CON Calves Research Articles

PSXIV-1 Impact of Slow-Release Nitrogen Or Regular Protein-Based Supplementation During Late Gestation on Maternal and Offspring Performance in Beef Cattle

Abstract The objective of this study was to determine whether supplementing pregnant beef cows with regular nitrogen or a slow-release nitrogen source at the late gestation could enhance the use of a low protein basal diet and improve the performance of cows and their offspring until weaning. Thirty-five pregnant Brahman cows (556 ± 47 kg and 4.5 ± 1.4 years old) were individually housed in covered pens and randomly divided into three groups. From 180 ± 19 days of gestation until calving, cows were fed either a control (CON, n = 12) low crude protein (CP) basal diet (6% of CP, ad libitum) plus mineral mixture (130 g·cow-1·d-1), or the CON treatment supplemented with protein concentrate supplements (40% CP, fed 2 g·kg of BW-1·d-1 in the morning) based either on a regular (REG, n = 11) composition (corn, soybean meal, and urea) or on a slow-release N (SRN, n = 12) source (Timafeed Boost, Roullier Group, Saint-Malo, France) which replaced 60% of soybean meal and urea in the supplement composition. The MN, fetal sex (FS), and MN×FS were used as fixed effects in the statistical model, while the number of previous calvings was considered as a random effect. Maternal initial BW was used as a covariate. Statistical differences were declared at P < 0.05. Supplementation with REG and SRN increased total dry matter intake (DMI) and basal diet intake compared with the control treatment (P < 0.01). Protein supplementation allowed the cows to have a higher average daily gain (P < 0.01; 0.177 and 0.193 kg/day, respectively, for REG and SRN) than the CON treatment (-0.255 kg/day). Body condition score (BCS) also increased (P < 0.01) when cows received protein supplementation in late pregnancy, but with no differences between REG and SRN cows (P = 0.31). Interactions between MN and FS were observed for calf birth weight (CBW, P < 0.01) and calves' average daily gain up to 120 days of age (ADG120, P = 0.01), but not at weaning weight (P = 0.69). Male calves born from REG and SRN cows were born heavier and gained more weight up to 120 days after birth than calves born from CON cows (P < 0.05) but did not differ from each other (P = 0.94 and 0.92, respectively, for CBW and ADG120). Female calves had no differences in CBW and ADG120 as a function of maternal dietary treatment during pregnancy. The REG and SRN calves weaned heavier (P < 0.05) than CON calves. In conclusion, supplementing protein to pregnant beef cows during periods of low CP pasture improves maternal and progeny performance. The SRN-based product can replace the major part of soybean and urea in the protein supplement, achieving same level of improvement in forage utilization and animal performance as the regular protein-based supplement.

216 Alternative Trace Mineral Supplementation Strategies for Beef Cattle

Abstract This study evaluated an injectable trace mineral (ITM) source containing Cu, Mn, Se, and Zn (Multimin90) administered to gestating beef cows receiving a free-choice 2:1 mineral supplementation. Two hundred and eight multiparous and primiparous cross-bred cows (BW = 621 kg ± 96.6 kg; avg. 4 yr. old) were randomly allotted into one of two treatments and received either i) ITM + inorganic, granular 2:1 trace mineral free-choice; or ii) inorganic, granular 2:1 trace mineral free-choice alone (CON). A cross-over design was used for the study and cows in year 2 (n = 202) were allocated to the other treatment group. The ITM was administered at 4 weeks pre-calving and 4 weeks pre-breeding. Body weight and body condition score (BCS) were evaluated at injection times and pregnancy diagnosis using a weigh scale and a 5-point BCS scale (Lowman et al., 1976). Mineral status was determined from blood serum mineral concentration at 4 weeks pre-calving, 4 weeks pre-breeding, and at pregnancy diagnosis. Cows grazed grass-legume pastures in the summer and had access to dugout and well water sources. Cows were managed as two groups during spring and while on summer pasture during a 63-day breeding season until weaning. Serum blood mineral concentrations at 4 weeks pre-calving, 4 weeks pre-breeding, and pregnancy diagnosis did not differ (P > 0.05) between treatment groups. Copper conetrations at pregnancy diagnosis tended (P = 0.09) to be greater for the ITM cows compared with CON cows. At 4 weeks pre-calving and pregnancy diagnosis, Cu and Mn concentrations were numerically greater in the ITM group compared with the CON group. There were no significant results (P > 0.05) for cow BW, BCS, and days pregnant. Over 2-yr, pregnancy rates were 93.6% and 88.6% for the ITM and CON cows, respectively. Calves born to ITM and CON cows did not differ (P > 0.05) for birth weight, Julian birth date, age at weaning, average daily gain, or adjusted 205 d wean weight. However, CON calves tended (P = 0.07) to be heavier at weaning. Study findings suggest that administering an ITM source to beef cows does not improve cow and calf performance, which suggests that more research in this area is required. Additionally, pregnancy rates in beef cattle may be improved with the use of an injectable trace mineral.

