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South African Journal of Animal Science

versão On-line ISSN 2221-4062
versão impressa ISSN 0375-1589

Resumo

OKORO, V.M.O. et al. Effect of age on production characteristics of Boschveld indigenous chickens of South Africa reared intensively. S. Afr. j. anim. sci. [online]. 2017, vol.47, n.2, pp.157-167. ISSN 2221-4062.  http://dx.doi.org/10.4314/sajas.v47i2.7.

The Boschveld indigenous chicken is a breed that was developed in South Africa for rural household free-range production of meat and eggs. A performance test was carried out to identify their production characteristics when reared intensively, and to estimate the responses of the production characteristics to age, based on optimization functions. Day-old chicks were procured from the breeder and reared to point of lay, with 1432 layers generating the data. Parameters include egg weight (g), egg number, hen day egg production (HDEP) (%), feed intake (g/b/d), bodyweight (kg), bodyweight gain (g), feed conversion ratio (FCR), feed efficiency (FE), and mortality from start of lay until 44 weeks old. There was a significant effect of age on all these production parameters, except for FCR, which was not affected significantly by age as the birds grew. On fitting a prediction and optimization function using a regression model, these parameters showed significant linear response to age: HDEP, feed intake (g), and bodyweight (kg), while significant quadratic responses were found in egg weight and FCR. The prediction model shows that at age 34, 52 and 65 weeks of lay, bodyweight, HDEP and feed intake respectively, would be optimized, while at age 36 and 43 weeks, FCR and egg weight respectively, would be optimized. This implies that Boschveld indigenous chicken production characteristics can be targeted at the appropriate age and can be optimized, given the age of lay that the birds are in.

Palavras-chave : Egg laying; egg production; intensive production; native breed; optimization function; regression model.

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