Effect of Saccharomyces cerevisiae fermentation product on oxidative status, inflammation, and immune response in transition dairy cattle.

Dairy cattle are subjected to oxidative stress, inflammation, and altered immune function during the transition to lactation. The objective of this study was to evaluate the effects of a dietary Saccharomyces cerevisiae fermentation product (SCFP; NutriTek, Diamond V) on oxidative status, inflammation, and innate and adaptive immune responses during the transition period. Holstein cows were blocked by parity, expected calving date, and previous milk yield and then randomly assigned to treatment within block. Treatment was a control total mixed ration (n = 30) or SCFP total mixed ration (n = 34) fed from -29 ± 5 to 42 d relative to calving (RTC). Blood was sampled during wk -4, -2, 1, 2, and 5 and liver tissue at wk -3 and 2 RTC. Oxidative status was evaluated in plasma by retinol, α-tocopherol, and malondialdehyde concentrations, glutathione peroxidase activity, and Trolox equivalent antioxidant capacity, and in liver by mRNA abundance of nuclear factor E2-related factor 2 (NFE2L2), metallothionein 1E (MT1E), and glutathione peroxidase 3 (GPX3). Inflammation was evaluated in plasma by haptoglobin (HP) and serum amyloid A (SAA) concentrations and in liver by mRNA abundance of HP, serum amyloid A3 (SAA3), and nuclear factor kappa-light-chain-enhancer of activated B cells (NFKB1). Innate immune response was measured by stimulated oxidative burst of polymorphonuclear cells (neutrophils) isolated from blood. Ovalbumin (OVA) was administered with adjuvant on d 7 and 21 RTC, and adaptive immune response was evaluated by serum anti-OVA IgG content on d 28 and 35. Mixed models were used to assess effects of treatment, time, parity, and all interactions. We previously reported that SCFP had limited effects on productivity in this cohort, although milk fat yield was transiently increased and subclinical ketosis incidence was increased. Supplementation with SCFP did not affect overall oxidative, inflammatory, or immune parameters. The only treatment × week interaction detected was for plasma α-tocopherol concentration, which tended to be greater in control cows during wk 2 RTC. A tendency for a treatment × parity interaction was detected for serum anti-OVA IgG titer, which tended to be greater for SCFP than for controls among primiparous cows. Plasma inflammatory biomarkers were not affected by SCFP but, unexpectedly, plasma HP was elevated at both prepartum time points and plasma SAA was elevated during wk -2 RTC compared with the expected increases in both biomarkers postpartum. In this cohort of transition cows with low disease incidence, SCFP generally did not affect oxidative, inflammatory, or immune parameters.

Effect of kernel breakage on the fermentation profile, nitrogen fractions, and in vitro starch digestibility of whole-plant corn silage and ensiled corn grain.

The objective of this experiment was to analyze the effect of kernel breakage on the fermentation profile, nitrogen fractions, and ruminal in vitro starch digestibility of whole-plant corn silage and ensiled corn grain. Whole corn plants were harvested, and ears were separated from the forage portion and shelled. Corn kernels were either left intact or broken manually using a hammer. The remaining forage portion of the corn plants was chopped. Samples of the intact and broken kernels were stored for 0 or 30 d in quadruplicate vacuum pouches. Remaining intact and broken kernels were each reconstituted with the chopped forage portion of the corn plant to simulate whole-plant corn forage and were also stored for 0 or 30 d. In kernels separated from whole-plant corn silage, kernel form had no effect on zein protein concentrations. However, it was observed that in vitro starch digestibility at 7 h increased with ensiling only in kernels that were broken. When corn kernels were ensiled alone, concentrations of soluble crude protein and ammonia nitrogen increased with ensiling to a greater extent when kernels were broken. Finally, fermentation of ensiled corn grain was enhanced when kernels were broken. Overall, this study gives insight into the importance of kernel breakage to improve starch digestibility in corn silage through means other than a reduction in particle size and opens the door for continued investigation into the proteolytic activity occurring in the silo.

Effect of microbial inoculation and particle size on fermentation profile, aerobic stability, and ruminal in situ starch degradation of high-moisture corn ensiled for a short period.

Dairy farmers are often challenged with the need to feed high-moisture corn (HMC) after less than 30 d of fermentation. The objective this study was to assess the effects of microbial inoculation and particle size on fermentation profile, aerobic stability, and ruminal in situ starch degradation of HMC ensiled for a short period. High-moisture corn was harvested, coarsely ground (3,798 ± 40 µm, on average) or finely ground (984 ± 42 µm, on average), then ensiled in quadruplicate vacuum pouches untreated (CON) or with the following treatments: Lactobacillus plantarum CH6072 at 5 × 104 cfu/g and Enterococcus faecium CH212 at 5 × 104 cfu/g of fresh forage (LPEF); or Lactobacillus buchneri LB1819 at 7.5 × 104 cfu/g and Lactococcus lactis O224 at 7.5 × 104 cfu/g (LBLL). Silos were allowed to ferment for 14 or 28 d. Ruminal in situ starch degradation increased when HMC was finely ground. In addition, in situ starch degradation was greater and aerobic stability increased approximately 5-fold with LBLL compared with CON and LPEF. An interaction between microbial inoculation and storage length occurred for lactic acid. At 14 d, concentrations of lactic acid were greatest in LPEF and lowest in LBLL. Lactic acid concentrations increased from 14 to 28 d with CON and LPEF, but decreased with LBLL. At 28 d, concentrations of lactic acid were lower in LBLL compared with CON and LPEF. An interaction between particle size, microbial inoculation, and storage length occurred for acetic acid and ammonia-N. At 14 and 28 d, acetic acid concentrations were greatest in finely ground LBLL followed by coarsely ground LBLL. Ammonia-N concentrations increased across all treatments from 0 to 28 d. At 14 and 28 d, concentrations of ammonia-N were greatest in finely ground LBLL and lowest in coarsely ground CON and coarsely ground LPEF. Results from this study suggest that L. buchneri LB1819 can produce acetic acid in as little as 14 d, and that by 28 d, it has the potential to improve the aerobic stability of HMC. Additionally, results indicate that L. buchneri LB1819 has the potential to improve ruminal degradation of starch by 28 d of storage. Finally, results confirm enhanced fermentation and improved ruminal starch degradation with finely ground HMC by 28 d of storage.

