Skip to content

"Experientia docet" - Experience is the best teacher

Phenotypic and genetic parameters for selected production and reproduction traits of Mpwapwa cattle in low-input production systems

  • 2017
  • Issue: 3
  • Volume: 47
A.R. Chawala, G. Banos, D.M. Komwihangilo, A. Peters & M.G.G Chagunda Page: 307 - 319

The objective of this study was to assess the genetic improvement programme of the Mpwapwa dairy cattle breed over the past four decades,  based on on-station selection and breeding. Estimates of genetic parameters and genetic trends for total lactation milk…

Read more

Genetic parameter estimates for tick resistance in Bonsmara cattle

  • 2009
  • Issue: 4
  • Volume: 39
M.A. Budeli, K.A. Nephawe, D. Norris, N.W. Selapa, L. Bergh and A. Maiwashe Page: 321 - 327

The objectives of the study were to estimate genetic parameters for tick resistance and to evaluate the effect of the level of tick infestation on the estimates of genetic parameters for South African Bonsmara cattle. Field data of repeated tick…

Read more

Heterogeneity of variance and its implications on dairy cattle breeding

  • 2007
  • Issue: 3
  • Volume: 37
T.K. Muasya, E.D. Ilatsia, T.M. Magothe and A.K. Kahi Page: 170 - 175

Milk yield data (n = 12307) from 116 Holstein-Friesian herds were grouped into three production environments based on mean and standard deviation of herd 305-day milk yield and evaluated for within herd variation using univariate animal model procedures. Variance components…

Read more

Genetic parameter estimates for type traits in the South African Jersey breed

  • 2000
  • Issue: 3
  • Volume: 30
D.J. van Niekerk, F.W.C. Neser and G.J. Erasmus Page: 186 - 192

Known environmental effects influencing type trait scores in South African Jersey cattle were identified. Variance components and heritabilities were estimated for these traits as well as genetic correlations among them and with production traits. Heritability estimates were generally low to…

Read more

Direct and maternal variance component estimates for clean fleece weight, body weight and mean fibre diameter in the Grootfontei

  • 1994
  • Issue: 4
  • Volume: 24
J.J. Olivier, G.J. Erasmus, J.B. van Wyk and K.V. Konstantinov Page: 122 - 124

Direct and maternal variance components and resulting heritabilities were estimated by DFREML-procedures for clean fleece weight (CFW), body weight (BW) and mean fibre diameter (MFD) in the Grootfontein Merino stud. Direct heritabilities were estimated as 0.381, 0.289 and 0.626 for…

Read more

Genetic parameter estimates in the South African Jersey breed

  • 1998
  • Issue: 3
  • Volume: 28
J. duToit, J.B. van Wyk and J. van der Westhuizen Page: 146 -

Data obtained from the INTERGIS for Jersey breeders participating in the NationalDairy Cattle Performance and Progeny Testing Scheme were analysed. The registered and grade records commenced in test year 1977 through 1992 (incomplete) and consisting of lactations between 240 and…

Read more

Variance components and genetic parameters for body weight and fleece traits of Merino sheep in an arid environment

  • 1996
  • Issue: 1
  • Volume: 26
M.A. Snyman, J.J. Olivier and W.J. Olivier Page: 11 - 14

Data collected on the Carnarvon Merino flock over the period 1962 to 1983 were used for this study. Variance components resulting from direct additive genetic effects, maternal additive genetic effects, maternal permanent environmental effects, as well as the relationship between…

Read more
Back To Top