Please use this identifier to cite or link to this item: https://hdl.handle.net/1959.11/9072
Title: Unravelling the complex interactions between genetics, animal age and nutrition as they impact on tissue deposition, muscle characteristics and quality of Australian sheep meat
Contributor(s): Warner, RD (author); Pethick, David W (author); Greenwood, Paul (author); Ponnampalam, EN (author); Banks, Robert  (author); Hopkins, DL (author)
Publication Date: 2007
DOI: 10.1071/EA07229
Handle Link: https://hdl.handle.net/1959.11/9072
Abstract: The combined effects of age and genetics and Poll Dorset sire and growth path were studied in two separate experiments (n = 595 and 627, respectively). In the first experiment, containing genotype crosses typically used in Australia (Merino, Poll Dorset, Border Leicester) and sires selected for growth or muscling, sheep were slaughtered at 4, 8, 14 and 22 months. The second experiment used Poll Dorset sires selected for high muscling, fat or growth with progeny having two levels of nutrition postweaning. Border Leicesters expressed higher levels of carcass fat percentage and intramuscular fat and produced the heaviest carcass. Merinos had the lowest subcutaneous fat depth and highest carcass lean percentage when compared at the same age. The progeny of Poll Dorset sires selected for high muscling (PDm) expressed a shift toward glycolytic fibres relative to those from Merino sires, and PDm sires produced progeny with reduced spine and limb length and higher carcass muscle : mineral ratios, suggesting skeletal stunting. Genotype meat quality differences were minimal except that PDm sire topsides were tougher and Merinos produced higher pH meat. With age (4-22 months), lambs became heavier and fatter, fibres shifted towards oxidative and away from glycolytic, muscle myoglobin increased, the meat became darker and redder and tenderness declined. Early weaning had no effect on the time to reach slaughter weight, provided nutrition was not restricted. The sire genetics influence on the carcass composition far outweighed the effect of nutrition postweaning. Lambs on a restricted diet tended to have less acceptable meat quality but this was not evident in lambs from sires selected for high fatness. Sensory tenderness was improved and intramuscular fat was higher in lamb progeny from sires selected for high fatness.
Publication Type: Journal Article
Source of Publication: Australian Journal of Experimental Agriculture, 47(10), p. 1229-1238
Publisher: CSIRO Publishing
Place of Publication: Australia
ISSN: 1446-5574
0816-1089
1836-5787
1836-0939
Fields of Research (FoR) 2008: 070202 Animal Growth and Development
070201 Animal Breeding
070204 Animal Nutrition
Socio-Economic Objective (SEO) 2008: 830310 Sheep - Meat
Peer Reviewed: Yes
HERDC Category Description: C1 Refereed Article in a Scholarly Journal
Appears in Collections:Animal Genetics and Breeding Unit (AGBU)
Journal Article

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