Remodeling of intestinal bacterial community and metabolome of Dezhou donkey induced by corn silage

Corn silage can usually improve the growth performance and the meat quality of ruminants, and subsequently increase the economic benefits of farming. However, little is known about the effects of corn silage on donkeys. This experiment investigated the effects of corn silage on the weight gain, gut microbiota and metabolites of Dezhou donkeys. A total of 24 Dezhou donkeys, sourced from the same farm and exhibiting similar age and average body weight, were utilized in this experiment. The donkeys were allocated into two groups: a control group receiving a basic diet and a test group receiving a basic diet supplemented with 30% corn silage. Each group comprised 12 donkeys, evenly distributed by sex (6 males and 6 females). The experiment lasted for 100 days. Results showed that dietary supplementation with corn silage significantly (P < 0.05) improved the weight gain of Dezhou donkeys at the end of the experiment. And the supplementation of corn silage in the diet significantly altered the bacterial community composition and metabolome in the feces of the donkeys. Notably, the relative abundance ratio of Bacteroidetes to Firmicutes was 0.76 in the control group compared to 0.96 in the test group. Furthermore, members of the Bacteroidetes and Firmicutes phyla were associated with differentiated metabolites enriched in the arachidonic acid metabolism and pentose and glucuronate interconversion pathways, both of which have been reported to be related to animal growth. Specifically, Bacteroidia exhibited statistically (P < 0.05) positive correlations with 15S-HpETE, while Bacilli demonstrated statistically (P < 0.05) negative correlations with D-Xylulose. The findings of this study can advance our mechanistic understanding of the remodeling of intestinal microbiota and metabolome induced by corn silage, as well as their relationships with the growth performance of Dezhou donkeys, which in turn favor the improvement in nutrition of Dezhou donkeys.

Reducing energy and carbon footprint in semi-arid irrigated cropping systems through crop diversification

Energy and carbon (C) footprints of agricultural production practices have garnered high attention due to rising energy costs and increasing global warming. However, the contribution of conservation and regenerative farming practices, including cover cropping, on energy and C footprints have not yet been documented for cropping systems in arid and semi-arid regions. This study evaluated the energy and C footprint of cover crop integrated silage maize (Zea mays L.) and sorghum (Sorghum bicolor L. Moench) production systems in the semi-arid region of the southwestern US. The treatments were mixtures of winter cover crops: i) grasses and legumes (GL), ii) grasses, brassicas, and legumes (GBL), iii) grasses and brassicas (GB), and iv) no cover crops (NCC) control for each crop production system. Results showed cover crops had 24.1-24.5% greater energy input than NCC. In silage maize rotation, energy output was 17-22% greater in GBL and GL than in NCC. In silage sorghum rotation, the energy output was 15-24% greater in all cover crops than in NCC. The resulting net energy was 16-21% greater in GBL and GL than in NCC under silage maize, while it was 18-24% greater in GBL and GB than in NCC under silage sorghum. In the silage maize system, the C-footprint per kg yield was not different among treatments, whereas in silage sorghum, it was 58% greater in GBL than in NCC. The benefit-to-cost ratio was greater than one for all treatments, but the additional revenue through C credit programs could make cover cropping a more feasible and beneficial approach, improving economic and environmental sustainability while producing silage crops. While the C footprint was crop rotation specific, cover cropping should be encouraged over crop-fallow systems to producers in semi-arid environments to reduce energy usage and increase C-credit benefits. Clear national and state policy on the C credit program will also enhance economic and environmental benefits by adopting cover cropping and other regenerative farming practices.

Evaluation of the effects of corn silage maturity and kernel processing on steer growth performance and carcass traits