Effects of supplementing a direct-fed microbial containing Enterococcus faecium 669 on performance, health, and metabolic responses of preweaning Holstein dairy calves

This study aimed to evaluate the effects of Enterococcus faecium 669 supplementation on performance, health, parasitological, microbiological, and hematological responses of pre-weaning dairy calves. Forty-two newborn Holstein female calves [initial body weight (BW) 44 ± 4.5 kg] were used in the present study. At birth, calves were ranked by initial BW and assigned to 1 of 2 treatment groups: 1) whole milk (CON; n = 21) and 2) whole milk with the addition of E. faecium 669 (DFM; n = 21). During the entire experimental period (63 d), DFM was daily-fed at a rate of 2.5 × 109 colony forming units/head. All calves were offered a mixture of a starter feed and wheat straw for ad libitum consumption. Supplement intake was evaluated daily, whereas calves were weighed on a weekly basis from d 0 to weaning (d 63). Diarrhea was assessed once a day, whereas fecal and blood samples were collected for microbiological, parasitological, and hematological responses. All data were analyzed with SAS and using calf as the experimental unit. A treatment × week interaction was observed for BW, as DFM-supplemented calves were heavier than CON cohorts on d 56 (+ 4.7 kg) and at weaning on d 63 (+ 4.8 kg). A similar interaction was observed for ADG and dry matter intake (DMI), with greater ADG for DFM-supplemented calves from d 35 - 42, greater ADG and DMI from d 49 - 56, and greater DMI from d 56 - weaning. Moreover, diarrhea occurrence tended to be lower, whereas rectal temperature was 0.2°C lower for DFM supplemented calves. Treatment × day interactions were observed for the occurrence and counts of Eimeria spp., as DFM-supplemented calves tended to have a reduced number of positive observations on d 42 of the study vs. CON and a significant reduction in positive animals from d 21 to 42 was observed in DFM, but not in CON calves. For Cryptosporidium spp., no treatment effects were observed on overall occurrence (%), but DFM-supplemented calves had a greater count of oocyst per gram vs. CON. No treatment × day interaction or main treatment effects were observed for any of the blood variables analyzed herein, exception being monocytes concentration. In summary, pre-weaning E. faecium 669 supplementation improved performance, diarrhea occurrence, and reduced the number of calves positively-detected for Eimeria spp.

Prenatal transportation stress does not impact resting skeletal muscle mitochondrial function or antioxidant activity in Brahman calves

In cattle, prenatal transportation stress has been associated with differential methylation of genes related to metabolism, but the effects of prenatal transportation stress on skeletal muscle mitochondria and oxidative stress have not been investigated. We tested the hypothesis that prenatally stressed calves would exhibit increased skeletal muscle mitochondrial function resulting in greater oxidative stress than calves from non-stressed dams. Serum and longissimus thoracis muscle samples were collected from yearling Brahman calves whose mothers were stressed by transportation at five time points during gestation [i.e., prenatally stressed (PNS); eight bulls and six heifers] and control calves (CON; four bulls and six heifers). Serum was evaluated for concentration of the stress hormone, cortisol and for a marker of muscle perturbation, creatine kinase activity. Muscle samples were analyzed for concentration of a by-product of lipid peroxidation, malondialdehyde, and activity of the antioxidants, superoxide dismutase and glutathione peroxidase. Additionally, muscle mitochondrial volume density and function were estimated by citrate synthase and cytochrome c oxidase activities, respectively. Data were analyzed using mixed linear models with sex, treatment, and the sex × treatment interaction as fixed effects. No investigated variable differed between CON and PNS calves (p ≥ 0.3). These data suggest that prenatal transportation stress does not have an impact on skeletal muscle mitochondrial metabolism or markers of stress or muscle damage in Brahman yearling calves at rest. However, previously reported negative impacts of prenatal stress on inflammatory responses suggest that PNS calves may be differentially equipped to handle an acute stressor. Future research should investigate the energetic and inflammatory implications of acute stressors in animals subjected to prenatal stress.

The age at first consumption of forage in calves and its effect on growth and rumination in the short- and long-term

BackgroundPrevious investigations into the effect of dietary forage on calf performance have been inconsistent, and there is a paucity of information exploring the effect of age on the growth performance and rumination of calves. Eighty-four female Holstein calves (41.5 ± 4.2 kg) were enrolled at birth, a subset of the calves were fed calf starter only (CON, n = 21) while the rest (n = 63) were classified into three treatment groups: the early (EHAY, n = 26, 5.1 ± 0.8 d), the middle (MHAY, n = 21, 7.9 ± 0.8 d) and the late (LHAY, n = 16, 12.1 ± 1.4 d) hay consumers. The short-term effect of the age at first forage consumption (AFF) on calves’ feed intake was monitored until d 84. In addition, the long-term effects of AFF on body weight, structural growth and rumination behavior were recorded until d 196. Rumen samples were collected on d 1, 7, 35, 84 and 196 to analyze the rumen fermentation, while fecal samples were collected from d 78 to 84 to estimate digestibility parameters.ResultsTreatment had no effect on feed intake. While, the EHAY calves tended to have lower BW and ADG compared to LHAY and CON calves. Several total-tract apparent digestibility parameters and digestible nutrients intake were significantly lower in EHAY calves compared with CON and LHAY calves. Calves in the EHAY group tended to begin ruminating ealier, while CON calves were the latest (12.3 vs. 15.5 days of age). A treatment and time interaction was present for rumination time due to greater rumination in calves consuming hay compared to CON calves in week 10 to 12, the differences in rumination disappeared afterwards, no long-lasting significant differences in the rumination and rumen fermentation parameters were found between treatments.ConclusionsIn conclusion, this study showed that hay consumption earlier in life (in the first week, around 5 days of life) could negatively affect the growth of the calf in the short and long term. Compared to consuming hay from the second week (around 12 days of life) or feeding concentrate only without hay, starting to consume hay from the first week could compromise nutrient digestibility and digestible nutrient intake independent of developing rumination behaviour and rumen fermentation.

