Translational Animal Science最新文献

This study was conducted to evaluate the effects of dietary medium-chain fatty acid (MCFA) levels on growth performance, fecal score, gut permeability, energy status, and apparent total tract digestibility (ATTD) of weaning pigs. At weaning, a total of 100 pigs [18.4 ± 1.8 d of age; initial body weight (BW) of 5.72 ± 1.4 kg] were allotted to 5 treatments in 5 replicates with 4 pigs per pen for a 35-d feeding trial. Treatments were dietary MCFA levels of 0.0, 0.2, 0.5, 1.0, and 1.5% for d 0 to 21 postweaning (Phase 1) replacing soybean oil and a common nursery diet was fed to all pigs for d 21 to 35 postweaning (Phase 2). With increasing dietary MCFA levels, quadratic increases were observed in BW (P ≤ 0.05), average daily gain (ADG; P ≤ 0.05), and average daily feed intake (ADFI; P = 0.08, tendency) in d 0 to 14 postweaning, peaking at the 0.5% MCFA level. The BW from d 21 to 35 postweaning and ADG in d 0 to 21 and 21 to 35 postweaning increased linearly with increasing MCFA levels (P ≤ 0.05), while linear and quadratic increases were observed in overall ADG (P ≤ 0.05), with the greatest value observed at the 1.0% MCFA level. The ADFI increased linearly (P ≤ 0.05) with increasing MCFA levels in d 21 to 35 postweaning and overall period, while gain-to-feed ratio was not different in each phase and overall period. Fecal score was not affected in the overall period (P > 0.21). The ATTD of gross energy (P ≤ 0.05), dry matter (P = 0.10, tendency) and crude protein (P = 0.07, tendency) increased linearly with increasing MCFA levels. At d 7 postweaning, plasma β-hydroxybutyrate levels decreased linearly (P = 0.06, tendency) with increasing MCFA levels, while plasma free fatty acid levels showed a quadratic response (P = 0.06, tendency) with the lowest levels at the 0.5% MCFA level. Increasing MCFA levels decreased plasma diamine oxidase levels at d 7 postweaning (P = 0.06, tendency), while showing quadratic decreases in plasma d-lactate levels at d 7 (P ≤ 0.05) and 21 (P = 0.10, tendency) postweaning, with lower values observed at the 0.2% to 1.0% MCFA levels compared to the 0.0% MCFA level. In conclusion, increasing dietary MCFA levels up to 1.0% enhanced overall growth rate and feed intake, energy and protein digestibility in nursery pigs, improved energy status by lowering plasma β-hydroxybutyrate and free fatty acid levels, and reduced gut permeability in the early nursery period.

[This corrects the article DOI: 10.1093/tas/txae158.].

A total of 87 sows (Line 241, DNA) and their offspring were used to evaluate the effects of increasing standardized ileal digestible (SID) Lys in late gestation diets on lactating sow and litter performance. Sows were blocked by parity and body weight (BW) on day 90 of gestation and allotted to one of three treatments with 29 replications per treatment. Diets included increasing dietary SID Lys (0.60, 0.80, or 1.00%) accomplished by increasing soybean meal (14, 21, or 29% of the diet). Sows were allowed 2.04 kg/d of their treatment diet from day 90 of gestation until farrowing for average SID Lys intakes of 11.9, 15.8, or 19.9 g/d. After farrowing, sows had ad libitum access to a common lactation diet containing 1.10% SID Lys. Urine samples were collected on day 90 and 110 of gestation to determine urinary creatinine levels. Litters were cross-fostered within dietary treatment by 48 h after farrowing to equalize litter size. Parity group was included in the statistical model as a fixed effect with classifications of primiparous (n = 35) or multiparous (n = 52) sows. Weight gain from day 90 to 110 of gestation increased (linear, P < 0.001) as SID Lys increased. Change in urinary creatinine level from day 90 to 110 of gestation tended to decrease (linear, P = 0.063) as SID Lys increased suggesting that muscle catabolism decreased with increasing SID Lys. There were no differences in starting litter size or piglet birth weight with increasing SID Lys in late gestation. Piglet average daily gain (ADG) from day 2 to 10 of lactation increased (linear, P = 0.017) as SID Lys increased. From day 2 until weaning, litters from sows fed 15.8 g/d of SID Lys in gestation had the greatest (quadratic, P = 0.044) litter weight gain. Pre-weaning mortality from birth until day 2 of lactation was greatest for sows fed 15.8 g/d of SID Lys (quadratic, P = 0.025). There was a parity group × gestation diet interaction (P = 0.049) for pre-weaning mortality from day 2 to weaning where mortality increased as SID Lys increased in primiparous sows but decreased in multiparous sows. However, the differences in mortality did not influence the number of pigs weaned per treatment. In conclusion, increased SID Lys through increased soybean meal linearly increased late gestation sow BW gain and piglet ADG during early lactation. Litters from sows fed 15.8 g/d of SID Lys had the greatest litter ADG during late lactation and overall.

