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Previous work led to the proposal that the precision feeding of a high-concentrate diet may represent a potential method with which to enhance feed efficiency (FE) when rearing dairy heifers. However, the physiological and metabolic mechanisms underlying this approach remain unclear. This study used metabolomics analysis to investigate the changes in plasma metabolites of heifers precision-fed diets containing a wide range of forage to concentrate ratios. Twenty-four half-sib Holstein heifers, with a similar body condition, were randomly assigned into four groups and precision fed with diets containing different proportions of concentrate (20%, 40%, 60% and 80% based on DM). After 28 days of feeding, blood samples were collected 6 h after morning feeding and gas chromatography time-of-flight/MS was used to analyze the plasma samples. Parameters of oxidative status were also determined in the plasma. The FE (after being corrected for gut fill) increased linearly (P < 0.01) with increasing level of dietary concentrate. Significant changes were identified for 38 different metabolites in the plasma of heifers fed different dietary forage to concentrate ratios. The main pathways showing alterations were clustered into those relating to carbohydrate and amino acid metabolism; all of which have been previously associated with FE changes in ruminants. Heifers fed with a high-concentrate diet had higher (P < 0.01) plasma total antioxidant capacity and superoxide dismutase but lower (P ≤ 0.02) hydroxyl radical and hydrogen peroxide than heifers fed with a low-concentrate diet, which might indicate a lower plasma oxidative status in the heifers fed a high-concentrate diet. Thus, heifers fed with a high-concentrate diet had higher FE and antioxidant capacity but a lower plasma oxidative status as well as changed carbohydrate and amino acid metabolism. Our findings provide a better understanding of how forage to concentrate ratios affect FE and metabolism in the precision-fed growing heifers. [ABSTRACT FROM AUTHOR]

In order to improve the high-rate discharge properties of La11.3Mg6.0Sm7.4Ni61.0Co7.2Al7.1(AB3.0) alloy electrodes, the effects of plasma milling (PM) and graphene addition on their electrochemical properties and kinetics have been investigated. It was found that the discharge capacity of AB3.0 at a high discharge current density was significantly improved after the addition of graphene followed by PM for only 10 min. Moreover, the high-rate dischargeability (HRD) and the exchange current density I0 of the alloy electrodes were also increased. The PM technique exhibits obvious advantages for improving the high-rate discharge properties of hydrogen-storage alloys. [ABSTRACT FROM AUTHOR]

An apparatus and method that can allow continuous and precise total collection of urine under normal conditions was developed that could satisfy the urinesampling requirement of balance studies, metabolic experiments, and hormone trials of cows and heifers. The apparatus is composed of an anterior urethra, a urine cup, and a collection barrel. Total and precise collection of urine can be achieved without leakage, fecal contamination, or urethra infection. The apparatus hasfew negative effects on the cows and does not influence the cows' normal physiological activities. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The objectives of this study were to determine the effects of an increased jugular supply of L-Gln on the autophagy of weaned calves. At 35 d of age, 24 Holstein calves (initial body weight of 50 ± 0.5 kg; 35 ± 2 d of age) were randomly allocated to 4 treatments, with each treatment including 5 male calves and 1 female calf. Holstein calves were assigned to treatments of (1) intravenous infusion of 2 L of 0.85% NaCl (control group) (2) intravenous infusion of 8 g/d of L-Gln mixed with 2 L of 0.85% NaCl solution, (3) intravenous infusion of 16 g/d of l-Gln mixed with 2 L of 0.85% NaCl solution, and (4) intravenous infusion of 32 g/d of L-Gln mixed with 2 L of 0.85% NaCl. The infusion was administered 2 h/d for 7 consecutive days starting on d 1 after weaning. Feed and water were freely available to all calves. All calves were killed on d 7 postweaning to measure the autophagy of liver cells. The level of autophagy in liver cells was improved when the Gln infusion dose increased. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the effects of different stocking densities of 82 (0.82 cows per freestall and feed bin), 100, and 129% on behavior, productivity, and comfort indices of lactating Holstein dairy cows. Twenty-seven lactating cows (15 primiparous and 12 multiparous) were assigned to 1 of the 3 treatments, which were balanced for parity, milk yield, days in milk, and body weight in a 3 × 3 Latin square design with 14-d periods. After 7 d of adaptation to the treatments, lying time and bouts were recorded at 1-min intervals for 3 d, DMI and feeding time were monitored electronically by feed bins, and rumination time was quantified at 2-h periods for 5 d during each period. The cow comfort index, stall standing index, stall perching index, and stall use index (SUI) were calculated using 10-min scan samples of video recording from d 8 to 10 of each period. Milk yield was recorded from d 8 to 12 and milk composition was determined from composite samples on d 12 in each period. Daily lying time, lying bouts, and bout duration did not differ among the stocking densities. The ratio of lying time ≥12 h/d (the number of cows with daily lying time ≥12 h/d divided by number of cows per pen) was higher for cows housed at 82% stocking density compared with those housed at 100% stocking density, with stocking density of 129% intermediate. Hourly lying time was lower at 100% stocking density compared with 82 and 129% stocking densities during the peak period (2300-0400 h), determined based on diurnal pattern of lying time. Daily dry matter intake, feeding time, and feeding rate were not affected by stocking density. After morning milking, dry matter intake and feeding time was reduced at 129 versus 82% stocking density during peak feeding time (0600-0800 h), determined based on diurnal patterns of feeding behavior. Stocking density had no effect on rumination time, milk yield and milk composition. The ratio of SUI ≥85% (mean of the number of SUI ≥85% divided by the number of SUI at 10-min scan samples during a 24-h period) was lower at 129 versus 82% stocking density, with stocking density of 100% intermediate. During peak lying time after evening milking (2300-0400 h), both cow comfort index and SUI were higher at 129 than at 100% stocking density. The SUI was lower 2 h after morning milking (0800-0900 h) for cows housed at 129% compared with those housed at 82 and 100% stocking densities. In conclusion, when compared with 100% stocking density, understocking contributed to natural behaviors of cows that including lying, feeding, and rumination behavior, whereas overstocking did not cause negative effect on behavior, productivity, and comfort indices of cows in this study. [ABSTRACT FROM AUTHOR]