71 Effects of Periparturient Vaginal Betadine Lavages on Dam and Neonatal Immune Responses

Abstract The vaginal microbiota (VM) is one of the initial contacts of the neonate with microorganisms and can attribute to neonatal health outcomes. The impacts of an altered VM on post-partum dam and neonatal immune responses has not been evaluated. Betadine lavages (BL) have been used to mitigate bacterial infections within the reproductive tract by ablating the VM. Thus, this study aimed to determine if an altered VM impacts passive transfer and immune responses in post-partum dams & calves. Commercial beef cows (n = 22) were randomly assigned to either the control group (CON) or BL treatment group (BTL) two weeks before calving. Treatment BL bags were infused into the anterior vagina and cows received 1 of 3 treatments depending on calving date. Blood samples were gathered from the dam and calf at 0, 5, 30 and 60 days post-partum. Processed blood serum and dam colostrum samples were stored at -80°C. Calf serum (0 d) and dam colostrum were analyzed for immunoglobulin (IgG) concentration via a commercial ELISA. A D2Dx testing kit was used to determine immune status in both dam and calves at 1,5, 30, and 60 days by using gold nanoparticles as a pathogen substitute to identify immune system factors within serum samples. The test produces a numerical score that can be correlated to immune response strength. All IgG data were analyzed using R software. All D2Dx data were analyzed using repeated measures of ANOVA (SAS software version 9.4). There was no difference in passive transfer status between CON and BTL calves, represented by no significant differences in calf serum (P = 0.62) or dam colostrum (P = 0.32) concentrations of IgG. In dams, there was a main effect of day with immune responses decreasing at 60 days postpartum compared with 0d (P < 0.001),5d (P < 0.001), and 30d (P < 0.001). In calves, there was a main effect of day where immune responses were increased on5d compared with 30d (P = 0.046) but decreased on d 5 compared with d 60 (P = 0.005). Moreover, there was a decreased immune response in calves at d 0 (P < 0.001) and d 30 (P < 0.001) compared with d 60. In calves, there was a tendency (P = 0.08) for BTL calves to have a decreased immune response compared with CON. Interestingly, immune status fluctuated in both dams and calves from calving to 60 d post-partum. While full elucidation of causes behind these fluctuations is limited, more research evaluating their implications is warranted.

Effects of feeding Saccharomyces cerevisiae fermentation postbiotic on the fecal microbial community of Holstein dairy calves

BackgroundThe livestock industry is striving to identify antibiotic alternatives to reduce the need to use antibiotics. Postbiotics, such as Saccharomyces cerevisiae fermentation product (SCFP), have been studied and proposed as potential non-antibiotic growth promoters due to their effects on animal growth and the rumen microbiome; however, little is known of their effects on the hind-gut microbiome during the early life of calves. The objective of this study was to measure the effect of in-feed SCFP on the fecal microbiome of Holstein bull calves through 4 months of age. Calves (n = 60) were separated into two treatments: CON (no SCFP added) or SCFP (SmartCare®, Diamond V, Cedar Rapids, IA, in milk replacer and NutriTek®, Diamond V, Cedar Rapids, IA, incorporated into feed), and were blocked by body weight and serum total protein. Fecal samples were collected on d 0, 28, 56, 84, and 112 of the study to characterize the fecal microbiome community. Data were analyzed as a completely randomized block design with repeated measures when applicable. A random-forest regression method was implemented to more fully understand community succession in the calf fecal microbiome of the two treatment groups.ResultsRichness and evenness of the fecal microbiota increased over time (P < 0.001), and SCFP calves tended to increase the evenness of the community (P = 0.06). Based on random-forest regression, calf age as predicted by microbiome composition was significantly correlated with the calf physiological age (R2 = 0.927, P < 1 × 10−15). Twenty-two “age-discriminatory” ASVs (amplicon sequence variants) were identified in the fecal microbiome that were shared between the two treatment groups. Of these, 6 ASVs (Dorea-ASV308, Lachnospiraceae-ASV288, Oscillospira-ASV311, Roseburia-ASV228, Ruminococcaceae-ASV89 and Ruminoccocaceae-ASV13) in the SCFP group reached their highest abundance in the third month, but they reached their highest abundance in the fourth month in the CON group. All other shared ASVs reached their highest abundance at the same timepoint in both treatment groups.ConclusionsSupplementation of SCFP altered the abundance dynamics of age discriminatory ASVs, suggesting a faster maturation of some members of the fecal microbiota in SCFP calves compared to CON calves. These results demonstrate the value of analyzing microbial community succession as a continuous variable to identify the effects of a dietary treatment.

Maternal nutrient restriction during late gestation reduces vigor and alters blood chemistry and hematology in neonatal beef calves.