While boars constitute a relatively small portion (less than 0.005%) of the total swine herd, they have significant genetic influence on the swine population. An individual boar has the potential to sire thousands of offspring every year, yet when it comes to science-based recommendations for boar development from weaning to puberty, there is little in the way of recommendations. Similarly, the management and nutritional recommendations of today's boar population are based on studies that may not be relevant to current genetics or based on recommendations for gilts and sows. Historically with rapid genetic turnover in boar studs there has been little pressure to produce research in this area. However, with boar studs reporting increasing incidence of lameness and health related removals, rising developmental costs, and a need to maintain herd fertility it has created opportunities to increase the scientific understanding of boar development and management. In this literature review, we aim to overview development and management of commercial boars in the United States and highlight what is understood in the way of science-based research.

[This retracts the article DOI: 10.1093/tas/txae125.].

A 3-yr study evaluated the effect of late gestation supplementation strategy on cow-calf performance, subsequent steer feedlot performance, and carcass characteristics. Mature March-calving crossbred cows (n = 357) were stratified by body weight (BW) and body condition score (BCS) and assigned to one of 4 treatments: 1) no supplementation (NoSupp), 2) 0.91 kg/d of a 30% CP distillers-based supplement (DBS) (Supp), 3) 0.91 kg/d of a 30% CP DBS with 160 mg/cow/d of monensin (RUM; Rumensin 90, Elanco Animal Health), and 4) 0.91 kg/d of a 30% CP DBS with 40 g/cow/d propionate salt (CaProp, NutroCal 100, Kemin Industries). Cows were individually supplemented daily using a Super SmartFeed (C-Lock Inc., Rapid City, SD) from November to February. After weaning, steers (n = 181) were transported to the West Central Research and Extension Center and placed in a GrowSafe feeding system for finishing. Steers were slaughtered at a commercial facility (Tyson Fresh Meats, Lexington, NE) after fed to a common endpoint each year. Cow BW was not different (P = 0.87) at the initiation of the study in November. However, NoSupp cows were lighter (P < 0.01) at pre-calving and pre-breeding compared to supplemented cows. In contrast, NoSupp cows lost less (P < 0.01) BW from pre-calving to pre-breeding than supplemented cows and gained more (P = 0.01) BW from pre-breeding to weaning. Treatment tended to influence overall pregnancy rates (P = 0.09). Supp and CaProp dams had increased pregnancy rates over NoSupp and RUM (P ≤ 0.05). Offspring from NoSupp dams had lighter (P < 0.01) BW at birth, pre-breeding, and weaning than their counterparts from supplemented dams. In addition, steer feedlot entry, final BW, and hot carcass weight were greater (P < 0.01) when dams were supplemented compared to NoSupp. Steer feedlot average daily gain and gain:feed ratio was not influenced (P ≥ 0.31) by dam supplementation strategies; however, dry matter intake tended (P = 0.09) to be influenced by treatment. Percentage of carcasses grading Choice or greater was not influenced (P = 0.66) treatment; however, steers from dams fed CaProp had increased (P = 0.04) marbling scores. Protein supplementation during late gestation is an effective strategy to increase cow BW, maintain cow BCS, and increase progeny BW. Providing dams with propionate salts during late gestation positively improved marbling score of the subsequent steer carcass characteristics.

