Translational Animal Science最新文献

Several calf studies demonstrated growth advantages when feeding greater protein and/or milk solids amounts, however, studies comparing 2 times per day vs. 3 times per day feeding are limited. The study objective was to evaluate feeding 2 times per day vs. 3 times per day thereby increasing milk solids intake. Forty 2- to 5-d old Holstein bull calves were blocked by body weight (BW) and randomly assigned to 1 of 2 treatments (N = 20/treatment) using a randomized complete block design. Treatments were 1) 2×: milk replacer (MR) fed 2 times per day; and 2) 3×: MR fed 3 times per day for increased solids intake. The MR was fed at 15% solids at 0630 and 1800 hours and the 3rd 3× feeding was at 1200 hours. Calves on 2× were fed MR at 0.567 kg/d for days 1 to 14, increased to 0.85 kg/d for days 15 to 35, and reduced to 1 time per day at 0.425 kg/d for days 36 to 42 to facilitate weaning at 42 d. Calves on 3× were fed MR 0.851 kg/d for days 1 to 14, increased to 1.275 kg/d for days 15 to 35, and reduced to 1 time per day at 0.425 kg/d for days 36 to 42 followed by weaning. Calf starter (CS; amounts and orts weighed daily) and water were offered for ad libitum intake. Initial BW was not a significant covariate and final BW (81.5 and 80.9 kg, for 2× and 3×, respectively) was similar. A treatment-by-week interaction (P < 0.01) indicated variable BW gains during the study with calves fed 3× demonstrating greater BW during weeks 4 (P < 0.10) and 5 (P < 0.05) compared with calves fed 2×. However, BW gains for calves fed 3× were reduced (P < 0.05) during the weaning period resulting in similar BW gains (36.8 and 36.4 kg) at the study end. Intake of CS (0.65 and 0.46 kg/d) was lower (P < 0.04) for calves fed 3× compared with calves fed 2×. Feed conversions (0.64 and 0.58 kg/kg) were greater (P < 0.02) for calves fed 2× compared with 3× fed calves. Calves fed 2× had less (P < 0.01) scours (fecal score = 0; 34.3 and 29.7 d) compared with 3× fed calves. Providing an additional MR feeding demonstrated minimal BW gains due to lower CS intake. Providing greater MR intake using a 3rd daily feeding reduces CS intake that can inhibit transition to dry feed when weaning calves.

The objective of the current experiment was to evaluate the effects of supplementation with different dietary fatty acid profiles on the dam during the first third of gestation and on the offspring during growth on the offspring's cognitive behavior. Seventy-nine postweaning lambs were blocked by body weight and sex using a 2 × 2 factorial arrangement of treatments. The first factor (maternal supplementation; MS) was supplementation to the ewes in the first third of gestation with 1.61% Ca salts of palm fatty acid distillate (PFAD) or Ca salts enriched with eicosapentaenoic (EPA) and docosahexaenoic acids (DHA) to early pregnant ewes. The second factor (offspring supplementation; OS) was to supplement the offspring during their growing phase with diets that contained 1.48% of PFAD or Ca salts of PFAD or EPA and DHA. Ewes were housed in groups, 3 ewes per pen and 12 pens per treatment, with different treatments until day 50 of gestation. From day 51 of gestation until weaning, all the animals (ewes and lambs) were housed in a common pen. After weaning, lambs were housed in group pens (5 pens per treatment, 3 to 5 per pen). The lambs ran maze tests on weeks 5 and 7 after weaning to evaluate cognitive ability. The maze contained 2 trap zones and had the pen conspecific lambs at the end of the maze. The measurements were the times to solve the traps and the total time to complete the maze. Data were analyzed using a mixed procedure considering the 2×2 factorial arrangement of treatments. There was an MS × OS × time interaction for the time to complete the maze (P = 0.02). Lambs receiving a different type of fatty acid supplementation during gestation than postweaning took less time to complete the maze on the second relative to the first day compared with the lambs fed the same type of fatty acids during gestation and growing. In conclusion, combining different fatty acids during different life stages may improve lambs' cognitive abilities.