Fall-calving primiparous beef females [body weight: 451 ± 28 (SD) kg; body condition score: 5.4 ± 0.7] were individually-fed either 100% (control; CON; n = 13) or 70% (nutrient restricted; NR; n = 13) of metabolizable energy and metabolizable protein requirements for maintenance, pregnancy, and growth from day 160 of gestation to parturition. Calves were reared naturally by their dams and monitored for latency times from birth to first sternal recumbency, attempt to stand, and stand; vigor scores were assigned at 2, 5, 10, and 20min of age. Rectal temperatures and jugular blood were obtained at 0 (pre-suckling), 6, 12, 24, and 48h of age, and blood chemistry, hematology, cortisol, and insulin were determined. Data were analyzed with fixed effects of late gestational nutritional plane (single data point) or nutritional plane, hour, and their interaction (data over time, repeated measures). Calving date was a fixed effect; calf sex was included when P < 0.25. We previously reported that late gestational nutritional plane did not affect gestation length or calf size at birth, but calving assistance and fetal malpresentations occurred more often in NR. Nutritional plane did not affect (P = 0.65) duration of parturition, but calves born to NR dams had slower times to attempt to stand (P = 0.09), slower times to stand (P = 0.02), and had poorer 20min vigor scores (P = 0.05). Serum immunoglobulin G and A concentrations at 48h were greater (P ≤ 0.03) for NR calves. Rectal temperature of NR calves was less (P = 0.02) at 0h, but greater (P = 0.04) at 24h compared with CON. Circulating glucose, non-esterified fatty acids, triglycerides, cortisol, and insulin were not affected by nutritional plane (P ≥ 0.18). Total protein and globulin from 6 to 48h were greater (P ≤ 0.02) in NR calves. Calves from NR dams had greater (P < 0.08) gamma-glutamyl transferase at 6, 12, and 48h. Serum aspartate aminotransferase was greater (P ≤ 0.07) from 0 to 24h and creatine kinase was greater (P ≤ 0.04) from 6 to 24h in NR calves. At 0h, potassium was greater (P = 0.03) in NR calves. Calves born to CON had greater chloride (P = 0.08; main effect), sodium (P ≤ 0.09) from 0 to 48h, and anion gap (P = 0.02) at 6h. Hematocrit from 6 to 24h and red blood cells and hemoglobin at 6 and 12h were greater (P ≤ 0.09) in CON calves. These data indicate that nutrient restriction during late gestation resulted in less vigorous calves with more indicators of trauma in early life.

Effect of vitamin D source and amount on vitamin D status and response to endotoxin challenge

The objectives were to test the effects of dietary vitamin D3 [cholecalciferol (CHOL)] compared with 25-hydroxyvitamin D3 [calcidiol (CAL)] on vitamin D status and response to an endotoxin challenge. Forty-five Holstein bull calves (5 ± 2 d of age) were blocked into weekly cohorts, fed a basal diet that provided 0.25 µg/kg body weight (BW) CHOL, and assigned randomly to 1 of 5 treatments: control [(CON) no additional vitamin D], 1.5 µg/kg BW CHOL (CHOL1.5), 3 µg/kg BW CHOL (CHOL3), 1.5 µg/kg BW CAL (CAL1.5), or 3 µg/kg BW CAL (CAL3). Calves were fed milk replacer until weaning at 56 d of age and had ad libitum access to water and starter grain throughout the experiment. Treatments were added daily to the diet of milk replacer until weaning and starter grain after weaning. Measures of growth, dry matter intake, and serum concentrations of vitamin D, Ca, Mg, and P were collected from 0 to 91 d of the experiment. At 91 d of the experiment, calves received an intravenous injection of 0.1 µg/kg BW lipopolysaccharide (LPS). Clinical and physiological responses were measured from 0 to 72 h relative to LPS injection. Data were analyzed with mixed models that included fixed effects of treatment and time, and random effect of block. Orthogonal contrasts evaluated the effects of (1) source (CAL vs. CHOL), (2) dose (1.5 vs. 3.0 µg/kg BW), (3) interaction between source and dose, and (4) supplementation (CON vs. all other treatments) of vitamin D. From 21 to 91 d of the experiment, mean BW of supplemented calves was less compared with CON calves, but the effect was predominantly a result of the CHOL calves, which tended to weigh less than the CAL calves. Supplementing vitamin D increased concentrations of 25-hydroxyvitamin D in serum compared with CON, but the increment from increasing the dose from 1.5 to 3.0 µg/kg BW was greater for CAL compared with CHOL (CON = 18.9, CHOL = 24.7 and 29.6, CAL = 35.6 and 65.7 ± 3.2 ng/mL, respectively). Feeding CAL also increased serum Ca and P compared with CHOL. An interaction between source and dose of treatment was observed for rectal temperature and derivatives of reactive metabolites after LPS challenge because calves receiving CHOL3 and CAL1.5 had lower rectal temperatures and plasma derivatives of reactive metabolites compared with calves receiving CHOL1.5 and CAL3. Supplementing vitamin D increased plasma P concentrations post-LPS challenge compared with CON, but plasma concentrations of Ca, Mg, fatty acids, glucose, β-hydroxybutyrate, haptoglobin, tumor necrosis factor-α, and antioxidant potential did not differ among treatments post-LPS challenge. Last, supplementing vitamin D increased granulocytes as a percentage of blood leukocytes post-LPS challenge compared with CON. Supplementing CAL as a source of vitamin D to dairy calves was more effective at increasing serum 25-hydroxyvitamin D, Ca, and P concentrations compared with feeding CHOL. Supplemental source and dose of vitamin D also influenced responses to the LPS challenge.

