Genetic and environmental variation in reproductive and lactational performance of Jersey cattle in the coastal lowland semi-humid tropics

Abstract

Reproductive and lactational performances, including length of productive life, were evaluated from records for 1960 to 1988 for a Jersey herd in coastal lowland semi-humid Kenya. The herd grazed natural pastures and until the mid 1970s received supplementary feeding. Mean performance included 31 months age at first calving, lactation milk yield (MY) of 1,788 kg in 3.3 lactations and a calving interval (CI) of 408 days. Mean milk yields declined from over 2,200 kg in the 1960s to about 1,500 kg in the 1980s with concomitant changes in calving interval, length of productive life and infertility. While annual genetic components of change in MY and CI were not significantly different from zero, the environmental components were large and significant (P < 0.01) showing that the declines in performance probably resulted from decreased feed availability and less efficient disease control. Estimates of genetic parameters were consistent with those in the literature. With good management purebred Jersey cows in coastal lowland semi-humid Kenya were productive, but animal and herd productivity were highly dependent on management level which had a major effect on both milk yield and reproductive wastage.

Milk production performance of Jersey cows at Wolaita Sodo State Dairy Farm, Southern Ethiopia

“…The absence of seasonal influence on lactation yield and length in this study could be due to the fact that the animals managed on farm and lactating cows were given supplemental feed during the dry season. The finding that parity had significant influence on lactation length is in contrast with the report of Njubi et al (1992). In this study, lactation yield increased with parity number up to third, which is in agreement with the reports by Mureja Shibru (2002), and Nega Tolla and Sendros Demeke (2001).…”

“…The mean productive herd life found in the present study was much higher than the observation of Narasimha and Mohan (1996) and Njubi et al (1992), which were 48.25 and 36 months respectively. The productive life for Jersey crosses with Boran, Horro and Sahiwal were 5.1 and 6.8 (Gebreegiziabher GebreYohannes and Mulugeta Kebede, 2006) and 5.7 years (Singh et al, 1988) respectively.…”

“…The long calving interval found in this study could have contributed to the low lifetime lactation performance. The average length of herd life in the present study was by far higher than the reports of Njubi et al (1992) and Narasimha and Mohan (1996). But Gebreegiziabher Gebre-Yohannes and Mulugeta Kebede (2006) reported higher herd life for Boran and Horro crosses of Jersey.…”

“…However, there was a report indicating that year of birth had significant effect on productive herd life of Holstein cattle (Gebeyehu Goshu et al, 2007) and effective productive herd life of crosses of Friesian and Boran cattle (Gebeyehu Goshu, 2005). On the other hand, non-significant effect of year of birth on length of productive life was reported by Njubi et al (1992).…”

Estimation of Genetic and Non-Genetic Parameters of Friesian Cattle under Hot Climate

“…While Tadesse et al (2010) reported non-significant effect of parity number on the trait for Friesian cattle in Ethiopia. Season of calving have no significant (p < 0.05) effect on the trait, this agreed with Njubi et al (1992) and disagreed with Juma and Al-Samarai. (1987).…”