PREDICTION OF THE BODY WEIGHT OF NGUNI GOATS
By S. Slippers, B. Letty, J. F. D. Villiers. 2000
66 citations recorded by the source corpus.
Data on the age, body weight, heart girth and gender of 54 Nguni goats were collected from a flock belonging to a small-scale farmer near Impendhle, Kwazulu-Natal. Age was determined by counting the number of permanent incisors present. Body weight (kg) was determined with an electronic scale. Heart girth (cm) was measured with a measuring tape across the chest, directly behind the forelegs, with the goat standing squarely on all four legs. No distinction was made between pregnant and open does, since pregnancy status of the does was not known. Means, standard deviations, Pearson correlation coefficients, and the parameter estimates for the linear regression relationship (Y = a + bX) between heart girth (X) and body weight (Y), were derived (Minitab Inc., 1998). Separate prediction equations were developed for bucks and does. Body weight was then predicted for individual goats in two different ways: using the prediction equations developed in this study or using the prediction equations developed by Myeni & Slippers (1997). Hence, it was possible to make within-gender comparisons amongst actual body weight and the two sets of predicted body weights by means of the paired t-test (Minitab Inc., 1998). Results and Discussion The body weight results of bucks and does are summarised in Tables 1 and 2 respectively. Body weight was highly correlated (P < 0.01) with heart girth measurement for both gender categories studied, namely r = 0.939 (bucks), and r = 0.971(does).The respective prediction equations developed for bucks and does were: Y = -43.0277 + 0.992924.X (P < 0.01; R 2 = 88.1%), and Y = -47.6799 + 1.07677X ( P < 0.01; R 2 = 94.3%). For bucks there was no significant difference between actual body weight (23.25 kg ± 2.73) and body weight predicted with the equation from the present study (23.25 kg ± 2.57), nor between actual body weight and predicted body weight based on the equation of Myeni & Slippers (1997) (24.93 kg ± 2.26), but the two sets of predicted weights differed significantly (P < 0.01) from one another. None of the three pair-wise comparisons of actual and predicted body weight of does differed significantly from one another (being 26.25 kg ± 1.35, 26.25 kg ± 1.31 and 26.52 kg ± 1.16 for actual body weight, current prediction and the previous study respectively). Variation in body weight was explained to a large extent by heart girth in this study, in concert with the findings of Myeni & Slippers (1997). The results of both studies therefore confirm that the body weight of Nguni goats can be predicted with confidence from
Subfields: Agronomy and Crop Science, Genetics
View Paper: https://www.semanticscholar.org/paper/c67184fdfe4af8c2189b23d62e7cff51d4b4e296
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Citations in the corpus
- Fixing collinearity instability in the estimation of body weight from morpho-biometrical traits of West African dwarf goats. (2009, methodology): “Body measurements have been used in animals to contrast variation in size and shape (4, 5), and to estimate body weight (6,7).”
- The accuracy of prediction of body weight from body measurements in beef cattle (2009, unknown): “MSANGI et al. (1999), SLIPPERS et al. (2000), FOUIRE et al. (2002), WILLEKE and DÜRSCH (2002) and BOZKURT (2006) indicated that chest girth can be used to predict body weight that it is the best prediction parameter.”