2 Effects of Multiple Bovine Appeasing Substance Administration During a 42-Day Preconditioning Program on Physiologic, Health, and Performance Responses of Feeder Cattle

Abstract This experiment evaluated the effects of multiple bovine appeasing substance administration during a 42-day preconditioning program followed by feedlot receiving period on productivity, health, and physiological variables of feeder cattle. Ninety recently weaned calves were obtained from Red Bluff Ranch (Norris, MT). All calves were weaned and weighed (prior to transport). Calves were loaded into a livestock trailer, transported for 70 km, and unloaded at the Bozeman Agricultural Research and Teaching Farm for a 42-day preconditioning program. Upon arrival, calf body weight was recorded, and both pre- and post-transport body weight were averaged and used as calf weaning initial body weight. Calves were sorted by body weight, sex, and age, and assigned to receive 1) multiple administration of bovine appeasing substance at weaning (d0), d 14, 28, and before transport and feedlot entry (d 42; BAS; RSEA Group, Quartier Salignan, France), or 2) placebo (diethylene glycol monoethyl ether; CON). Treatments (5 mL) were applied topically to the nuchal skin area of each animal every 14 d during the preconditioning period. Calves within treatment groups were ranked by initial BW, sex, and age, and allocated to 1 of 18 drylot pens. On day 42, calves were combined within treatment group, loaded into 2 different single double-deck commercial livestock trailers, and transported for 1000 km (approximately 16 h). Upon arrival (day 43), calves were unloaded at the same feedyard and with the same pen distribution used prior to transport and fed ad libitum a TMR diet. Blood samples were collected on day 0 (weaning), 3, 7, 14, 21, 28, 42 (prior transport), 43 (feedlot arrival), 46, 50, 57, 64 and 90. Average daily gain and final BW did not differ (P &amp;gt; 0.52) between BAS and CON calves in both the preconditioning and receiving phases. No treatment effects were also detected (P &amp;gt; 0.44) for daily TMR intake in any of the phases. Overall feed efficiency did not differ between BAS and CON calves (P &amp;gt; 0.54). No treatment effects were detected (P = 0.98) for plasma concentrations of cortisol. A treatment × day interaction was detected (P &amp;lt; 0.001) for plasma haptoglobin concentrations, which was greater (P &amp;lt; 0.01) in CON on day 3 and 7 vs. BAS calves. Therefore, multiple applications of BAS mitigated an acute-phase response associated with accumulative stress caused by weaning, transport, and vaccination.

Effects of mixing a high-fat extruded pellet with a dairy calf starter on performance, feed intake, and digestibility.

During weaning, withdrawal of milk replacer is not directly compensated for by an increase in solid feed intake. Therefore, greater fat inclusion in the starter might mitigate this temporary dietary energy decline. However, fat inclusion in solid feeds may generally limit rumen fermentability and development. To address these potentially conflicting outcomes, we conducted 2 experiments to evaluate the effect of supplementing a high-fat extruded pellet mixed with a calf starter on feed intake, performance, and nutrient digestibility in calves. In experiment 1, 60 Holstein bull calves were blocked by serum IgG (2,449 ± 176 mg/dL) and date of arrival (2.5 ± 0.5 d of age). Within each block, calves were randomly assigned to 1 of 3 treatments: a standard control calf starter (CON; 3.1% fat) and mixtures of CON with 10% inclusion of 1 of 2 different high-fat extruded pellets containing 85% of either hydrogenated free palm fatty acids (PFA, 7.1% fat) or hydrogenated rapeseed triglycerides (RFT, 6.7% fat). Calves were offered milk replacer up to 920 g/d until 42 d of age, followed by a gradual weaning period of 7 d. Calves had ad libitum access to the starter diets, straw, and water. No differences were observed between CON, PFA, and RFT calves on body weight (BW) or average daily gain (ADG) until 49 d of age. From weaning (50 d) until 112 d, PFA calves had a greater BW and ADG than RFT and CON animals. Moreover, PFA calves had the highest intakes of starter, straw, calculated metabolizable energy, and crude protein after weaning. Overall, no differences were present in blood β-hydroxybutyrate and glucose concentrations between treatments; however, calves in the RFT treatment had a higher concentration of insulin-like growth factor-1. In experiment 2, 24 Holstein bull calves at 3 mo of age were assigned to 1 of 8 blocks based on arrival BW and age. Within each block, calves were randomly assigned to 1 of the 3 treatments previously described for experiment 1. Calves on the RFT treatment had the lowest total-tract apparent dry matter and fat digestibility, potentially explaining the differences in performance observed between PFA and RFT calves. Inclusion of the PFA pellet at 10% with a calf starter improved BW, solid feed, and energy intake after weaning. However, these benefits were conditioned by fat source and its digestibility.

152 Effect of Continuous or Intermittent Feeding of Ergot Contaminated Grain in a Mash or Pelleted Form on the Performance of Backgrounding Beef Steers

Abstract The objective of this study was to evaluate the effect of feeding pelleted or mash ergot contaminated grain continuously or intermittently on performance and blood parameters of backgrounding steers. Sixty black angus steers (300 ± 29.4 kg) were used in a complete randomized backgrounding (60% barley silage:40% concentrate DM basis) 84 d study. Steers were randomly assigned to 4 different treatments and housed individually. Treatments included: 1) control ration (CON; no added ergot), 2) continuous ergot mash (CEM; fed continuously at 2 ppm), 3) intermittent ergot mash (IEM; fed at 2 ppm on the first wk of each 21 d period and control diet for the remaining 2 wk), and 4) intermittent ergot pellet (IEP; fed at 2 ppm during the first wk of each 21 d period and control diet for the other 2 wk). Calves were weighed every 21 days and blood samples were collected on d 0, 42, and 84. No treatment effects (P&amp;gt;0.05) were observed for complete blood count. Steer DMI was reduced for all ergot diets compared to the CON diet (P&amp;lt; 0.01, 7.45 vs. 8.05 kg/d). Steer ADG was reduced for all ergot diets compared to the CON diet (P&amp;lt; 0.01). CEM fed steers had lower ADG (P&amp;lt; 0.01, 0.980 vs. 0.735 kg) and shrunk final weight (P&amp;lt; 0.01, 366 vs. 350 kg) than CON calves, but CEM and IEM were no different. CEM fed steers had lower Gain:Feed (P&amp;lt; 0.07, 0.130 vs. 0.142) than CON calves. Pelleting ergot contaminated grain did not reduce the impact of ergot alkaloids on any of the measured parameters. Results suggest that continuously or intermittently feeding an ergot contaminated TMR (2 ppm) can significantly reduce the growth performance of backgrounded feedlot steers but no effects were observed for blood parameters. Pelleting was not an effective method of reducing ergot toxicity.

