Journal of animal science最新文献

The number of beef × dairy animals entering feedlots has increased, but the response of beef × dairy cattle to growth-promoting implants has not been well characterized. The objective of this study was to evaluate the effects of breed type and implant administration on live performance, carcass characteristics, sera metabolites, and immunohistochemical (IHC) outcomes. Forty-eight steers (average body weight [BW] = 417±22 kg) were sorted by breed into groups of predominantly Angus (B), black-hided beef × primarily Holstein (B×D), or Holstein (D), and half of the steers within each breed type were administered a steroidal implant. Data were analyzed as a 3×2 factorial, including repeated measures for sera metabolite and IHC outcomes. Main effects were breed (B, B×D, or D) and implant status (no implant [CON] or Revalor-XS [200 mg trenbolone acetate + 40 mg estradiol-17β] on d 0 [IMP]). Interaction of main effects to determine breed-specific responses to implants were also evaluated. Steers were fed to a target final shrunk BW of 658 kg within breed type. Blood, longissimus thoracis biopsies, and BW were collected on d 0, 28, 70, 98, and 126; BW was also collected prior to harvest. Implanted steers had greater average daily gain (ADG), interim BW, and final BW (P ≤ 0.04). Overall ADG tended to be greatest (P = 0.07) in B×D steers. The IMP treatment, and B×D and D steers had increased (P < 0.01) mean sera concentrations of non-esterified fatty acids and insulin-like growth factor-I (IGF-I), compared to CON and B steers. The IMP carcasses had greater hot carcass weight (HCW), dressing percentage, and REA (P ≤ 0.03) and decreased KPH (P < 0.01). By analyzation of IHC, myosin heavy chain (MHC) Type I fibers were the largest and most abundant in D (P ≤ 0.03). Increased abundance of estrogen receptors and greatest G protein-coupled receptor-1 score was observed for D, while B×D were intermediate, and B had the fewest estrogenic receptors (P ≤ 0.02). Regardless of breed type, IMP steers had increased estradiol-17β and trenbolone-17β concentrations (P < 0.01) with no effect on MHC fiber type and minimal effects on satellite cell outcomes. These results indicated B×D and IMP treatments increased muscling and decreased internal fat deposition compared to D and CON, respectively. Dairy-influenced breed types exhibited increased estrogenic receptor abundance. Additionally, few breed × implant interactions suggest B, B×D, and D steers responded similarly to growth-promoting implants.

This study aimed to quantify the effects of physiological status (PS) and the potential interaction of this factor with days of pregnancy (DOP) on beef heifers' weight variation, intake, and digestion kinetics. Twelve rumen-cannulated zebu beef heifers (n = 7 pregnant; n = 5 nonpregnant) were used. Heifers were placed in individual pens and fed medium-quality corn silage plus a protein-based supplement. Heifers' body weight was assessed at the beginning and end of each collection period. The feed intake was measured daily. Target outcomes were evaluated at 107, 170, 208, 240, 267, and 286 DOP. The apparent total-tract digestibility was determined considering the fecal spot collection, during 5 d within each collection period. Omasal and ruminal digesta samples were collected at 107, 208, and 267 DOP for determination of partial digestibilities and diet component outflow. For these purposes, Co-EDTA and indigestible neutral detergent fiber (iNDF) were used as indicators. All data were analyzed using a mixed model framework, considering the PS and DOP as fixed effects and the animal as a random effect. Significant differences were declared when P ≤ 0.05. Pregnant heifers showed an increase in body reserves (+35 kg) from 107 to 240 DOP, but experienced a decrease in shrunk body weight (-36 kg) from 240 to 286 DOP. The intake of dry matter (DM), organic matter (OM), crude protein (CP), and ash- and protein-free neutral detergent fiber (apNDF) increased as pregnancy progressed (P < 0.04). The apparent total-tract digestibility of DM tended to be lower (P = 0.09), and the apparent total-tract digestibility of apNDF was reduced (P < 0.01) in pregnant heifers. The digestibility of CP was higher (P < 0.01) on days 267 and 286 in pregnant cows compared to nonpregnant heifers. The ruminal digestibility of OM tended to be lower (P = 0.09) in pregnant beef heifers, while the ruminal digestibility of apNDF was lower (P = 0.02) in pregnant heifers compared to nonpregnant ones. The ruminal pool of wet matter and DM was lower (P ≤ 0.01) in pregnant heifers at 267 DOP. In all periods, the outflow tended to be greater (P = 0.06) in pregnant heifers compared to nonpregnant heifers. Pregnant beef heifers exhibited a faster (P = 0.01) digesta passage rate during late gestation. In conclusion, late-gestating beef heifers are less efficient in extracting energy from feed compared to nonpregnant animals.

