Translational Animal Science最新文献

This study evaluated how the backgrounding diet can affect water intake, animal performance and water and feed efficiency of steers fed finishing diets based on grains or forages. Twenty-four crossbred Angus steers (298 ± 10.2 kg) were fed during backgrounding either a moderate (MP, n = 12; triticale hay only, 9.1%crude protein [CP], 1.07 Mcal/kg net energy available for maintenance [NEm], and 0.52 Mcal/kg net energy available for gain [NEg]) or high plane of nutrition (HP, n = 12; 85% alfalfa hay and 15% beardless wheat hay, 12.62%CP, 1.23 Mcal/kg NEm, and 0.66 Mcal/kg NEg) during the background phase (85 d). After this period, steers were assigned to two finishing phase groups containing half of the animals from each backgrounding diets. During the finishing phase, animals were fed either a forage-based (Alfalfa hay; CP: 20.8% DM, NEm: 1.47 Mcal/kg, NEg: 0.88 Mcal/kg) or a grain-based diet (80% whole corn and 20% wheat hay; CP: 10.6% DM, NEm: 1.96 Mcal/kg, NEg: 1.31 Mcal/kg). There was no interaction between the effects of the previous plane of nutrition [(moderate (MP) or high (HP)] and finishing diets (forage or grain-fed) on any of the variables studied (P > 0.05). Animals backgrounded on MP were lighter and had a lower DMI when compared with HP (P < 0.01). However, no differences were observed on the drinking water intake (DWI) between MP and HP (P > 0.05). HP animals were more efficient in gross water efficiency (P < 0.01), but less efficient on residual feed intake (P < 0.05), compared to MP animals. During the finishing phase, forage fed animals had a greater DMI and DWI compared with grain-fed animals (P < 0.01), however, no differences were observed on the final BW (P > 0.05). Grain-fed animals were more efficient for water and feed intake and had a greater marbling score (P < 0.01) compared to forage-fed. Animals fed on HP and finished in a grain-fed diet had the least DWI (P < 0.05) and greatest body condition score (P < 0.05), marbling score (P < 0.01) and rib depth (P < 0.05). In the first 20 d of the finishing period, the previous plane affected the variables ADG, DMI, CPi, and DWI (as kg DMI and CP) in the finishing plane. Altogether, our results highlight the individual effects of backgrounding and finishing systems on DWI and the efficiency of finishing animals, as well as the importance of providing adequate nutrition during the earlier stages of life.

This study aimed to characterize the physicochemical properties and microbiota composition of a direct-fed microbial (DFM) and evaluate its protective effect on intestinal permeability in Sprague-Dawley rats using fluorescein isothiocyanate dextran (FITC-d) as a biomarker. The DFM was further characterized using Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), environmental scanning electron microscopy (ESEM), energy-dispersive X-ray spectroscopy (EDS), and cell surface hydrophobicity (microbial adhesion to hexadecane [MATH] assay). The 16S rRNA gene was sequenced using short-read sequencing. In general, the DFM exhibited the characteristic FTIR bands associated with probiotic cells with a protein/carbohydrate ratio of 1.3:1. It was also found from the DLS analysis that the average particle size and surface electrical potential of the probiotic cells were 1,062 ± 77 nm and -32.6 ± 3.7 mV, respectively. ESEM studies confirmed the size of the cells (1,010 to 1,060 nm), showing a quasi-spherical cocci-type morphology, whereas EDS spectroscopy revealed a higher Nitrogen/Carbone ratio on the cell surface. Moreover, the MATH assay showed the hydrophobic character of the DFM (92% adhesion). Furthermore, based on the 16S rRNA gene analysis, the predominant genus in the DFM was Streptococcus (99%). Regarding the protective effect on the gut barrier, animals supplemented with 10¹¹ CFU/mL exhibited a significantly reduced intestinal permeability compared with the control group. DFM supplementation also increased villi and crypt dimensions and Goblet cells (P < 0.05) in the ileum and cecum. These results demonstrate that the DFM presented adequate surface and colloidal properties that help maintain the functionality of the gut barrier.

