title: Relationship between linear type and fertility traits in Nguni cows.
abstract: The objective of the study was to assess the dimensionality of seven linear traits (body condition score, body stature, body length, heart girth, navel height, body depth and flank circumference) in Nguni cows using factor analysis and indicate the relationship between the extracted latent variables and calving interval (CI) and age at first calving (AFC). The traits were measured between December 2012 and November 2013 on 1559 Nguni cows kept under thornveld, succulent karoo, grassland and bushveld vegetation types. Low partial correlations (-0.04 to 0.51), high Kaiser statistic for measure of sampling adequacy scores and significance of the Bartlett sphericity test (P1. Factor 1 included body condition score, body depth, flank circumference and heart girth and represented body capacity of cows. Factor 2 included body length, body stature and navel height and represented frame size of cows. CI and AFC decreased linearly with increase of factor 1. There was a quadratic increase in AFC as factor 2 increased (P<0.05). It was concluded that the linear type traits under study can be grouped into two distinct factors, one linked to body capacity and the other to the frame size of the cows. Small-framed cows with large body capacities have shorter CI and AFC.
authors.affiliation: 1Department of Animal and Poultry Science,School of Agricultural,Earth and Environmental Sciences,University of KwaZulu-Natal,P. Bag X01,Scottsville 3209,Pietermaritzburg,South Africa.
authors.forename: T J
authors.initials: TJ
authors.lastname: Zindove
authors.affiliation: 1Department of Animal and Poultry Science,School of Agricultural,Earth and Environmental Sciences,University of KwaZulu-Natal,P. Bag X01,Scottsville 3209,Pietermaritzburg,South Africa.
authors.forename: M
authors.initials: M
authors.lastname: Chimonyo
authors.affiliation: 2Department of Animal Sciences,Tshwane University of Technology,Private Bag X680,Pretoria 0001,South Africa.
authors.forename: K A
authors.initials: KA
authors.lastname: Nephawe
mesh_terms: D000818:Animals; D002417:Cattle / Q000502:physiology*; D005260:Female; D005298:Fertility; D008954:Models, Biological; D010641:Phenotype; D013019:South Africa
keywords: Nguni cows; body depth; calving interval; flank circumference; heart girth