, fermentation characteristics, and methane production responses to different forage ratios of alfalfa and orchardgrass. The results indicate that dry matter and organic matter degradability and methane production were greater for mixed silages compared to mixed hays. A forage ratio of 50:50 for orchardgrass and alfalfa favor the growth of rumen microorganisms without compromising nutrient digestion and rumen fermentation.

Abstract

This study aimed to investigate the effects of different forage ratios of orchardgrass (Dactylis glomerata) and alfalfa (Medicago sativa) on in vitro rumen degradation and fermentation characteristics. Orchardgrass and alfalfa were harvested separately and prepared as hay and silage mixtures at ratios of 100:0, 75:25, 50:50, 25:75, and 0:100 (w/w on a dry matter basis) and anaerobically incubated for 48 h with rumen fluid obtained from lactating dairy cows. Fermented residues and cultured fluids were used to determine nutrient degradability, fermentation parameters, and associative effect indices. Increasing the proportion of alfalfa in hay and silage mixtures quadratically increased in vitro organic matter disappearance (IVOMD, up +5.14%) and marginally decreased in vitro neutral detergent fiber disappearance (NDFD, down −1.79%). Meanwhile, increasing the proportion of alfalfa accelerated the rumen fermentation process (e.g., gas production) and remarkably enhanced the growth of rumen microbes as indicated by microbial protein production (MCP, 13.4% increase). Increments of rumen degradability and methane production were more pronounced in silage mixtures than hay mixtures. In combination, a forage ratio of 50:50 for orchardgrass and alfalfa is recommended for both hay and silage in order to improve the feed use potential in ruminants.

Comparative analysis of ensiling characteristics and protein degradation of alfalfa silage prepared with corn or sweet sorghum in semiarid region of Inner Mongolia

This study was conducted to evaluate silage fermentation and protein degradation of alfalfa prepared with corn or sweet sorghum (SS) at different mixing ratios. The chemical composition, ensiling characteristics, and protein degradation of alfalfa prepared with and without corn or SS at mixing ratios of 7:3, 1:1, and 3:7 on a fresh matter (FM) basis were studied. The alfalfa had the highest crude protein (CP) content and lactate buffering capacity (LBC), but lower water-soluble carbohydrate (WSC) content than corn and SS. After 60 days of ensiling, the corn and SS silages had good quality, with lower pH and ammonia-N content, and higher dry matter (DM) content than the alfalfa silages. In the alfalfa and corn mixture silages, the DM contents linearly increased with an increase in the proportion of corn, while the pH, non-protein N (NPN), ammonia-N, and peptide-N contents linearly decreased. In the alfalfa and SS mixture silages, the DM and NPN contents linearly increased with an increase in the proportion of SS, while the pH, lactic acid, and ammonia-N contents linearly decreased. This study suggests that alfalfa silage prepared with corn has more positive effect on fermentation quality and inhibiting protein degradation than addition of SS.

Structural and quantitative changes of saponins in fresh alfalfa compared to alfalfa silage

BACKGROUND

Alfalfa (Medicago sativa) is an important legume used in animal feed. The primary objective of the present study was to analyze and trace the individual saponins in fresh and ensiled alfalfa of ten varieties, with the aim of evaluating the structural changes that saponins undergo during ensiling. A secondary objective was to examine whether any of the changes in saponin content were associated with changes in the basic nutrient composition of the ensiled alfalfa.

RESULTS

The total saponin concentration increased when the fresh alfalfa was processed into silage. Three of the zanhic acid glycosides were degraded substantially, whereas the other two increased in all the tested varieties. Five of the seven medicagenic acid glycosides were not changed, whereas the remaining saponins completely disappeared. Finally, two glycosides of soyasapogenol B displayed an inverse relationship to each other.

CONCLUSION

The nutrient content of fresh material and silages remained relatively constant, with some variations in the crude protein content of the selected alfalfa varieties. The total concentration of saponins increased two- to three-fold after ensilation over the levels present in fresh alfalfa material. The increases in saponin concentration showed a negative linear relationship between protein on a dry matter basis and saponin content. These findings are significant because no known published data have shown this transformation in the ensiling of alfalfa. © 2018 Society of Chemical Industry.

Ensiling characteristics, in vitro rumen fermentation, microbial communities and aerobic stability of low-dry matter silages produced with sweet sorghum and alfalfa mixtures

BACKGROUND

Silages produced with grass and legume mixtures may have positive associative effects on silage quality and animal performance when ruminants are fed the silages. The present study aimed to determine the preservation characteristics, in vitro rumen fermentation profile and microbial abundance of silages, produced with mixtures of sweet sorghum (SS) and alfalfa (AF) in different ratios: 100:0 (Control), 75:25 (SA25), 50:50 (SA50), 25:75 (SA75) and 0:100 (SA100) on a fresh weight basis.

