Translational Animal Science最新文献

[This corrects the article DOI: 10.1093/tas/txae055.].

Two experiments were conducted to determine the effect of increasing retention time in the conditioner prior to pelleting on digestibility of energy, protein, and amino acids (AA) in diets for growing pigs. Four dietary treatments were used in both experiments and consisted of a mash diet, and 3 pelleted diets that were conditioned for 30, 60, or 180 s. In Exp. 1, 12 ileal canulated barrows with an initial average body weight of 44.9 ± 2.70 kg were allotted to a triplicated 4 × 4 Latin square with 4 dietary treatments and 4 experimental periods in each square for a total of 12 replicate pigs per treatment. Each period consisted of 5 days of adaptation and 2 days of collection of ileal digesta. In Exp. 2, 12 barrows (initial average body weight: 34.1 ± 1.03 kg) were allotted to a triplicated 4 × 3 incomplete Latin square design with 4 dietary treatments and 3 experimental periods. Each period consisted of 5 d of adaptation and 5 d of collection of feces and urine. Pigs were individually housed in metabolism crates and feces, and urine were collected. Results of Exp. 1 indicated an overall treatment effect (P < 0.05) on standardized ileal digestibility (SID) of crude protein and all AA except Lys, Met, and Trp. The SID of crude protein, Arg, Leu, Thr, Ala, Ser, and Tyr was greater (P < 0.05) in all pelleted diets compared with the mash diet. The SID of His, Ile, Phe, Val, Asp, and Glu was less (P < 0.05) in the mash diet compared with the pelleted diets conditioned for 60 s or 180 s. The SID of Cys was less (P < 0.05) in the mash diet compared with the pelleted diet conditioned for 180 s. Increasing the retention time in the conditioner from 30 to 180 s increased (linear; P < 0.05) the SID of CP and most AA. Results of Exp. 2 demonstrated that pelleted diets had greater (P < 0.05) apparent total tract digestibility (ATTD) of gross energy compared with the mash diet, but no treatment effects were observed for ATTD of dry matter or on digestible energy, metabolizable energy or the metabolizability of digestible energy. These results indicate that increasing conditioning time up to 180 s improved AA digestibility for most AA and pelleting also increased ATTD of gross energy.

The National Beef Quality Audit (NBQA)-2022 systematically evaluated quality characteristics of cattle, carcasses, and by products generated from the fed steer and heifer sectors. This audit was conducted from September 2021 through November 2022 in 22 beef processing facilities across 11 states. Approximately 7800 live animals were evaluated exiting the trailer and in holding pens, and about 23,200 carcasses were evaluated on the harvest floor for multiple characteristics. Cattle were transported on average 245.3 km for a travel time of 2.9 h, averaging 36 animals per load. On average, trailers had 41.3 m² of floor surface area, and cattle were housed in 3.7 compartments, allotting 1.2 m² per animal. Cattle received 91.7% mobility score 1 (walks easily, no stiffness). Cattle identification was observed on 93.3% of the those evaluated with the following frequencies: lot visual tags (61.3%), individual visual tags (58.1%), electronic tags (29.4%), low frequency electronic tags (28.9%), and metal clip tags (11.0%). For hide color/apparent breed type, most were black hided (62.3%), followed by Holstein (12.3%), red (11.3%), tan (4.9%), yellow (2.6%), gray (2.0%), brown (2.0%), non-Holstein dairy (1.7%), and white (1.1%). Most cattle were not branded (70.5%), followed by presence of butt brands (22.4%), side brands (7.0%), and shoulder brands (1.1%). For mud/manure on the hide, 49.6% had none that was visible; when observed, the most common areas were on the legs (38.7%) and belly (31.1%). Most cattle had no horns (84.1%); for those with horns, 4.6% were <2.54 cm in length, 7.9% were 2.54 to 12.7 cm in length (7.9%), and 3.3% were > 12.7 cm in length. For bruises, 47.7% of the carcasses had none, and for those with bruises, the loin (30.0%), rib (23.7%), chuck (19.7%), and round (19.3%) were the most common locations. For dentition, 95.4% had 2 or fewer permanent incisors deemed as less than 30 mo of age. Offal/byproducts condemnations occurred for liver (28.5%), lung (20.9%), viscera (12.5%), head (4.5%), and tongue (1.8%). Compared numerically to NBQA (2016), although we observed an increased area allotted per animal, travel time to the harvest facility was longer and mobility scores were lower (less mobile) exiting the trailer. Fewer cattle were identified via ear tagging, however, there was an increase in the use of electronic tags. Numerically, the percentage of black-hided cattle increased, and percentage of Holsteins declined, branding increased, mud/manure amount found on the hide declined, cattle without horns increased, and cattle 30 mo of age or older increased. Carcasses found with 1 or more bruises increased drastically (13.4% increase compared the NBQA-2016). Metrics observed in this study provide industry updates on improvements and deficiencies found in the fed beef cattle system.

