Translational Animal Science最新文献

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.

The aim of this experiment was to evaluate the effect of the level of prior nutritional restriction during backgrounding in Angus steers on methane (CH₄) emissions, diet digestibility, rumen fermentation, and ruminal microbiome under either a forage or grain-based finishing diet. Eighty steers (body weight [BW]: 444 ± 39 kg, age: 18 ± 1 mo) were blocked and randomly assigned within the block to either an optimal (0.6 to 0.7 kg/d) or suboptimal (0.3 to 0.4 kg/d) growth rate to exploit compensatory growth (CG), during 97 d of backgrounding. Following, for 84 d, half of the steers in each group were finished on a forage diet while the other half were finished on a grain-based diet. During the backgrounding period, CH₄ emissions tended (P ≤ 0.07) to be higher; however, CH₄ intensity expressed by BW gain was 50% lower (P < 0.01) for optimal compared to suboptimal growth steers. BW gain, dry matter intake, diet digestibility, and ammonia nitrogen in the rumen were greater (P < 0.01) for optimal compared to suboptimal steers. During the finishing period, CH₄ emissions in either forage or grain finishing diets were similar (P > 0.05) for both backgrounding treatments. However, due to greater BW gain in suboptimal steers (1.20 vs. 0.97 kg/d), their CH₄ intensity-related coefficient decreased (P < 0.05) during the finishing period. Diet digestibility or any fermentation parameter was unaffected (P > 0.05) by previous backgrounding during the finishing period. In fact, rumen microbial abundance measured during finishing was not modified (P > 0.05) by previous backgrounding. Steers finished under grain conditions, had lower (P < 0.01) daily CH₄ emissions and CH₄ intensity. Additionally, grain-fed steers increased (P < 0.05) BW gain, diet digestibility, propionic, lactic, and valeric acids, Succinivibrionaceae family and Succiniclasticum, Erysipelotrichaceae UCG-002, Sharpea, and Megasphaera bacteria genera, compared to forage-fed steers. In conclusion, ruminal microbiome and fermentation, diet digestibility, and CH₄ emissions were unaffected during finishing between prior levels of backgrounding growth. However, given the higher BW gain in suboptimal steers in both finishing diets, CH₄ intensity was reduced in comparison to the optimal backgrounded steers. Nevertheless, lifetime emissions of the steers need to be assessed with the different dietary regimens, since suboptimal steers reduced CH₄ emissions during the backgrounding period but, additional days of finishing were required to achieve the same BW as their contemporaries.

Grass-fed beef is becoming increasingly popular and is expected to be a $14 billion industry by 2024. Even so, grass-fed beef is typically darker in appearance than that of conventional grain-fed beef. Aging has been shown to improve lean color (L*, a*) of dark-cutting beef however little work has focused on aging as it relates to improving the lean color of grass-fed beef. Therefore, the aim of this study was to evaluate the effect of dry aging on grass-fed beef compared to varying lengths of grain-feeding. Thirty commercial Angus crossbred steers were randomly assigned to either pasture finishing (CON), short (SF), or long fed (LF) programs. The SF and LF treatments ranged from 90 to 114 d (average: 98 d) and 118 to 134 d (average: 125 d) on ad libitum high concentrate feeding, respectively. Cattle were randomly identified from each treatment group and harvested over a consecutive 3-wk span. Carcass evaluation and longissimus lumborum samples were collected 24 h postmortem. Carcasses were aged for 21 d, and steaks were collected on 1-, 3-, 7-, 10-, 14-, and 21-d postharvest, and objective color was evaluated following 1 h bloom. Our data show color (L*, a*, b*) was improved with aging regardless of treatment. However, grass-fed (CON) showed the greatest improvement in both lightness (L*) and redness (a*) ultimately making grass-fed comparable to that of grain-fed beef by day 21. These data argue that dry-aging grass-fed beef improves color development similar to that of grain-fed beef.

