DEVELOPMENT OF A TRACEABILITY MODEL APPLIED TO GOAT AND SHEEP MEAT PRODUCTION

Changes in the sheep industry over the last 20 years represent a trend that is unlikely to be reversed. The farm gate value of wool production has decreased from over $6 billion to ~$2.5 billion and the value of sheep meat has increased from $0.5 to $2.2 billion. Wool and meat are now on an equal footing in terms of the economic value of each sector of the industry. Future profitability of both wool and sheep meat production depends on achieving a high rate of productivity gain and improving quality attributes valued by consumers. Wool and sheep meat cannot compete on price or volume with synthetics and cotton in the textile market or with chicken and pork in the meat market. Differentiation based on quality and consistency needs to be measurable and clearly understood by consumers. The combination of genetic selection and good management can deliver improved productivity gain. Skills development and training will be essential for the industry to fully utilise available knowledge and new technologies.

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Identifying QTL for meat quality and carcass composition traits in Blackface sheep

Proceedings of the British Society of Animal Science ◽

10.1017/s175275620000956x ◽

2005 ◽

Vol 2005 ◽

pp. 45-45

Author(s):

E. Karamichou ◽

G.R. Nute ◽

R.I. Richardson ◽

K. McLean ◽

S.C. Bishop

Keyword(s):

Meat Quality ◽

Quantitative Traits ◽

Carcass Composition ◽

Farm Animals ◽

Meat Production ◽

Livestock Species ◽

Sheep Meat ◽

Qtl Identification ◽

Genomic Regions ◽

Qtl Effects

The development of genetic markers and their application to farm animals has progressed rapidly, opening new prospects for identifying chromosomal regions that control quantitative traits (quantitative trait loci or QTL). However, there is less activity in QTL identification in sheep than in other livestock species. Surprisingly few QTL have been published for traits of direct relevance to sheep meat production, apart from studies of individual major genes such as the callipyge locus (Freking et al, 2002). This suggests there may be more QTL effects still to be found in sheep. Hence, this study aims to identify QTL for carcass composition and meat quality traits. This will provide a basis for targeting genomic regions to verify QTL in independent sheep populations.

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Genotype and age effects on sheep meat production. 1. Production and growth

Australian Journal of Experimental Agriculture ◽

10.1071/ea06236 ◽

2007 ◽

Vol 47 (10) ◽

pp. 1119 ◽

Cited By ~ 15

Author(s):

D. L. Hopkins ◽

D. F. Stanley ◽

L. C. Martin ◽

A. R. Gilmour

Keyword(s):