79 Effects of Nutrient Restriction During Late Gestation of the First Parity on cow and Calf Performance During the Second Lactation

Abstract Fall-calving Herford-SimAngus heifers were individually fed either 100% (control; CON, n = 10) or 70% (nutrient restricted; NR, n = 12) of NASEM metabolizable energy and metabolizable protein requirements from d 160 of gestation to calving. Postpartum cows were individually fed 100% of energy and protein requirements until d 149 of lactation, then fed tall fescue hay or pasture as a single group through parity 2. Second parity cow performance and calf size were measured at birth, d 30, and d 60 post-calving. Single-quarter colostrum yield was collected pre-suckling. At d 30 and 60 of lactation, 4-hour milk yield was collected. Data were analyzed with the fixed effect of first parity nutritional plane, and calving or breeding date, calf sex, and calf sire (calf measures) were covariates. Milk yield included day and day x treatment (repeated measures). We previously reported that in parity 1, NR reduced (P ≤ 0.04) colostrum and milk yield, calf weaning weight, and dam weaning BCS. From calving to d 60 of parity 2, CON cows had greater (P ≤ 0.008) BCS and greater (P = 0.003) backfat on d 30. Additionally, CON cows had greater (P ≤ 0.002) BW compared with NR at d 30 and 60 of lactation. Calf size was not affected (P ≥ 0.17) by first parity nutritional plane except that cannon length at birth and d 60 tended (P ≤ 0.08) to be longer in CON calves. Colostrum and milk volume and weight were not affected (P ≥ 0.37) by first parity nutritional plane. Milk yield was greater (P ≤ 0.001) at d 30 than d 60. These data indicate that cow BW and energy reserves remained less in parity 2 when heifers experienced late gestational nutrient restriction, but calf size, colostrum yield, and milk yield were unaffected in the second parity.

Effects of dietary betaine on body temperature indices, performance, metabolism, and hematological variables of dairy heifer calves during hot summer conditions.

Background and Aim:Heat stress (HS) can negatively impact farm animal productivity and adversely affect animal welfare worldwide, placing a major financial burden on global livestock producers. Dietary betaine (trimethylglycine) has been known to have several biological functions, which may aid in offering beneficial effects on livestock productivity during HS conditions. However, information on the role of dietary betaine in heat-stressed dairy heifer calves is yet to be documented. Therefore, this study aimed to assess the effects of supplementing dietary betaine on body temperature indices, blood metabolites, productive performance, and complete blood count (CBC) (hematological indices) in hyperthermic dairy heifer calves.Materials and Methods:In total, 14 Holstein heifer calves (4.0 ± 0.9 months old) were individually housed and randomly allocated to one of two dietary treatments: (1) a control diet (CON; n = 7) and (2) a control diet complemented with 21 g/d of natural betaine (BET; n = 7) top-dressed once daily. The experiment lasted for 28 d, during which all animals were subjected to natural cyclic HS conditions (26.1–39.2°C; 73.2–84.0 temperature–humidity index). Rectal temperature (RT) and respiration rate (RR) were measured twice daily (0700 and 1500 h), whereas dry matter intake (DMI) was measured once daily (0800 h). In addition, blood samples (collected from the jugular vein) were analyzed for metabolites and CBC on days 7, 14, 21, and 28.Results:Relative to CON, BET supplementation was able to decrease RT on day 23 of the experiment (p = 0.04). Alternatively, RR was similar between the dietary treatments (p = 0.73). Feeding BET did not affect DMI compared with CON during HS conditions (p = 0.48). Furthermore, compared with CON, BET supplementation did not change leukocytes, neutrophils, lymphocytes, and hematocrit levels during HS conditions (p ≥ 0.17). However, a post hoc analysis indicated that hematocrit levels were decreased in BET-fed calves on day 7 of the study compared with CON calves during HS conditions (p = 0.05). Moreover, circulating glucose, albumin, and triglycerides were found to be similar between dietary treatments (p ≥ 0.55).Conclusion:BET supplementation slightly reduced RT and circulating hematocrit but did not affect other metrics in this HS experiment. More research into the effects of different doses of dietary BET on dairy heifer calves is needed.

Maternal Conjugated Linoleic Acid Supply in Combination With or Without Essential Fatty Acids During Late Pregnancy and Early Lactation: Investigations on Physico-Chemical Characteristics of the Jejunal Content and Jejunal Microbiota in Neonatal Calves.

