Journal of animal science最新文献

Tannin extracts (TE) of isolated condensed or hydrolyzable tannins have been evaluated for their methane (CH4) mitigation potential in beef cattle. Despite the potential for a combination of tannin types to yield synergistic effects, the dose-response pattern and optimal supplementation rate of a TE blend remain unclear. Our objectives were to investigate changes in nutrient utilization and gas emission patterns in response to supplementation with a TE blend (Silvafeed ByPro; SILVATEAM, San Michele Mondovi, Italy), and to determine the optimal dose to minimize emissions in growing steers (308 ± 9.4 kg BW). Supplementation rates were 0.0, 0.3, 0.6, and 0.9% of DM (TE0.0, TE0.3, TE0.6, and TE0.9, respectively) within a total mixed ration fed at 1.62% of BW (DM basis). Whole-animal gas exchange and total fecal and urine production were measured over 48 h using two open-circuit, indirect calorimetry respiration chambers in a 4 × 8 Latin rectangle design with four periods and eight animals. Blood and ruminal parameters were evaluated from samples collected from steers upon removal from chambers. Nutrient and water intake were not influenced (P ≥ 0.42) by TE rate. Fecal excretion of acid detergent fiber (ADF) displayed a dose-response pattern (quadratic P < 0.01, cubic P = 0.01) with increasing TE rate. Apparent digestibility of ADF decreased at an increasing rate (quadratic P < 0.01, cubic P = 0.01) with TE. There was a quadratic effect (P = 0.01) on ruminal propionate concentration, but no other ruminal parameters were influenced by TE rate (P ≥ 0.13). There was a quadratic pattern (P = 0.04) in fecal N excretion and N digestibility. The rate of TE did not affect urinary N excretion (P ≥ 0.58), but N retention tended to linearly decrease (P = 0.06) with increased TE and blood urea N tended (P = 0.06) to follow a cubic pattern. There was a quadratic (P ≤ 0.05) dose-response relationship for gaseous energy loss. Although oxygen consumption and carbon dioxide production were not influenced by TE rate (P ≥ 0.64), the respiratory quotient increased linearly (P = 0.02) with TE inclusion. However, no other energy partitioning was influenced by TE supplementation rate (P ≥ 0.18). Regardless of how it was expressed, CH4 production displayed a quadratic pattern (P ≤ 0.04) in relation to increased TE rate, with equations suggesting an optimal TE dose between 0.20 and 0.22% of DM for CH4 mitigation without compromising nutrient utilization or energy efficiency.

Ectoine is a small, amino acid-derived osmolyte produced by extremophilic bacteria that acts as a compatible solute, protecting cellular macromolecules and structures from extreme environmental stress without disrupting essential cellular functions. The aim of this study was to evaluate the biocompatibility of ectoine with bull sperm and to assess the potential of ectoine to enhance the resilience of sperm under varying stress conditions. Thawed bovine sperm in the presence (0.5, 5 and 50 mM) or absence (control; 0 mM) of ectoine were subjected to a biocompatibility test (37 °C for 6 h; n = 8 bulls), heat stress (39 or 42 °C for 6 h; n = 8 bulls), osmotic stress (150 or 400 mOsm for 15 min; n = 12 bulls) whereby motility and kinematic parameters, as well as viability, acrosome integrity and membrane fluidity by flow cytometry were assessed. Sperm motility in cervicovaginal mucus (37 °C for 3 h; n = 6 bulls) was also assessed. All results are reported as mean ± s.e.m. Ectoine displayed a non-toxic effect across all motility and functional parameters (viability, acrosome integrity and membrane fluidity). Nonetheless, a reduction in kinematic parameters including straight line velocity (VSL), average path velocity (VAP) and straightness (STR) was observed at 50 mM ectoine. Under heat stress at 39 and 42 °C, ectoine concentrations of 0.5 and 5 mM maintained motility and viability, comparable to controls across all time points. In hypoosmotic conditions (150 mOsm), individual bulls displayed different degrees of osmotic resistance. In those bulls with poor osmotic resistance (n = 4), ectoine (0.5 and 5 mM) maintained sperm viability similar to the 0 mM control. However, the viability of sperm incubated with 50 mM solute was 2-fold higher relative to the control (P < 0.001). In hyperosmotic conditions, addition of ectoine to sperm prior to exposure did not affect the total motility or viability compared to the no ectoine treatment (P > 0.05). When sperm were incubated in cervicovaginal mucus, there was an effect of ectoine treatment. Sperm treated with 50 mM ectoine exhibited higher motility throughout incubation compared to the control (0 mM) (P < 0.05). In conclusion, these findings establish ectoine as a promising candidate for improving sperm resilience and warrants further studies to assess additional protective effects of ectoine.

This study aimed to investigate the effects of positive or negative emotional contagion on the environmental adaptability and pain sensitivity of the naïve pigs. In the study, 54 pigs were selected and paired into 27 test units, then assigned to the reward, punishment, and control groups (n = 9) randomly. In the reward or punishment groups, one pig in each pair was randomly chosen as the treated pig (TP), receiving either food rewards or electric shock treatments, while the other pig was the naïve pig (NP). The NPs did not have treatment or receive treatment information from the TPs. After the treatment, the paired pigs were allowed to interact for one hour. The paired pigs in the control group received no treatment and were allowed to interact with each other for one hour directly. Subsequently, the salivary physiological, open field, and pain sensitivity tests were performed. In the punishment group, the NPs showed elevated serotonin (p = 0.02) and amylase (p < 0.01), indicating negative emotion arousal. In the reward group, the NPs had higher cortisol (p = 0.01) and dopamine (p < 0.01), suggesting positive emotion arousal. The NPs in the punishment group spent less time in the central zone of the arena (p < 0.01), showing increased motivation to explore unfamiliar environments, while the NPs in the reward group spent more time in central zone (p = 0.04), indicating reduced anxiety and improved environmental adaptation. Neither positive nor negative emotional contagion had a significant effect on the pain sensitivity of pigs. In conclusion, positive emotional contagion can improve pigs' adaptability to unfamiliar environments, while negative emotional contagion did not.