A study was conducted to assess growth performance, methane (CH₄) emissions, and feeding behavior of feedlot steers consuming backgrounding and finishing diets with an essential oil blend (EO), monensin (Mon), and their combination (EO + Mon). The study was structured as a 2 × 2 factorial, with two feed additive treatments (Control, EO) and two monensin treatments (no Monensin, Monensin). One hundred Angus × steers were evenly distributed across each treatment into four pens, and each dietary phase consisted of four, 28-d periods. Using the GreenFeed system to estimate CH₄ yield (g CH₄/kg dry matter intake [DMI]), the mean CV (coefficient of variation) within the same steer across measurement periods was 14.0% and 15.2% for the backgrounding and finishing phases, respectively. The mean CV of CH₄ production for steer within period and time-of-day block was up to 83.4% and 102.9% for the backgrounding and finishing phases, respectively. There was no difference in overall average daily gain (P ≥ 0.22) or gain:feed ratio (P ≥ 0.26) with EO or Monensin during the backgrounding or finishing phases. There were variable period effects on CH₄ emissions, but overall control had lower (EO × Mon; P ≤ 0.01) CH₄ production, yield, and CH₄ energy as a percentage of gross energy intake (GEI) (Ym, Mcal CH₄ % GEI), during the backgrounding phase. During the finishing phase, CH₄ yield (EO × Mon; P = 0.02) and Ym (EO × Mon; P ≤ 0.01) were greatest in the EO + Mon treatment. Monensin, irrespective of EO, decreased DMI (P < 0.01) and eating rate (P = 0.01), and increased intermeal interval (P < 0.01) for the backgrounding phase. In the finishing phase, Monensin decreased (P < 0.01) DMI, variation of DMI (EO × Mon), meal size, and eating rate. Number of GreenFeed visits was negatively (P < 0.01) correlated with all feeding behavior metrics in the finishing phase. In conclusion, supplementation of EO or Monensin and their combination into backgrounding and finishing diets of feedlot steers had no effect on overall feedlot performance or CH₄ emissions. Additionally, the high variability in CV of CH₄ production and yield suggests a need to improve the accuracy and precision of the GreenFeed system for estimating enteric CH₄ emissions from cattle.

Heat stress (HS) is widely recognized by researchers and veterinarians as a major issue impacting swine health, productivity, and welfare, but there is limited understanding of how HS is perceived and managed at the farm level. Therefore, the study objective was to assess U.S. swine farm managers' perceptions of HS impacts, thresholds, and management for multiple pig categories including preweaned pigs, nursery pigs, grow-finish pigs, market pigs, nonpregnant and gestating sows, lactating sows, and mature boars. Sixty-two swine farm managers completed an electronic Qualtrics survey, presented in both English and Spanish, which included questions on perceived HS thresholds, ventilation setpoints, mitigation practices, and environmental management support tools. Respondents rated their agreement with HS impacts on productivity, health, and welfare using a Likert scale, and Pearson's correlations were used to establish relationships between responses. A majority of respondents agreed or strongly agreed that HS negatively affects pig productivity (87.1%), health (83.9%), and welfare (85.5%). However, perceived HS thresholds were variable across pig categories including preweaning pigs (31.22 ± 3.59 °C), nursery pigs (31.46 ± 3.79 °C), grow-finish pigs (28.16 ± 4.27 °C), market pigs (26.22 ± 5.56 °C), nonpregnant sows (27.77 ± 3.81 °C), gestating sows (26.99 ± 3.34 °C), lactating sows (26.71 ± 3.08 °C) and mature boars (26.61 ± 3.99 °C). The standard deviations for reported thresholds ranged from ±3.08 to ±5.56 °C, underscoring the variability in perceptions among respondents. This variability extended to ventilation temperature setpoints with high ventilation temperature setpoints of 24.34 ± 3.75 °C and 25.41 ± 2.80 °C, and low ventilation temperature setpoints of 17.32 ± 3.10 °C and 18.86 ± 2.96 °C for gestation barns and farrowing barns, respectively. Finally, a majority of producers (64.5%) agreed or strongly agreed that a decision support tool for improved HS management would be beneficial to their operation. Producer responses emphasize the need for clearer guidelines and more consistent application of HS management practices to optimize swine health, productivity, and welfare across different production stages.