Choline is vital in a variety of physiological processes that influence brain development, growth, and carcass characteristics in birds and mammals. In this study, we investigated the influence of graded supplemental choline chloride on growth performance, carcass quality, and liver characteristics in grow-finish pigs. Pigs (672 barrows and 588 gilts) were obtained from a commercial nursery facility at 8 weeks of age and assigned to treatment based on body weight and sex, with 21 same-sex pigs comprising a replicate pen. Each dietary treatment was provided to 15 replicate pens, with 8 pens of barrows and 7 pens of gilts per each of 4 dietary treatments, which included: 1) C0, basal diet containing 0% of supplemental choline chloride; 2) C300, C0 + 0.06% supplemental choline chloride, to provide 300 mg/kg of choline ions; 3) C600, C0 + 0.12% supplemental choline chloride, to provide 600 mg/kg of choline ions; and 4) C900, C0 + 0.17% supplemental choline chloride, to provide 900 mg/kg of choline ions. Feed and water were provided ad libitum throughout the study, and pigs were managed using standard commercial practices. Data were analyzed by two-way ANOVA using the MIXED procedure of SAS, with factors including dietary treatment and sex. There was no dietary impact (P > 0.05) on growth performance. Pigs receiving intermediate levels of supplemental choline had higher (P < 0.05) tenderloin weights compared with other dietary treatments. Furthermore, and as expected, sex differences were denoted in both growth performance and carcass characteristics. Overall, graded supplementation of choline chloride did not significantly alter growth performance or carcass characteristics of pigs raised in a commercial setting.

Bacterial contamination is an inevitable issue during the processing of semen preservation in pigs. As a prototypical endotoxin from Gram-negative bacteria in semen, lipopolysaccharide (LPS) undermines sperm function during liquid preservation. Spermine and spermidine could protect cells against LPS-induced injury, and the content of spermine and spermidine in seminal plasma is positively correlated with sperm quality. Thus, the present study aimed to clarify whether addition of spermine or spermidine is beneficial to porcine semen preservation and able to prevent LPS-induced sperm damage. The supplementation of spermine and spermidine in the diluent resulted in higher sperm motility, viability, acrosome integrity, and mitochondrial membrane potential (ΔΨm) after preservation in vitro at 17 °C for 7 d (P < 0.05). LPS-induced sperm quality deterioration, ΔΨm decline, cellular adenosine-triphosphate depletion, mitochondrial ultrastructure abnormality, mitochondrial permeability transition pore opening, phosphatidylserine (PS) translocation, and caspase-3 activation (P < 0.05). Interestingly, spermine and spermidine alleviated the LPS-induced changes of the aforementioned parameters and mitigated the decrease in the microtubule-associated protein light chain 3-II (LC3-II) to LC3-I ratio. Meanwhile, the α and β subunits of casein kinase 2 (CK2) were detected at the connecting piece and the tail. Significantly, addition of 4,5,6,7-tetrabromobenzotriazole, a specific CK2 inhibitor, counteracted the beneficial effects of spermine and spermidine on sperm quality, mitochondrial activity, and apoptosis. Together, these results suggest that spermine and spermidine improve sperm quality and the efficiency of liquid preservation of porcine semen. Furthermore, spermine and spermidine alleviate LPS-induced sperm mitochondrial dysfunction and apoptosis in a CK2-dependent manner.

