Mercadante Vitor R G, Stewart Jamie L, Clark Sherrie G, Redifer Tracey, Belknap Craig R, Currin John F
Department of Large Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
School of Animal Sciences, College of Agriculture and Life Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
Transl Anim Sci. 2025 Jun 7;9:txaf063. doi: 10.1093/tas/txaf063. eCollection 2025.
The study aimed to evaluate the effects of Saccharomyces cerevisiae fermentation product (SCFP) supplementation during the breeding season on reproductive performance of beef cows grazing fescue-dominated pastures (Festuca arundinacea). A total of 883 multiparous suckled beef cows across eight locations were stratified by age and days postpartum (DPP) and randomly assigned to one of two treatments: 1) CON-mineral supplementation at 90 g/hd/d (n = 439 cows; 13 experimental units), or 2) SCFP-mineral with 9 g SCFP (NaturSafe, Diamond V, Cedar Rapids, IA; n = 444 cows; 13 experimental units). Supplementation began 21 d pre-breeding and continued through the breeding season (approx. 171 d). Cows grazed tall-fescue pastures and followed a fixed-time artificial insemination (TAI) protocol (7-d CO-Synch + CIDR) with natural service and clean-up bulls for a 70-d breeding season. Pregnancy diagnoses were performed by ultrasonography at 55 d post-TAI and 40 d after the breeding season. Cow body weight (BW) and body condition score (BCS) were recorded at TAI (day 0) and weaning (day 150). Mineral disappearance was measured weekly. Data were analyzed using GLIMMIX for binomial data and MIXED for continuous data. Cow age and DPP did not differ ( > 0.10) between treatments (6.0 ± 1.0 yr and 79.7 ± 2.6 d, respectively). Mineral disappearance was similar ( = 0.97) between treatments (99.2 and 99.8 ± 8.76 g/hd/d for CON and SCFP, respectively). No differences were observed ( > 0.10) in BW and BCS between treatments on days 0 and 150. SCFP supplementation did not affect estrus expression (63.2% vs 63.7% ± 2.6% for CON and SCFP, respectively; = 0.91), but TAI pregnancy rates were higher ( = 0.025) in SCFP (65.9% ± 2.5%) compared to CON (57.9% ± 2.5%). Final pregnancy rates tended to be higher ( = 0.057) for SCFP (92.9% ± 1.4%) vs CON (89.0% ± 1.4%), with no effect on calf performance ( > 0.10). In conclusion, SCFP supplementation during the breeding season did not influence BW or BCS but improved TAI pregnancy rates in beef cows grazing endophyte-infected tall fescue.
本研究旨在评估在繁殖季节补充酿酒酵母发酵产物（SCFP）对放牧以羊茅为主的牧场（高羊茅）的肉牛繁殖性能的影响。来自八个地点的总共883头经产哺乳肉牛按年龄和产后天数（DPP）分层，并随机分配到两种处理之一：1）对照组，每天每头补充90克矿物质（n = 439头母牛；13个实验单元），或2）SCFP组，补充含9克SCFP的矿物质（NaturSafe，Diamond V，爱荷华州锡达拉皮兹；n = 444头母牛；13个实验单元）。补充从配种前21天开始，持续整个繁殖季节（约171天）。母牛在高羊茅牧场放牧，并遵循固定时间人工授精（TAI）方案（7天CO - Synch + CIDR），并在70天的繁殖季节中与自然交配公牛和清理公牛一起饲养。在TAI后55天和繁殖季节结束后40天通过超声检查进行妊娠诊断。在TAI（第0天）和断奶（第150天）时记录母牛体重（BW）和体况评分（BCS）。每周测量矿物质消耗量。使用GLIMMIX分析二项数据，使用MIXED分析连续数据。处理组之间的母牛年龄和DPP没有差异（P>0.10）（分别为6.0±1.0岁和79.7±2.6天）。处理组之间的矿物质消耗量相似（P = 0.97）（对照组和SCFP组分别为99.2和99.8±8.76克/头/天）。在第0天和第150天，处理组之间的BW和BCS没有观察到差异（P>0.10）。补充SCFP不影响发情表现（对照组和SCFP组分别为63.2%和63.7%±2.6%；P = 0.91），但SCFP组的TAI妊娠率高于（P = 0.025）对照组（65.9%±2.5%）与对照组（57.9%±2.5%）相比。SCFP组的最终妊娠率趋于高于（P = 0.057）对照组（92.9%±1.4%）与对照组（89.0%±1.4%），对犊牛性能没有影响（P>0.10）。总之，在繁殖季节补充SCFP不影响BW或BCS，但提高了放牧内生真菌感染的高羊茅的肉牛的TAI妊娠率。