Significant Interaction ◽

Meat Production ◽

Age Group ◽

Weaning Weight ◽

Genotype Effect ◽

Ewe Lambs ◽

Sheep Meat ◽

Fleece Weight ◽

Estimated Breeding Values ◽

Sire Breed

The growth, wool production and teeth eruption of animals from five genotypes [Poll Dorsetgrowth (PD) × Border Leicester × Merino (BLM); PDg × Merino (M); Poll Dorsetmuscling (PDm) × M; M × M; BL × M] were evaluated over the age span of 4 to 22 months of age. In total, 16 sires were used to generate the animals and these were selected for growth based on estimated breeding values (EBVs), apart from one group (PDm) which was selected for muscling based on EBVs. In total, 595 animals were slaughtered at 4, 8, 14 or 22 months of age. The birthweight of lambs born to BLM ewes was 0.6 kg heavier (P < 0.001) than those born to Merino ewes, and wether lambs were 0.2 kg heavier than ewe lambs (P < 0.001). The yearling weight (YWT) EBV had no effect on birthweight. There were significant (P < 0.001) differences between genotypes for predicted weaning weight at 4 months of age, with a range of 10.6 kg among the groups. The PDg × BLM were the heaviest (37.8 ± 0.7 kg) and the Merino the lightest (27.3 ± 0.8 kg). Wether lambs were 2.0 kg heavier (P < 0.001) than ewe lambs at weaning. The YWT EBV had no effect on weaning weight. There was a significant (P < 0.001) interaction between the age at slaughter and genotype for final liveweight of each age group. The PDg × BLM were the heaviest at each age and the Merinos the lightest, and for the oldest animals, the BLM were significantly (P < 0.05) heavier than PDm × M, whereas at younger ages this was not the case. The significant interaction (P < 0.001) between sex and age at slaughter reflected the increasing difference in liveweight between the sexes as age at slaughter increased. There was also a significant (P < 0.05) interaction between the YWT EBV and age at slaughter. The overall coefficients were –0.01, 0.14, 0.34 and 0.65 for slaughter ages 4, 8, 14 and 22 months, respectively, indicating that in young animals there was no effect of sire YWT EBV on liveweight, but as the animals aged there was an increasing effect such that progeny of sires with high sire YWT EBV were heavier. This effect was evident within all genotypes. There was a sire breed effect on fleece weight and total wool weight (P < 0.001) with Merino-sired hoggets producing 0.4 kg more wool than Border Leicester-sired hoggets and 1.5 kg more than Poll Dorset-sired hoggets. There was a weak genotype effect on time to erupt the first permanent incisor, which if modelled as a proportion of Border Leicester (0, 1/4, 1/2) was significant (–34 ± 12 days, P < 0.05), Border Leicester earlier than not Border Leicester. Ewe lambs took 9 days longer (P < 0.05) to erupt their first permanent incisor compared with wether lambs.

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Produção e qualidade da carne ovina no trópico úmido / Sheep meat production and quality in the humid tropics

Brazilian Journal of Animal and Environmental Research ◽

10.34188/bjaerv4n4-053 ◽

2021 ◽

Vol 4 (4) ◽

pp. 5557-5572

Author(s):

Alondra Elena Álvarez Díaz ◽

Armando Gómez Vázquez ◽

Nancy Patricia Brito-Manzano ◽

Ricardo Martínez Martínez ◽

Alejandro Córdova Izquierdo ◽

...

Keyword(s):

Humid Tropics ◽

Meat Production ◽

Sheep Meat

Foi realizado um experimento com 100 cordeiros dos cruzamentos Katahdin, Pelibuey, Dorper e Blackbelly, distribuídos em cinco tratamentos: T1) Pastoreio, T2) T1 + Ração comercial (AC), T3) T1 + Dieta 1, T4) T1 + Dieta 2, T5) T1 + Dieta 3. No primeiro mês, AC, D3 e D1 registraram as maiores ingestões (P 0,05), em comparação ao tratamento D2. Durante o segundo mês, o tratamento com alimento comercial (AC) foi o mais consumido (P 0,05) em comparação com o D2. No último mês de avaliação, quase todos os tratamentos foram estatisticamente iguais, com exceção do tratamento D2, que apresentou o menor consumo (P 0,05), e em geral o mesmo comportamento foi observado ao longo do experimento. Em relação à digestibilidade da matéria seca, o tratamento CA foi o que apresentou melhor digestibilidade (P 0,05). Em relação ao ganho de peso, observou-se que, no primeiro mês de avaliação, os cordeiros que receberam o tratamento AC apresentaram o maior (P 0,05) ganho de peso, seguidos dos tratamentos D1 e D3; o menor (P 0,05) ganho foi observado no tratamento somente pastejo e D2. No segundo mês, a contribuição da CA superou (P 0,05) o ganho de peso dos demais tratamentos. No terceiro mês, os cordeiros do tratamento AC apresentaram os maiores ganhos de peso, sendo estatisticamente semelhantes (P 0,05) ao ganho de peso observado no tratamento D3. Quanto à digestibilidade in situ e à taxa de digestão da matéria seca (MS), observou-se baixa resposta (P 0,05) à degradabilidade ruminal do capim-estrela africana em cada época de avaliação, em relação aos demais tratamentos. Conclui-se que D1 e D3 favoreceram o melhor desempenho produtivo dos cordeiros e, consequentemente, o menor ganho de peso.

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An alternative approach for sustainable sheep meat production: implications for food security

Journal of Animal Science and Biotechnology ◽

10.1186/s40104-020-00472-z ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Eric N. Ponnampalam ◽

Matthew I. Knight ◽

Peter J. Moate ◽

Joe L. Jacobs

Keyword(s):

Food Security ◽

Meat Production ◽

Sheep Meat ◽

Alternative Approach

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Sire and growth path effects on sheep meat production. 2. Meat and eating quality

Australian Journal of Experimental Agriculture ◽

10.1071/ea06334 ◽

2007 ◽

Vol 47 (10) ◽

pp. 1219 ◽

Cited By ~ 27

Author(s):

D. L. Hopkins ◽

D. F. Stanley ◽

E. S. Toohey ◽

G. E. Gardner ◽

D. W. Pethick ◽

...

Keyword(s):

Shear Force ◽

Sarcomere Length ◽

Subcutaneous Fat ◽

Eating Quality ◽

Meat Production ◽

Growth Path ◽

Treatment Groups ◽

Sheep Meat ◽

Australian Sheep ◽

The Impact

The meat and eating quality characteristics of 627 crossbred lamb progeny from 20 Poll Dorset sires were studied. The sires were selected on the basis of Australian sheep breeding values (ASBVs) for postweaning growth (PWWT), depth of loin muscle (PEMD) and subcutaneous fat (PFAT). Lambs were either weaned at 20- or 30-kg liveweight and then within each of these groups held at their weaning weight for 55 days or fully fed, giving four treatment groups. Restricted lambs were realimentated subsequent to the period of feed restriction and the lambs within each treatment group were slaughtered when their mean liveweight reached 45 kg.Shear force of the M. longissimus thoracis et lumborum (LL) decreased with temperature at pH 6.0, increased with LL ultimate pH and decreased as sarcomere length increased. Within LL aged for 5 days there was no difference between (P > 0.05) between treatments for shear force. There was a treatment effect on M. semimembranosus (SM) shear force, such that for a sire having an average ASBV PWWT of 9.34, topsides from lambs early weaned and restricted had significantly (P < 0.05) lower values. Further within these same lambs, i.e. early weaned and restricted, as the sire ASBV PWWT increased there was a significant (P < 0.001) reduction in shear force. There was a significant (P < 0.05) increase in sensory tenderness as the sire ASBV PFAT increased and across the range of ASBV PFAT this represented a change in sensory tenderness of four points. Overall liking increased with an increase in the temperature at pH 6.0 (P < 0.05) with a coefficient of 0.43 ± 0.19. There was a significant (P < 0.05) interaction between feeding level and the sire ASBV PFAT, such that for restricted fed lambs overall liking increased as the ASBV PFAT increased (coefficient 2.80 ± 0.89) after adjusting for temperature at pH 6.0, but this is not the case for fully feed lambs (coefficient –0.01 ± 0.89). Subtle interactions between sire ASBVs and growth path suggest that the impact of a period of restriction and refeeding on meat and eating quality will be meditated by the sire genetics.

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Role of the dog, fox, cat and human as carnivore vectors in the transmission of the Sarcosporidia that affect sheep meat production

Australian Journal of Agricultural Research ◽

10.1071/ar9860079 ◽

1986 ◽

Vol 37 (1) ◽

pp. 79 ◽

Cited By ~ 13

Author(s):

GE Ford

Keyword(s):