Farrowing durations that exceed 240 min cause stillborn rates to increase. Therefore, feeding strategies in late gestation have been studied to mitigate the negative consequences of extended farrowing durations. A total of 1,501 sows (PIC 1050 Camborough) were used for this study at two individual farms near Carthage, IL. Farm 1 (758 sows) was a porcine reproductive and respiratory virus (PRRSv) stable (previously experienced a PRRSv outbreak and is currently vaccinated for PRRSv) with an older parity structure (3.67). Farm 2 (743 sows) was PRRSv positive (sows with pigs demonstrating Ct values <36 determined by pig processing fluids) and had a younger parity structure (2.96). Sows were moved into farrowing rooms at approximately day 112 of gestation and started on their respective treatment. Treatment 1 sows were fed 1 meal of 2.27 kg per day at 0600 h. Treatment 2 sows were fed two equal meals of 1.13 kg (2.27 kg total) at 0600 and 1400 h. Treatment 3 sows were fed two equal meals of 1.13 kg (2.27 kg total) at 0600 and 1800 h. Treatment 4 sows were fed three equal meals of 0.77 kg (2.27 kg total) at 0600, 1400, and 2200 h. Treatments were assigned to farrowing rooms in a replicated 4 × 4 Latin Square arrangement of treatments where each treatment was fed in each room one time at each farm. Daily feed intakes were recorded from the time sows were introduced to the farrowing room until 5 d after farrowing. The total number of pigs born, pigs born alive, stillbirths, and mummies were recorded for each litter within 24 h of farrowing. Live pigs were weighed as a group to record litter birth weight. Pig mortality and morbidities were recorded until 5 d after farrowing. The total number of pigs born and pigs born alive were not different (P ≥ 0.59) among treatments. The number of stillborn pigs was not different (P = 0.33) among treatment 1(1.15 ± 1.41), treatment 2 (1.20 ± 1.36), treatment 3 (1.30 ± 1.46), and treatment 4 (1.14 ± 1.28). Sows fed three times per day at 8 h intervals tended (P = 0.08) to reduce the percentage of sows farrowed under supervision compared with sows fed once a day. Sows fed twice per day at 12 h intervals reduced (P = 0.01) the percentage of sows provided assistance compared with feeding sows once per day. Feeding a sow one meal of 2.27 kg, two meals (2.27 kg total), or three meals (2.27 kg total) of feed a day before farrowing did not reduce the number of stillborn piglets regardless of farm health status or parity structure.

Three hundred and sixty sows were used to investigate the effect of various dietary branched-chain amino acids (BCAA) levels on sow lactation and piglet growth performance. On day 112 ± 1.4 of gestation, sows were blocked by the parity group (P1, P2, P3+) and randomly assigned to 1 of 6 dietary treatments containing various levels of standardized ileal digestible (SID) Leu, Ile, and Val. The experimental diets were formulated to the desired levels of BCAA by replacing cornstarch in a basal diet with l-leucine, l-isoleucine, and l-valine. Dietary BCAA levels relative to SID Lys were 114% or 180% for Leu, 56% or 64% for Ile, and 64% or 120% for Val. Diets were formulated to be isocaloric (3.23 Mcal ME/kg) and met or exceeded all other NRC (2012) essential amino acid and vitamin and mineral recommendations. Sow body weight (BW) and backfat thickness were measured at the time of entry into the farrowing room and at weaning. Piglet litter weights were recorded after cross-fostering and weaning to calculate the litter growth rate. Data were analyzed using generalized linear mixed models with fixed effects of dietary treatment and parity group and a random effect of lactation group. The models were fit using R (v4.4.1; R Core Team, 2024). The sow and her litter were the experimental unit, and results were considered significant if P < 0.05. On average, sows nursed their litters for 21.3 d (P = 0.998). The mean parity by treatment ranged from 3.8 to 3.9 (P = 0.999). After farrowing, the mean sow BW was 220 kg with a range between treatments of 216 to 222 kg (P = 0.523). On average, sows gained 2.3% of their BW (P = 0.740) with an average daily feed intake of 8.74 kg/d (P = 0.903). As expected, sow Leu, Ile, and Val intakes were different across treatments (P ≤ 0.001) and corresponded to the varying dietary levels of BCAA. Sows entered farrowing with an average backfat thickness of 11.50 mm (P = 0.919) and lost 6.5% backfat through lactation (P = 0.880). Sows started the trial with an average of 14.1 piglets/sow (P = 0.967) and weaned 12.7 piglets/sow (P = 0.995) with a piglet ADG of 0.22 kg/d (P = 0.280) and a daily litter growth rate of 2.90 kg/d (P = 0.547). In conclusion, there was no evidence of an effect of the various leucine, isoleucine, and valine levels evaluated in this study on lactating sow and piglet performance.

