Translational Animal Science最新文献

The objective of this study was to evaluate net returns for Central U.S. high plains feedyard cattle identified with acute interstitial pneumonia (AIP) ante-mortem and postmortem (n = 5,339) and to examine economic outcomes across sex, placement weight, and number of AIP treatments. A decision tree framework was implemented to estimate net returns of cattle identified with AIP, where decision nodes represented choices made by the producer, and branches represented potential outcomes following a decision. The initial decision node was whether to treat cattle for AIP after the first identification for illness or to sell (cull) soon after diagnosis at reduced weight and price compared to cattle in the cohort sold at finished weight. Following initial treatment, cattle that remained in the feedyard either finished (with or without further treatment), were culled, or died after additional diagnosis and treatment. Probabilities of incidents at each node were obtained from the data distribution. This research indicates that estimated net returns for feedyard cattle identified with AIP vary by sex, placement weight, and number of AIP treatments. The expected net return to feeding healthy cattle was $193.67/animal, while the expected net return for cattle that finished after AIP treatment was -$639.71/animal for cattle treated once for AIP, -$612.41/animal for those treated twice for AIP, and -$529.57/animal for those treated three or more times for AIP. However, other health indicators and risk factors not included in this analysis should be considered when deciding whether to keep or cull feedyard cattle identified with AIP.

Trypsin inhibitor proteins are antinutritional compounds innate to soybeans that reduce protein digestibility, amino acid bioavailability, and growth performance of pigs. The objective of this study was to evaluate the impact of increasing levels of dietary trypsin inhibitor unit activity (TIU/mg) on nursery pig growth performance and health. In a 41-d study, 1,140 newly weaned nursery pigs (5.9 ± 0.34 kg BW) were allotted into split sex pens, blocked by body weight, assigned randomly to one of five dietary treatments (n = 19 pens/treatment) varying in TIU/mg concentration, and fed over three dietary phases. Treatments targeted 0.41, 1.32, 2.20, 3.08, and 3.96 TIU/mg of complete feed averaged over the three phases and were achieved by using a corn-soybean meal basal diet with added soybean flour. Analyzed dietary treatments averaged 0.61, 1.22, 2.19, 3.41, and 3.51 TIU/mg. Pen BW and feed disappearance were recorded at the start and end of each phase to calculate ADG, ADFI, and G:F. Fecal consistency was scored and recorded daily. On d 21 of the study, 10 pigs per treatment were sacrificed for intestinal sample collection. Data were analyzed with pen as the experimental unit, the random effect of block, and the fixed effect of TIU, including polynomial contrasts for linear and quadratic effects of 0.61 to 3.51 TIU/mg treatments. No quadratic responses to dietary TIU/mg activity were reported in any parameters. Overall, as active dietary TIU/mg increased, ADG, ADFI, and G:F linearly decreased (P < 0.001). Pigs fed the highest level (3.51 TIU/mg) exhibited reduced ADG by 25%, ADFI by 17%, and G:F by 8% compared to pigs fed the lowest level (0.61 TIU/mg). Dietary TIU/mg did not affect fecal consistency, mortality, or removals (P > 0.10). Individual and total concentrations of colonic biogenic amines and short chain fatty acids did not differ (P > 0.10). Histological lesions of the ileum and colon did not differ (P > 0.10). Ileum VH tended to decrease (P = 0.078) and CD linearly decreased as TIU/mg increased (P = 0.004), but VH:CD and colonic CD were similar (P > 0.10). Moderate relationships between TIU intake and G:F (R² = 0.393), caloric efficiency (R² = 0.378), and lysine efficiency (R² = 0.376) were observed. In conclusion, soybean-derived active TIU concentrations negatively impact nursery pig performance above 1.22 TIU/mg, with minimal impacts on intestinal and pig health.

