Tributyrin supplementation in pasteurized waste milk: Effects on growth performance, health, and blood parameters of dairy calves.

This study evaluated the effects of incremental tributyrin supplementation in pasteurized waste milk on growth performance, health, and blood metabolism of dairy calves before and after weaning. Forty-eight newborn female Holstein dairy calves (39.6 ± 2.75 kg; mean ± standard deviation) were blocked by age and randomly assigned to 3 treatments: pasteurized waste milk (1) without supplementation, (2) with 1 g/L of tributyrin products (unprotected solid powder; containing 35% tributyrin), or (3) with 2 g/L of tributyrin products. The calves were weaned on d 56 and were raised until d 77. Data were analyzed for the preweaning, postweaning, and overall periods. The results showed that starter intake and hay intake were not different among treatments in any period of the trial, but the crude protein intake tended to increase linearly with tributyrin supplementation during the overall period. Although tributyrin supplementation had no effects on body weight during preweaning and overall periods, body weight increased linearly with tributyrin supplementation postweaning. The average daily gain tended to increase linearly during postweaning and overall periods. No effects were observed on feed efficiency in any period. A positive linear relationship between body length and tributyrin supplementation was observed during the postweaning period, but no differences were found for the other body structural measurements in any period. The results of diarrhea showed that tributyrin concentration had a negative linear relationship with diarrhea frequency during preweaning and overall periods. The rectal temperature did not differ among treatments in any period, but a treatment × week effect for rectal body temperature was observed. For blood metabolism, tributyrin supplementation had no effects on insulin, growth hormone, total protein, albumin, or globulin. No differences were found in serum amyloid A concentration in any of the periods, yet haptoglobin concentration decreased linearly with increasing tributyrin concentration during postweaning and overall periods. Endothelin concentration showed a tendency to decrease linearly during preweaning and postweaning periods and decreased linearly with tributyrin supplementation during the overall period. An increasing tributyrin concentration was associated with a negative linear relationship with IL-1ß concentration during the preweaning period, and no differences were found in the other periods. The concentration of IL-6 and tumor necrosis factor α were not different among treatments in any of the periods. These data suggest that increasing the concentration of tributyrin in pasteurized waste milk could increase growth performance and health of dairy calves, and incremental tributyrin supplementation could linearly reduce haptoglobin, endothelin, and IL-1ß concentrations, indicating a positive effect of tributyrin on alleviating oxidative stress and inflammatory status of dairy calves. Calves fed pasteurized waste milk supplemented with tributyrin products (containing 35% tributyrin) at 2 g/L compared with 1 g/L of milk had more improved growth and health.

Effects of different feed type exposure in early life on performance, rumen fermentation, and feed preference of dairy calves.

The aim of the study was to evaluate the effects of early feed exposure (EFE) to different feedstuffs in dairy calves on feed preference once fed a free-choice diet and a total mixed ration later in life. Thirty (30) female Holstein calves were randomly assigned at birth to 1 of 3 EFE treatments-concentrate only (CON), hay only (HO), and concentrate and hay (COH)-from d 2 to 56. After that, all calves were offered both concentrate and hay in different buckets from d 57 to 70 to allow them free choice between the 2 feedstuffs. Calves were then transferred to a heifer barn, housed within treatment in pairs (2 calves/pen), and fed TMR from d 71 to 196. Feed intake was recorded daily from d 2 to 70 to determine the feed preference before and after weaning. Fresh TMR and orts were collected daily in the last week of the experiment (d 190 to 196) for analysis of feed sorting and intake. Body weight and structural growth were recorded at d 1, 28, 56, 70, and 190. Blood for determining glucose and rumen fluid for determining ruminal pH and volatile fatty acids concentrations were sampled on d 28, 56, 70, and 190. Early feed exposure did not affect feed intake, body weight, average daily gain, blood glucose, and structural growth before and after weaning but did affect feed preference and rumen fermentation. After transition to a free-choice diet, HO calves consumed more hay (550.2 g/d) than CON (177.4 g/d) and COH (396.4 g/d) calves on the first day only. However, COH calves consumed a greater amount of hay, resulting in a higher ratio of hay to total solids compared with either CON or HO calves during d 57 to 70. Upon transition to a TMR, a similar sorting pattern was exhibited between treatments, with calves sorting against the long and for the fine particle fractions. Although no significant long-term effects of different EFE on rumen pH, volatile fatty acids, and blood glucose persisted at wk 27 (from d 190 to 196), calves exposed to COH early had an improved ability to sort for long feed particles compared with CON and HO calves later in life. Our results suggest that EFE could influence choice of feed immediately after weaning and may have long-lasting effects on feed preference in heifers later in life. Further studies with more calves are recommended.

