Non Genetic Factors Effect on Reproductive Performance and Preweaning Mortality From Artificially and Naturally Bred in Bali Cattle

Abstract

The aim of this study was to evaluate effect of non genetic factors on reproductive performance of Bali cattle. Data on reproduction performance were collected from Breeding Centre of Bali Cattle in Denpasar-Bali. Reproductive traits studied were age at first calving (AFC), calving interval (CI) and pregnancy rate (PR). To observe the effect of non genetic factors on the reproductive traits, a mixed model was used because all of the traits studied were measured repeatedly in individuals. The overall means for AFC, CI, PR and preweaning mortality were 43.86±0.70 months, 360.93±4.47 days, 88.44±1.91% and 7.58±1.07%, respectively. The results showed that AFC and PR were significantly (P<0.01) influenced by dam year of birth but mating system had no significant (P>0.05) effect. With regard to CI, dam year of birth and parity affected CI while mating system had no significantly affect (P>0.05) on CI. The preweaning mortality was only affected by the age of dam significantly (P<0.01). The average of reproductive performance and preweaning mortality in Bali Cattle were not depended remarkably on the mating system being practiced. It might be concluded that an improvement in Bali cattle reproductive traits is possible through improving management systems and utilisation of controlled breeding techniques.

Bayesian estimates of genetic parameters for reproductive traits in Nellore cows raised on pasture in tropical regions

“…The decreasing trend observed for AFC and CI indicates an improvement in the genetic merit for these traits (Makgahlela et al, 2008;Gunawan et al, 2011a). Gunawan et al (2011b) considered that this might be partly a correlated response to selection for increased daily gain.…”

Genetic Analysis of Reproductive Traits in Bali Cattle Maintained on Range Under Artificially and Naturally Bred

“…In general, there were decreasing phenotypic and genetic trend for AFC, CI and PR. There were consistent phenotypic trend for AFC, CI and PR over the years from 2003 onwards (Figure 1 (Table 3) The decreasing trend observed for AFC, CI indicated an improvement in the genetic merit of these traits (Gunawan et al, 2011;Makgahlela et al, 2008). This may be a part of correlated response to selection for increase daily gain.…”

“…The records number of AFC, CI and PR were 138 heads, 96 heads and 450 heads, respectively. Detail of data structure according to traits studied with various classes and subclasses were described previously in Gunawan et al (2011). Data available for AFC and CI were from year of 2001-2006, records for PR was available from 2000 to 2007 from artificial insemination and natural mating.…”

“…A reduced age at first calving will increase the number of calves born for a given number of animals (Javed et al, 2000). Morever, the reduction in age at first calving indicated an improvement in the genetic merit of this trait including managemental practices and nutritional management (Gunawan et al, 2011).…”

“…However, the decreasing trend for PR more fluctuation compared to AFC and CI. The fluctuation of values observed for pregnancy rate indicated that environment may play a great role in the ability of cow to become pregnant in the breeding centre (Gunawan et al, 2011). A possible cause of this undesirable trend is intense selection to increase daily gain, without giving much attention on fertility.…”