With increasing emphasis on sustainability, beef producers are evaluating potential environmental impacts of production practices. However, gaps remain in understanding how cattle health and performance metrics align with environmental impacts and global protein needs. This study quantified how feedlot performance and health metrics for beef-breed steers and heifers are associated with total greenhouse gas (GHG) emissions and emissions per unit of production. Using data on 9,436 single-lot pens in nine U.S. commercial feedlots (2017 to 2021), we fit mixed-effects multivariable models, based on directed acyclic graphs, to evaluate four key explanatory variables: average daily gain (ADG), feed efficiency (G:F), medicine costs per pen (proxy for disease burden), and cumulative mortality. Sex, season of arrival, days on feed, and arrival body weight were assessed as potential confounders. The primary outcome was estimated carbon dioxide equivalent emissions per kg of final body weight (emissions intensity), derived from Uplook 1.0 (Elanco Animal Health). Across all study pens, 19.2% of estimated lifetime emissions occurred during the feedlot phase, while 41.8% of total body weight gain occurred at the feedlot; demonstrating how feedlots reduce emissions intensity and enhance production efficiency. Higher ADG and G:F were associated with lower emissions intensity, while higher mortality and disease burden were linked to increased emissions intensity. Significant interactions were observed in all models, with effects of ADG and G:F modified by sex and season (P values < 0.01). Improved growth and feed efficiency were consistently associated with lower emissions, but the magnitude of effects differed between steers and heifers and varied by season. Disease burden and mortality impacts also varied by season and arrival weight, with significant three-way interactions (P values < 0.01). Pens with poorer health consistently had higher emissions intensity, with the largest effects in lighter-weight pens during certain seasons. This study quantifies how improving health, G:F, and ADG can reduce emissions intensity. For example, reducing mortality from 5% to 0% lowers lifetime emissions by nearly 6%. Findings highlight the importance of health and performance in sustainability and help quantify potential impacts of strategies for improving health and performance to reduce GHG emissions intensity and improve production efficiency.

Land-Grant Institutions and Cooperative Extension Services seek to disseminate information to the public; however, Extension agents differ in areas of expertise, leaving some counties with minimal ability to provide 4-H horse project members with sufficient content knowledge while agents in other counties are more well versed in equine-specific areas. Results from the 2021 and 2023 Tennessee regional and 2022 Eastern National 4-H Hippology contests were used to determine areas of knowledge deficiency. Nutrition, tack, selection, health, and breeds were categories identified as areas in which 4^th-12^th grade youth lacked adequate knowledge and a training program and new curriculum was developed and delivered to county extension agents in effort to greater their equine knowledge and teaching strategies to disseminate this information to their 4-H Horse Project members and hippology teams. Statistical analysis was conducted using SAS v9.4 (Cary, NC). Nutrition questions were most often missed by senior and junior high youth (k = 7.8, 51.94%; k = 7.5, 44.22%) whereas junior youth missed training questions most frequently (k = 4.9, 54.14%). Of the 5 topic areas of deficiency, selection questions were the lowest percentage missed by senior and junior high youth (k = 5.9, 36.81%; k = 7.1, 39.53%) whereas junior youth missed health questions least frequently (k = 4, 39.87%). It was found that training status had no significant effect on scores from year to year. However, significant effects were found when comparing across question category (P < 0.0001), age group (P < 0.0001), and year (P < 0.0001). Despite the lack of training effect, these findings still prove valuable when assessing performance upholding the extension mission of delivering science-based information to the next generation of industry professionals.

Identifying alternative practices to control gastrointestinal parasites and overcome resistance to chemical anthelmintics is critical to maintain the productive and economic viability of the small ruminant sector. Here, we evaluated in vivo potential effects of orange oil and sericea lespedeza (Lespedeza cuneata [Dumont] G. Don) supplementation on suppressing gastrointestinal nematodes (GIN) and improving performance of goats. Twenty-four bucks were used in a randomized complete block design and were assigned to12 pens after deworming. Experimental duration was 6 wk (1 wk adaptation and 5 wk of data collection) and treatments were arranged in a factorial combination of two levels of orange oil, at 0 or 600 mg/kg BW, and lespedeza hay, at 0% or 9% of the diet DM, in three replicates. Response variables included dry matter intake (DMI), growth performance, nutrient digestibility, fecal egg counts (FEC), and blood parameters. The inclusion of orange oil and/or lespedeza decreased DM (-12.6%) and neutral detergent fiber digestibility (-14.3%) but did not decrease DMI (1.06 kg DM/goat/day) or growth performance (78.3 g/animal/day). Orange oil administration decreased 46% of Trichostrongyle FEC, but no effects were observed on strongyloide and coccidia FECs. Orange oil also increased neutrophil concentration, potentially indicating an inflammatory response. Although orange oil showed promise as a natural alternative to synthetic dewormers for controlling GIN in goats, its efficacy is variable and may be influenced by dosage, formulation, and treatment duration. However, lespedeza hay, despite its known antiparasitic effects, was ineffective in reducing FEC when included at levels in this experiment.

