Prime Lamb Research Articles

Some variables influencing production of prime lamb and wool from pasture

In an experiment at Canberra, A.C.T., extending over four years, crossbred and Merino ewes were grazed at three stocking rates on pastures of either phalaris (Phalaris tuberosa), phalaris combined with separate paddocks of brome grass (Bromus inermis), and cocksfoot (Dactyllis glomerata), or separate paddocks of brome grass and cocksfoot. Subterranean clover (Trifolium subterraneum) was present in all pastures. One-, two-, and three-paddock systems and two times of lambing were also compared. Pasture availability and animal productivity were measured. Early lambing resulted in more prime lambs although the later lambs had slightly higher rates of gain. At the highest crossbred stocking rate studied (seven ewes per acre) wool production per acre was still increasing, but number of prime lambs and lamb liveweight gain did not increase above stocking rates of five ewes per acre. More feed was available to ewes during late pregnancy on treatments allowing feed rationing in autumn and early winter, but neither rationing nor including brome grass and cocksfoot in the system increased animal productivity beyond that achieved by grazing phalaris continuously. At stocking rates up to six ewes per acre, animal production was greatest from phalaris grazed continuously. Stocking rates were designed to provide similar weights of either Merino or crossbred ewes per acre at each stocking level. Because more lambs were born to crossbred ewes they had less feed than Merinos in spring and summer at all stocking rates. Lambs from crossbred ewes were heavier at birth and grew faster than lambs from Merino ewes. More prime crossbred lambs were produced per acre at all stocking levels. The reproductive rate and lamb production of Merino ewes dropped sharply with increased stocking rate. Fleeceweights were similar for both breeds, particularly at low stocking rates. Wool production per acre increased with stocking rate and was higher from Merinos at each level.

Performance of sheep and cattle grazed separately and together

Groups of two young steers and eight autumn lambing ewes, mated for prime lamb production and each rearing a single lamb, grazed together at three stocking rates and separately each at five stocking rates on annual pasture. Results were rejected for animals fed a supplement. In most instances when pasture conditions were fairly good throughout the year, mixed stocking increased production. In one year when pasture was very poor during winter, mixed stocking resulted in little or no increase in production. The weight changes of the animals suggest that most of the benefit from mixed stocking occurred during winter. The effect of mixed stocking on production varied with stocking rate only in the first pear. In general, the competition between sheep and cattle, as measured by annual production, did not vary with stocking rate. The sheep appeared to benefit more than the steers from mixed stocking, but this may have been a consequence of the stocking ratio selected.

PRIME LAMB PRODUCTION

Australian Veterinary JournalVolume 44, Issue 5 p. 206-206 PRIME LAMB PRODUCTION W. J. Pryor, W. J. PryorSearch for more papers by this authorD. D. Charles, D. D. CharlesSearch for more papers by this author W. J. Pryor, W. J. PryorSearch for more papers by this authorD. D. Charles, D. D. CharlesSearch for more papers by this author First published: May 1968 https://doi.org/10.1111/j.1751-0813.1968.tb09081.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume44, Issue5May 1968Pages 206-206 RelatedInformation

Prime lamb production: the influence of stocking rate on response to early weaning

The relationship between response to weaning and stocking rate was examined for prime lambs, and, within the conditions of the experiment, critical stocking rates were established above which weaning was more productive than not weaning. Similar critical stocking rates were deduced for two hypothetical situations. The measurements made and considered were for gain, carcass weight, and carcass quality for both weaned and suckling lambs, and weight change for their dams.

The effects of castration and of the poll gene on prime lamb production

During 1961 and 1962 experiments were conducted at Tamworth Agricultural Research Station to evaluate the effect of several castration treatments and of the poll gene on prime lamb production. Ram lambs and lambs sterilized by removal of the cauda epididymis had significantly heavier live weights at 16 weeks of age than did partially castrated lambs (half of each testis removed). These in turn were significantly heavier than wethers and ewes. Among single lambs, rams and sterilized rams had carcasses that were nine per cent heavier than those of wether and ewe lambs (P<0.01). With twins this difference was reduced to 1.3 per cent for wethers (n.s.) and eight per cent for ewes (P<0.05). The average carcass weight of partially castrated lambs was between these two groups. Mean horn volumes and preputial adhesion scores suggested that these lambs had less endogenous androgen than rams and sterilized lambs. All single lamb carcasses were classed as First Grade. There were no significant differences in the number of twin lambs that were down-graded in each treatment. Fifty-four per cent of the ram and sterilized ram carcasses were classed as Ram and would be subject to a price penalty regardless of their carcass grade. Taste panel tests of meat from the hind legs of wether and sterilized ram carcasses showed that the sterilized ram meat was slightly more acceptable. There were no significant differences in live weight, carcass weight or carcass grade between polled and horned lambs.