The objective of this study was to evaluate the effects of methionine supplementation prior to and during a lipopolysaccharide (LPS) challenge on the performance and inflammatory biomarkers of receiving beef steers. Steers (n = 65; 295.8 ± 46.5 kg) were randomly assigned to 3 treatment groups: L0 = Control, receiving no supplement; L1 = 10 g/hd/d rumen-protected methionine (MetaSmart, Adisseo USA Inc., Alpharetta, GA); and L2 = 20 g/hd/d rumen-protected methionine and fed for 40 d at the West Texas A&M University Research Feedlot. On day 40, a subset of steers (n = 32; L0 = 10; L1 = 11; L2 = 11) were transported to the USDA Livestock Issues Research Unit, and on day 41 steers were weighed and fitted with indwelling rectal thermometers and jugular catheters. On day 42, steers were challenged i.v. with LPS (0.25 µg/kg BW). Blood samples were collected at -2, 0, 2, 4, 6, 8, 10, 12, 18, 24, 36, and 48 h relative to the LPS administration at 0 h. Serum was isolated to determine serum chemistry and inflammatory marker concentrations. Whole blood was used for hematology analysis. There were no differences in DMI or ADG (P ≥ 0.75) during 35 d of supplementation. A treatment × time interaction (P = 0.01) occurred for rectal temperature, where L2 steers had the greatest temperature following the challenge (P ≤ 0.05) compared to L1 and L0 steers. There was a treatment × time interaction (P = 0.03) for the change in white blood cells where L0 steers had the greatest change compared to L1 and L2 steers at various timepoints. There was a treatment × time interaction (P = 0.02) for the change in tumor necrosis factor-α concentration, where there was a greater increase in concentration in L0 compared to L1 and L2 steers. Additionally, there was a treatment × time interaction (P < 0.01) for Macrophage Inflammatory Protein-1β (MIP-1β) concentrations, where concentrations were greater in L0 compared with L1 and L2 steers from 2 to 4 h post-challenge. There was a treatment × time interaction for plasma total protein concentration (P < 0.01) where L0 steers had less plasma total protein compared with L1 and L2 steers, while L1 steers had less plasma total protein than L2 steers at -2 h prior to LPS challenge. These data suggest that methionine supplementation may have an immunomodulatory effect in beef steers that may improve response to pathogens.

A total of 557 mixed parity sows (PIC 1050) were used to evaluate the effect of lactation feeder design on sow farrowing performance, litter growth performance, feeder cleaning criteria, and economics. The experiment was conducted during the summer of 2023 at a commercial sow farm located in northwest Texas. The study used two sequential farrowing groups with approximately 279 sows per group. On approximately days 112 to 114 of gestation, sows were moved to the farrowing house and randomly allotted to one of three feeder types based on parity and caliper score. Feeder types consisted of 1) a dry feeder with a nipple drinker located next to the feeder, 2) a wet-dry feeder with a divider to separate feed and water, or 3) a wet-dry feeder without a divider. The three feeder types were used in one of every three stalls with the same sequence from the front to the end of all rooms to balance for environmental effects. Sows were weighed before entering the farrowing house and at weaning. Sows were provided approximately 1.81 kg per day of a common lactation diet prefarrowing, and after farrowing, sows were provided ad libitum access to lactation feed. There was no evidence of a difference in sow weight at entry or weaning, overall BW change, caliper score at entry or weaning, total litter weight or individual pig weight at birth, total pigs born, or percentage of pigs born alive. However, sows fed with the dry lactation feeder had decreased (P < 0.05) total daily feed disappearance and average daily feed disappearance compared to either wet-dry feeder design. There was no evidence of difference for litter or pig weaning weight, or litter average daily gain. As a result, litter feed efficiency was improved (P < 0.05) for sows fed via the dry feeder compared to either wet-dry feeder. For feeder cleaning criteria, dry feeders had increased (P < 0.05) washing time and washing cost compared to either wet-dry feeder design. In addition, sows fed via the dry feeder had decreased (P < 0.05) total lactation feed cost and feed cost per piglet weaned compared to either wet-dry feeder design. In summary, using the wet-dry feeder design in this study with or without a divider separating the feed from the water increased feed disappearance with no effects on sow and litter performance compared to dry feeders, thus worsening litter feed efficiency and increasing feed cost per sow and litter.