For years, high zinc levels (up to 3000 mg/kg feed) have been used to aid piglets during the weaning phase. However, studies revealed drawbacks like antimicrobial resistance and environmental impact. Since 2022, the EU limits zinc inclusion levels to 150 mg total zinc per kg. Therefore, alternative strategies for replacing high levels of zinc are of great interest. This study compares a potentiated zinc oxide source (HiZox^®) and feed grade zinc oxide at various levels on piglet performance, fecal consistency and fecal microbiome. The trial involved a total of 1,440 healthy weaned piglets (DanBred × Duroc; 50% barrows, 50% gilts; initial BW 10.1 ± 1.46 kg) over the 28-day duration of the experimental period. Piglets were randomly assigned to 12 treatment groups, each consisting of 12 pens, with 10 piglets per pen. The trial comprised two periods: the starter period (days 1 to 14) focused on comparing the two zinc products, while all animals received a diet supplemented with 150 mg/kg of potentiated ZnO in the grower period (days 15 to 28). Treatment groups receiving feed grade ZnO were denoted as Z150, Z300, Z600, Z900, Z1500, and Z3000, while corresponding groups with the potentiated ZnO product were labeled H150, H300, H600, H900, H1500, and H3000, respectively. Body weight (BW) and feed intake (FI) were measured for every pen at days 1, 14 and 28. Fecal samples were collected on the same days. During the starter phase (days 1 to 14), potentiated ZnO significantly improved average daily gain (ADG) compared to feed-grade ZnO (P ≤ 0.001), with the highest values observed at 3000 mg/kg (H3000: 247 g/d vs. Z3000: 233 g/d). Feed intake (FI) was also higher in potentiated ZnO groups (P ≤ 0.001), and feed conversion ratio (FCR) was more efficient (e.g., H3000: 1.2 vs. Z3000: 1.24; P = 0.001). In the grower phase residual effects from the starter phase persisted: animals previously fed potentiated ZnO had improved FCR (P = 0.003). Fecal microbiota analysis revealed that higher zinc levels reduced Lactobacillus abundance (P ≤ 0.001) and increased the presence of genera typical of adult pigs, such as Clostridium sensu stricto 1 and Terrisporobacter (P < 0.01). In conclusion, based on the observed shift in fecal microbiota composition characterized by a reduction in lactobacilli and an increase in proteobacteria due to heightened dietary zinc levels, it is advised to adjust zinc supplementation to 150 mg/kg after the initial 2 wk post-weaning.