Conjugated linoleic acids (CLAs) modulate the fatty acid composition in dairy cow milk, which represents the most important nutrient source of neonatal calves. In turn, dietary fatty acids are known to influence the gut microbiota. The current preliminary study investigated effects of a maternal fatty acid supplementation (MFAS) during transition period with coconut oil (CON, control), CLA (Lutalin®), or CLA + EFA (Lutalin® + essential fatty acids–linseed oil; safflower oil) on physico-chemical characteristics of jejunal content and microbiota of 5-day-old calves. MFAS of CLA + EFA increased α-linolenic, eicosapentaenoic, docosapentaenoic, and n-3 fatty acid proportions in jejunum compared to the other groups (P < 0.05). Proportions of n-6 and polyunsaturated fatty acids increased by MFAS of CLA + EFA compared to CON (P < 0.05). Most abundant phyla in the jejunum were Proteobacteria, Firmicutes, and Bacteroidota. CLA + EFA decreased the relative abundance of Diplorickettsiales (Proteobacteria) compared to CON and CLA (P < 0.05). CLA calves showed a lower abundance of Enterobacterales (Proteobacteria) compared to CON calves (P = 0.001). The abundance of Veillonellales-Selenomonadales and RF39 (Firmicutes) decreased in CLA + EFA calves compared to CON calves (P < 0.05). Bacteroidales (Bacteroidota) decreased in CLA + EFA calves compared to CLA calves (P < 0.05). The relative abundance of Cyanobacteria and Euryarchaeota decreased and the abundance of Chloroflexi increased in CLA + EFA calves compared to CON and CLA calves (P < 0.05). MFAS alters the fatty acid composition and microbial milieu in the intestinal content of neonatal calves due to their ability to modulate colostral fatty acid composition of dams.

Effects of feeding Saccharomyces cerevisiae fermentation products on the health of Holstein dairy calves following a lipopolysaccharide challenge

Before weaning, dairy calves are at high risk for illness, especially respiratory and digestive diseases, which reduces average daily gain, age at first calving, and first-lactation milk production. Although these illnesses are commonly treated with antibiotics, efforts are being made to reduce antibiotic use, due to concerns about antibiotic-resistant bacteria. The objective was to evaluate the effects of Saccharomyces cerevisiae fermentation products (SCFP) on the immune status of calves, following a lipopolysaccharide (LPS) challenge administered just before weaning. Thirty Holstein bull calves were blocked based on initial body weight and then assigned to 1 of 2 study treatments. The control group (CON) was fed a 24% crude protein:17% fat milk replacer (MR) and calf starter with no SCFP added. The SCFP treatment was fed the same 24% crude protein:17% fat MR with 1 g/d of SmartCare (Diamond V) and calf starter with 0.8% NutriTek (Diamond V). SmartCare and NutriTek are both produced from anaerobic fermentation of S. cerevisiae. Calves were offered 2.84 L (12.5% solids) of MR twice daily at 0630 and 1630 h through d 51; from d 52 to 56, calves were fed MR once daily at 0630 h; and calves were weaned on d 57. Calves also received ad libitum access to a texturized calf starter and water. On d 50, a subset of calves (n = 20, 10 calves per treatment) were enrolled in an LPS challenge. At -1.5, -0.5, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 7, 8, and 24 h relative to dosing with LPS, 20 mL of blood was collected, and rectal temperature and respiration rate were measured for each calf. Blood serum samples were analyzed for interleukin 6, TNF-α (tumor necrosis factor-α), interferon-gamma, haptoglobin, serum amyloid-A, fibrinogen, nonesterified fatty acid, cortisol, and glucose. This study observed increased concentrations of TNF-α at 1 h and 1.5 h and glucose at 0.5 h after dosing with LPS in SCFP calves compared with CON. Calves supplemented with SCFP also had an increase in respiration rate 0.5 h after dosing with LPS and reduced feed intake the day of the challenge compared with CON calves. These results suggest that dairy calves supplemented with SCFP exhibit an increased acute immune response, as observed by increased TNF-α, glucose, and respiration rate immediately after dosing with LPS, compared with CON calves.

PSI-14 Effects of maternal nutrient restriction during late gestation on neonatal beef calf serum chemistry and complete blood cell count

Abstract To determine effects of late gestational nutrient restriction (NR) on neonatal blood chemistry and hematology, primiparous fall-calving crossbred beef heifers [BW: 451 ± 28 (SD) kg; BCS: 5.4 ± 0.7] were individually fed either 100% (control; CON; n = 12) or 70% (n = 13) of NASEM net energy and metabolizable protein requirements for maintenance, pregnancy, and growth from d 160 of gestation to parturition. Calf jugular blood was obtained at 0 (pre-suckling), 6, 12, 24, and 48 h postnatally to determine serum chemistry and complete blood cell count. Data were analyzed with fixed effects of treatment, hour, and their interaction, using repeated measures. Calving date was a fixed effect; calf sex was included when P &amp;lt; 0.25. The treatment x hour interaction (P &amp;lt; 0.10) affected total protein, globulin, gamma-glutamyl transferase (GGT), aspartate aminotransferase (AST), creatinine, creatine kinase, red blood cells (RBC), hemoglobin, hematocrit, sodium, anion gap, and potassium. Total protein and globulin at 6 to 48 h were greater (P ≤ 0.02) in NR calves. Calves from NR heifers had greater (P &amp;lt; 0.08) GGT at 6, 12, and 48 h and greater (P ≤ 0.07) AST at 0 to 24 h. Creatinine at 24 h and creatine kinase at 6 to 24 h were greater (P &amp;lt; 0.04) in NR calves. Hematocrit from 6 to 24 h and RBC and hemoglobin at 6 and 12 h were greater (P ≤ 0.09) in CON calves. Sodium from 0 to 48 h and anion gap at 6 h were greater (P &amp;lt; 0.09) in CON calves. Calves from NR heifers had greater (P = 0.03) 0 h potassium. Treatment affected chloride, which was greater (P = 0.08) in CON calves. These data indicate calves born to nutrient restricted heifers may experience more trauma at calving but have improved passive transfer.