The objective of this study was to analyze the effects of immunological suppression of ovarian function and estrus (Improvest®; Zoetis Inc.) on carcass cutting yields and meat quality. A total of 1,080 gilts were allocated by weight and assigned to pens of 27 pigs/pen. Pens were then randomly selected to be managed with or without immunological suppression of ovarian function and estrus (IMP vs. CON). Improvest was administered to each IMP gilt on days 7 and 67 of the study. Pigs were marketed on day 89 (n = 8 heaviest gilts per pen), 103 (n = 8 next heaviest gilts per pen), and 117 (remaining pigs/pen) of the study. The heaviest 47 to 50 carcasses for each treatment from each marketing group were selected for carcass cutting tests and evaluation of meat quality the day following slaughter (approximately 32-h postmortem). A smaller subset of 18 to 20 pork loins per treatment from each marketing group were selected for meat quality evaluation following 14 d of postmortem storage. Carcasses were fabricated according to institutional meat purchase specifications (IMPS) and meat quality analyses included pH and instrumental color at 32-h postmortem and purge loss, pH, instrumental color, intramuscular fat (IMF), cooking loss, and star probe following 14 d of postmortem storage. Live performance data were analyzed using the pen as the experimental unit, while carcass data were analyzed using the individual carcass as the experimental unit. During the post-second dose period (measured from days 70 to 85), IMP gilts consumed 10.8% more feed (P < 0.01) and grew 13.5% faster (P < 0.01) compared with CON gilts. Hot carcass weight (HCW), and the weights of many cuts, were significantly influenced by the interaction of Improvest management and marketing group. Therefore, the focus was directed toward primal weights and merchandized cut weights when expressed as a percentage of HCW. When expressed as a percentage of HCW, primal-cut yield and merchandized-cut yield calculations were not different (P = 0.33 and P = 0.65, respectively) between CON and IMP gilts. Meat quality traits did not differ (P > 0.05) between CON and IMP gilts, with the exception of instrumental a* at 32-h postmortem which was 0.32 units greater for CON gilts compared with IMP gilts. In summary, managing market gilts with immunological suppression of ovarian function and estrus improves the rate of weight gain through increased feed intake; however, carcass-cutting yields were not significantly changed.

Evidence suggests that nucleotide supplementation in diets improves intestinal development, immune function, and cell growth. Stressful events such as weaning in pigs may increase nucleotide demand, making exogenous supplementation potentially beneficial. This study evaluated the effects of low-protein (LP) diets supplemented with dietary nucleotides on growth performance, postweaning diarrhea (PWD), nutrient digestibility, and blood metabolites. A total of 210 piglets were weaned at 21 d of age, allowing a 3-d adaptation to a common nursery diet. At 24 d, pigs were reweighed (6.02 ± 0.05 kg) and allocated to 5 dietary treatments in a randomized complete block design to give 7 replicates per treatment (n = 6 piglets per replicate). The 5 dietary treatments included (i) a high protein positive control diet (PC) with 24% crude protein (CP); (ii) a low protein negative control (NC) with 16% CP; (iii) an NC diet with nucleotide supplementation at 1 g/kg (NC01), 3 g/kg (NC03), or 9 g/kg (NC09). Diets were provided ad libitum for 35 d, and weekly feed intake (FI) and body weight (BW) were recorded. Blood samples were collected on day 32 and fecal samples were collected on days 33, 34, and 35 to determine serum metabolites and nutrient digestibility, respectively. Relative to PC, the NC diet had lower overall average daily gain (ADG) (343.5 vs. 305.5 g/d), incidence of PWD (2.5 vs. 1.2 diarrhea score), and blood urea nitrogen (BUN) (11.3 vs. 3.4 mg/dL); (P < 0.05, < 0.05, and < 0.0001, respectively). The nucleotide-supplemented diets, NC01, NC03, and NC09, had comparable (P > 0.05) overall ADG to the PC and decreased (P < 0.0001) BUN. Additionally, NC09 had decreased (P < 0.05) incidence of PWD compared to PC. The apparent total tract digestibility (ATTD) of nitrogen increased linearly (P < 0.05) with nucleotide supplementation, although reducing CP decreased (P < 0.05) serum glutathione and insulin-like growth factor-1 (IGF-1) concentrations. However, IGF-1 concentration was linearly increased (P < 0.05) with nucleotide supplementation. Results suggest that feeding LP diets supplemented with dietary nucleotides after weaning can increase ATTD of nitrogen and protein utilization, reduce the incidence of PWD, and increase serum IGF-1 concentration while partially ameliorating the negative effects of LP diets on growth performance.