In two experimental approaches, this study aimed to evaluate the effects of increasing levels of soybean hulls (SBH) (Exp. 1) and the withdrawal of high SBH from diets prior to marketing (Exp. 2) on growth performance, carcass characteristics, and apparent total tract digestibility (ATTD) of nutrients in grow-finish pigs. In Exp. 1 (n = 12 pens/treatment), 192 pigs (initial BW 21.99 ± 2.75 kg) were fed a corn-soybean meal-based diet containing 0% (0SBH), 7.5% (7.5SBH), 15% (15SBH), or 22.5% (22.5SBH) SBH. In Exp. 2 (n = 15 pens/treatment), 240 pigs (initial BW 26.5 ± 3.03 kg) were fed either 0SBH or 22.5SBH continuously until marketing (-0d) or switched from 22.5SBH to 0SBH either 27 (-27d) or 13 (-13d) days before marketing. Pig body weight (BW) and feed disappearance were measured to calculate average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (G:F). A balance study was conducted on 32 gilts (n = 8 pigs/treatment) of Exp. 1 beginning on d 56 to determine ATTD of nutrients. Hot carcass weight (HCW), back fat depth (FD), loin depth (LD), and carcass yield were recorded at the processing plant. Data were analyzed using ANOVA, with linear and quadratic contrasts applied for Exp. 1. Pen served as the experimental unit for live performance and carcass characteristics and pig as the experimental unit for ATTD analyses in Exp. 1. In Exp. 1, increasing SBH levels linearly decreased G:F (P < 0.05) and tended to reduce ADG (P = 0.059), without affecting ADFI (P > 0.10), resulting in a 4 kg reduction of final BW (P = 0.067). Inclusion of SBH up to 22.5% decreased HCW, yield, FD, and LD (P < 0.05). In Exp. 2, although 22.5SBH had no effect on ADG and ADFI (P > 0.10), pigs fed 22.5SBH (-27d, -13d, or -0d) had a 6.5% reduction in G:F compared to 0SBH (P < 0.05). Pigs in the -13d and -0d treatment groups had reduced HCW compared to 0SBH (P < 0.05), while yield was reduced by 2% and 5% in the -27d and -0d groups, respectively (P < 0.05). Pigs fed 22.5SBH (-0d) had a 30.7% reduction in FD and a 6.4% reduction in LD compared to 0SBH (P < 0.05). These data suggest that increasing SBH levels in the diet of grow-finish pigs negatively affects feed efficiency, carcass weight and yield, fat and loin depth. However, carcass yield, HCW, FD, and LD loss may recover if pigs are transitioned back to a diet without soybean hulls, depending on the timing of withdrawal before marketing.

In Thailand, small- to medium-scale (SM) dairy farms typically have fewer than 100 cows. They are often family-owned or independently operated, and vary in infrastructure and mechanization depending on their size. In contrast, large-scale (L) farms, with more than 100 cows, are more industrialized, utilizing advanced technology, higher production systems, and usually employ multiple workers. To date, few studies have reported the prevalence of methicillin-resistant staphylococci (MRS) and methicillin-susceptible staphylococci (MSS) and their antimicrobial resistance (AMR) at different farm scales. This study aimed to investigate the prevalence of Staphylococcus spp., MRS, MSS and their AMR as well as their genetic backgrounds on SM and L dairy farms in Thailand. A total of 157 mastitis milk samples were collected from 106 cows on 42 SM farms, and 65 samples from 37 cows on one L farm, all located in Kanchanaburi Province. Antimicrobial susceptibility testing was conducted by determining the minimum inhibitory concentration. Whole-genome sequencing and analysis were performed for genetic characterization. There was a significant difference in the prevalence of Staphylococcus spp. on L farm (26.2%) and SM farms (14%) (P = 0.031, χ² test). The phenotypic resistance of trimethoprim/sulfamethoxazole in L farm (58.8%) was significantly greater than that in SM farms (27.3%) (P = 0.049, χ² test). Six methicillin-resistant staphylococci (27.3%), including Staph. haemolyticus sequence type (ST) 3 (N = 1) and ST42 (N = 3) and Staph. epidermidis ST59 (N = 2) were discovered on SM farms, whereas a single Staph. aureus ST398 (5.9%, N = 1) was found on an L farm. These strains were multidrug-resistant and carried multiple, diverse antimicrobial resistance genes, including β-lactam resistance genes (mecA, blaZ), tetracycline resistance genes [tet(K), tet(M)], and macrolide resistance genes [msr(A), mph(C)]. Compared with MRS, MSS carried fewer diverse antimicrobial resistance genes and had distinct STs at both farm scales. At each farm scale, a particular type of resistance may originate from a certain species or specific ST. In conclusion, the prevalence of Staphylococcus spp. and their resistance traits and genetic background on SM and L farms differ according to different production farm scales. The specific management and monitoring of the information on Staphylococcus spp. circulated on each farm type could help to limit the spread of antimicrobial-resistant staphylococci.