Animal science is an applied discipline and post-secondary curriculum must prepare students for matriculation into a dynamic and complex industry. As the backgrounds of students pursuing animal science degrees are shifting, there may be a disconnect between how they perceive food animal production versus industry realities and traditional lecture courses may fail to adequately address these gaps. Experiential learning, which is a high-impact pedagogical approach, immerses students in real world settings, allowing them to view and experience practical applications of technical and complex concepts. Within the context of beef production, such opportunities may be valuable to illustrate the multifaceted interactions of sustainability, welfare, technology, and economic factors underlying beef production. The objective of this study was to assess changes in perceived understanding and perceptions of beef cattle production resulting from experiential learning during a beef industry tour. College students (n = 26) attended a 5-day beef industry field trip in the Texas Panhandle in May 2024, including tours of cow-calf operations, feedlots, a packing plant, and allied industries. Identical pre- and post-surveys were administered immediately before and after the trip. Data were analyzed via paired sample t-tests using SPSS v.26. After participating in the trip, students reported that the concept of sustainability was easier to understand (P = 0.02). Students also perceived greater understanding of the environmental impacts of beef production (P ≤ 0.01), economic factors affecting beef production (P ≤ 0.01), and the role of technology in beef production (P ≤ 0.01). When asked if environmental impacts of beef production were a major concern, students agreed less strongly (P = 0.04) after the tour. After the tour, students' strength of agreement increased when asked if beef production positively contributes to the rural economy (P ≤ 0.01), if technology improves animal welfare (P = 0.03), and if the beef industry is modern and innovative (P ≤ 0.01). Measures of sense of belonging within agriculture did not change as a result of the field trip (P ≥ 0.86). These data indicate that experiential learning enhances perceived understanding and influences perceptions of beef production in college students studying agricultural sciences.

The definition of breeding objectives in meat rabbits' breeding programs requires assigning economic weights to relevant traits. Our objective in this study was to estimate economic values for 12 key traits in meat rabbit production by calculating the first partial derivative of the profit function in a full-cycle production system. The model was parameterized to represent a semi-technified farm with 250 does managed in two triweekly groups, with natural mating occurring at 11 d postpartum. Economic data were expressed in U.S. dollars. Production costs were categorized into feed and non-feed costs associated with adult does, replacement does, bucks, replacement bucks, and growing rabbits. Revenues were derived from carcasses, pelts, and culled animals. Relative economic values (REV), expressed per doe per year, were obtained by multiplying the absolute economic value of each trait by its respective additive standard deviation. Feed costs accounted for 72.8% of the total. The REVs for litter size traits were $46.05 for the number of kits born alive, $42.83 for the total number of kits born, and $0.22 for the proportion of kits born alive. Efficiency traits' REV were -$6.93 for feed conversion ratio, $0.08 for feed efficiency, $2.98 for daily weight gain during the fattening period, and $0.14 for carcass yield. The functional traits' REV were $0.03 for female fertility, $0.002 for replacement doe fertility, and $0.57 for longevity. Health traits' REV were $0.18 and $0.19 for survival during lactation and fattening, respectively. Sensitivity analyses showed that increasing feed costs by 50% and carcass rabbit sale price by 40% resulted in changes ≤ 4% for most traits in the relative proportion of economic values, compared to that of the number of kits born alive. The traits with higher changes were efficiency traits (1-16%) and mainly feed conversion ratio (15-136%). The estimated economic values provide a basis for defining breeding objectives under the given production and market conditions. The methodological framework allows adaptation of selection goals to market fluctuations and the incorporation of new traits as they become relevant. Although the economic weights were relatively stable under these variations, it is recommended that they be re-estimated periodically.

