Growth and reproductive development in Brahman bulls fed diets containing gossypol

Abstract

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)

Reproductive toxicologic effects of gossypol on male rabbits: biochemical, enzymatic, and electrolytic properties of seminal plasma

“…Thus, increasing the percentage of dead spermatozoa in a semen sample causes high concentrations of transaminase enzymes in the extracellular fluid as a result of sperm membrane damage and, consequently, the ease of leakage of enzymes from spermatozoa. As indicated for LDH in a previous paragraph, gossypol exerted its cytotoxic effect by the formation of reactive oxygen species (37), which may cause plasma membrane rupture and mitochondrial destruction of sperm (38)(39)(40), in addition to degeneration of cells lining seminiferous tubules (42,43). These effects are expected to induce cytoplasmic leakage and subsequent increase in transaminase concentrations in extracellular fluid (seminal plasma).…”

Molecular approach of gossypol-induced reproductive toxicity in male rabbits. Changes in seminal plasma amino acids and fatty acids

“…Gossypol administration was reported to cause testicular destruction (Arshami and Ruttle, 1988;Chase et al, 1994), which could impair seminal amino acid synthesis. This would explain the marked reduction in total free amino acids observed in the present study on rabbits due to gossypol administration (Table 1).…”

Deleterious Actions of Gossypol on Bovine Spermatozoa, Oocytes, and Embryos1

“…that has been implicated as a reproductive toxicant [1]. Feeding cottonseed high in gossypol content to bulls has been associated with reduced sperm production, increased sperm abnormalities, decreased sperm motility, and decreased thickness of the germinal epithelium of the testis [2,3]. Gossypol has been reported to compromise function of cultured spermatozoa from cattle [4,5] and other species [6,7].…”