Two experiments evaluated the effects of an injectable trace mineral (ITM) solution at weaning on trace mineral (TM) status, inflammatory and antioxidant responses, grazing behavior, response to vaccination, and growth of beef calves. Experiment 1 used 86 Nellore calves (40 females and 46 males; body weight [BW] = 198 ± 30.8 kg; 8 ± 1 mo of age) weaned (day 0) and assigned into one of two treatments: saline (0.9% NaCl) or ITM (60 mg of Zn/mL, 15 mg of Cu/mL, 5 mg of Se/mL, and 10 mg of Mn/mL). Saline and ITM were administered subcutaneously at a dose of 1 mL/45 kg of BW. On day 0, calves were vaccinated against infectious bovine rhinotracheitis (IBR), parainfluenza-3 (PI₃), bovine viral diarrhea virus types 1 and 2 (BVDV-1 and 2) and bovine respiratory syncytial virus (BRSV). Blood samples and BW were collected on days 0, 3, 8, 15, 51, and 100, and grazing behavior was evaluated on days 1, 2, 4, 5, 6, 7, and 9. The ITM did not affect (P ≥ 0.56) serum mineral concentrations of Zn and Cu, but decreased (P ≤ 0.02) plasma concentrations of cortisol on days 3 and 8 and haptoglobin on day 3. The ITM increased (P < 0.01) plasma concentration of superoxide dismutase on days 8, 15, and 51 and tended to decrease (P = 0.08) plasma concentration of glutathione peroxidase on day 3. Furthermore, there were no effects of treatment (P ≥ 0.14) on most of the behavior variables evaluated, ITM reduced (P = 0.01) the seeking time on days 0 and 4. Furthermore, ITM tended to increase (P = 0.10) the serum titer concentration against IBR on days 15 and 51 but did not affect (P ≥ 0.12) titer concentration against PI₃, BVDV-1, and 2, and growth. Experiment 2 used 50 Brangus male calves (BW = 264 ± 34.1 kg; 8 ± 1 mo of age) weaned on day 0, vaccinated against respiratory diseases, stratified by BW, and randomly assigned to saline or ITM as described in experiment 1. Liver samples were collected on days 0, 14, and 197, blood samples on days 0, 14, and BW on days 0, 14, 44, 78, 122, 162, and 197. The ITM increased (P ≤ 0.03) the liver concentration of Cu and Se on day 14 but did not affect (P ≥ 0.17) the liver concentration of Zn and Mn. In addition, ITM increased (P = 0.05) the serum titer concentration against BVDV-2 but did not affect (P ≥ 0.20) the titer concentrations against IBR, PI₃, BVDV-1, and BRSV, and did not affect (P ≥ 0.29) the growth. In conclusion, ITM application at weaning improved Cu and Se status, enhanced antioxidant and immune responses, and reduced stress and inflammation in calves, though it did not affect growth.

Hempseed meal (HSM) is a potential alternative feedstuff for livestock due to its high protein content, but it has not been approved for animal feed in the United States due to safety concerns. This study was conducted to determine the effects of HSM on feed intake, growth performance, serum biochemistry, ruminal papillae morphology, ruminal fermentation profiles, and carcass characteristics of intact male goats. Thirty-six Boer × Spanish intact male goats were randomly assigned to one of four experimental diets (n = 9 goats/diet): 0%, 10%, 20%, and 30% HSM on as-fed basis. Diets were formulated to be isonitrogenous and fed free-choice for ad libitum consumption in the 60-day experiment. Linear and quadratic effects of different concentrations of HSM were determined. Total feed intake, crude protein intake, ruminal papillae morphology (papillae density, length, width, absorptive surface area, stratum corneum, and stratum granulosum thickness), carcass traits (longissimus muscle area, body wall thickness, backfat thickness, shrink percentage), and serum concentrations of most metabolites were similar among treatments (P > 0.05). Intake of acid detergent fiber (ADF) and nitrogen detergent fiber (NDF) increased linearly (P < 0.05) with increasing inclusion of HSM in the diet. Average daily gain (ADG), gain-to-feed ratio, and dressing percentage decreased linearly (P < 0.05) with an increasing percentage of HSM in the diet. Similarly, concentrations of propionic, butyric, iso-butyric, valeric, and isovaleric acids in ruminal fluid decreased linearly (P < 0.05) with an increasing percentage of HSM in diet, whereas concentration of acetic acid and total volatile fatty acids in ruminal fluid tended to decrease linearly (P-value nearly 0.10) with an increasing percentage of HSM in diet. The level of blood urea nitrogen increased linearly (P < 0.05) with increasing concentration of HSM, but values were within the normal range for goats. Findings from the serum metabolite analysis and ruminal papillae morphometrics suggest that goats can be fed HSM at a concentration of up to 30% in their diet. However, growth performance results indicate that further cost-benefit analysis is required to compare HSM with other commonly used protein sources such as soybean meal. These findings will be useful for legal bodies to review during the approval process of HSM as a feed ingredient for goats in the United States.