The objective of this study was to evaluate the effects of a Saccharomyces cerevisiae fermentation product (SCFP) compared to a direct-fed microbial (DFM) on growth performance, health, carcass characteristics, and liver abscess prevalence in beef × dairy crossbred steers. Two thousand steers [50% beef, 25% Holstein, 25% Jersey genetics; initial shrunk body weight (SBW) = 288.2 ± 8.0 kg] were blocked by arrival date and randomly assigned to receive 1 of 2 treatments: 1) SCFP supplied in the starter diet at 12 g per steer daily and then 9 g per steer daily in the finishing diet (NS; NaturSafe™, Diamond V, Cedar Rapids, IA) or 2) DFM fed at 50 mg per steer daily throughout the feeding period (BD; Bovamine Defend, Chr. Hansen, Milwaukee, WI). Pen served as the experimental unit (200 steers/pen), with 5 pens per treatment. Data were analyzed as a randomized complete block design in R 4.2.2. with the main effect of treatment and random effect of block included in the model. Results were reported on a deads-in basis unless otherwise stated. Cattle were fed for a total of 275 ± 6.2 d. Initial and final SBW did not differ (P ≥ 0.84) by treatment. Initial treatment pulls were observed more frequently for NS compared to BD cattle (29.43% vs. 21.67%; P < 0.01). However, NS cattle had a lesser rate of repulls as a proportion of initial pulls (10.08% vs. 16.61%; P = 0.03). Fewer (P < 0.01) bullers were reported amongst NS cattle. Cattle supplemented with NS had a lower case fatality rate (6.08% vs. 11.96%; P < 0.01) and tended to have a lower total mortality rate (1.60% vs. 2.70%; P = 0.09) than BD. With deads included, average daily gain (ADG) tended (P = 0.06) to be greater for NS cattle. Dry matter intake did not differ (P = 0.99) by treatment; however, NS cattle had a numeric advantage in feed efficiency (G:F) nearing a tendency (0.132 vs. 0.130; P = 0.11). On a deads-out basis, ADG and G:F were similar (P ≥ 0.85). Dressing percentage tended (P ≤ 0.10) to be greater for NS carcasses. Cattle fed BD had a greater (P = 0.03) proportion of USDA Prime carcasses. While treatment had no impact on liver abscess severity or total abscess occurrence, NS cattle tended to have less A- abscesses (1.72% vs. 3.87%; P = 0.10). In this large-pen comparison, SCFP supplementation improved feedlot cattle health and positively influenced performance compared to a DFM.

Cannabis sativa (varieties for industrial use or animal feed are termed hemp), and its extracted byproducts are being considered for animal feed due to their high protein content. However, if hemp disrupts fertility and reproduction in livestock, it should not be used as a feed source. We hypothesized that the phytocannabinoids in hemp would disrupt fertility and reproduction, cause craniofacial defects (cyclops, cleft palate, misshapen head), and low birth weight in lambs. To test this hypothesis, 22 timed pregnant ewes were dosed with hemp in the form of dried ground hemp plant material at 150 mg/kg body weight per day total cannabinoids, and from gestational days 10 to 20 and a separate 22 timed pregnant ewes were dosed similarly with dried ground grass hay as a control. The most prevalent cannabinoids in the plant material were cannabidiolic acid (CBDA) at a concentration of 23.2 mg/g, and cannabidiol (CBD) at a concentration of 5.8 mg/g. Delta 9-tetrahydrocannabidiol was present in the plant material at a concentration of 0.3 mg/g. The hemp used in this study had crude protein concentrations of 15.6%, neutral detergent fiber concentrations of 42.2%, and in vitro true digestibility concentrations of 83.6%. After 10 d of dosing with hemp, a serum sample was obtained from each of the ewes, CBDA was measured at a concentration of 652 ± 38 ng/mL and CBD was measured at 16 ± 0.9 ng/mL. THC was not detected in the serum. The average gestation length for lambs from the hemp treated ewes was 148 ± 0.38 d, and the average gestation length for lambs from the grass hay treated ewes was 149 ± 0.38 d (P = 0.23). The numbers of male and female lambs did not significantly vary from expected (50:50) (P = 0.32). There were no significant fetal deformities (P > 0.05) or weight differences between the treatment groups (P > 0.05), and as expected, the lamb weights significantly increased over time (P < 0.05). These results suggest that Cannabis sativa may have the potential with further research to be a suitable protein source for gestating sheep.