Effect of Saccharomyces cerevisiae fermentation product on feed intake parameters, lactation performance, and metabolism of transition dairy cattle.

The transition period in dairy cattle is characterized by many stressors, including an abrupt diet change, but yeast product supplementation can alter the rumen environment to increase dairy cattle productivity. Saccharomyces cerevisiae fermentation product (SCFP) was fed from -29 ± 5 to 42 d relative to calving (RTC) to evaluate the effects on feed intake, milk production, and metabolism. Treatments were control (n = 30) or SCFP (n = 34) incorporated into a total mixed ration. Cows were individually fed 3×/d prepartum and 2×/d postpartum. Blood samples were collected once during each of the following time points RTC: d -28 to -24 (wk -4), d -14 to -10 (wk -2), d 3 to 7 (wk 1), d 12 to 16 (wk 2), and d 31 to 35 (wk 5). Liver biopsies were taken once between d -19 and d -12 (wk -3) and at 14 d in milk. Cows were milked 2×/d, and samples were taken 2 d/wk for composition analysis. Dry matter intake did not differ by treatment, but SCFP increased meals per day and decreased time between meals. Body weight (measured at enrollment, d 0, and d 42 RTC) and body condition score (scored weekly) were not affected by treatment. Milk, energy-corrected milk, and fat-corrected milk yields did not differ by treatment. Milk fat concentration was greater for SCFP, with significant differences in wk 4 and 5. Milk lactose concentration tended to be greater for the control and milk urea nitrogen tended to be lesser for the control, but there were no treatment effects on milk protein concentration or somatic cell count. Assuming equal digestibility, energy balance deficit was greater for SCFP than for the control (-6.15 vs. -4.34 ± 0.74 Mcal/d), with significant differences in wk 4 and 5. Plasma concentrations of free fatty acids, ß-hydroxybutyrate, glucose, and insulin did not differ with treatment, but cholesterol was greater for SCFP. Liver triglyceride increased and liver cholesterol decreased with time. Liver triglyceride did not differ by treatment, but liver cholesterol tended to be lesser in SCFP. Relative mRNA abundance of cholesterol-related genes (SREBF2, HMGCS1, HMGCR, MTTP, SPOB100, APOA1), FGF21, and CPT1A did not differ by treatment, but PCK1 tended to be greater for SCFP. The ketogenic transcript HMGCS2 was greater for SCFP, which aligns with SCFP increasing incidence of subclinical ketosis; however, BDH did not differ between treatments. In conclusion, SCFP supplementation increased meals per day with less time between meals, increased milk fat concentration, altered cholesterol metabolism, and increased incidence of subclinical ketosis, but early-lactation milk yield and metabolism were generally unaffected.

Productivity of lactating dairy cows fed diets with teff hay as the sole forage.

Groundwater depletion is one of the most pressing issues facing the dairy industry in arid regions. One strategy to improve the industry's drought resilience involves feeding drought-tolerant forage crops in place of traditional forage crops such as alfalfa and corn silage. The objective of this study was to assess the productivity of lactating dairy cows fed diets with teff hay (Eragrostis tef) as the sole forage. Teff is a warm-season annual grass native to Ethiopia that is well adapted to drought conditions. Nine multiparous Holstein cows (185 ± 31 d in milk; mean ± standard deviation) were randomly assigned to 1 of 3 diets in a 3 × 3 Latin square design with 18-d periods (14 d acclimation and 4 d sampling). Diets were either control, where dietary forage consisted of a combination of corn silage, alfalfa hay, and native grass hay, or 1 of 2 teff diets (teff-A and teff-B), where teff hay [13.97 ± 0.32% crude protein, dry matter (DM) basis] was the sole forage. All 3 diets were formulated for similar DM, crude protein, and nonfiber carbohydrate concentrations. Control and teff-A were matched for concentrations of neutral detergent fiber (NDF) from forage (18.2 ± 0.15% of DM), and teff-B included slightly less, providing 16.6% NDF from forage. Dry matter intake, milk and component production, body weight, body condition score, as well as DM and NDF digestibility were monitored and assessed using mixed model analysis, with significance declared at P < 0.05. Treatment had no effect on dry matter intake (28.1 ± 0.75 kg/d). Similarly, treatment had no effect on milk production (40.7 ± 1.8 kg/d). Concentrations of milk fat (3.90 ± 0.16%) and lactose (4.68 ± 0.07%) were also unaffected by treatment. Teff-A and teff-B increased milk protein concentration compared with the control (3.07 vs. 3.16 ± 0.09%). Treatment had no effect on energy-corrected milk yield (43.4 ± 1.3 kg/d), body weight, or body condition score change. Additionally, treatment had no effect on total-tract DM or NDF digestibility. Results from this study indicate that teff hay has potential to replace alfalfa and corn silage in the diets of lactating dairy cattle without loss of productivity.