C. B. Silva

Influence of category-heifers, primiparous and multiparous lactating cows-in a large-scale resynchronization fixed-time artificial insemination program

This study was conducted to evaluate the influence of category (heifers, primiparous or multiparous cows) on pregnancy rates in a large scale resynchronization ovulation program. Nelore heifers (n = 903), primiparous lactating cows (n = 338) and multiparous lactating cows (n = 1,223) were synchronized using a conventional protocol of estradiol/P4-based fixed-time artificial insemination (FTAI). Thirty days after ultrasonography, females who failed the first FTAI were resynchronized with the same hormonal protocol prior to a second FTAI. The pregnancy status of each cohort was evaluated by ultrasonography 30 days after each FTAI. The average conception rate after the first FTAI and resynchronization was 80.5%. Heifers had a higher conception rate (85%) than primiparous (76%) or multiparous cows (78%; p = 0.0001). The conception rate after the first FTAI was similar among heifers (57%), primiparous cows (51%) and multiparous cows (56%; p = 0.193). After the second FTAI, heifers exhibited a higher conception rate (66%) than primiparous or multiparous cows (51%; p = 0.0001). These results demonstrate the feasibility of resynchronization in large beef herds for providing consistent pregnancy rates in a short period of time. We also demonstrated that ovulation resynchronization 30 days after FTAI is particularly effective for heifers, providing a conception rate of up to 66%.

AVALIAÇÃO DA CULTURA DO RABANETE EM FUNÇÃO DE DIFERENTES LÂMINAS DE ÁGUA

RESUMO: O rabanete (Raphanus sativus L.) é uma hortaliça pertencente à família das Brassicaceae. Essa cultura vem sendo produzida principalmente por pequenos e médios produtores, no entanto, ainda é uma produção pouco expressiva no Brasil. Este experimento teve como objetivo avaliar a produção do rabanete em função de diferentes de lâminas de água. O experimento foi conduzido na área experimental da Universidade Federal de Alagoas – Campus de Arapiraca, AL. O delineamento experimental utilizado foi em blocos casualizados (DBC), recebendo cinco tratamentos de lâminas de água, distinguindo-se pelas quantidades de: 50%; 75%; 100%; 125% e 150% da ETc. Trinta dias após o plantio direto da cultura foram analisadas as seguintes variáveis: área foliar (AF), teor de açúcar (BRIX), diâmetro do bulbo (DB), massa fresca da parte aérea (MFPA), massa seca da parte aérea (MSPA). Contudo, das variáveis analisadas, a área foliar (AF) apresentou maior desenvoltura com a lâmina de água correspondente a 150% da ETc, diâmetro do bulbo (DB) 125% , teor de açúcar (BRIX) 50% e massa fresca da parte aérea (MFPA) 150%. Apenas a variável massa seca da parte aérea (MSPA) não foi significativa. PALAVRAS CHAVES: Raphanus sativus L, DBC, tratamentos.

Antral follicle count in cattle: advantages, challenges, and controversy

The antral follicle count (AFC) represents the number of follicles visualized by ultrasonography in the ovaries. Antral follicle count tends to be variable among cows but with high repeatability within the same individual. In the last decade, AFC has been considered a biological marker of fertility with many positive aspects of reproductive efficiency for those animals with high AFC. For instance, a larger number and better-quality embryos, better pregnancy rates, increased concentrations of circulating progesterone, in addition to other characteristics linked to fertility, are all responses observed in individuals with high compared with those with low AFC in Bos taurus cattle. However, the positive association between AFC and fertility did not follow the same pattern for Bos indicus. Recent articles showed no connection between fertility and number of antral follicles or better reproductive efficiency for high AFC group in Zebu cows. Thus, the aim of this review is to discuss the various data concerning AFC between indicus and taurus cattle. Additionally, we consider AFC to be a possible tool to improve cattle performance in reproductive biotechnology.