The first meal of a neonatal calf after birth is crucial for survival and health. The present experiment was performed to assess the effects of colostrum quality on IgG passive transfer, immune and antioxidant status, and intestinal morphology and histology in neonatal calves. Twenty-eight Holstein neonatal male calves were used in the current study, 24 of which were assigned to 1 of 3 treatment groups: those that received colostrum (GrC), transitional milk (GrT, which was obtained after the first milking on 2-3 d after calving), and bulk tank milk (GrB) only at birth. The 4 extra neonatal calves who were not fed any milk were assigned to the control group and were killed immediately after birth to be a negative control to small intestinal morphology and histology detection. Calves in GrC gained more body weight than in GrT, whereas GrB calves lost 0.4 kg compared with the birth weight. Serum total protein, IgG, and superoxide dismutase concentrations were highest in GrC, GrT was intermediate, whereas GrB was the lowest on d 2, 3, and 7. Apparent efficiency of absorption at 48 h, serum complement 3 (C3), and complement 4 (C4) on d 2, 3, and 7 in GrB was low compared with GrC and GrT. On the contrary, malondialdehyde on d 7 increased in GrB. Calves in GrC had better villus length and width, crypt depth, villus height/crypt depth (V/C) value, and mucosal thickness in the duodenum, jejunum, and ileum, whereas GrT calves had lower villus length and width, crypt depth, and mucosal thickness than those fed colostrum. Villi of calves in GrB were nonuniform, sparse, severely atrophied, and apically abscised, and Peyer's patches and hydroncus were detected. Overall, colostrum is the best source for calves in IgG absorption, antioxidant activities, and serum growth metabolites, and promoting intestinal development. The higher quality of colostrum calves ingested, the faster immune defense mechanism and the more healthy intestinal circumstances they established. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the effects of methionine hydroxy Cu [(HMTBA)2-Cu] supplementation on lactation performance, nutrient digestibility, and blood biochemical parameters in lactating cows. Thirty lactating Holstein cows were assigned to 1 of 3 treatments in a randomized block design: (1) Cu sulfate only (S): 12 mg of Cu provided by CuSO4 per kilogram of concentrate; (2) Cu sulfate and (HMTBA)2- Cu (SM): 6 mg of Cu provided by CuSO4 and 6 mg of Cu provided by (HMTBA)2-Cu per kilogram of concentrate; or (3) (HMTBA)2-Cu only (M): 12 mg of Cu provided by (HMTBA)2-Cu per kilogram of concentrate. The level of dietary Cu was determined according to the NRC (2001) requirement. This experiment lasted for 120 d, with the first 20 d for adaptation and with sample and data collection beginning on d 21. The milk yield and 4% fat-corrected milk yield of cows in the SM treatment tended to increase compared with those in the S and M treatments. Cows fed SM also tended to have higher NDF and ADF apparent digestibility values than did cows fed S or M. Plasma Cu concentration significantly increased for the SM treatment compared with the S and M treatments. Cows fed S had higher plasma K concentration than did cows in the other 2 treatments. In conclusion, replacing one-half of the dietary Cu sulfate with (HMTBA)2-Cu increased plasma Cu concentration and tended to improve the neutral and acid detergent fiber apparent digestibility values and the lactation performance of lactating dairy cattle. [ABSTRACT FROM AUTHOR]