• Publications
  • Influence
(Co)variances for reproduction, egg weight and chick weight in ostriches
The study investigated genetic parameters for egg and chick production recorded over an 8-month breeding season, as well as average egg and chick weight for pair-bred ostrich females. Estimates of h²Expand
  • 26
  • 5
  • PDF
Genetic relationships between water loss and shell deaths in ostrich eggs, assessed as traits of the female
The ostrich industry suffers from a high rate of embryonic mortality during artificial incubation of eggs. Data from 34285 eggs were used to derive 969 female-year records for evaporative water lossExpand
  • 12
  • 5
Heritability estimates and correlations between subjectively assessed and objectively measured fleece traits in Merino sheep
Data from 2801 individuals (born from 1996 to 2002) were used to obtain heritability (h 2 ) estimates for five objectively measured and six linearly assessed type fleece traits (scored on a 1-50Expand
  • 12
  • 4
  • PDF
Genetic change in some South African Merino Studs Participating in the Merino Plan
Data from the Merino Plan database were used to estimate genetic parameters for body weight (BW), clean fleece weight (CFW), fibre diameter (FD), staple length (SL) and total weight of lamb weaned.Expand
  • 9
  • 3
Reproductive performance of commercial Merino, Dohne Merino and SA Mutton Merino flocks in the Southern Cape
Data of 23 189 Merino ewes (8 farms), 7692 Dohne Merino ewes (3 farms) and 2399 SA Mutton Merino ewes (1 farm) were recorded for the 1988-1991 lambing seasons. The udders of ewes present at lambExpand
  • 18
  • 3
Genetic parameters for ostrich incubation traits in South Africa
Data obtained from a pair-mated ostrich flock located at Oudtshoorn, South Africa, were used to estimate genetic parameters for egg weight (EWT), weight of day-old chicks (CWT), water loss to 21Expand
  • 8
  • 3
  • PDF
Observations on neonatal progress of Dormer and South African Mutton Merino lambs
Data of Dormer (n = 290) and SA Mutton Merino (n = 306) lambs, born by ewes which were observed continuously during lambing in 1989-1991, formed the basis of this investigation. Progeny of SA MuttonExpand
  • 25
  • 2
Genetic parameters for reproduction rate in the Tygerhoek Merino flock. 2. Genetic correlations with wool and live mass traits
Data of the Tygerhoek Merino flock were used to obtain estimates of genetic correlations of 18 months wool and pre-mating live mass traits with average reproduction over two to five lambingExpand
  • 8
  • 2
Gas exchange of the ostrich embryo during peak metabolism in relation to incubator design
Oxygen (O2) consumption and carbon dioxide (CO2) excretion of ostrich embryos were studied on 45 ostrich eggs in various stages of development. A closed respirometry system was used for eggsExpand
  • 9
  • 1
  • PDF