Two experiments were conducted to investigate the effects of feeding kernel processed corn silage to growing calves at 65% inclusion (dry matter [DM] basis; Exp. 1] and finishing beef steers at 20% inclusion (DM basis; Exp. 2). In Exp. 1, steers (n = 184; initial shrunk body weight [BW] = 388 ± 22.3 kg) were used to evaluate the influence that kernel processing of corn silage has on production responses when fed at 65% diet inclusion (DM basis) during a 46-d growing period. Steers were allotted to 1 of 24 pens (12 replicate pens/treatment). Treatments were based upon corn silage that was either kernel processed or not. In Exp. 2, steers (n = 192; initial shrunk BW = 446 ± 28.3 kg) were used in a 112-d finishing experiment. Treatments were grouped in a 2 × 2 factorial arrangement (24 pens total; 8 steers/pen) to evaluate corn silage harvest maturity (1/2 to 2/3 milk line or black layer) and kernel processing (processed or not) at time of corn silage harvest on finishing steer growth performance and carcass traits when corn silage is fed at a dietary DM inclusion of 20%. Both experiments were analyzed as a randomized completed block design with pen as experimental unit. In Exp. 1, final BW tended (P = 0.07) to be increased by 3 kg in kernel processed corn silage. Daily weight gain and DM intake were increased (P ≤ 0.04) by 6% and 2%, respectively, in steers fed kernel processed corn silage compared to controls; however, gain efficiency was not appreciably influenced by treatment (P = 0.15). In Exp. 2, there were no harvest maturity × kernel processing interactions (P ≥ 0.26) for any growth performance measures or any parameters related to efficiency of dietary NE utilization. No harvest maturity × kernel processing interactions (P ≥ 0.08) were observed for any carcass traits except for the distribution of USDA Prime carcasses (P = 0.04). Steers fed 2/3 milk line and unprocessed corn silage had a lower (P = 0.05) proportion of carcasses grade USDA Prime (0.0%) compared to all other treatments (12.0%). Harvest time (P ≥ 0.07) and kernel processing (P ≥ 0.07) of corn silage had no appreciable influence on any other carcass trait measures. These data indicate that kernel processed corn silage fed to growing calves at 65% diet inclusion (DM basis) enhances intake and daily gain, while kernel processed corn silage fed to finishing steers at 20% diet inclusion (DM basis) does not appreciably influence daily gain, efficiency of gain, or carcass parameters.

Near-infrared spectroscopy for rapid evaluation of winter cereals and Italian ryegrass forage mixtures

Near-infrared (NIR) spectroscopy was employed to determine the differences between forage mixtures of winter cereals and Italian ryegrass and to evaluate fermentation characteristics of mixed silages. Forages were harvested on five phases (Cuts 1-5), with 1 week interval (n = 100). The yield of the last harvest (Cut 5) was ensiled and analyzed on four different days (D0, D7, D14, and D90) (n = 80). Principal component analysis based on the NIR data revealed differences according to the days of harvest, differences between winter cereals and Italian ryegrass forages, and differences in the fermentation stages of silages. The partial least square regression models for crude protein (CP), crude fiber (CF), and ash gave excellent determination coefficient in cross-validation (R² _CV  > 0.9), while models for ether extract (EE) and total sugar content were weaker (R² _CV  = 0.87 and 0.74, respectively). The values of root mean square error of cross-validation were 0.59, 0.76, 0.22, 0.31, and 2.36 %DM, for CP, CF, EE, ash, and total sugar, respectively. NIR proved to be an efficient tool in evaluating type and growth differences of the winter cereals and Italian ryegrass forage mixtures and the quality changes that occur during ensiling.

Assessment on the Fermentation Quality and Bacterial Community of Mixed Silage of Faba Bean With Forage Wheat or Oat

Faba bean (Vicia faba L.), although a kind of high-quality and high-yield forage, could hardly achieve a great quality of silage because of its high buffering capacity. Mixed silage of faba bean with forage wheat (Triticum aestivum L.) or oat (Avena sativa L.) at different ratios could improve the fermentation quality and bacterial community. Compared with 100% faba bean silage (BS), mixed silage improved the fermentation quality, not only increased lactic acid production and reduced pH, but reduced the production of propionic acid and ammonia nitrogen. The chemical compositions of faba bean with forage wheat (BT) mixed silage were better than that of faba bean with oat (BO) mixed silage, and that of 3:7, 5:5 (fresh matter basis) mixing ratios were better than 1:9. However, the fermentation quality of BO mixed silage was better than that of BT, and that of 3:7 mixed silage (BO30) was the best overall. Analysis of the bacterial community showed that mixed silage increased the relative abundance of lactic acid bacteria after ensiling, and the relatively higher abundance of Lactobacillus showed the inhibitory effects on the proliferation of Serratia and Hafnia_Obesumbacterium, so that it alleviated their negative effects on silage and stabilized the fermentation quality. This present study exhibited that mixed silage of faba bean with forage wheat or oat not only had significant effects on chemical compositions and fermentation quality of materials but modified bacterial community so that improved the fermentation quality effectively. The mixed silage of 30% faba bean with 70% oat (BO30) is recommended in the faba bean mixed silage.

