Estimates of genetic, environmental and phenotypic trends in indigenous Nguni cattle of Zimbabwe: implication for manage
Journal Title: Scientific Journal of Animal Science - Year 2013, Vol 2, Issue 12
Abstract
Growth traits in indigenous cattle are desirable economicparameters which should be improved and their trends monitored over time toinvestigate direction of change. Traits considered were birth weight (BWT) andweaning weight (WWT). BLUP breeding values were regressed on year to obtainannual direct and maternal genetic trends, while fixed effects solutions andmean performances were regressed on year to obtain environmental and phenotypictrends, respectively. Linear regression representing genetic trends for directeffects indicated a decrease of -0.02 kg per year for BWT, and an increase of0.12 kg per year for weaning weight. The environmental trend was positive forbirth weight and negative for weaning weight. A cubic regression produced arelative better fit for environmental values for WWT (R-square= 34%), ascompared to a linear regression of (R-square=18%). Environmental values for WWTdecreased from approximately 1983, suggesting that the environmental conditionshad a negative effects on WWT. There was a net phenotypic gain for birth weightof 0.48 kg per year, and a net phenotypic loss for WWT of -01.57 kg per year. The trend of maternal ability forBWT increased at the first quarter of the study (1983 to 1991), and thendeclined thereafter (1992 to 1997), and was insignificant for WWT. The resultsobtained in the present study on various trends demonstrate that very smallgenetic gains were realized signaling need for change in selection and/ormanagement procedure in the scheme.
Authors and Affiliations
N. Assan| Matopos Research Station, Bag K 5137, Bulawayo, Zimbabwe.
Keywords
Related Articles
- EP ID EP670
- DOI 10.14196/sjas.v2i12.1089
- Views 457
- Downloads 22
Goat production system in peri-urban areas of Khartoum state, Sudan
Data was collected from one hundred goats’ owners from peri- urban areas in Khartoum state and were used to study the characteristics of dairy goat production. Reproduction traits, diseases prevalence, breeding objective...
Live weight changes, gonadal and epididymal sperm reserves of Yankasa Rams fed different levels of dried layer litter in
The effects of feeding different levels of dried layer litter as a protein source on live weight, testicular weight, gonadal and epididymal sperm reserves of Yankasa rams was investigated in a 98-day study. Twenty heal...
Physiological groups of heterotrophic community bacteria present at River Actopan, Chachalacas barrier, Veracruz
The aim of this study was to determine physiological groups of heterotrophic community bacteria in River Actopan mouth, Chachalacas, Veracruz, Mexico. Water samples were collected in sterile jars in three zones of river:...
Ethno veterinary practices for poultry and cattle in Zimbabwe: A case study of Takavarasha village
Ethno veterinary practices are increasingly becoming important in theprimary health care of livestock the world over. This is so especially for smallholderfarmers in developing countries where conventional veterinary d...
Quantification of cytokines in the amniotic fluid at the moment of delivery of Nelore calves conceived by in-vitro produ
The aim of the present study was to compare the concentrations of cytokines in the conceptus’ amnioticfluid at the moment of delivery of Nelore calvesconceived from embryos produced by in-vitro(IVP) or after artificial...