Short communication: Effects of an immunomodulatory feed additive on phagocytic capacity of neutrophils and relative gene expression in circulating white blood cells of transition Holstein cows.

High-producing dairy cows typically experience immunosuppression with dysregulated neutrophil function (e.g., compromised phagocytosis) during the transition period (3 wk before to 3 wk after parturition), which is causally associated with increased risk of infections. Enhanced neutrophil immune competence has significant bearing with the wellbeing of transition dairy cattle. In the current study, we investigated the effect of OmniGen-AF (OG; Phibro Animal Health, Quincy, IL) and its dose in modulation of neutrophil function of transition cows. Forty-eight multiparous cows were stratified by parity, somatic cell count, and expected calving date and randomly assigned to 3 treatments: OG fed at 0 g/head per day (CON), 60 g/head per day (OG60; recommended dose), and 90 g/head per day (OG90; 1.5× recommended dose). The OG was added from dry off (61.8 ± 1.69 d before parturition) to 28 d in milk (DIM), and removed from all treatment groups at 29 to 35 DIM (the last week of the experimental period). Neutrophil phagocytic ability against Staphylococcus aureus and Escherichia coli was improved and tended to be improved, respectively, by OG from d 28 before parturition to 28 DIM. Cows in OG60 had higher neutrophil phagocytic ability against S. aureus and E. coli compared with CON cows from d 28 before parturition to 28 DIM. Neutrophil phagocytosis of S. aureus and E. coli was higher and tended to be higher for OG60 compared with CON on 35 DIM. The relative gene expression of CXCL8 and SELL were upregulated and tended to be upregulated by OG from 60 d before parturition to 28 DIM; this was due to cows in OG60 having greater SELL and CXCL8 gene expression than CON. Expression of SELL in circulating white blood cells of OG60-treated cows was greater than OG90 and the relative expression of CXCL8 gene tended to be greater for OG60 compared with CON on 35 DIM. In conclusion, feeding OG at the recommended dose of 60 g/head per day from dry off was effective in maintaining peripheral blood neutrophil function in transition dairy cows, and it is not necessary to feed OG beyond the recommended dose.

Effects of Saccharomyces cerevisiae fermentation products on dairy calves: Performance and health.

The aim of the study was to evaluate the effects of Saccharomyces cerevisiae fermentation products (SCFP) on performance and health of calves during the first 63 d of age. Sixty Holstein calves (30 males and 30 females) at 2 d of age were blocked by sex and date of birth then randomly assigned within blocks to 1 of 3 treatments. A texturized calf starter was fed ad libitum containing 0 (control), 0.5, or 1% SCFP (Original XPC, Diamond V, Cedar Rapids, IA) of DM. In addition, the supplemented calves were fed 1 g/d SCFP (SmartCare, Diamond V) in milk until d 30. All calves were fed 4 L of colostrum within 1 h of birth and were subsequently fed milk twice daily until weaned at 56 d of age. Male calves were harvested on d 56. Performance and health of weaned female calves were monitored until 63 d of age to determine the effect of preweaning treatment of SCFP on weaning stress. Starter intake, fecal scores, and medical treatments were recorded daily. Body weight measures and blood samples were collected on d 2, 28, 56, and 63. Serum was analyzed for blood urea nitrogen, fatty acids, insulin-like growth factor-1, glucose, and total protein. Oxidative biomarkers and total antioxidant capacity were also evaluated in the serum. Body weight, DMI, blood parameters, and oxidative biomarkers did not differ among treatments. Supplementation of SCFP lowered fecal scores in the pre- and postweaning periods. Saccharomyces cerevisiae fermentation products can be used to reduce the diarrhea in calves grown under normal commercial conditions.

Effects of Saccharomyces cerevisiae fermentation products on dairy calves: Ruminal fermentation, gastrointestinal morphology, and microbial community.

