Seminiferous epithelium of rats with food restriction and carbon tetrachloride-induced cirrhosis

OBJECTIVE: Analyze the changes in the seminiferous epithelium in rats with carbon tetrachloride-induced cirrhosis (CCl4). MATERIALS AND METHODS: Forty-eight male Wistar rats aged 45-50 days, weighing 150-180 grams were used. Twenty-two rats underwent CCl4-induced cirrhosis with CCl4 0.25 mL/Kg weekly intragastrically once a week, during 10 weeks. Additionally, they had a 44 percent food restriction diet (Group 1). The control group was divided in two subgroups: 13 rats had a 44 percent food restriction diet and no CCl4 (Group 2) and 10 rats were not submitted to CCl4 or food restriction (Group 3). After 10 weeks, the rats were sacrificed and liver sections were collected for histological analysis. The testicular analysis was carried out to evaluate the frequency of tubules in stages VIII and XIV. RESULTS: The mean rates of stage VIII in animals with food restriction plus CCl4-induced cirrhosis and food restriction without CCl4 were significantly different from animals without either food restriction or CCl4 (18.1 ± 5.5 percent, 20.5 ± 2.5 percent and 13.4 ± 3.5 percent, respectively, p = 0.002). The mean rate of stage VIII in rats with cirrhosis was not significantly different from rats without cirrhosis (18.1 ± 5.5 percent and 17.4 ± 4.6 percent respectively). The mean frequency of stage XIV in rats with cirrhosis was significantly greater than rats without cirrhosis (4.7 ± 2.3 percent and 6.8 ± 1.9 percent respectively, p = 0.027). CONCLUSION: Animals with CCl4-induced cirrhosis and food restriction have shown alterations in spermatogenic cycle that were not seen in rats without CCl4-induced cirrhosis and food restriction.

Reproductive deficiency in bulls from synthetic breeds according to the type of crossbreed and the morphology of the Y chromosome

We used 550 Braford and 214 Brangus-Ibagé bulls to study the association between Y chromosome morphology and the evaluation of breeding-soundness, karyotyping and breeding records were used to assess Y chromosome morphology. In general, no direct association was detected between the individual type of Y chromosome and reproductive fitness as previously estimated through breeding soundness examination. The type of breeding strategy used to form the synthetic breeds was also analyzed. The Braford breed is about 3/8 Zebu (Bos taurus indicus) and 5/8 Hereford (Bos taurus taurus) but when the breeding strategy used 1/4 Zebu animals to produce Braford bulls which were 3/8 Zebu a greater percentage of the bulls had to be culled due to reproductive problems. Our study shows that certain interactions between genotypes can be detrimental to the reproductive efficiency of 3/8 Zebu animals and that breeding strategies avoiding or favoring certain genotypes can be used to reduce the percentage of bulls from synthetic breeds that are culled due to problems with semen quality.