Data/hora: 18/05/2024 22:48:13

Biblioteca(s): | Embrapa Suínos e Aves.
Data corrente: | 01/09/1998
Data da última atualização: | 11/07/2007
Autoria: | COOK, D. A.
Título: | The conceptual analysis of a dynamic mathematical model for the estimation of the amino acid requirements for pigs from weaning to maturity.
Ano de publicação: | 1991
Fonte/Imprenta: | Urbana: University of Illinois at Urbana-Champaign, 1991.
Páginas: | 168p.
Idioma: | Inglês
Notas: | Tese Doutorado
Conteúdo: | A deterministic model for the prediction of amino acid requirements ofgrowing pigs was developed. Comparisons between model outputs and literature values indicated that the model adequately predicts amino acid requirements. During the development of the model, limitations in the literature were identified. Therefore, the following experiments were conducted to provide needed components of the model. Two experiments were conduced to characterize the potential gain in body nitrogen (GBN)of growing pigs. In experiment 1, pigs were grow from weaning to 150 kg to characterize protein and fat growth. In experiment 2, proximate analysis of the whole body of pigs raised to maturity provided estimates of the nitrogen content of the body at maturity (NBmx). The following equation was used to characterize GBN: GBN = KNmx* FFBWaN* ((NBmx-BN)/NBmx). From data colleted above, three relationships were used to describe DE intake. Two exponential equations, containing body weight (BW) or body protein (BP) as variables, were used. Use of BP in place ofBW did not improve the statistical fit of the equation. Calculation ofDE intake from estimated utilization of energy provided values that followed a similar pattern but were consistently lower than observed feed intakes. An experiment was conducted to quantify the effect of energy density on DE intake and growth. Four DE levels (2.9, 3.2, 3.5 and 3.8 Mcal DE/kg) were fed. Increasing DE content resulted in a quadraticresponse (P<.01) for ADG and gain/feed and a cubic response (P<.05) for daily DE intake. A response surface regression (R2=.93) was used to describe the change in DE intake relative to DE concentration and BW. In a final experiment, the effect of energy intake on protein and fat growth was investigated. Treatments consisted of four levels of feed intake: ad libitum (100%), 70%, 50% and 30%. Increasing ME intake resulted in a quadratic response (P<.05) for ADG and gain/feed. The response of GBN was dependent upon gender and BW gain in body fat response linearly (P<.001). An equation to describe GBN relative to BW and ME intake was developed. The use of fat-free BW in place of BW did not improve the statistical fit.
Palavras-Chave: | Amino acid; Growing; Mathematical model; Predicao; Requerimento; Requirements.
Thesagro: | Aminoácido; Crescimento; Modelo Matemático; Suíno; Terminação.
Thesaurus Nal: | finishing; prediction; swine.
Categoria do assunto: | --
Registro original: | Embrapa Suínos e Aves (CNPSA)
Exemplares: | CNPSA - (5477-1) - ADD - TS - -- -  -  - 1998.00812 - DIS