Schoeman S.J.,University of Pretoria |
Cloete S.W.P.,Private Bag X1 |
Cloete S.W.P.,Institute for Animal Production |
Olivier J.J.,Private Bag X1 |
Olivier J.J.,ARC Animal Production Institute
Livestock Science | Year: 2010
The small stock industry in South Africa is of crucial importance as 80% of the agricultural land is unsuitable for intensive agricultural production. The contribution of 19 resource sheep flocks and goat herds towards breeding objective formulation, genetic improvement and parameter estimation was summarized. Substantial genetic gains resulting from selection for a range of economically important traits were demonstrated, lending impetus to the development and extension of the National Small Stock Improvement Scheme (NSIS). Responses in monetary values in the respective participating small stock breeds ranged from R0.098 for the Dormer to R0.818 for the S.A. Mutton Merino per small stock unit per annum for animals born in the interval from 2000 to 2006. This response is well below what was attained in the resource flocks and in the best participating flocks and herds. Even with this less than optimal change on a national basis, the impact on the sectoral economy is substantial. When related to the cost associated with the NSIS, this improvement is highly cost-effective. The impact of research and development in the small stock industry is therefore substantial, and the small stock industry is foreseen to continue playing an integral role in the national economy. © 2010 Elsevier B.V. All rights reserved.
Pieterse A.,Stellenbosch University |
Pitcher G.,Fisheries Research and Development |
Pitcher G.,University of Cape Town |
Naidoo P.,Institute for Animal Production |
Jackson S.,Stellenbosch University
Journal of Shellfish Research | Year: 2012
The Pacific oyster Crassostrea gigas is cultured at 8 commercial farms in South Africa. Worldwide, environmental-specific intensive selection on the species optimizes commercially beneficial traits, but its performance has not been studied in South Africa. From May 2010 to March 2011, we compared 2-mo measurements of growth rate, condition, and survival of 3 cohorts of different origin in longline culture at 3 different South African environments: 2 sea-based farms located in Saldanha Bay (Western Cape) and Algoa Bay (Eastern Cape) and a land-based farm at Kleinzee (Northern Cape). Overall, Saldanha Bay was cooler (mean sea surface temperature of 16.0°C; CV, 16.2%) than the other 2 localities, which did not differ significantly from one another (Kleinzee: 18.6°C; CV, 20.4%; Algoa Bay: 17.8°C; CV, 8.9%). The high variability at Kleinzee reflected stronger summer warming than at the other 2 farms. Saldanha Bay had higher phytoplankton biomass (mean, 14.3 mg chlorophyll a/m3; CV, 54.2%; May 2010 to March 2011) than did Algoa Bay (mean, 5.3 mg chlorophyll a/m3; CV, 81.0%; September 2010 to March 2011). The 3 cohorts showed similar trends in growth and condition. Growth rates, expressed as live or dry mass gains, were 2-10 times those reported elsewhere in the world, and dry weight condition indices were also high. High live mass growth rates in Algoa Bay, despite its relatively low phytoplankton biomass, seem to reflect a similar phenomenon to that reported in other relatively phytoplankton-poor grow-out environments, such as the Mediterranean Thau Lagoon in France. Dry meat mass gain and condition were highest for oysters in Saldanha Bay, with high food availability offsetting the thermal advantages of the warmer Algoa Bay site. Oysters in the bottom layers of the cages grew significantly faster than those in the top layers, particularly in Saldanha Bay, possibly reflecting fine-scale vertical differences in phytoplankton biomass. Saldanha Bay is the best of the 3 locations to produce market-ready oysters. Algoa Bay yields faster growth but leaner oysters and is a good nursery location, as is Kleinzee, which yields overall slow growth but good shell quality in winter and early spring. Copyright © 2013 BioOne.
Cloete J.J.E.,Stellenbosch University |
Cloete J.J.E.,Cape Institute for Agricultural Training Elsenburg |
Hoffman L.C.,Stellenbosch University |
Cloete S.W.P.,Stellenbosch University |
Cloete S.W.P.,Institute for Animal Production
Meat Science | Year: 2012
The slaughter and meat quality traits of 20-month-old wool (Merino), dual-purpose (Dohne Merino and South African Mutton Merino [SAMM]) and mutton (Dormer) type sheep were compared. Average live weights of SAMM and Dormer sheep were 23% heavier than those of Dohne Merinos which were 28% heavier than Merinos. Fat depths at the thirteenth rib and lumbar regions of Merino and Dohne Merino sheep were lower than those of SAMM and Dormer sheep. The cooking loss, drip loss and shearing value from the M. longissimus dorsi did not differ between breeds. The initial juiciness and sustained juiciness of meat from Merinos were rated significantly lower by sensory analysis. Meat from Dohne Merino was rated significantly more tender for the attribute first bite. It was demonstrated that Dormer and SAMM sheep had heavier but fatter carcasses than Merinos and Dohne Merinos, with differences in meat quality between breeds. © 2012 Elsevier Ltd.
Heinz S.,University of Rostock |
Kanswohl N.,University of Rostock |
Romer A.,Institute for Animal Production
Archiv fur Tierzucht | Year: 2011
Aim of the present study was to examine the relationship between the herd status for claw health and herd parameters. Herd parameters were derived from an assessment of the housing conditions and were based on a welfare index and critical checkpoints. Data has been collected on four conventional large dairy farms in northeast Germany. All farms have free-stall systems with cubicles offering a lying area. During the period from 2005 to 2008 on each farm claw disorders were recorded at time of regular hoof trimming, i.e. two or three times a year. Data was augmented by data on veterinary treatments of feet and legs. The Data comprises 18 119 observations of 3 690 cows. Housing conditions were assessed in the year 2008. The results show that a consequent and determined management of herd health is necessary to substantially improve the status of claw health. Housing and management confirming the rules of animal welfare will contribute to the well-being of dairy cows. © Leibniz Institute for Farm Animal Biology, Dummerstorf, Germany.
Hough D.,Stellenbosch University |
Swart P.,Stellenbosch University |
Cloete S.,Stellenbosch University |
Cloete S.,Institute for Animal Production
Animals | Year: 2013
It is a difficult task to improve animal production by means of genetic selection, if the environment does not allow full expression of the animal's genetic potential. This concept may well be the future for animal welfare, because it highlights the need to incorporate traits related to production and robustness, simultaneously, to reach sustainable breeding goals. This review explores the identification of potential genetic markers for robustness within the hypothalamic-pituitary-adrenal axis (HPAA), since this axis plays a vital role in the stress response. If genetic selection for superior HPAA responses to stress is possible, then it ought to be possible to breed robust and easily managed genotypes that might be able to adapt to a wide range of environmental conditions whilst expressing a high production potential. This approach is explored in this review by means of lessons learnt from research on Merino sheep, which were divergently selected for their multiple rearing ability. These two selection lines have shown marked differences in reproduction, production and welfare, which makes this breeding programme ideal to investigate potential genetic markers of robustness. The HPAA function is explored in detail to elucidate where such genetic markers are likely to be found. © 2012 by the authors; licensee MDPI, Basel, Switzerland.