Effect of supplementary feeding and zeranol on puberty in feral Cashmere goats

Eruption of first permanent incisors and live weight gain in grazing yearling Angora goats

OBJECTIVE

To investigate the effects of the timing and duration of eruption of the first permanent incisors, live weight, sex and other factors on contemporaneous live weight gain in Angora goats.

DESIGN

Goats were previously part of a pen study on the effects of energy intake of Angora does during pregnancy and lactation on kid development. The design was 3 levels of nutrition in mid-pregnancy by 2 levels of postnatal nutrition in 17 randomised blocks.

METHODS

Artificial insemination, ultrasound examination and feeding does in pens enabled accurate conduct of the study. After weaning, goats were grazed in sex groups. Live weight change between 14 and 20 months of age was related to deciduous first incisor loss and permanent first incisor development and other attributes assessed before the study.

RESULTS

Live weight change was related to the elapsed time for first permanent incisors to commence eruption and to the length of time for first permanent incisors to erupt. This response was affected by sex. Over summer and autumn, entire males with short eruption intervals gained 2-3 kg more than entire males with long eruption intervals. Females that reached first permanent incisor eruption by mid-summer had a live weight gain of 3 kg more than those that reached the same development 3 months later.

CONCLUSIONS

Live weight change in yearling Angora goats was associated with the process of first permanent incisor eruption. In females, live weight gain was greater when first permanent incisor eruption was earlier. In males, live weight gain was greater when first permanent incisor eruption was faster.

Relationship of weaning weight to the mature liveweight of cashmere does on Australian farms

Median weaning weight and its relationship with the median mature liveweight of does was quantified for four commercial Australian cashmere farms in various parts of Australia. Individual liveweights, of does of all ages at the time of weaning in December, ranged from 9 to 61 kg. Individual farm means of adult does (>1 year old) ranged from 24.6 to 38.8 kg. The model for the logarithm of liveweight was: log10(liveweight) = a + br(Age + 0.6); where a, b and r are parameters that are different for each farm. The result that the r parameter differs with farm was statistically significant (P = 9.4 × 10−6). The percentage variance accounted for was 84.4% and the residual standard deviation was 0.042. Farms differed greatly in the median mature liveweight with some farms reaching ~44 kg and others only 31 kg. Median weaning weight was 14.1 kg (range 11.4–16.8 kg). Median weaning weight as a percentage of median mature doe liveweight on a particular farm varied from 32 to 42%. These weaning weights appear low in absolute and relative terms and thus are likely to incur production penalties.