Chase C C, Bastidas P, Ruttle J L, Long C R, Randel R D
Agricultural Research Service, U.S. Department of Agriculture, Brooksville, FL 34605-0046.
J Anim Sci. 1994 Feb;72(2):445-52. doi: 10.2527/1994.722445x.
To determine the effect of gossypol on growth and reproductive development, Brahman bulls (n = 30) were fed diets containing gossypol (6 or 60 mg.kg BW-1.d-1) or a diet free of gossypol from weaning through puberty. Diets contained cottonseed meal (CSM), whole cottonseed (WCS), or soybean meal (SBM) as the major sources of dietary CP. Diets were formulated to provide similar NEg for medium-framed bulls to gain .9 kg/d. Measurements of BW and scrotal circumference were obtained at 28-d intervals, and beginning at 10 mo of age electroejaculates were collected at 14-d intervals. By 196 d on feed, bulls fed WCS had gained less (P < .05) BW and tended (P < .10) to have lower gain/feed than bulls fed CSM. When spermatozoa were first detected in an ejaculate, bulls fed CSM tended (P < .10) to be younger than bulls fed WCS (357 vs 386 d; SBM = 380 d); bulls fed SBM were heavier (P < .05) than bulls fed gossypol (333 vs 310 kg), but they had similar scrotal circumferences. Bulls fed WCS reached puberty at an older (P < .05) age (613 d) than bulls fed CSM (528 d; SBM = 550 d) but had similar BW and scrotal circumferences. Electroejaculated semen quality and quantity did not differ (P > .10) between treatments at puberty. Seminiferous tubule diameters did not differ (P > .10) among treatments, but bulls fed diets that contained gossypol had larger (P < .01) lumenal diameters, smaller (P < .01) germinal epithelium thickness, and fewer (P < .01) germ cell layers than bulls fed SBM diets.(ABSTRACT TRUNCATED AT 250 WORDS)
为确定棉酚对生长和生殖发育的影响，婆罗门公牛（n = 30）从断奶到青春期被饲喂含棉酚（6或60毫克·千克体重⁻¹·天⁻¹）的日粮或不含棉酚的日粮。日粮以棉籽粕（CSM）、全棉籽（WCS）或豆粕（SBM）作为日粮粗蛋白的主要来源。日粮配方旨在为中等体格的公牛提供相似的净能以使其日增重0.9千克。每隔28天测量体重和阴囊周长，从10月龄开始每隔14天采集电刺激射精样本。采食196天后，饲喂WCS的公牛体重增加较少（P < 0.05），且增重/采食量有降低趋势（P < 0.10），低于饲喂CSM的公牛。首次在射精样本中检测到精子时，饲喂CSM的公牛年龄有小于饲喂WCS公牛的趋势（P < 0.10）（357天对386天；SBM = 380天）；饲喂SBM的公牛比饲喂棉酚的公牛更重（P < 0.05）（333千克对310千克），但阴囊周长相似。饲喂WCS的公牛比饲喂CSM的公牛（528天；SBM = 550天）达到青春期的年龄更大（P < 0.05）（613天），但体重和阴囊周长相似。青春期时各处理间电刺激射精的精液质量和数量无差异（P > 0.10）。各处理间曲细精管直径无差异（P > 0.10），但与饲喂SBM日粮的公牛相比，饲喂含棉酚日粮的公牛管腔直径更大（P < 0.01），生精上皮厚度更小（P < 0.01），生殖细胞层数更少（P < 0.01）。（摘要截断于250字）
