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Exploration of the Hypothalamic-Pituitary-Adrenal Axis to Improve Animal Welfare by Means of Genetic Selection: Lessons from the South African Merino.

Hough D, Swart P, Cloete S - Animals (Basel) (2013)

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry, Stellenbosch University, Stellenbosch 7602, South Africa. houghdenise@gmail.com.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus

Summary of the strategy proposed by the National Small Stock Improvement Scheme for the genetic improvement of cost per animal. CV: coefficient of variation; FD: fibre diameter. Adapted by S.W.P. Cloete from Olivier [18].
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animals-03-00442-f001: Summary of the strategy proposed by the National Small Stock Improvement Scheme for the genetic improvement of cost per animal. CV: coefficient of variation; FD: fibre diameter. Adapted by S.W.P. Cloete from Olivier [18].

Mentions: Livestock recording and evaluation programmes, such as the National Small Stock Improvement Scheme in South Africa, have been developed to assist sheep farmers to select genetically superior animals [19,20]. The improved levels of production in such animals are expected to assist in the fight against rising input costs. A diagrammatic summary of this strategy is shown in Figure 1. The strategy proposes the genetic improvement of income per animal by increasing the total weight of lamb weaned, growth rate, as well as quantity and quality of fibre produced [18]. Genetic selection based on these parameters is aimed at improving production traits (e.g., fibre yield, meat quantity) or fitness traits (e.g., lamb survival). Genetic selection is also a preferable alternative to improve fitness and production compared to some husbandry procedures, which increases the cost per animal and may be detrimental to the animals’ welfare (such as mulesing) [15].


Exploration of the Hypothalamic-Pituitary-Adrenal Axis to Improve Animal Welfare by Means of Genetic Selection: Lessons from the South African Merino.

Hough D, Swart P, Cloete S - Animals (Basel) (2013)

Summary of the strategy proposed by the National Small Stock Improvement Scheme for the genetic improvement of cost per animal. CV: coefficient of variation; FD: fibre diameter. Adapted by S.W.P. Cloete from Olivier [18].
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4494397&req=5

animals-03-00442-f001: Summary of the strategy proposed by the National Small Stock Improvement Scheme for the genetic improvement of cost per animal. CV: coefficient of variation; FD: fibre diameter. Adapted by S.W.P. Cloete from Olivier [18].
Mentions: Livestock recording and evaluation programmes, such as the National Small Stock Improvement Scheme in South Africa, have been developed to assist sheep farmers to select genetically superior animals [19,20]. The improved levels of production in such animals are expected to assist in the fight against rising input costs. A diagrammatic summary of this strategy is shown in Figure 1. The strategy proposes the genetic improvement of income per animal by increasing the total weight of lamb weaned, growth rate, as well as quantity and quality of fibre produced [18]. Genetic selection based on these parameters is aimed at improving production traits (e.g., fibre yield, meat quantity) or fitness traits (e.g., lamb survival). Genetic selection is also a preferable alternative to improve fitness and production compared to some husbandry procedures, which increases the cost per animal and may be detrimental to the animals’ welfare (such as mulesing) [15].

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry, Stellenbosch University, Stellenbosch 7602, South Africa. houghdenise@gmail.com.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus