Avoidance-related behaviour, bleeding times and the quality of meat from sheep slaughtered at a commercial and a municipal abattoir
- Authors: Njisane, Yonela Zifikile
- Date: 2012
- Subjects: Mutton -- Quality , Sheep -- Quality , Slaughtering and slaughter-houses -- South Africa , Animal behavior , Dorper sheep , Meat -- Quality , Sheep -- Carcasses -- Handling
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11818 , http://hdl.handle.net/10353/d1004195 , Mutton -- Quality , Sheep -- Quality , Slaughtering and slaughter-houses -- South Africa , Animal behavior , Dorper sheep , Meat -- Quality , Sheep -- Carcasses -- Handling
- Description: The objective of the study was to determine the avoidance-related behaviour, bleeding times and the quality of meat from sheep of different gender, breed (Dorper, Merino, and their crosses) and age groups, slaughtered at a commercial and municipal abattoir. Castrates and ewes of different age groups (1= <10months, 2= 11-12months, and 3= >12months) and breeds were used. From the commercial abattoir, 90 castrates and 110 ewes were used, while 66 castrates and 19 ewes were obtained from the municipal abattoir. Meat samples were obtained to determine meat colour, ultimate pH, temperature, cooking loss and tenderness. Correlations between bleeding times and meat quality variables were also determined. The two abattoirs differed in terms of technology and the procedures used, and this brought about different response behaviours in sheep at slaughter, bleeding times at exsanguination and the quality of meat produced. Animal-related factors (breed, gender and age classes) had no effect on the avoidance-related behaviour of sheep slaughtered at the commercial abattoir, while these factors affected those sheep slaughtered at the municipal abattoir. These factors also had an effect on the quality of meat produced at both abattoirs. Gender and weight of the animals had effects on the bleeding times at exsanguination at both abattoirs. Bleeding times did no correlate with any of the meat quality variables, but correlations among meat quality variables were observed. Avoidance-related behaviour, bleeding times, and the quality of mutton from sheep slaughtered at a commercial and a municipal abattoir was affected by breed, age, and gender.
- Full Text:
- Date Issued: 2012
Effects of pre-slaughter sheep handling and animal-related factors on creatine kinase levels and physico-chemical attributes of mutton
- Authors: Chulayo, Amanda Yucca
- Date: 2012
- Subjects: Sheep -- South Africa , Mutton , Slaughtering and slaughter-houses -- South Africa , Creatine -- Physiological effect
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11810 , http://hdl.handle.net/10353/433 , Sheep -- South Africa , Mutton , Slaughtering and slaughter-houses -- South Africa , Creatine -- Physiological effect
- Description: Effects of pre-slaughter sheep handling and animal-related factors on Creatine Kinase levels and physico-chemical attributes of mutton By Chulayo Amanda Yucca The objective of the study was to determine the effects of pre-slaughter sheep handling and animal-related factors on Creatine kinase (CK) levels and physico-chemical characteristics of mutton from South African sheep breeds. One hundred and seventy-three castrated male sheep from four breeds (15 Dormer, 46 South African Mutton Merino, 77 Dorper and 35 Blackhead Persian) were used. The animals were grouped according to age categories. The grouping was as follows: Group 1 (6 ≤ 8 months), Group 2 (9 ≤ 12 months) and Group 3 (13 ≤ 16 months). Blood samples for CK determination were collected at exanguination using disposable vacutainer tubes. Representative samples of the Muscularis longissimuss thoracis et. lumborum (LTL) muscle were taken for the determination of ultimate pH (pHu), colour (L*-lightness, b*- redness and a*- yellowness), thawing and cooking losses and meat tenderness. Significant (P<0.01) breed effects were observed on CK levels with Dormer having the highest CK values. Significant linear relationships were observed between pre-slaughter condition and CK levels. There were positive correlations between colour coordinates L* and b* (r =+0.22) and between a* and b* (r =+0.63). Cooking loss and Warner Braztler Shear Force (WBSF) values were positively correlated (r =+0.29). The Principal Component Analysis (PCA) showed a significant variance for CK and between physico-chemical characteristics of mutton. There were no relationships between CK levels and physico-chemical characteristics of mutton. Significant breed and age effects on pHu, L, a*, b*, thaw %, CL and WBSF of mutton were observed. iv It was concluded that, pre-slaughter conditions affect CK levels and physico-chemical characteristics of mutton. However, there were no relationships between CK levels and physico-chemical characteristics of mutton.
- Full Text:
- Date Issued: 2012