Castration detrimentally affects weaned calves, and painful procedures in production animals are a public concern. The objective of this study was to determine the effects of castration (by banding) with or without administration of meloxicam (Mel), a non-steroidal anti-inflammatory drug in weaned beef calves. Forty-eight (62 d post-weaning) beef calves [8.2 ± 0.1 (mean ± SE) mo old; 319 ± 10 kg BW] were blocked by age and body weight and randomly assigned to 1 of 3 treatments (n = 16 calves per treatment): 1) intact bulls (BULL), 2) castration by banding (BAN), or 3) castration by banding with orally-administered Mel (3 mg per kg BW on d 0 and 14; BAN + M). Within each treatment group, calves were randomly assigned to 8 pens (2 calves per treatment within each pen). Body weight and plasma haptoglobin and fibrinogen concentrations were determined on 0, 3, 7, 14, and 28 d after treatment administration. Rectal temperature was recorded at 5-min intervals for the first 14 d by dataloggers. Behaviors [mean lying time (h/d), mean lying bouts (n/d), and steps (n/d)] were recorded at 1-min intervals for 27 d by dataloggers. Ethogram data was recorded on 8 d for two hours with collection times of every 10 min. Behaviors recorded from the ethogram included eating, ruminating, not ruminating, drinking, location within the pen, and body position (standing or lying down). Data were tested for effects of treatment, day, pen, and treatment by day interaction using mixed models accounting for repeated measures. BULL gained more (0.69 ± 0.12 kg/d; P < 0.05) than BAN (0.15 ± 0.11 kg/d) or BAN + M (0.14 ± 0.11 kg/d) over 28 d. There was an effect of treatment (P < 0.001) and treatment by time interaction (P < 0.001) on mean rectal temperature during the 14 d after treatment administration. Over 14 d, BAN + M had the greatest mean rectal temperature (39.47 ± 0.006 °C), BAN had the second greatest temperature (39.42 ± 0.006 °C), and BULL had the lowest temperature (39.41 ± 0.005 °C). BULL increased time lying (P < 0.05) and decrease steps (P < 0.05), compared to BAN, Days 2, 3, 16, and 17, and compared to BAN and BAN + M Days 18 and 19 post-castration. Mel administration had an insignificant effect on pen-level behaviors recorded with the ethogram. Decreased weight gain indicates that castration by banding during the post-weaning period was painful regardless of attempts and pain abatement with Mel. While benefits of Mel were not evident from changes in growth or inflammatory response, behavior and rectal temperature were affected by Mel administration.

Transportation at weaning is an integral component of the American swine industry. However, the long-term effects on growth performance have not been well characterized. Previous research suggests transportation causes weight loss immediately following weaning, but few studies have followed this effect further than 7 d post-weaning, with transport causing decreased body weight in those that have. In experiment 1, average weight pigs at 20 ± 1.3 d of age were weaned and either 1) transported for 9 hour without feed and water (TR), 2) had their feed and water restricted for 9 hour (FR), or 3) were weaned and provided immediate access to feed and water (WN). Subsequent weight gain was tracked to market. No differences in body weight (BW) or average daily gain (ADG) were observed among treatment groups. In experiment 2, low (LBW), average (ABW), and high body weight (HBW) pigs at 20.7 ± 1.2 d of age were weaned and either transported for 9 hour (TR) or weaned without transport (WN) and placed in a nursery with access to feed and water to determine if the response to weaning and transport stressors was influenced by weaning weight. While TR pigs regardless of weight class did lose a larger percentage of their weight after 9 hour (P < 0.001), by 7 d post-weaning that effect had disappeared (P > 0.10). The BW gap between ABW and HBW pigs as a proportion of BW decreased with age, but LBW pigs remained lighter than the other two weight classes (P < 0.01). Additionally, ADG was lower in the nursery period (P < 0.05) and tended to be lower in the grow-finish period (P = 0.062) for LBW pigs at weaning, causing them to continue to fall behind their larger counterparts. While this research found no effect of transportation on long-term growth, it suggests that weaning weight is a meaningful predictor of future body weight in the grow-finish phase.