Complete uncoated extruded kibble was coated with a premium chicken fat spiked with 0%, 5%, 10%, 15%, or 20% free fatty acids (Oleic acid, Millipore Sigma. Burlington, MA), and 3% liquid chicken-based natural flavor. Kibbles were then utilized in oral palatability (20 dogs, 10M/10F), aromatic palatability (20 dogs, 10M/10F), and apparent total tract digestibility (36 dogs, 18M/18F). Kibble odors were analyzed by flash gas chromatography electronic nose (AlphaMOS, Toulouse, France), and SPME GC/q-TOF (MUMC, Columbia, MO). In the aromatic palatability trials, there were no significant differences in first approach (P ≥ 0.21), percent interaction time (P ≥ 0.16), or interaction ratio (P ≥ 0.94). In the oral palatability trials, there were no significant differences in first approach (P ≥ 0.26), first bite (P ≥ 0.50), percent consumed (P ≥ 0.15), or intake ratio (P ≥ 0.59). There was no significant difference in protein, carbohydrate, or dry matter digestibility (P ≥ 0.06), and no significant difference in fat digestibility between coated diets by Tukey's post hoc (P ≥ 0.09). Principle component analysis of e-nose peaks showed minimal odor changes between samples (DI = -3). Volatile analysis identified 16 compounds correlated with oleic acid percentage (r ² ≥ 0.50). Kibble coated with chicken fat containing up to 20% oleic acid did not negatively impact odor profile or palatability in Labrador retrievers.

Tannins are natural compounds known to suppress methane-producing microbes and bind dietary proteins in the rumen, potentially improving nitrogen use efficiency. This study evaluated the effects of condensed tannin extract (TE) from Bauhinia hookeri hay on in vitro rumen fermentation and protein degradation of canola and soybean meals. We hypothesised that TE would suppress methane production and enhance protein protection in both meals. Each meal was treated with 0%, 2%, 4%, or 6% TE in dry matter basis and incubated for 24 h using the ANKOM gas production system. Total gas production was reduced in treated canola meal by 16.4% at 2% TE (P = 0.014), 30.1% at 4% TE (P < 0.001), and 52.7% at 6% TE (P < 0.001). Methane production was unaffected at 2% TE (P = 0.267) but declined by 37.2% at 4% TE and 40.4% at 6% TE (P < 0.001). Lag time before gas production began increased in both feeds (P < 0.05). Total volatile fatty acid (VFA) concentration of soybean meal was unchanged at 2% and 4% TE but declined at 6% TE (P = 0.006). Soluble protein (fraction 'a') decreased in both meals with TE inclusion (P < 0.001), while the slowly degradable protein fraction ('b') increased (P < 0.05). The degradation rate of fraction 'b' was reduced across all TE-treated groups (P < 0.05). These results suggest that TE from Bauhinia hookeri hay can reduce methane emissions and protect protein from excessive ruminal degradation. The 4% inclusion rate consistently showed optimal results across fermentation and protein parameters, making it a promising level for practical application.

The main objective of this study was to investigate environmental factors affecting yearling weight (YW) in pasture-raised Nellore cattle. The dataset encompassed records from 143,332 animals across 60 farms, integrating animal-level information (i.e., phenotype and pedigree relationships) with farm-level data on environmental conditions (climate, soil classifications, and elevation) and management practices at the rearing sites, hereafter referred to as descriptors. Farm-level descriptors were carefully selected based on three steps: (i) evaluation of each descriptor's contribution to explaining the variance of YW across farms, (ii) assessment of collinearity among farm management descriptors, and (iii) comparison of models using a stepwise selection procedure. The selected descriptors were subsequently included as fixed effects in the genetic evaluation of YW. The analysis began with a traditional animal model (M₁ , benchmark model). It was extended to three alternative models that incorporated environmental descriptors (M₂ ), farm management descriptors (M₃ ), or both (M₄ ). Model comparisons were based on the Akaike Information Criterion (AIC) and the proportion of the farm variance in YW explained by the fixed effects. The results indicate that climate and soil classifications, elevation, guidance from animal breeding technicians, period of the breeding season, age and weight of heifers at first breeding, no-till farming, reproductive technique (categorized as natural service, fixed-time artificial insemination-FTAI, synchronization protocols and/or herd bulls), years enrolled in the breeding program and livestock land area (categorized as small: ≤100 ha; medium: 101-999 ha; or large: ≥1000 ha) are key factors describing the macro-environmental effects contributing to variation of YW across farms. Among them, guidance from animal breeding technicians, age and weight of heifers at first breeding, and no-till farming were directly or indirectly associated (P < 0.05) with several descriptors of soil, supplemental feeding, and reproductive management. Indeed, when these environmental and farm management descriptors were simultaneously included in the genetic evaluation model (M₄ ), they explained 65.7% of the YW variance across farms, while maintaining the model's goodness-of-fit. This finding explains substantial sources of environmental variation commonly accounted for by contemporary groups (CG) in genetic evaluations. This suitable characterization of environmental factors might be essential for future genetic evaluation in the context of genotype-by-environment interaction (GxE), as well as for forecasting cattle performance under different environmental conditions.

