@conference {40868,
	title = {A comparison of two methods of castration of post-pubertal beef cattle and their effect on behaviour, growth and ultimate pH},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {56},
	year = {1996},
	month = {Jan},
	pages = {394-397},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {This study aimed to evaluate the effect of surgical and  immunocastration of post-pubertal beef cattle on their sexual and aggressive  behaviour, growth and meat quality. Forty mixed-breed bulls were assigned  to one of four treatments (n = 10): steers (S) castrated at 11 months of age,  late castrates (LC) surgically castrated at 17 months of age (Day 1),  immunocastrates (I) vaccinated against GnRH at 17 months of age (Day 1)  and entire bulls (B). Sexual and aggressive behaviour was monitored at  monthly intervals and prior to slaughter, animals were weighed and blood  sampled fortnightly. All treatments were slaughtered at 22 months of age  after which carcass composition and meat quality (pHu) were assessed.  Plasma testosterone concentrations declined to the level of steers by Day 14  for late castrates and by Day 28 for immunocastrates and remained lower  than for entire bulls through to slaughter. Entire bulls had a heavier hot  carcass weight (HCW) than I, LC and S. Immunocastrates were heavier than  LC and S. Treatment had no effect on pHu although late castrates tended to  have a higher mean pHu than immunocastrates and steers. From Day 0 to  slaughter, rates of sexual and aggressive behaviour declined significantly for  bulls, late castrates and immunocastrates to be similar to steers. There was a  tendency for bulls to show higher levels of both sexual and aggressive  behaviour during lairage.},
	issn = {1176-5283},
	author = {Jago JG and Matthews L and Bass JJ and Knight TW}
}