Two experiments were conducted to determine the effects of low acid-binding capacity (ABC) specialty soy protein sources on weanling pig performance. In experiment 1, 2,260 pigs, initially weighed 6.7 kg, were used to determine the effects of low ABC soy proteins as a replacement to poultry meal (PM) or spray-dried blood plasma (SDBP). Treatments were arranged in a 2 × 2 factorial plus a control diet fed in two phases. There were 20 or 21 pigs per pen with 22 replications (pens) per treatment. The control diet contained PM (AV-E Digest, XFE Products, Des Moines, IA) and SDBP (Appetein, APC Inc., Ankeny, IA). Specialty soy protein concentrate (SSPC; AX3 Digest, Protekta, Newport Beach, CA) and microbial-enhanced soybean meal (MESBM; MEPRO; Prairie Aquatech, Brookings, SD) were used to replace PM or PM and SDBP on a standardized ileal digestible Lys basis. From d 0 to 21 and d 0 to 42, pigs fed either soy protein source replacing PM had greater (P ≤ 0.016) average daily gain (ADG) and average daily feed intake than pigs fed PM. From d 0 to 21, pigs fed SSPC had increased (P < 0.001) G:F compared with pigs fed MESBM and those fed either soy protein source replacing SDBP had increased (P = 0.044) G:F compared with pigs fed SDBP. In experiment 2, 1,057 pigs, initially weighed 6.2 kg, were used to determine the effects of diet ABC at a pH of 4 (ABC-4) with specialty soy proteins with or without pharmacological levels of Zn from ZnO. Experimental diets were fed in two phases with 22 pigs per pen and 12 replications per treatment. Dietary treatments were arranged in a 2 × 2 factorial with main effects of ABC-4 (low or high) and pharmacological levels of Zn from ZnO (105 or 2,000 mg/kg). The low ABC-4 diet without ZnO was formulated to 150 and 200 meq/kg using SSPC in phases 1 and 2, respectively. The high ABC-4 diet used enzymatically treated soybean meal (HP 300, Hamlet Protein, Findlay, OH) which increased the ABC-4 by 127 and 104 meq/kg in phases 1 and 2, respectively. From d 0 to 21 and d 0 to 42, there was an ABC-4 × ZnO interaction (P ≤ 0.026) observed where pigs fed low ABC-4 diets had greater (P < 0.05) ADG and G:F than pigs fed high ABC-4 diets without ZnO, but when diets contained added ZnO, there were no differences based on ABC-4. In conclusion, low ABC specialty soy proteins can be used to achieve low dietary ABC-4 levels to improve the performance of weanling pigs and provide a similar response to those fed pharmacological levels of Zn.

The National Beef Quality Audit (NBQA)-2022 serves as a benchmark of the current market cow and bull sectors of the U.S. beef industry and allows comparison to previous audits as a method of monitoring industry progress. From September 2021 through May 2022, post-slaughter hide-on animals (n = 6,674), carcasses (n = 5,746), and offal items (heads and tongues: n = 7,282; lungs and hearts: n = 6,708; viscera, kidneys, and livers: n = 6,358) were surveyed at 20 commercial beef processing facilities across the United States. There were 37.8% of cattle with no visible mud contamination. Native (unbranded) hides were observed in 88.3% of cattle. Carcass bruising was observed on 66.7% of cow carcasses and 46.4% of bull carcasses, similar to percentages observed in the 2007 and 2016 audits. Nearly all cattle were free of knots (98.2%) or injection-site lesions (97.1%). Harvest-floor assessments found that 45.0% of livers, 22.2% of viscera, 19.3% of kidneys, 46.6% of lungs, 19.9% of hearts, 11.2% of heads, and 6.4% of tongues were condemned. The leading cause of condemnation for these offal items was contamination, aside from livers with the majority resulting in condemnation from the presence of an abscess. Of the cows surveyed, 25.4% carried a fetus, an 8% increase compared to those observed in 2016, and a 14.8% increase compared to cows surveyed in 2007. Findings from the NBQA-2022 identified areas of improvement and areas that required continued research and producer education to improve market cow and bull welfare, by-product quality, and offal value.