This study evaluated the effects of maternal supplementation of a Bacillus-based direct-fed microbial (DFM) on fecal microbiome of heifer-calf pairs. At the start of the study (day 0), 72 pregnant Brangus crossbred beef heifers (20 to 22 mo of age) were stratified by body weight (BW; 431 ± 31 kg) and body condition score (BCS; 6.0 ± 0.36) and randomly allocated into 1 of 12 bahiagrass pastures (1 ha and 6 heifers/pasture). Treatments were assigned to pastures and consisted of heifers supplemented with 1 kg/hd/d of soybean hulls added (BAC) or not (CON) with DFM containing Bacillus subtilis 810 and B. licheniformis 809 (3 g/hd/d; 6.6 × 10⁹ colony forming unit; Bovacillus; Novonesis, Lyngby, Denmark) from day 0 to 242 (139 ± 4 d prepartum to 104 ± 4 d postpartum). Calves were early weaned on day 242 and then allocated to drylot pens and fed the same diet until day 319. On days 271 and 287, calves were vaccinated against pathogens associated with bovine respiratory disease. Fecal samples were collected from 3 heifers per pasture on days 0, 90 and 180 and from 2 to 3 calves per pen on days 242 and 272. Shannon and Simpson diversity indexes tended to be greater (P = 0.09) for BAC vs. CON heifers. Clostridium and Blautia relative abundances on day 90 and average Mogibacterium relative abundance were lower (P ≤ 0.03) for BAC vs. CON heifers, whereas Bacteroides and Porphyromonas relative abundances tended (P ≤ 0.08) to be greater for BAC vs. CON heifers. Shannon diversity index did not differ (P ≥ 0.14) between CON and BAC calves, whereas Simpson diversity index remained constant (P = 0.98) for CON calves from day 242 to 272 but increased (P = 0.02) for BAC calves from day 242 to 272. Effects of maternal treatment × day tended (P = 0.06) to be detected for Paraprevotella genus, which Paraprevotella relative abundance on day 242 was lower (P = 0.05) for BAC vs. CON calves on day 242, and did not differ (P = 0.89) between treatments on day 272. Relative abundance of Bacteroides was greater (P = 0.01), whereas Slackia was lower (P < 0.01) for BAC vs. CON calves. Blautia, Butyrivibrio, and Methanobrevibacter relative abundance tended (P = 0.08) to be lower for BAC vs. CON calves. In conclusion, exclusive maternal supplementation with a Bacillus-based DFM during gestation and early lactation modulated the fecal microbiota of both heifers and their offspring.

Three experiments were conducted to evaluate the effects of incorporating Saccharomyces cerevisiae fermented Moutai distiller's grains (FMDG) into diets for growing-finishing pigs across three body weight (BW) phases: 30 to 50 kg (Exp. 1), 50 to 75 kg (Exp. 2), and 90 to 130 kg (Exp. 3). The experimental diets were corn-soybean meal based with 0%, 5% or 10% FMDG. Metabolomic analysis revealed that fermentation enriched FMDG with beneficial compounds, including carbohydrates, quercetin, and tripeptides, compared to unfermented Moutai dried distiller's grains. Results form the animal experiments showed that dietary inclusion of FMDG at levels up to 10% did not adversely affect growth performance in any phase. Notably, 5% FMDG inclusion during the later finishing phase (90 to 130 kg) significantly increased (P < 0.05) average daily feed intake (ADFI) and numerically improved average daily gain (ADG) and feed conversion ratio (FCR), reducing meat production cost by 0.54 RMB/kg. Apparent total tract digestibility (ATTD) of nutrients varied by phase, with enhanced crude protein and calcium utilization at 30 to 50 kg but reduced (P < 0.05) calcium digestibility at 90 to 130 kg. In later finishing pigs, inclusion of 5% and 10% FMDG significantly decreased (P < 0.05) serum endotoxin, diamine oxidase, and interleukin-6 levels. We further confirmed that dietary inclusion of FMDG increased (P < 0.05) the expression of tight junction proteins including claudin-4, occludin, and zonula occludens protein-1 (ZO-1) in the jejunum. Carcass traits and meat quality were maintained or improved, with increased (P < 0.05) loin eye area and meat redness (a*) in the 5% FMDG group. Overall, these findings demonstrate that FMDG can be effectively included at up to 10% in swine diets without compromising animal health and performance, with 5% FMDG providing particularly beneficial for later finishing pigs due to its positive impacts in improving feed efficiency, carcass traits and meat quality, as well as enhancing intestinal integrity.