92 Maternal Nutrient Restriction of Primiparous Beef Heifers During Late Gestation Decreases Colostrum Yield and Reduces Calf Vigor

Abstract We hypothesized that late gestational nutrient restriction (NR) would reduce colostrum yield and impair offspring transition to postnatal life. Primiparous, fall-calving crossbred beef heifers (BW: 451 ± 28 [SD] kg; BCS: 5.4 ± 0.7) were individually-fed either 100% (control; CON; n = 12) or 70% (n = 13) of NASEM net energy and metabolizable protein requirements for maintenance, pregnancy, and growth from d 160 of gestation to parturition. Delivery duration was determined as minutes from first fetal feet expulsion to birth. Calves were reared naturally by their dams and monitored for times from birth to first sternal recumbency, attempt to stand, and stand; vigor scores (1 = very weak, 5 = extremely vigorous) were assigned at 2, 5, 10, and 20 min of age. Total colostrum from one rear quarter was collected pre-suckling. Calf rectal temperatures were recorded at 0, 6, 12, 24, and 48 h postnatally. Data were analyzed with the fixed effects of treatment (single point) or treatment, hour, and their interaction (over time, using repeated measures). Date of calving was a fixed effect; calf sex was included when P &amp;lt; 0.25. Heifers fed CON had greater (P = 0.04) colostrum weight and volume than NR. Although gestational nutrition did not affect (P = 0.72) calf birth weight, calves born to CON heifers had faster (P = 0.02) times to stand and tended to have faster (P = 0.09) times to attempt to stand. Calves from CON heifers had greater (P = 0.05) 20 min vigor scores. Rectal temperatures at 0 h were greater (P = 0.02) in CON calves, but at 24 h were greater (P = 0.04) in NR calves. These data indicate that heifers nutrient restricted during late gestation have reduced colostrum yield and less vigorous calves, which may influence postnatal calf survival.

318 Effect of Initial Providing Time of Oat Hay on Performance, Health, Behavior and Rumen Fermentation in Calves

Abstract To determine the appropriate time to feed hay to calves, 210 healthy Holstein calves at d 2 were randomly divided into 3 groups: feeding basic diet (starter) without hay (CON), inclusion of oat hay from the second week (H2) or fourth week (H4) in addition to the basic diet. All calves were weaned on d 56 and raised in the same hutches until the end of the experiment (d 70). Calf starter intake and fecal score were recorded daily throughout the experimental period. Body weight, body size, blood and rumen fluid samples were collected every 2 weeks before weaning and once a week after weaning. Inclusion of oat hay in the basic diet (H2 and H4) resulted in increased body weight (P &amp;lt; 0.01) and average daily gain (P &amp;lt; 0.01) throughout the experiment when compared to the basic diet (CON) only. Calves fed oat hay from 2 weeks of life had the highest starter intake (P &amp;lt; 0.01), average daily gain (P &amp;lt; 0.01) in the pre- and post-weaning periods. Body length and heart girth was similar between treatments. The H2 calves had lower diarrhea frequency (P &amp;lt; 0.05) and diarrhea days (P &amp;lt; 0.05) during the post-weaning period. Compared to the CON calves, inclusion of hay increased the rumen pH (P &amp;lt; 0.01), while decreasing the NH3-N (P &amp;lt; 0.01) and tend to decrease the total VFA (P &amp;lt; 0.06) during the entire trial. Calves in H2 treatment spent more time ruminating (P &amp;lt; 0.01), but less time standing (P &amp;lt; 0.05), eating starter (P &amp;lt; 0.01) and engaging in abnormal behaviors (P &amp;lt; 0.01). In conclusion, calves supplemented with oat hay improved growth rate and rumen fermentation when compared with calves fed only starter, and adding hay from 2 weeks of calves life may be the best choice for the farm to have the greatest growth and health performance.

Intranasal oxytocin treatment on the day of weaning does not decrease walking behavior or improve plasma metabolites in beef calves placed on pasture

The purpose of this study was to evaluate the effect of intranasal oxytocin administered at abrupt weaning on weaning behaviors such as walking distance and time devoted to walking, calf body weight, and plasma non-esterified fatty acids (NEFAs), β-hydroxybutyrate (β-HB), and cortisol. Twenty Simmental × Angus heifer calves were randomly assigned to one of two treatments: intranasal oxytocin (OXT; n = 10) or intranasal saline (CON; n = 10). All calves were given the respective intranasal treatment on the day of weaning (day 0) and then placed on pasture together. Calves were weighed and a blood sample was obtained on days 0, 1, 7, and 14 postweaning. Blood samples were subsequently used to quantify plasma NEFA, β-HB, and cortisol concentrations. All calves in both treatment groups were fitted with an individual global positioning system that recorded calf location every 10 s for a 16-h period on days 0, 7, and 14 to quantify and evaluate walking behaviors. There was no treatment × day effect for distance walked (P = 0.82), walking time (P = 0.80), non-walking time (P = 0.88), area utilization index (P = 0.84), calf body weight (P = 0.82), average daily gain (P = 0.54), NEFA (P = 0.22), or cortisol concentrations (P = 0.32). There was a tendency for a treatment × day effect observed for average walking speed (P = 0.09) and β-HB (P = 0.10), such that calves in the CON treatment tended to have lesser average walking speeds on day 14 and tended to have greater β-HB concentration after weaning. There was a treatment effect (P = 0.02) for NEFA concentrations, with the CON calves having a greater plasma NEFA concentration throughout the study compared with OXT calves. These data imply that OXT calves may have had differing metabolic responses immediately after weaning that could have altered the mobilization of NEFA, but this change was not substantial enough to impact body weights or walking behaviors.