Investigation into the relationship between leptin genotypes, body condition and carcass traits of Nguni and Hereford cattle.
Leptin, a 16 (kilo Dalton) kDa hormone secreted predominantly by white adipocytes, regulates reproduction, energy intake and expenditure, and is involved in immune system function. Previous studies have identified associations between polymorphism E2FB in the leptin gene (lep) of cattle and milk quality and quantity, feed intake, and fat deposition in dairy and beef cattle though further studies have shown inconclusive results. Furthermore, indigenous South African cattle have not been involved in lep investigations or the applicability of the marker in South African beef grading systems. An investigation was conducted into the association of an SNP of a cytosine (C) to thymine (T) SNP (single nucleotide polymorphism) mutation in exon 2 of the bovine lep (leptin) gene with weight gain, body condition, carcass fat content and quality in a population of indigenous Nguni cattle (n = 70) as well as a population of exotic British Hereford cattle (n = 54). The Hereford population had higher T-allele frequencies and a lower P-value (P = 0.172) for the E2FB genotypes than the Nguni population (P = 0.958). The resulting E2FB lep genotypes CC, CT and TT did not show an association with the pre- and post-slaughter traits initial live weight (ILW), body condition score (BCS), slaughter live weight (SLW), carcass fat content (FAT), carcass conformation (CFN) or warm carcass mass (WCM) for either population though t-tests revealed an association with the CT genotype with increased ILW than TT and a significantly higher WG in the TT genotypes than the CT (P<0.05). Subsequently, differences in pre- and post-slaughter traits in both populations were largely attributable to breed differences. The Hereford population exhibited significantly higher WG, CFN, SLW, WCM and CCM (P<0.05) than the Nguni population. The Nguni displayed significantly higher ILW and BCS values when graded in terms of the commercial South African AAA feedlot system.
Showing items related by title, author, creator and subject.
The development and evaluation of a community-based programme offering psychosocial support to vulnerable children affected by HIV/AIDS, poverty and violence. Killian, Beverley Janet. (2004)This research programme endeavours to develop, implement and evaluate an effective method of offering psychosocial support to vulnerable children. Vulnerability is defined by trained community members as including children ...
Worth, Steven Hugh. (2008)This thesis is about agricultural extension education. The context is agricultural extension in South Africa. It addresses the following questions: To what extent does current agricultural extension education in South ...
Loan products to manage liquidity stress when broad-based black economic empowerment (BEE) enterprises invest in productive assets. Finnemore, Gareth Robert Lionel. (2005)Investments in productive assets by broad-based black economic empowerment (BEE) enterprises in South Africa (SA) during the 1990s have been constrained, in part, by a lack of access to capital. Even if capital can be ...