The objective of this study was to evaluate the impacts of stress challenge duration on metabolic, hematologic, and rumen fermentation parameters of beef steers. Thirty steers (416 ± 19 kg) were used in a randomized complete block design with 2 blocks and 3 treatments. Treatments were intravenous injection of (1) saline at 0, 24, 48, and 72 h (n = 10; control); (2) corticotropin-releasing hormone (CRH) and vasopressin (VP) at 0 h and saline at 24, 48, and 72 h (n = 10; acute); or (3) CRH and VP at 0, 24, 48, and 72 h (n = 10; chronic). Serum samples were collected at various time points for analysis of serum chemistry and nonesterified fatty acids (NEFA). Whole blood was collected for analysis of complete blood count, and ruminal fluid was collected via oral lavage to evaluate volatile fatty acid (VFA) composition. Serum cortisol was greater (treatment × hour; P ≤ 0.01) for cattle receiving acute and chronic than control at 1 h (P < 0.01) and greater for chronic than acute and control at 25, 26, 49, 50, 73, and 74 h (P < 0.01). Similarly, there was a treatment × hour interaction (P < 0.01) for serum glucose concentrations such that cattle receiving acute and chronic had greater glucose at 1 h than control (P < 0.01), and cattle receiving chronic had greater glucose at 25, 49, 73, and 74 h than acute and control (P ≤ 0.04). Serum insulin concentrations were greater (treatment × hour P < 0.01) in chronic and acute than control at 1 h (P < 0.01) and greater for chronic compared to acute and control at 25, 49, and 73 h (P ≤ 0.01). Serum NEFA tended (P = 0.09) to be greater in stressed cattle compared to control. There was a treatment × hour interaction (P = 0.003) for total white blood cell count such that chronic had greater concentration than control at 72 h (P < 0.01). Conversely, monocyte concentration was less (treatment × hour interaction P < 0.01) for chronic than acute and control at 144 h (P < 0.01) and eosinophil concentration was greater (treatment × hour interaction P = 0.02) for chronic than control steers at 48 h (P = 0.02) and greater for chronic than acute at 72 and 144 h (P ≤ 0.03). Minimal differences were observed in VFA concentrations with the exception of acetate (treatment × hour interaction P = 0.05). These results demonstrate that administration of CRH and VP affects complete blood count and serum chemistry, and longer duration of treatment exposure prolongs the physiological responses to a stress challenge.

Haemonchus contortus is an extremely harmful blood-feeding nematode affecting small ruminants, leading to anemia, weight loss, and, in severe cases, animal death. Traditional methods of monitoring anemia in sheep, such as regular physical examinations by veterinarians and laboratory tests, can be expensive and time-consuming. In this work, we propose an anemia monitoring system that uses a web-based app. The methodology for the SheepEye app is based on deep learning algorithms, including the U-net model for segmentation and the VGG19 model for classification. All learning algorithms, as well as the development of the app, were implemented in Python. The SheepEye web-based app is a promising technology that can facilitate and improve the diagnosis of parasitic infections in sheep and enhance sheep productivity. By using the app, farmers can detect anemia in their flocks and implement target selective treatment, which reduces the use of anthelmintics and consequently minimizes the risk of parasitic resistance. The SheepEye app is still in a prototype stage, but its prospective is extremely promising and our goal is to further develop it so that it can be made available for producers to use.