@conference {40876,
	title = {Genetic studies of bloat susceptibility in cattle.},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {57},
	year = {1997},
	month = {Jan},
	pages = {19-21},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Bloat costs the dairy industry about $50 million per year and one of the possible long- term solutions is to breed cattle for reduced susceptibility. Studies on two herds established at Ruakura in 1972/73, and selected divergently for high susceptibility (HS) or low susceptibility (LS) to bloat, have shown that: (1) bloat score on any single day of serious challenge has a heritability of 0.19{\textpm}0.04; (2) the within-animal repeatability of scores across days is 0.44{\textpm}0.02; (3) divergence of bloat score between herds has now reached 2.4 genetic standard deviations; (4) the recent response rate in the HS herd has been approximately linear whilst the LS response has plateaued; (5) 75\% of the HS herd and 2\% of the LS herd are at risk of death from bloat if left untreated. Alternative definitions of the bloat syndrome have been investigated; one of these (maximal bloat score) has a heritability of 0.30{\textpm}0.06. Using this definition, a mixed-inheritance segregation analysis was undertaken, which led us to the conclusion that a major gene for susceptibility was segregating as an autosomal recessive. The implication is that the use of non-carrier AI sires in industry could minimise the bloat problem in one generation, by avoiding production of all homozygous double-recessive progeny. },
	issn = {1176-5283},
	author = {Morris CW and Cullen NG}
}