By 2050, the U.S. beef industry must produce an extra 40 million tons of beef to satisfy the global demand. Such an increase in inventory will undoubtedly enhance methane (CH4) production from livestock, which should be reduced by over 20%. The addition of plant secondary metabolites, such as anacardic acid present in cashew nutshell extract (CNSE), has shown promising results in reducing CH4 yield, although its effects seemed to be diet-dependent. This study evaluated the addition of CNSE to a high-grain diet (85:15 grain:forage) on in vivo CH4 emissions, nutrient digestibility, performance, feeding behavior, and ruminal fermentation parameters of beef steers. Sixteen Angus crossbred steers [599 ± 40 kg of bodyweight (BW)] and 6 ruminally cannulated crossbred steers (490 ± 51 kg of BW) were utilized in a crossover design with 2 experimental periods of 56 d each, composed by 14 d of adaptation, 35 d of measurement, and 7 d of washout. Following adaptation, steers were sorted by BW, and assigned to receive no additive (CON) or CNSE at 5 g/steer/d. Data were analyzed using the MIXED procedure of SAS. Inclusion of CNSE increased (P < 0.05) propionate concentration and molar proportion (MP; mol/100 mol), tended to decrease acetate MP (P = 0.10), reduced the acetate:propionate (A:P) ratio (P = 0.05), and MP of branched-chain volatile fatty acids (P < 0.01). Neither in vitro organic matter digestibility nor in vitro CH4 yield were affected by CNSE inclusion (P > 0.05). Steers receiving CNSE exhibited greater (P < 0.05) final BW, dry matter intake (DMI), and average daily gain (ADG) but lesser (P < 0.05) in vivo CH4 emission rate (g/d), yield (g/kg of DMI), and intensity (g/kg of ADG). Meal length, bunk visit duration, and apparent total tract digestibility of DM increased (P < 0.05) after CNSE addition. Considering CNSE-supplemented steers spent more time in the feedbunk and exhibited higher DMI, CH4 mitigation was unlikely associated with intake reduction. The addition of CNSE to a high-grain diet in beef steers demonstrated significant improvements in animal performance and reduced CH4 emissions, as the result of shifts in ruminal fermentation patterns, favoring propionate instead of acetate concentration, leading to a reduction in the A:P ratio. CNSE shows promise as a strategy to enhance beef industry sustainability.

Lipopolysaccharide (LPS) exposure triggers pulmonary inflammation, leading to compromised lung function in broiler. As amplified by policy restrictions on antibiotic usage, seeking antibiotic alternatives has become imperative. Mogroside V (MGV) has been reported to have a beneficial role in livestock and poultry production due to its remarkable antiinflammatory effects. Despite evidence showcasing MGV's efficacy against LPS-triggered lung inflammation, its precise mechanism of action remains elusive. In this study, we transplanted normal fecal microbiota (CF), fecal microbiota modified by MGV (MF), and sterile fecal filtrate (MS) into broiler with LPS-induced pneumonia. The results showed that through fecal microbiota transplantation (FMT), transplanting MGV-induced microbial populations significantly mitigated tissue damage induced by LPS and enhanced the mRNA level of pulmonary tight junction proteins and mucoprotein (P < 0.01). The expression levels of RORα (P < 0.001), Foxp3 (P < 0.01), and PD-L1 (P < 0.01) were significantly increased in the MF group than CF group. The concentrations of IL-6 and IL-17 in broilers lung tissue of MF group were lower than those in broilers of CF group (P < 0.05). Furthermore, the concentration of TGF-β in broilers serum of MS and MF groups was higher than those in broilers of CF group (P < 0.05). Microbial community analysis demonstrated that at genus level, the harmful bacterial populations Escherichia-Shigella and Helicobacter following FMT treatment were significantly reduced in MF group (P < 0.05), potentially mediating its protective effects. Compared with CF group, valerate content and FFAR2 mRNA expression levels in MF group were significantly increased (P < 0.05). The study suggests that MGV via the gut-lung axis, attenuates Th17-mediated inflammation, offering promise as a therapeutic strategy against LPS-induced lung inflammation in chickens.

This study aimed to investigate the effect of feed intake levels on the development of intestinal morphology and epithelial cell differentiation in piglets. Sixty-four 35-d-old healthy weaned piglets ([Large White × Landrace] × Duroc) with an initial weight (6.93 ± 0.12 kg) were randomly divided into 4 groups (100%, 80%, 40%, and 20% feed intake) with 8 replicates of 2 pigs each. Samples were collected on days 3 and 7. The results revealed that with an increase in feed restriction degree and time, the body weight and organ index of piglets significantly decreased, and the villus height (VH) and crypt depth of the duodenum, jejunum, and ileum also decreased linearly (P < 0.05). After 3 d of feed restriction, jejunal ki67, endocrine cells, goblet cells, and villus endocrine/VH all decreased linearly, but the villus cup/VH ratio increased linearly, and the 40% and 20% were significantly higher than those of the 100% and 80% (P < 0.05). There was also a linear decrease in jejunal ki67, endocrine cells, goblet cells, and villous endocrine/VH in piglets fed 7 d of food restriction; however, the villus goblet cells/VH ratio in the 20% was significantly higher than that in the 40% group and was not different from that in the 80% (P < 0.05). During 3 d of feed restriction, the expression of jejunal differentiation marker genes showed a linear decreasing trend (P < 0.05) but increased linearly after 7 d of feed restriction. The expression levels of interleukin17 (IL-17) and IL-22 also increased linearly (P < 0.05). Kyoto Encyclopedia of Genes and Genomes and gene set enrichment analysis analyses indicated that the PPAR signaling pathway, ECM-receptor interaction, and Th1, Th2, and Th17 cell differentiation were significantly enriched in these processes. real-time quantitative polymerase chain reaction demonstrated that both PPAR and ECM-receptor interactions were significantly activated during 7 d of feeding restriction (P < 0.05). The results showed that with an increase in feed restriction intensity and time, the intestinal morphology and epithelial cell proliferation and differentiation were significantly reduced, except for the goblet cells. This phenomenon is related to the regulation of intestinal differentiation by IL-17 and IL-22 secreted by the Th cells.

The length of ewe productive life (LPL), defined as the number of days between the first and last lambing, is a key indicator of ewe longevity and is directly related to the sustainability of the sheep industry. Therefore, the primary objective of this study was to investigate systematic effects influencing LPL in Katahdin sheep. The LPL of 10,474 Katahdin ewes (69.5% with uncensored and 30.5% with right-censored observations) born between 1992 and 2021 in 58 flocks located across the United States were analyzed. The Kaplan-Meier (K-M) and Cox proportional hazard (Cox PH) methods were used to estimate survival probability. Four Cox PH models were evaluated. Model 1 included contemporary group (CG; flock-year-season of ewe birth) as a random effect and the ewe's dam's age (EDA), ewe's own birth-rearing type (BR; 1/1, 2/1, 2/2, 3/2, 3/3, with the digit-3 including lamb counts ≥ 3), and age at first lambing (AFL) as fixed effects. Models 2 to 4 were an extension of model 1. Model 2 also included average lamb birth weight (ABW) per ewe lifetime, while model 3 included average lamb weaning weight (AWW) per ewe lifetime. Both ABW and AWW were fitted as fixed effects. Model 4 fitted all previous effects together. The factors CG, BR, ABW, and AWW affected LPL (P < 0.05) in all models in which these effects were fitted. The EDA effect only influenced LPL (P < 0.05) in model 1, while AFL had no effect (P > 0.05) in any model. The median LPL ranged from approximately 2 to 3 yr, depending on the risk factors analyzed. In general, Katahdin ewes themselves born in multiple litters, and that produced lambs weighing approximately 5 kg at lambing and 20 to 25 kg at weaning (over their lifespan) had better survival probability. Although the LPL of Katahdin sheep is relatively low, it appears to be a consequence of voluntary culling due to its association with both ABW and AWW. Future studies should quantify the rate of involuntary culling in Katahdin ewes to identify whether longevity indicator traits should be included in more comprehensive breeding objectives.