Phytohemagglutinin improves the development and ultrastructure of in vitro-cultured goat (Capra hircus) preantral follicles

The objective this study was to determine the effect of phytohemagglutinin (PHA) on survival, growth and gene expression in caprine secondary follicles cultured in vitro. Secondary follicles (&#8764;0.2&#8197;mm) were isolated from the cortex of caprine ovaries and cultured individually for 6 days in &#945;-MEM+ supplemented with PHA (0, 1, 10, 50, 100, or 200&#8197;&#181;g/mL). After 6 days of culture, follicle diameter and survival, antrum formation, ultrastructure and expression of mRNA for FSH receptors (FSH-R), proliferating cell nuclear antigen (PCNA), and neuronal nitric oxide synthase were determined. All treatments maintained follicular survival [&#945;-MEM+ (94.59%); 1&#8197;&#181;g/mL PHA (96.43%); 10&#8197;&#181;g/mL PHA (84.85%); 50&#8197;&#181;g/mL PHA (85.29%); 100&#8197;&#181;g/mL PHA (88.57%), and 200&#8197;&#181;g/mL PHA (87.50)], but the presence of 10&#8197;&#181;g/mL PHA in the culture medium increased the antrum formation rate (21.21%) when compared with control (5.41%, P < 0.05) and ensured the maintenance of oocyte and granulosa cell ultrastructures after 6 days of culture. The expression of mRNA for FSH-R (2.7 &#177; 0.1) and PCNA (4.4 &#177; 0.2) was also significantly increased in follicles cultured with 10&#8197;&#181;g/mL PHA in relation to those cultured in &#945;-MEM+ (1.0 &#177; 0.1). In conclusion, supplementation of culture medium with 10&#8197;&#181;g/mL PHA maintains the follicular viability and ultrastructure, and promotes the formation of antral cavity after 6 days of culture in vitro

Causes of rejection of beef bulls in breeding soundness evaluation

The objective of this study was to analyze the rates of rejection in the different steps of the breeding soundness evaluation of beef bulls in the state of Rio Grande do Sul, Brazil. The breeding soundness of 22,113 young and mature bulls of 14 beef breeds, participating in the Program of Reproductive Evaluation (PARTO) was evaluated in the experiment. Data concerning to the causes of rejection in the four steps of the breeding soundness evaluation (general physical examination, genital tract examination, semen evaluation and sexual behavior assessment) were analyzed by the Chi-square test and univariate regression analysis. According to year, general physical examination, genital tract examination and semen evaluation determined the rejection of 0.9% to 2.5%, 5.1% to 7.7%, 1.8% to 5.3%; and 4.2% to 6.7%, 7.3 to 9.3%, and 2.5% to 5.5% of young and mature bulls, respectively. Mature bulls presented higher chances of rejection than young bulls in the general physical examination in every year evaluated; as to the genital tract examination, their chances of rejection were higher in years I and II, but not in year III. In the semen evaluation, there was no difference between the ages assessed in any of the three years evaluated. Sexual behavior assessment accounted for the rejection of 1.9 to 6.0% of the young bulls and 2.9% to 3.9% of mature bulls, in accordance with the years evaluated; in years I and II, mature bulls presented higher rejection rates than young bulls. These results confirm the importance of performing all steps of the breeding soundness evaluation, including the sexual behavior assessment as a work routine, rather than an additional, optional stage of the evaluation, which should be carried out before the breeding season. The results indicate the relationship between bull age and rejection rate in the breeding soundness evaluation