Oudtshoorn, South Africa
Oudtshoorn, South Africa

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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.


Zishiri O.T.,University of KwaZulu - Natal | Cloete S.W.P.,Stellenbosch University | Cloete S.W.P.,Institute for Animal Production | Olivier J.J.,Stellenbosch University | And 2 more authors.
Small Ruminant Research | Year: 2014

Genetic parameter estimates for live weight traits were derived using Residual Maximum Likelihood (REML) procedures for the South African Dormer, Ile de France and Merino Landsheep terminal sire sheep breeds. Birth weight and weaning weight records were available for all breeds. However, pre-weaning weights were available for only the Ile de France and Merino Landsheep breeds, while post-weaning weights were available only for the Dormer breed. Direct heritability estimates (h2) derived using single-trait analyses were 0.25, 0.28 and 0.37 for birth weight, weaning weight and post-weaning weight respectively for the Dormer breed. Corresponding h2 estimates for the Ile de France and Merino Landsheep breeds were respectively 0.13, 0.53 and 0.14 and 0.23, 0.36 and 0.17 for birth weight, pre-weaning weight and weaning weight. The haphazard data structure of the respective populations resulted in complications in the partitioning of maternal effects into maternal genetic (m2) and maternal permanent environmental (c2) components. Low to moderate maternal heritability (m2) and dam permanent environmental (c2) estimates were derived for the Dormer and Ile de France breeds. Genetic, phenotypic and environmental correlations were estimated using three-trait analysis and were found to be moderate to high for live weight traits in the Dormer and Ile de France breeds. The moderate genetic parameter estimates obtained in this study led to the conclusion that direct selection for live weight traits in the terminal sire breeds will result in improved growth in the terminal sire sheep breeds. © 2013 Elsevier B.V.


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.


Engelbrecht A.,Institute for Animal Production | Engelbrecht A.,Stellenbosch University | Cloete S.W.P.,Stellenbosch University | Cloete S.W.P.,Institute for Animal Production
Animal Production Science | Year: 2012

The effect of ostrich feather lice (Struthiolipeurus struthionis) on productivity and leather quality was investigated in the light of louse-related skin damage on other livestock species that seems similar to defects, called pitting, seen on ostrich skins. The occurrence and spread of feather lice on ostriches were also studied. Natural infestation of louse-free ostriches within a group mixed with louse-infested ostriches was achieved within 6 months. Lousiness was determined by visual counts on the body and feathers of the ostriches on five locations. There was a relatively low correlation between the number of lice observed on the live ostriches and the actual number of lice extracted from harvested wing feathers. However, it was demonstrated that lice obtained from feathers increased at a rate of 3.29 (s.e. = 1.34) lice per 100 g of feathers for an increase of one louse observed on the live birds in the paddock (R2 = 0.23). Treatment with synthetic pyrethroid insecticides eradicated all lice. Louse infestation had no significant influence on growth or slaughter traits, while no causal relationship between louse infestation and pitting damage on the processed ostrich skins could be demonstrated. © 2012 CSIRO.


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.


Halachmi I.,Israel Agricultural Research Organization | Klopcic M.,University of Ljubljana | Polak P.,Institute for Animal Production | Roberts D.J.,Dairy Research Center | Bewley J.M.,University of Kentucky
Computers and Electronics in Agriculture | Year: 2013

Automatic and objective dairy cow body condition scoring has the potential to be used as a feed, reproduction, health and longevity management tool. The feasibility of including a body shape measurement in automatic monitoring of body condition was evaluated. The hypothesis tested was that the body shape of a fatter cow is more round than that of a thin cow and, therefore, may better fit a parabolic shape. The more prominent hooks and the tailhead depressions of a thin cow tended to diverge from the parabolic shape. An image-processing model appraised body shape. The novelties in this study compared to the previous ones (Halachmi et al., 2008; Bewley et al., 2008) were: (1) completing the full-automation of the system and (2) more accurate reference, not ultrasound. The model was implemented and its outputs were validated against manual body condition scoring (BCS) of 186 Holstein-Friesian cows. Pearson correlation between the thermally sensed BCS and the manual BCS was 0.94. © 2013 Elsevier B.V.


