Prediction of wool fibre diameter from protein and metabolisable energy digestibility coefficients in crossbred sheep.

摘要: Our objective in this study was to investigate the interactions between sire breed and supplement on digestibility ascertain its accuracy predicting wool fibre diameter. Forty first-cross Merino weaner sheep sired by Texel, Coopworth, White Suffolk, East-Friesian Dorset sires with initial BW range of 22.9 31.3 kg (average 26.8 ± 3.2 kg) were randomly assigned four treatment groups a 5 × 2 factorial experimental design representing breeds, supplementary feeds (canola lupins), feeding levels (1 2% bodyweight) sexes (ewes wethers). The trial lasted for six weeks an 3-week adjustment period last 7 days faecal collection. Factorial ANOVA orthogonal contrasts SAS used statistical analysis test results demonstrated that level significantly influenced (P<0.01) whereby Coopworth-sired sheep supplemented at 1% their body weight recorded highest ME N 54% 67% compared 42% 62% respectively, counterparts fed at weight. There highly significant effect type x interaction diameter end because canola supplements had finer (22.1 microns) than 2%-fed (25.4 microns). Regression revealed very poor prediction (R2 = 0.0087-0.169). We concluded variation is unlikely be useful predictor genetic merit first cross under same management.