Simulation of genetic and environmental interaction of three tropical hair sheep breeds
| Autor: | E.A.P. Figueiredo, T. C. Cartwright, H. D. Blackburn, M. H. Rajab |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Systems Analysis
Genotype Northeast brazil Forage Weaning Breeding Biology Poaceae Eating Animal science Dry season Genetics Animals Computer Simulation Mortality Gene–environment interaction Legume Plants Medicinal Sheep Lamb mortality Models Genetic Body Weight Domestic sheep reproduction Fabaceae General Medicine Animal Feed Fertility Animal Nutritional Physiological Phenomena Female Animal Science and Zoology Brazil Hair Food Science |
| Zdroj: | Journal of Animal Science. 69:4397-4405 |
| ISSN: | 1525-3163 0021-8812 |
| DOI: | 10.2527/1991.69114397x |
| Popis: | The Texas A&M Sheep Simulation Model was used to examine genetic-environmental interactions (GEI) among Brazilian Somali, Morada Nova, and Santa Ines breeds and type and level of feed supplement in northeast Brazil. Two sets of simulations were conducted to examine effects of different supplement quality (napier grass vs cunha legume) and quantity (napier grass only). The analyses indicated the benefits from supplementing lambs at weaning during the dry season and from supplementing lactating ewes at the beginning of lambing season when forage is scarce. The cunha legume was an effective supplement, but choosing between cunha legume and napier grass is an economic consideration. Increasing the amount of napier grass supplement per ewe from 200 g/d to 400 g/d resulted in a significant GEI (i.e., different levels of response such as lamb mortality rate, lamb weaning weight, and lambing rate for different breeds). The Brazilian Somali was the least responsive, whereas the Santa Ines was the most responsive to supplementation. It was concluded that the level of supplement should be higher for the Santa Ines and Morada Nova than for the Somali. The amount of supplement should be regulated so that it neither substitutes for nor lowers the utilization of the native caatinga forage. None of the breeds was simulated to be superior in all environments. Thus, considering the wide range of resources of individual farmers, any one of these breeds may be the preferred choice, depending on the individual set of production resources. |
| Databáze: | OpenAIRE |
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