Soybean-derived trypsin inhibitor proteins (TIU) impair amino acid bioavailability and increase exogenous and endogenous nitrogen flow to the hindgut, thereby attenuating pig growth performance. High protein diets potentiate proteolytic fermentation induced alterations to the gut microbiome, which may increase opportunistic enterotoxigenic Escherichia coli (ETEC) proliferation and exacerbate disease. We hypothesized that feeding high TIU diets to nursery pigs would reduce growth rates and exacerbate F18 ETEC disease. Two hundred and eighty-eight (5.42 ± 0.93 kg BW; Camborough 1050 × 337, [PIC, Hendersonville, TN]) newly weaned pigs were evenly allotted across two control rooms (CON) and two challenge rooms (ETEC). Pigs were allotted based on sex and α-(1,2) fucosyltransferase (FUT1) genotype, with both factors evenly distributed across all pens. Pens were randomly assigned to corn-soy diets consisting of 1.1, 2.4, or 4.2 TIU/mg, creating six treatments: CON1.1, CON2.4, CON4.2, ETEC1.1, ETEC2.4, and ETEC4.2 (8 pens/treatment). On day 10 (day post-infection [dpi] 0), pigs in the ETEC rooms were orally inoculated with 5 ml of 3.8 × 109 cfu/ml of an F18 ETEC culture. Pooled pen feces were assessed for dry matter (DM) on dpi 0, 3, 5, 7, 9, 11, 14, and 21. Pen growth performance, medical treatments, and mortality were assessed prior to infection (dpi -10 to 0) and post infection (dpi 0 to 28). On dpi 5 and 12, one pig/pen was sacrificed to assess ileal mucosal attachment of F18 ETEC via in situ hybridization. Pen was the experimental unit and data were analyzed for the interactive and main effects of diet and challenge. Increasing dietary TIU to 4.2 TIU/mg led to a 13-16% decrease in ADG compared to the 1.1 TIU/mg diets, regardless of the challenge (P = 0.014). A diet × challenge interaction was observed regarding mortality, with ETEC2.4 showing a 20.8% mortality rate compared to 0% in CON2.4 (P = 0.001). Similarly, 22.9% of ETEC2.4 pigs required antibiotic treatment compared with 0% of CON2.4 pigs (P = 0.001). Fecal DM from dpi 0-21 showed no interaction, but ETEC pens had lower fecal DM compared to CON pens from dpi 3-11 (P < 0.0001). On dpi 5, ileal F18 attachment was increased in ETEC versus CON pigs (3.7 × 10-3 vs 0.1 × 10-3 F18 copies/μm2, P < 0.0001). By dpi 12, ileal F18 attachment did not differ between challenge groups (P > 0.05), suggesting disease resolution. In conclusion, diets at or greater than 2.4 TIU/mg decreased pig growth and reduced livability in ETEC-infected nursery pigs.

The objectives of this study were to evaluate the effect of diet type on feed intake, animal performance and intake rank in mature, gestating Angus cows (130 ± 13 days pregnant at trial initiation) and to identify differentially expressed genes associated with each diet type. Forty-eight gestating commercial Angus cows (708 ± 52 kg of body weight; 7 ± 0.75 years old) were assigned to one of two diet sequences, concentrate-forage (CF) or forage-concentrate (FC), representing the order in which the two diets were consumed. In the first period, two of the four pens were assigned to the CF sequence and two to the FC sequence. Each pen contained an automatic waterer as well as four GrowSafe® feed intake units (GrowSafe System Ltd., Airdire, Alberta). The forage diet consisted of 100% processed hay (10.0% CP, 1.98 Mcal ME/kg DM) while the concentrate diet consisted of 43.0% hay, 22.0% corn, 24.0% soybean hulls, and 11.0% supplement on a DM basis (11.7% CP, DM basis and 2.43 Mcal ME/kg DM). Following a 14-day adaptation period, feed intake and body weight (BW) gain were recorded for 56 days. Subsequently, diet type was switched and followed by 14 days of adaptation to the new diet and 48 days of feed intake and BW gain measurement. Intake and performance data from this crossover study were analyzed using mixed model methods in SAS v9.4. There was a diet by period interaction (P < 0.01) for ADG with cows in the FC sequence gaining more weight than expected while consuming forage. Spearman rank correlation for dry matter intake (DMI) was 0.70 (P < 0.01) for FC cows and 0.36 (P < 0.1) for CF cows. In contrast, there was no significant relationship for average daily gain (ADG) among the two diet types, regardless of sequence (P > 0.4). In total, RNA sequencing of muscle tissue from the first period identified differentially expressed genes (DEG) associated with diet type. Enriched biological processes were identified by functional enrichment analysis of the DEG using g: Profiler and were primarily associated with energy metabolism and lipid biosynthesis. The results of this study support the hypothesis that gene expression in muscle responds differently when cows consume low-quality forage versus high-quality, energy-rich diets, even though feed intake rank correlations were high in the FC sequence and moderate in the CF sequence.