The aim of this study was to evaluate the effects of Saccharomyces cerevisiae fermentation products (SCFP) in the calf starter and milk on ruminal fermentation, gastrointestinal morphology, and microbial community in the first 56 d of life. Thirty Holstein bull calves were randomly assigned to 1 of 3 groups: a texturized calf starter containing 0 (CON), 0.5, or 1% SCFP (XPC, Diamond V, Cedar Rapids, IA) of dry matter from d 4 to 56. In addition, the XPC-supplemented calves were fed with 1 g/d SCFP (SmartCare, Diamond V, Cedar Rapids, IA) in milk from d 2 to 30. All calves were fed 4 L of colostrum within 1 h of birth and were subsequently fed milk twice daily until weaned on d 56. Rumen fluid was collected by an esophageal tube 4 h after the morning feeding on d 28 and 56 to determine ruminal pH, ammonia-N, and volatile fatty acids concentrations. On d 56, 15 (5 per treatment) calves were harvested and slaughter weight, gastrointestinal morphology parameters, and bacteria community were recorded. Papilla length, width, and surface area were measured from 5 locations within the rumen. Villus height, width, surface area, crypt depth, and villus height-to-crypt depth ratio were measured in the duodenum, jejunum, and ileum. Next-generation sequencing technology was used to test the microbial community of the rumen and duodenum samples on d 28 and 56. Data were analyzed by MIXED procedure in SAS (SAS Institute Inc., Cary, NC) with contrast statements to declare CON versus all SCFP and 0.5 versus 1% SCFP in starter grains. Ruminal pH, ammonia-N, and total volatile fatty acids were not altered by SCFP. However, the supplemented groups exhibited higher ruminal butyrate concentrations coinciding with higher Butyrivibrio and lower Prevotella richness than CON group. Supplementation of SCFP increased papilla length in the rumen. In the small intestine, SCFP reduced crypt depth of jejunum, and increased villus height-to-crypt depth ratio in all segments of the small intestine, especially when supplemented at a higher dosage in the starter. In conclusion, Saccharomyces cerevisiae fermentation products improved gastrointestinal morphology, possibly due to increased Butyrivibrio and decreased Prevotella richness of the rumen fluid, which resulted in an increase in butyrate production, and the effect was slightly greater with the higher dosage of SCFP in the starter.

Effects of replacing wild rye, corn silage, or corn grain with CaO-treated corn stover and dried distillers grains with solubles in lactating cow diets on performance, digestibility, and profitability.

The objective of this study was to measure the effects of partially replacing wild rye (Leymus chinensis; WR), corn silage (CS), or corn grain (CG) in dairy cow diets with CaO-treated corn stover (T-CS) and corn dried distillers grains with soluble (DDGS) on performance, digestibility, blood metabolites, and income over feed cost. Thirty tonnes of air-dried corn stover was collected, ground, and mixed with 5% CaO. Sixty-four Holstein dairy cows were blocked based on days in milk, milk yield, and parity and were randomly assigned to 1 of 4 treatments. The treatments were (1) a diet containing 50% concentrate, 15% WR, 25% CS, and 10% alfalfa hay (CON); (2) 15% WR, 5% CG, and 6% soybean meal were replaced by 15% T-CS and 12% DDGS (RWR); (3) 12.5% CS, 6% CG, and 5% soybean meal were replaced by 12.5% T-CS and 12%DDGS (RCS); (4) 13% CG and 6% soybean meal were replaced by 7% T-CS and 13% DDGS (RCG). Compared with CON treatment, cows fed RCS and RCG diets had similar dry matter intake (CON: 18.2 ± 0.31 kg, RCS: 18.6 ± 0.31 kg, and RCG: 18.4 ± 0.40 kg). The RWR treatment tended to have lower dry matter intake than other treatments. The inclusion of T-CS and DDGS in treatment diets as a substitute for WR, CS, or CG had no effects on lactose percentage (CON: 4.96 ± 0.02%, RWR: 4.97 ± 0.02%, RCS: 4.96 ± 0.02%, and RCG: 4.94 ± 0.02%), 4% fat-corrected milk yield (CON: 22.7 ± 0.60 kg, RWR: 22.1 ± 0.60 kg, RCS: 22.7 ± 0.60 kg, and RCG: 22.7 ± 0.60 kg), milk fat yield (CON: 0.90 ± 0.03 kg, RWR: 0.86 ± 0.03 kg, RCS: 0.87 ± 0.03 kg, and RCG: 0.89 ± 0.03 kg), and milk protein yield (CON: 0.74 ± 0.02 kg, RWR: 0.72 ± 0.02 kg, RCS: 0.73 ± 0.02 kg, and RCG: 0.71 ± 0.02 kg). Cows fed the RWR diet had higher apparent dry matter digestibility (73.7 ± 1.30 vs. 70.2 ± 1.15, 69.9 ± 1.15, and 69.9 ± 1.15% for RWR vs. CON, RCS, and RCG, respectively) and lower serum urea N (3.55 ± 0.11 vs. 4.03 ± 0.11, 3.95 ± 0.11, and 3.99 ± 0.11 mmol/L for RWR vs. CON, RCS, and RCG, respectively) than cows fed other diets. No significant differences were noted in apparent neutral detergent fiber digestibility among the treatments. Compared with CON treatment, the RWR, RCS, and RCG treatments generated an additional $0.77, $0.70, and $0.81 income over feed cost per cow per day, respectively. In conclusion, feeding diets containing a portion of T-CS and DDGS can improve profitability of the treatment groups without negatively affecting the lactation performance of mid- to late-lactation cows.