This study aimed to evaluate the effect of tannin (a mix of hydrolyzable and condensed) and its association with monensin on feed efficiency, growth performance, and carcass of bulls fed high-grain diets with 14% and 13% crude protein (CP). Bulls (64 Nellore and 96 crossbred Angus × Nellore; initial body weight (BW) = 342 ± 25 kg; 20 ± 1 months) were allocated into 20 pens (8 from the same breed per pen). The treatments were T14 - 1.5 g of tannin/kg of dry matter (DM) (Bypro; Silva Team Brasil, Estância Velha, Brazil) in a diet with 14% of CP; M14 - 25 ppm monensin (Rumensin; Elanco Saúde Animal, São Paulo, Brazil) in a diet with 14% of CP; TM14 - 1.5 g of tannin/kg of DM and 25 ppm monensin in a diet with 14% of CP; TM13 - 1.5 g of tannin/kg of DM and 25 ppm monensin in a diet with 13% of CP. Data were analyzed using a randomized block design with pens as experimental units. Supplementation with tannin resulted in greater final BW, average daily gain (ADG), and dry matter intake (DMI) compared with Monensin (P < 0.05). The association between Tannin and Monensin decreased (P < 0.05) DMI without affecting growth performance, consequently improving the gain-to-feed ratio compared to the Tannin-alone treatment. When Tannin was combined with Monensin, there was an increase (P < 0.05) in net energy for gain and net energy for maintenance compared with Tannin supplementation alone. Bulls supplemented with Tannin in their diet exhibited greater (P < 0.05) hot carcass weight, carcass gain, and gluteus medius area compared with those supplemented with Monensin alone. Final BW, ADG, and DMI were lower (P < 0.05) when the CP content of the diet was decreased from 14% to 13%. The optimal combination for achieving maximum growth and feed efficiency was observed when bulls were fed with tannin and monensin combined in a diet containing 14% CP.

Multiple reaction monitoring (MRM) profiling is a sensitive method of lipid screening that has the capability to distinguish between different fertility phenotypes in gilts. However, MRM profiling has not yet been utilized to evaluate fertility phenotypes in boars. Markers indicative of fertility status in boars would be valuable as inclusion of subfertile boars in breeding programs results in a loss of efficiency and negative economic consequences. In addition, semen samples for lipidomic analysis are transported in liquid nitrogen or on dry ice to suspend metabolic activity within the sperm cells, however, these cryopreservation techniques are not commonly available at commercial boar studs. Therefore, the objective of this study was to develop a method of sample processing for MRM profiling that suspends metabolic activity within semen without freezing the sample. Five, sexually mature boars of similar genetics enrolled in a commercial breeding program were collected for the study. Following collection, ejaculates were aliquoted into methanol to suspend metabolic activity and shipped to Purdue University overnight for lipid extraction. Lipids were extracted using the Bligh and Dyer method and MRM profiling was used for lipid screening. A total of 329 ion transitions (MRMs) related to lipids were detected with most lipids being characterized as plasma membrane lipids (74%) which were comprised of phosphatidylcholines (40%), ceramides (16%), phosphatidylethanolamines (11%), and phosphatidylserines (7%). acylcarnitines (AC) represented approximately 8% of the ejaculate lipidome. Hierarchical cluster and principal component analysis revealed that boars have a distinct ejaculate lipidome profile based on major plasma membrane lipid classes. In addition, we observed that one boar was unique in his abundance of AC which are related to progressive motility and sperm cell metabolism. These results indicate that this method of sample processing for MRM profiling is suitable to be used to evaluate the lipidome of ejaculates from commercial boars and has the potential for broader applications across different livestock species in commercial environments.