RESULTS

As the proportion of AF increased in the silages, pH, acetic acid, ammonia nitrogen and crude protein (CP) concentrations, and aerobic stability increased (P < 0.05), whereas lactic acid and neutral detergent fibre (NDF) and acid detergent fibre (ADF) concentrations decreased (P < 0.05). Increasing the proportion of AF in the silages, increased (P < 0.05) the in vitro degradability of dry matter and CP, as well as the proportions of genus Prevotella, but decreased (P < 0.05) the in vitro degradability of NDF (IVNDFD) and ADF (IVADFD) and proportions of Butyrivibrio fibrisolvens. Compared to the Control silage, SA25 silage had greater (P < 0.05) proportions of Fibrobacter succinogenes and Ruminococcus flavefaciens, IVNDFD, IVADFD, ruminal short chain fatty acids and microbial protein concentrations, as well as lower (P < 0.05) methane production.

CONCLUSION

The silage produced with the SS to AF ratio of 75:25 was the most suitable for ruminants use as a result of the optimal balance of fermentation quality, feed-nutritional value and aerobic stability. © 2018 Society of Chemical Industry.

Fermentation Characteristics of Lactobacillus Plantarum and Pediococcus Species Isolated from Sweet Sorghum Silage and Their Application as Silage Inoculants

This study aims to evaluate the fermentation characteristics of Lactobacillus plantarum and Pediococcus spp isolated from sweet sorghum silage to enhance the fermentation quality of Napier grass and sweet sorghum silage. Based on molecular 16S ribosomal ribonucleic identification the isolated strains were phylogenetically related to Lactobacillus plantarum (HY1), Pediococcus acidilactici (HY2) and Pediococcus claussenii (HY3). Strains HY1, HY2 and HY3 and commercial bacteria Lactobacillus plantarum, Ecosyl; (MTD\1( were ensiled with sweet sorghum and Napier grass and the non-inoculated grasses, have been arranged in a completely randomized experimental design in a 5 (inoculants) × 3 (ensiling periods). In both grasses, the fermentation characteristics chemical composition and microbial population were assessed at 5–30 and 90 days of ensiling. The results showed that the effect of addition inoculants significantly reduced (p < 0.05) the pH, ammonia-N, acetic acid and undesirable microbial population and increased (p < 0.05) lactic acid and lactic acid bacteria counting when compared to the control. The effect of ensiling days on silage quality through the increasing lactic acid, acetic acid, ammonia-N, propionic acid and butyric acid whereas decreasing pH and water-soluble carbohydrates and microbial counts. In both sweet sorghum and Napier silage treated with isolated strains showed the best results in silage quality. The HY3 belongs to Pediococcus claussenii was not extensively studied in silage but it has shown good fermentation quality which strongly recommended to apply as probiotic.

Effect of a mixed silage of king grass (Cenchrus purpureus) and forage legumes (Leucaena leucocephala or Gliricidia sepium) on sheep intake, digestibility and nitrogen balance

Ensiled king grass (Cenchrus purpureus (Schumach.) Morrone) is commonly used as feed in tropical ruminant production. However, ruminant performance can be limited by low nitrogen (N) content in tropical grass silage. A mixed feed of legume–king grass silage may be an option to improve ruminant production. We investigated the effects of feeding an ensiled mixture of king grass forage and foliage of a browse tree legume, either leucaena (Leucaena leucocephala (Lam.) de Wit) or gliricidia (Gliricidia sepium (Jacq.) Walp), on dry matter (DM) intake, DM digestibility, organic matter (OM) digestibility and N balance of Pelibuey sheep. Twelve male lambs 9–11 months old were blocked by initial bodyweight (33 ± 3 kg, mean ± s.d.) into three groups of four lambs and randomly assigned to one of three feed treatments: king grass silage (KS); mixed king grass and leucaena silage (KLS); and mixed king grass and gliricidia silage (KGS). Results showed that DM and OM were similar among silages. The N content was higher (P &lt; 0.001) in KLS and KGS than in KS. DM intake and DM digestibility were higher (P &lt; 0.001) in KLS and KGS than in KS. OM digestibility was higher (P &lt; 0.001) in KLS than in KS. Nitrogen intake, faecal N, urine volume, urinary N, digested N, N digestibility, N retention and retained N:N intake ratio from KLS and KGS treatments were higher (P &lt; 0.05) than from KS. A lower (P &lt; 0.01) urinary N:N intake ratio was detected from KGS and KLS than from KS. This study demonstrated that, compared with silage made from king grass alone, legume–king grass silage mixtures can improve intake and nutrient digestibility in Pelibuey lambs. Further, N retention can be enhanced when legume–king grass silages are used as feed compared with king grass silage alone.