In vitro degradation and methane production of short-season corn hybrids harvested before or after a light frost

In western Canada, short-season corn silage production is increasing due to its potentially high nutritive value. The objective of this study was to determine variability and relationships among nutrient concentration, degradability, and methane (CH4) production of short-season whole-plant corn hybrids harvested before or after light frost (−1.5 °C). Four hybrids, based on their corn heat unit rating (≤2600, CHU rating), were grown in 2 yr in central and southern Alberta (AB) with two field replications. The batch culture and Daisy fermenter techniques were used to characterize degradability and gas production measurements. At both locations, dry matter (DM) concentration was affected by harvest and hybrid (P ≤ 0.02). However, starch and neutral detergent fiber (NDF) concentrations differed (P ≤ 0.01) or tended (P = 0.07) to differ among harvest and hybrid only in central AB. Over both locations and harvest times, CH4production was related negatively to propionate and positively to acetate proportions. In conclusion, harvesting southern AB hybrids after frost increased DM concentration and NDF degradability with no effect on CH4emissions, but the high DM concentration may negatively affect silage quality and animal performance. Harvesting central AB hybrids after frost increased DM and starch concentrations, while reducing CH4emissions but had limited effects on nutrient degradability.

Engineering starch accumulation by manipulation of phosphate metabolism of starch

A new understanding of leaf starch degradation has emerged in the last 10 years. It has been shown that starch phosphorylation and dephosphorylation are critical components of this process. Glucan, water dikinase (GWD) (and phosphoglucan, water dikinase) adds phosphate to starch, and phosphoglucan phosphatase (SEX4) removes these phosphates. To explore the use of this metabolism to manipulate starch accumulation, Arabidopsis (Arabidopsis thaliana) plants were engineered by introducing RNAi constructs designed to reduce expression of AtGWD and AtSEX4. The timing of starch build-up was altered with ethanol-inducible and senescence-induced gene promoters. Ethanol induction of RNAi lines reduced transcript for AtGWD and AtSEX4 by 50%. The transgenic lines had seven times more starch than wild type at the end of the dark period but similar growth rates and total biomass. Elevated leaf starch content in maize leaves was engineered by making an RNAi construct against a gene in maize that appeared to be homologous to AtGWD. The RNAi construct was expressed using the constitutive ubiquitin promoter. Leaf starch content at the end of a night period in engineered maize plants was 20-fold higher than in untransformed plants with no impact on total plant biomass. We conclude that plants can be engineered to accumulate starch in the leaves with little impact on vegetative biomass.

The role of transitory starch in C(3), CAM, and C(4) metabolism and opportunities for engineering leaf starch accumulation

Essentially all plants store starch in their leaves during the day and break it down the following night. This transitory starch accumulation acts as an overflow mechanism when the sucrose synthesis capacity is limiting, and transitory starch also acts as a carbon store to provide sugar at night. Transitory starch breakdown can occur by either of two pathways; significant progress has been made in understanding these pathways in C(3) plants. The hydrolytic (amylolytic) pathway generating maltose appears to be the primary source of sugar for export from C(3) chloroplasts at night, whereas the phosphorolytic pathway supplies carbon for chloroplast reactions, in particular in the light. In crassulacean acid metabolism (CAM) plants, the hydrolytic pathway predominates when plants operate in C(3) mode, but the phosphorolytic pathway predominates when they operate in CAM mode. Information on transitory starch metabolism in C(4) plants has now become available as a result of combined microscopy and proteome studies. Starch accumulates in all cell types in immature maize leaf tissue, but in mature leaf tissues starch accumulation ceases in mesophyll cells except when sugar export from leaves is blocked. Proper regulation of the amount of carbon that goes into starch, the pathway of starch breakdown, and the location of starch accumulation could help ensure that engineering of C(4) metabolism is coordinated with the downstream reactions required for efficient photosynthesis.