The Targhee breed is important to range sheep production in the Western United States. The objective of this research was to integrate industry sires participating in national genetic evaluation through the National Sheep Improvement Program (NSIP) into the U.S. Sheep Experiment Station (USSES) flock, where the breed originated, to benchmark sire performance. Estimated breeding values (EBV) of industry sires (n = 16) and USSES sires (n = 12) from the 2023 NSIP Targhee genetic evaluation differed (P < 0.05) only for the NSIP Number Born EBV. This difference, and small (nonsignificant) differences favoring industry sires for maternal weaning weight, yearling fiber diameter, and yearling staple length EBV also resulted in greater (P < 0.05) Western Range Index scores for industry sires. The performance of sires' direct progeny born 2016 to 2018 was compared for 17 traits. After data cleaning, there were 664 progeny (417 from industry sires and 247 from USSES sires) with 146 to 664 records per trait. Least squares means differed (P < 0.05) for grease fleece weight, side fiber diameter, and britch fiber diameter in favor of the industry sires. Production traits were measured from the progeny and other retained descendants of both sire genetic groups from 2016 through 2022. After data cleaning, there was a range of 1,138 to 1,493 records per trait. A three-generation pedigree was constructed and the proportional assignment of each lamb to each genetic group (e.g., 0.5 industry, 0.5 USSES) was included in an augmented relationship matrix. A univariate animal model was fitted for each lamb trait and a repeated measures model for each of the three ewe traits was fitted to estimate variance components and predict breeding values. Genetic group solutions did not differ (P > 0.05) for any of these traits but provided a means by which to compare the two groups. Establishment of a Targhee genetic reference flock at USSES has been initiated, which can be used to address issues of importance to the industry.

A total of 3,329 commercial crossbred barrows and gilts were used to compare the efficacy of avilamycin on incidence and severity of diarrhea and growth performance of pigs naturally infected with Escherichia coli. An incomplete block design was used with a 2 × 4 factorial arrangement of treatments: 1) Stocking density (Single: 0.67 sq. m/pig vs. Double: 0.33 sq. m/pig) and 2) Nursery medication program [Nonmedicated control fed for 56 d (CON) vs. 80.5 mg/kg avilamycin fed for 21 d (AVI21) vs. 80.5 mg/kg avilamycin fed for 42 d (AVI42) vs. 55.1 mg/kg carbadox fed for 21 d (CAR21)]. Subjective diarrhea scores were collected weekly on each pen according to a 3-point scale. Pigs were weighed on days 0, 21, 42, and 56 of the study. Pigs had ad libitum access to feed and water throughout the study. Diets were formulated to meet or exceed NRC (2012) recommendations. Fecal swabs from pigs were collected and confirmed the presence of hemolytic E. coli within the first two weeks of study. During the first 21 d, feeding AVI21 and AVI42 lowered (P < 0.05) diarrhea severity compared to controls, with CAR21 being intermediate. In the second 21 d, feeding AVI42 lowered (P < 0.05) diarrhea incidence and severity compared to the other treatments. In general, feeding medication resulted in lower maximum diarrhea scores compared to nonmedicated controls. For the overall study period (day 0 to 56), there were no (P > 0.05) stocking density × nursery medication program interactions for growth performance measures. A significant interaction (P < 0.05) was observed for day 0 to 42; feed conversion did not differ between double and single stocking density treatments for AVI42, whereas for CON, AVI21, and CAR21, feed conversion was lower in the single stocking density treatment. For the overall study period, there was no effect (P > 0.05) of nursery medication program on final BW, ADG, ADFI, or incidence of morbidity and mortality. Overall G:F was improved (P < 0.05) for pigs fed avilamycin compared to carbadox, with controls being intermediate. Double stocking resulted in lower overall ADFI (P < 0.05) and improved G:F (P < 0.05) compared to single stocking, but increased overall morbidity and mortality and diarrhea severity, incidence, and overall scores (P < 0.05). The results of this study demonstrate relatively similar performance with improved feed conversion and improvements in diarrhea incidence and severity for pigs fed avilamycin compared to carbadox.