Factors Affecting Fertility According to the Postpartum Period in Crossbred Dual-Purpose Suckling Cows in the Tropics

Abstract

To determine the relationship between first service conception rate (FSC) and the postpartum period (PP), 6160 calvings from 2250 crossbred dual-purpose cows were analysed. The effects of breed predominance (BT: Bos taurus and BI: Bos indicus), season of service (dry, intermediate and humid), parity (1 or 2 and more), agroecological region (Sub-humid and Dry Tropical Forest) and milk production were studied. The postpartum period was grouped according to the calving-first service interval as G1 < or = 60 days (n = 1889); G2 > 60 < or = 90 days (n = 1436); G3 > 90 < or = 120 days (n = 1030); and G4 > 120 days (n = 1805). Data were analysed by chi-squared test. The overall mean for FSC was 58.2% and was lower in G1 (p < 0.01). All PP showed a breed effect on FSC, with mean values of 61.6% and 53.3% for BI and BT, respectively. Season of service also affected FSC, which was significantly lower during the humid period: 51.2% versus 57.4% and 61.5% for the intermediate and dry periods (p < 0.01), respectively. Parity and environmental effects were not observed on FSC. Levels of milk yield did influence the FSC, which decreased from 66.7% and 61.0% for milk yields of < 1500 kg and between 1501 and 2000 kg to 46.0% in milk yields > 2000 kg (p < 0.01).

Determination of Ovarian Cysts in Cattle with Poor Reproductive Performance Using Ultrasound and Plasma Progesterone Profile

“…This might generally indicate that genetic differences between breeds in the incidence and types of AOC can result in differences in fertility parameters such as conception rate. 20 In addition, adaptation differences to the hot and humid tropical environment may account for the large difference between the local KK and the other three breeds. Under the hot and humid conditions, despite high rainfall that produces more forage, high humidity, and temperature, could cause stress and affect their reproductive functions by modifying the endocrine balance and altering the oviductal uterine environment that delays or interrupts embryo development.…”

“…Under the hot and humid conditions, despite high rainfall that produces more forage, high humidity, and temperature, could cause stress and affect their reproductive functions by modifying the endocrine balance and altering the oviductal uterine environment that delays or interrupts embryo development. 20 According to, 21 dairy cows with COD have been reported to have increased heat shock protein (Hsp27) expressions theca cells in relation to tertiary follicles of normal cycling cows, indicating the possible link between COD occurrence and heat stress in cattle. Zebu cows (Bos indicus) and their crossbreeds show lower levels of milk production and better adaptation to the adverse tropical environment, and hence show lesser effects on the postpartum body condition but a higher reproductive efficiency than the predominantly Bos taurus cows.…”

Ovarian activity in beef and dairy cows with prolonged postpartum period and heifers that fail to conceive

“…This is not surprising as these cows were selected from a herd of cattle with a record of very high calving rate, >92% in the previous year, compared with the other breeds, dairy FRX (56.6%), BRFX (33.3%), and BRX (43.5%). This generally might indicate the presence of genetic differences among breeds in the incidence and types of abnormal ovarian cycles that can result in differences in fertility parameters such as conception rate (Perea-Ganchou et al 2005). In addition, adaptation differences to the hot humid tropical environment may account for the big difference between the local KKX and the other three breeds.…”

“…Under the hot and humid condition, despite high rainfall that produces more forage, high humidity and temperature cause stress and affect the reproductive function through modifying endocrine balance and altering oviductaluterine environment that delays or interrupts embryo development (Perea-Ganchou et al 2005). Zebu cows (Bos indicus) and their crossbreeds have lower levels of milk production and better adaptation to adverse tropical environment and hence show lower postpartum body condition losses but a higher reproductive efficiency than the predominantly B. taurus cows (Perea-Ganchou et al 2005) Abnormal luteal function in lactating cows have been reported to be associated with reduced pregnancy rate, whereby cows with normal progesterone profiles showed significantly higher pregnancy rate than cows with abnormal profiles (87% vs 33%) following AI (Hommeida et al 2004). Moreover, a significantly higher AI submission rate, conception rate, and pregnancy rate between 44 and 100 days postpartum were reported in dairy cows with normal ovarian cycle in the first 44 days postpartum than those with prolonged luteal phases (Shrestha et al 2004a, b).…”

Comparative Analysis of Mafriwal (Bos taurus × Bos indicus) and Kedah Kelantan (Bos indicus) Sperm Proteome Identifies Sperm Proteins Potentially Responsible for Higher Fertility in a Tropical Climate

“…Mafriwal showed higher milk production and weight gain compared to indigenous breeds for example, Kedah Kelantan (KK). However, its fertility was shown to suffer from heat stress [3,4]. …”