Rotavirus and other pathogenic microorganisms are known to cause scours, respiratory infection, and increased mortality, spread from pig to pig via contaminated equipment, insuffcient washing, and improper disinfection processes in farrowing rooms on commercial sow farms. Pig producers have adopted cleaning procedures and biosecurity policies as an attempt to ensure farrowing rooms are free of infectious organisms before the next group of sows is introduced. Adenosine triphosphate (ATP) bioluminescence has been used in other industries to provide real-time feedback on surface cleanliness through the detection of ATP from organic sources. That technology may provide producers a way of objectively characterizing a farrowing room's suitability for a new group of sows to be moved into the farrowing room. Three ATP luminometers (Charm Sciences novaLUM II-X, 3M Clean Trace, and Neogen AccuPoint) were used to estimate relationships between ATP bioluminescence relative light units (RLU) and coliform plate counts (CPC). Five farrowing crate locations and the room entryway floor were swabbed to determine locations within a farrowing crate that can accurately estimate room cleanliness. Coliform plate counts were strongly correlated with Charm novaLUM II-X RLU (r = 0.70, P < 0.01). The Clean-Trace CPCs and RLU (r = 0.48, P < 0.01) were moderately correlated. There was a weak correlation between CPCs and AccuPoint RLU (r = 0.32, P < 0.01). The greatest area of surface contamination was the entryway floor and the sow feeder. Because CPCs and luminometer RLU were correlated, statistical process control charts were developed to provide cleanliness thresholds based on RLU values. Based on an adjusted 3σ from the mean RLU critical limit, 7.7% of crates for the Charm novaLUM II-X, 10.6% of crates for the 3M Clean Trace, and 0% of crates for the Neogen AccuPoint would have failed the critical limit for the sow feeder cleanliness thresholds. Using a similar approach, 11.4% of crates for the Charm novaLUM II-X, 10.5% of crates for the 3M Clean Trace, and 15.2% of crates for the Neogen AccuPoint would have failed the critical limit for the crate sorting bar cleanliness thresholds. These data suggest that ATP bioluminescence may be a reliable method to monitor cleaning effectiveness in farrowing rooms on commercial sow farms. Bioluminescence is a monitoring tool that should be used in conjunction with periodic microbial validation to monitor procedures for cleaning and disinfection.

Previous research suggested that feeding sows with a product containing an inactivated strain specific Pichia guilliermondii yeast postbiotic (PG; Citristim, ADM Animal Nutrition, Quincy, IL) has the potential to support fecundity, and progeny performance at birth, weaning, and after weaning. To summarize these effects, a systematic review followed by a meta-analysis was carried out to determine the effects of feeding sows with PG during gestation and lactation on reproductive the performance of sows and the growth of progeny after weaning. All experiments included were randomized trials reporting side-by-side comparisons of an appropriate control (CON) and the CON with the inclusion of PG. The effects of PG inclusion in sow diets were evaluated using the raw mean difference and effect size calculations. Analysis included seven trials for sow reproductive and litter performance until weaning, and eight trials for progeny performance after weaning. The risk of publication bias was assessed by funnel plots. In the case of publication bias, the Trim and Fill method was used. Heterogeneity was assessed using I ² statistics. Sows fed PG during gestation and lactation had more piglets born alive (BA), BA + stillborn, and BA + stillborn + mummies (P < 0.001). The individual birth weight of the piglets was not affected by the supplementation (P = 0.835). As a result, litter weight at birth was greater in sows-fed PG (P < 0.001). Piglets born from PG-fed sows tended to be weaned 0.34 d younger than those from CON-fed sows (P = 0.060). Twenty-one-day adjusted pig weight at weaning tended to be lighter by 0.122 kg in the PG sow group (P = 0.069); however, litter weight at weaning adjusted to 21 d remained similar across groups (P = 0.516). The number of piglets weaned and mortality-adjusted number of piglets weaned per sow were greater in PG than in CON sows (P < 0.023). A carryover effect was observed for progeny of PG-fed sows after weaning. Piglets born from PG-supplemented sows had greater weight gain (P = 0.030) and tended to have a better survival rate (P = 0.055) until the end of the nursery phase. These results indicate that feeding PG to sows during gestation and lactation consistently and significantly improves not only the performance of sows at farrowing but also performance of the progeny after weaning.