Genetic and phenotypic parameters for birth and weaning weights of purebred and crossbred N'dama and West African Shorthorn cattle

Calf records for a 30 year period (1965-1995) on purebred and crossbred N'dama and West African Shorthorn (WASH) cattle and their crosses with Santa Gertrudis or Red Poll were analyzed to determine factors affecting birth and weaning weights and to estimate genetic parameters. Male calves weighed heavier (p< 0.05) at birth and at weaning. Similarly period (year grouping) significantly influenced birth and weaning weights of calves. Season of birth did not influence calf weight at birth but significantly affected calf weaning weights. Purebred calves were similar in weight at birth and at weaning. Santa Gertrudis crossbreds weighed heavier than Red Poll crossbreds at birth only but not at weaning. Generally the poor level of nutrition of the natural pasture did not permit improved weaning weights in calves, which were heavier at birth. Additive direct heritability estimates were 0.45±0.08 for birth weight and 038±0.18 for weaning weight. Moderate genetic correlation (0.48) between birth and weaning weights indicates that selection for one trait would lead to moderate positive correlated response in the other trait. Due to negative genetic correlation (-0.29±0.16) between direct and maternal effects for weaning weight, and moderate heritabilities for both traits, selection for both the direct and maternal components of preweaning traits is advised

Morphological characterization of local pigs in Ghana

Characterization is essential for conservation and sustainable utilization of farm animal genetic resources, especially local breeds that are often less fancied due to their relatively low production potential. A total of 163 local Ashanti Dwarf pigs (ADP) and their crossbreds with exotic breeds, sampled from six regions of Ghana were characterized morphologically following FAO’s methodology on phenotypic characterization of Animal Genetic Resources (AnGR). Results indicated no significant (p &gt; 0.05) effect of type of breed and sex on linear body measurements. There was a significant (p &lt; 0.05) effect of location on linear body measurements. Local pigs presented concave head profile (85.89%), black coat colour type (67.48%), plain coat colour pattern, erect ear type (84.66%), projecting backwards (52.15%) and a short and cylindrical snout type (62.58%). A greater number of the local pigs (70.55%) showed aggressive temperament. The data gathered from this study should contribute to the development of sustainable conservation schemes for local pig genetic resources and prevent their extinction.Keywords; characterization, morphological, ADP, conservatio

Crossbreeding Jersey with Ghana Shorthorn and Sokoto Gudali cattle in a tropical environment: Additive and heterotic effects for milk production, reproduction and calf growth traits

Crossbreeding data involving Ghana Shorthorn, Sokoto Gudali and their Jersey F1S and backcrosses collected over a 16-year period were analysed to estimate additive and heterotic effects for milk production, reproduction and calf growth traits. Sokoto Gudali was significantly better than Ghana Shorthorn in all milk production traits. Calving interval and annualized milk production were better in Gudali than in the Shorthorn. The F1s had higher lactation milk yield, milked longer, produced their first calves earlier and had shorter dry periods and calving intervals than their corresponding purebreds. However, genotype was not significant for number of services per conception. Both F1s had higher average daily gain and weaning weight than their corresponding purebreds. Sokoto Gudali backcross (Jersey X F1) was significantly (P<0.05) better than the F1 in lactation length. However, in Gudali crosses, there was no advantage in increasing the proportion of Jersey genes beyond 0.5 for milk production traits. Additive effects were significantly (at least P<0.05) lower in the Shorthorn and the Gudali than in Jersey for milk production traits except proportion of butterfat. Heterosis estimates were significant (P<0.01) for milk production traits for the Shorthorn but not for the Gudali. Heterotic effects were large and significant (at least P<0.05) in improving annualized milk production in Shorthorn crosses, whilst none of the heterotic effects for reproductive traits was significant. At both 0 and 0.5 levels of Jersey inheritance, the Gudali was superior (P<0.01) to the Shorthorn in birth weight, weaning weight and pre-weaning average daily gain. Heterotic effects for calf traits were postive and much larger in Gudali crosses than in Shorthorn crosses. In general, backcrosses were, at best similar to the F1s, implying that upgrading these indigenous breeds beyond 0.5 European inheritance may not be desirable