02841naa a2200277 a 450000100080000000500110000800800410001910000190006024500830007926000090016252021030017165000240227465000100229865000090230865000100231765000170232765000100234465000170235465300170237165300160238865300220240465300230242665300180244970000180246777300780248515210952023-03-31       1986    bl uuuu     u00u1 u    #d1 aPROBERT, A. D.  aA study of short scrotum, castred and entire ram lambs.h[electronic resource]  c1986  aGrowth rates,carcasscomposition and management problems of“short scrotum”rams (made byelevating the testes toa position against the abdominal wall using rubber rings), wethers and entire male lambs were compared on a hill country property in northern Hawkes Bay. Of 3groups of65 Perendale lambs selected randomly at dockingat about 4 weeks of age. I group was left entire, I was made short scrotum and thr other was castrated. The lambs were weaned at about IO weeks of age, separated from the main flock at about 14 weeks of age and thereafter kept as I flock until slaughter at 9 months of age. They were weighed every 6 weeks from 14 weeks ofage. After the~removal of 6 lambs fromeachgroup for detailed investigation at Massey University, the top 50 lambs from each group were slaughtered and their carcass characteristics recorded. Short scrotum rams showed management advantages over normal ram lambs. They were easier to handle. and avoided the works hygiene problem of dirty genitalia. Short scrotum rams had an overall live-weight advantage 01 3kg over wether lambs. This was found not to be due to fat deposition, as short scrotum rams showed a significantly lower GR of 3.3mm, compared with normal rams (4.6mm) and wethers (6.2mm). as predicted by regression for lambs ol32kg live weight. There was no significant difference in carcass weight or dressing percentage between lambs of this live weight, although more normal rams and short scrotum rams fell into heavier grades than did the wcther lambs. In detailed investigations on 6 lambs from each group, no differences were found in muscle:bone ratio or fat distribution between the groups. Short scrotum rams had very low fertility; 50 of 56 had no epididymal sperm reserves and 6 had extremely low sperm production. Most sperm from short scrotum rams were abnormal. Short scrotum rams had significantly lighter testes and epididymides than normal rams. Short scrotum rams had plasma LH levels intermediate to normal rams and wethers. Differences between entire and short scrotum rams in testosterone levels varied inconsistently.  aCarcass composition  aLambs  aRams  aSheep  aTestosterone  aOvino  aReprodução  aCryptorchids  aLive weight  aMale reproduction  aManejo reprodutivo  aShort scrotum1 aDAVIES, A. S.  tProceedings New Zealand Society Animal Productiongv. 46, p. 55-58, 1986.