The objective of this study was to evaluate the effect of coating on the recovery rate (RR) of phytase activity during the steam conditioning-pelleting (SCP) process. A split-plot design was employed, with phytases assigned to the main plot and two conditioning temperatures (75 or 85 °C) assigned to the subplot. The whole plot was repeated four times. In Exp. 1, six phytases were analyzed, including an uncoated phytase (NP) NP1 (NP1), two coated phytases (CP) CP1 and CP2 derived from NP1, and three commercial phytases (MP) MP1-MP3. In Exp. 2, coating technology was refined based on the results of Exp. 1, and nine phytases were analyzed, including an NP2, five coated phytases CP3-CP7 derived from NP2, and three commercial phytases MP4-MP6. Phytase activity after the steam-conditioning, pelleting, and cooling process was analyzed, and the RR of phytase activity was calculated for each process. In Exp. 1, significant interactions between phytase and conditioning temperature on the RR of phytase activity were observed (P < 0.05). The RR of CP1 and CP2 did not differ from that of NP1. Commercial phytase MP3 exhibited a lower RR than the other four phytases when conditioned at 75 °C (P < 0.05). Except for MP3, the RR of phytases decreased as the conditioning temperature increased (P < 0.05). In Exp. 2, the RR of phytase decreased as the conditioning temperature increased from 75 to 85 °C (P < 0.05). Compared with NP2, the RR increased, and the loss rate of activity for all five coated phytase (CP3-CP7) decreased after the conditioning process (P < 0.05). Commercial phytase MP4 and MP6 had comparable RR to NP2, while MP5 exhibited a comparable RR to CP3-CP7. In conclusion, the coating technology used in Exp. 1 did not increase the RR of phytase during the pelleting process, whereas the improved coating process employed in Exp. 2 effectively increased the thermostability of phytase.

The use of beef genetics in dairy herds is becoming increasingly popular due to higher value for dairy × beef crossbred compared to purebred dairy calves. While previous research has documented higher-quality neonatal care for female compared to male dairy calves, few studies have investigated colostrum management between purebred dairy and dairy × beef crossbred calves. The aims of this cross-sectional study were to 1) compare transfer of passive immunity (TPI) between purebred dairy and dairy × beef crossbred calves and 2) investigate colostrum management practices associated with TPI on farms rearing both calf breeds. A blood sample was collected from the jugular vein of 12 purebred dairy and 12 dairy × beef crossbred calves (1 to 7 d of age) across 15 dairy farms to measure serum total protein (STP) concentration using serum refractometry. Sex, age, and breed were recorded for each calf. A 29-question survey was also administered to dairy farm managers that included questions on colostrum management, calf sale, and farm demographics. Descriptive statistics were computed for survey-based questions, and mixed effects ordinal regression models were created to evaluate factors at the calf and farm-level that were associated with TPI, categorized according to Lombard et al. (2020). Consensus recommendations on calf- and herd-level passive immunity in dairy calves in the United States. J. Dairy Sci. 103:7611-7624. doi:https://doi.org/10.3168/jds.2019-17955) as excellent TPI (STP ≥ 6.2 g/dL), good TPI (STP 5.8 to 6.1 g/dL), fair TPI (STP 5.1 to 5.7 g/dL), and poor TPI (STP < 5.1 g/dL). All farms reported similar colostrum management practices between purebred dairy and dairy × beef crossbred calves. Most farms (60%, 9/15) fed 2 colostrum feedings, 33% (5/15) of farms fed 1 colostrum feeding, and 7% (1/15) fed 3 or more colostrum feedings. Serum total protein concentration ranged from 3.2 to 8.0 g/dL, and the distribution of calves within each TPI category was: 20.8% (74/355) excellent, 25.4% (90/355) good, 26.5% (94/355) fair, and 27.3% (97/355) poor. There was no evidence to suggest differences in TPI between breeds. The reported timing of the first colostrum feeding influenced TPI; calves born on farms that reported feeding colostrum within 1 h after birth had reduced odds of being within a lower TPI category (OR: 0.48, 95% CI: 0.30 to 0.77; P = 0.002). The results of this study indicate that colostrum management practices and TPI did not differ between purebred dairy and dairy × beef crossbred calves. Future research should continue to explore strategies to improve TPI for dairy calves regardless of breed.