Total replacement of corn silage with sorghum silage improves milk fatty acid profile and antioxidant capacity of Holstein dairy cows

Total mixed rations containing corn silage (CS) or forage sorghum silage (SS) were fed to mid-lactation Holstein cows to determine the effects on feed intake, lactation performance, milk composition and fatty acid profile, nutrient digestibility, blood metabolites, rumen microbial N synthesis, and antioxidant status. The experiment was designed as a 2-period change-over (two 28-d periods) trial with 2 diets including CS diet or SS diet and 12 cows. Total replacement of CS with SS had no significant influence on dry matter intake. Substituting CS with SS had no effect on milk production, feed efficiency, and milk concentrations of fat, protein, lactose, and solids-not-fat, whereas yields of milk fat, protein, and lactose were greater for cows fed the CS diet. Blood parameters including glucose, albumin, cholesterol, triglyceride, total protein, urea N, and fatty acids were not affected by the dietary treatments. Apparent digestibility coefficients of dry matter, organic matter, crude protein, ether extract, neutral detergent fiber, and acid detergent fiber were not significantly influenced by the diets. Replacing CS with SS had no effect on total saturated fatty acids and total monounsaturated fatty acids, whereas total polyunsaturated fatty acid percentage was greater with the SS diet. Proportions of C20:0, C18:3n-3, and C18:3n-6 were affected by feeding SS. Cows fed CS had a greater amount of urinary purine derivatives. Feeding SS had a positive effect on total antioxidant capacity of blood and milk. In conclusion, SS can be fed to lactating Holstein cows as a total replacement for CS without undesirable effects on animal performance, but with positive effects on antioxidant capacity and polyunsaturated fatty acids of milk. This forage can be an excellent choice for dairy farms in areas where cultivation of corn is difficult due to water shortage.

Inoculant effects on the fermentation quality, chemical composition and saponin content of lucerne silage in a mixture with wheat bran or corn husk

This study evaluated the effects of lactic acid bacteria inoculants on the fermentation quality and chemical composition of lucerne silage (A), a mixture of lucerne and wheat bran (A+WB), and a mixture of lucerne and corn husk (A+CH). The application rates of wheat bran in A+WB or corn husk in A+CH were 10%, 15%, and 20% of the whole fresh material. These different materials were treated with distilled water (Control), Lactobacillus plantarum 1 (LAB1), L. plantarum 2 (LAB2), L. plantarum 8 (LAB8) or a commercial inoculant (LALMAND) at a rate of 106 CFU/g of fresh forage. As the application rate of the by-products increased, the dry matter, lactate, propionate, and neutral detergent fibre (after heat-stable amylase treatment) contents increased, and the pH and the acetate, ammonia nitrogen, crude protein, and non-fibre carbohydrate contents decreased. The A+WB showed better fermentation quality than A and A+CH. The inoculants had beneficial effects on the silages, but the effects varied. The results indicate that the use of LAB1, LAB2, or LAB8 was better with A, whereas LALMAND was preferable for use with A+WB or A+CH. The saponin content decreased during ensiling and was positively correlated with the pH and the acetate and ammonia nitrogen content but negatively correlated with the dry matter content. The increase in the application rate of by-products and the addition of LALMAND further decreased the saponin content. Overall, the combined effects of the inoculants, by-products, and different application rates improved the fermentation quality and chemical composition and led to greater a reduction of saponin in lucerne silage, but the selection of suitable types and application rates of by-products and inoculants is essential.

Fermentation quality and in vitro methane production of sorghum silage prepared with cellulase and lactic acid bacteria

Objective

The effects of lactic acid bacteria (LAB) and cellulase enzyme on fermentation quality, microorganism population, chemical composition and in vitro gas production of sorghum silages were studied.

Methods

Commercial inoculant Lactobacillus plantarum Chikuso 1 (CH), local selected strain Lactobacillus casei (L. casei) TH 14 and Acremonium cellulase (AC) were used as additives in sorghum silage preparation.

Results

Prior to ensiling Sorghum contained 10⁴ LAB and 10⁶ cfu/g fresh matter coliform bacteria. The chemical compositions of sorghum was 26.6% dry matter (DM), 5.2% crude protein (CP), and 69.7% DM for neutral detergent fiber. At 30 days of fermentation after ensiling, the LAB counts increased to a dominant population; the coliform bacteria and molds decreased to below detectable level. All sorghum silages were good quality with a low pH (<3.5) and high lactic acid content (>66.9 g/kg DM). When silage was inoculated with TH14, the pH value was significantly (p<0.05) lower and the CP content significantly (p<0.05) higher compared to control, CH and AC-treatments. The ratio of in vitro methane production to total gas production and DM in TH 14 and TH 14+AC treatments were significantly (p<0.05) reduced compared with other treatments while in vitro dry matter digestibility and gas production did not differ among treatments.

Conclusion

The results confirmed that L. casei TH14 could improve sorghum silage fermentation, inhibit protein degradation and decrease methane production.