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.


Zishiri O.T.,Stellenbosch University | Zishiri O.T.,University of KwaZulu - Natal | Cloete S.W.P.,Stellenbosch University | Cloete S.W.P.,Institute for Animal Production | And 3 more authors.
Small Ruminant Research | Year: 2013

Breed improvement in the Dorper sheep breed is based mainly on subjective assessment in the show ring. Information is limited about the genetic relationships between subjectively assessed and objectively measured traits in the breed. In an effort to establish genetic parameters as well as relationships amongst these traits, this study was conducted using Restricted Maximum Likelihood (REML) procedures. Live weight and growth traits were moderately to highly heritable ranging from 0.18±0.04 for post weaning weight to 0.54±0.15 for yearling weight using single-trait analyses. However, when multi-trait analyses were implemented, weaning weight and average daily gain to weaning assumed moderate h2 of 0.30±0.03 and 0.27±0.03 respectively. Maternal effects were significant, although of fairly low magnitude with the exception of estimates for post weaning weight and average daily gain to post weaning. Heritabilities of subjectively assessed traits were fairly low, ranging from 0.07±0.02 for Conformation and Type to 0.15±0.03 for Size using both single-trait and multi-trait analyses. It was established through multi-trait analyses that subjectively assessed and objectively measured traits had mainly positive genetic correlations. Five-trait analyses led the conclusion that there are some moderate to high maternal genetic correlations as well as dam permanent environmental correlations between live weight, growth, Size and Type. A few negative direct genetic correlations were found for trait combinations of Colour with yearling weight and average daily gain to yearling. It was concluded that despite most of the traits being positively correlated more emphasis should be put on breed improvement basing on objectively measured traits. © 2012 Elsevier B.V.


Zishiri O.T.,Stellenbosch University | Zishiri O.T.,University of KwaZulu - Natal | Cloete S.W.P.,Stellenbosch University | Cloete S.W.P.,Institute for Animal Production | And 3 more authors.
Small Ruminant Research | Year: 2013

Across flock genetic parameter estimates for growth, reproduction and fitness traits were derived using residual maximum likelihood (REML) procedures for the South African Dorper sheep breed. Data were retrieved from the National Small Stock Improvement Scheme (NSIS) data base from breeders that were constantly submitting performance data for a period spanning 30 years (1980-2009). Weaning weight and post-weaning weight were moderately heritable with estimates being 0.21. ±0.01 and 0.27. ±0.02 respectively. Maternal effects were significant, although of fairly low magnitude in live weight traits. It was demonstrated that reproductive and fitness traits such as total weaning weight per ewe lambing (TWW/L), number of lambs born per ewe lifetime (NLB/EL), number of lambs weaned per ewe lifetime (NLW/EL), lamb survival to weaning and litter size were lowly heritable with their estimates being 0.12. ±0.02, 0.10. ±0.01, 0.09. ±0.01, 0.07. ±0.01 and 0.07. ±0.02 respectively. Selection of Dorper sheep with the objective of improving reproduction and fitness is feasible although relatively low heritability estimates indicate that annual genetic progress may be slow. Low heritabilities for ewe productive life (EPL) and stay ability at two, three and four years of age were estimated to be 0.05. ±0.01, 0.05. ±0.02, 0.09. ±0.03 and 0.11. ±0.04 respectively. This indicated that these traits are, to some extent, influenced by genetics. Lambing chances per ewe lifetime (LC/EL) and times lambed per ewe lifetime were demonstrated to have a moderate heritability (0.23. ±0.01 and 0.11. ±0.04 respectively) and would also result in a correlated selection response in both reproduction and longevity. No genetic basis was found for inter-lambing period (ILP). It was therefore deduced that ILP can be improved through sound management. Live weight traits were positively correlated with reproduction and fitness traits. TWW/L was genetically and environmentally positively correlated with survival, litter size and EPL. It was concluded that despite the low additive genetic variances for reproduction and fitness, genetic improvement is feasible. Therefore, breeders should incorporate these traits in their selection strategies to achieve maximum production. © 2013 Elsevier B.V.


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.

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