Meat Production ◽

Predator Prey ◽

Source Of Infection ◽

Sheep Meat ◽

Large Numbers ◽

Faecal Samples ◽

Pasture Contamination ◽

Series Of Experiments ◽

Sheep Production ◽

Meat Animal

The roles of six carnivores as potential sources to sheep of the sarcosporidial parasites causing cysts in meat were compared in a series of experiments carried out between 1973 and 1980. The research was concomitant with other studies that confirmed the prey-predator-prey-predator cycle of transmission. Infected carnivores act as vectors, excreting in their faeces coccidial sporocysts infective to the meat animal. For 60 experimental infections, sheep meat containing sarcocysts or sarcocysts removed from sheep meat were fed to experimental carnivores. Faecal samples were examined for sporocysts over 60 days post infection. Neither macroscopic (visible) sarcocysts nor microscopic sarcocysts from sheep carcasses were transmissible by humans or by ferrets (domestic polecats). Microscopic sarcocysts were readily infective to dogs, both domestic and dingo, as well as to foxes, but not to cats. Large numbers of sporocysts that could contaminate the environment were excreted. Both fat and thin visible sarcocysts were transmitted exclusively to cats. Although cats responded with relatively low levels of sporocysts, these were considered adequate to provide sufficient pasture contamination for the life cycle to be perpetuated. It is concluded that, while domestic dogs may be the greatest source of infection for sheep with microscopic sarcocysts, foxes as vectors also pose a threat to sheep production. Similarly, due to their widespread presence, feral cats play a role as well as domestic or semi-domestic cats in the spread of sarcocysts causing visible carcass lesions.

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Genotype and age effects on sheep meat production. 4. Carcass composition predicted by dual energy X-ray absorptiometry

Australian Journal of Experimental Agriculture ◽

10.1071/ea07008 ◽

2007 ◽

Vol 47 (10) ◽

pp. 1172 ◽

Cited By ~ 20

Author(s):

E. N. Ponnampalam ◽

D. L. Hopkins ◽

F. R. Dunshea ◽

D. W. Pethick ◽

K. L. Butler ◽

...

Keyword(s):

Bone Mineral ◽

Mineral Content ◽

Dual Energy ◽

Carcass Composition ◽

Age Effects ◽

Meat Production ◽

Semitendinosus Muscle ◽

Eye Muscle ◽

X Ray ◽

Sheep Meat

This study compares the carcass composition of different genotypes of Australian sheep slaughtered at four ages (110, 236, 412 and 662 days of age, or 4, 8, 14 and 22 months of age). The genotypes used were Poll Dorsetgrowth × Border Leicester Merino (PDg × BLM), Poll Dorsetgrowth × Merino (PDg × M), Poll Dorsetmuscling × Merino (PDm × M), Merino × Merino (M × M) and Border Leicester × Merino (BL × M). Approximately 150 mixed sex animals were slaughtered at each age and the right sides (half carcass) were scanned by dual energy X-ray absorptiometry (DXA) for chemical lean, fat and bone mineral percentages of the carcass. Carcass lean percentage decreased (P < 0.001) across sire groups from Merino to Poll Dorset to Border Leicester at each age, while fatness increased (P < 0.001) in the opposite direction. With age, the magnitude of difference between genotypes for fatness became greater. There was a marked increase (P < 0.01) in ash mineral percentages in M × M and PDg × M genotypes relative to other genotypes in the 14- and 22-month groups. There were no differences (P > 0.1) between PDg × M and PDm × M in either chemical lean or fat percentages at any age but ash mineral percentage was higher in the PDg × M genotype at older ages (P < 0.05). This in turn led to differences in chemical lean : ash mineral content at later ages between PDg × M and PDm × M. Wethers had higher chemical lean (P < 0.05) and lower fat (P < 0.05) percentages in the carcass than ewes at all ages but ash mineral and chemical lean : ash mineral content did not differ between sexes. It was clear that the level of chemical lean or fat or ash mineral composition reached by some genotypes at one age was equivalent to that reached by other genotypes at the next measurement age. Those genotypes that reach a specification at younger ages will be more productive for meat production. Purebred Merino genetics will always be less productive in terms of carcass weight and muscle related productive traits (loin weight, semitendinosus muscle weight, eye muscle area) than BL and PD genetics, but the relative productivity of PD and BL genetics will depend on the traits used in the specification [see also Ponnampalam EN, Hopkins DL, Butler KL, Dunshea FR, Warner RD (2007) Genotype and age effects on sheep meat production. 2. Carcass quality traits. Australian Journal of Experimental Agriculure 47, 1147–1154]. The results suggest that selection for muscling had a greater impact on reducing ash mineral content associated with bone mineral mass than on increasing lean mass in the carcass.

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