02930nab a2200313 a 4500 AR-ReUNN 20260702002259.0 260630s2007 ag |||||||||||||||||spa spa eng Coppo, José Antonio 117924 Multivariate analysis about causes of growth delay in early weaned calves / J.A. Coppo 2007 9 páginas Abstract: The purpose of this trial was to check if early weaned calf growth delay is due to stress or inadequate feeding. In 4 successive years, assays of 120 days each were carried out, using in total 120 half-bred Zebu calves (2 months old) grazed on natural pasture. Sixty animals were controls fed on maternal milk (C), and other 60 made up the experimental group (E), which was submitted to early weaning and supplemented with balanced food. Weightings and blood extractions were made in days 0, 7, 14, 21, 28, 60, 90 and 120. Hematological and biochemical determinations (42 parameters) included stress and malnutrition indicators, which were evaluated by radio-immune-assay, chemoluminiscency, spectrophotometry, electrophoresis, and electronic particle recount. Such procedures generated more than 40,000 data, which were statistically processed by multivariate techniques, to eliminate the additive effect of random intervention probability (alpha error), characteristic from univariate methods that comprise numerous dependent variables. Variables that obtained significant differences for treatment and/or time effects in repeated measures univariate techniques, were selected for analysis of principal components. Four orthogonal supervariables, susceptible to stress, malnutrition and ontogeny, were created. Weight gains were 79.9 kg (666 g/animal/day) in C, and 61.6 kg (513 g/animal/day) in E. Variations of cortisol, aldosterone, fructosamine, glucose, sodium, potassium, leukocytes, gamma globulins and enzymes suggested absence of stress, examined under an ontogenic frame. On the other hand, decrease of protein, carbohydrate, lipid, and mineral nutritional indicators, revealed malnutrition in E. Selected principal components indicated that most of total variance was due to malnutrition and ontogeny, but not to stress. It is important to develop more appropriate balanced supplements for early weaned calves.Key words: half-bred Zebu calf, liveweight gain, biochemical alterations, stress, malnutrition. Ternero 65768 Ganancia de Peso 122983 Cruzamiento 61275 Cebu 62637 Medicina Veterinaria 19512 Estres 9129 Alteraciones 116820 Crecimiento 10886 Desnutrición 1737 Respuesta Fisiologica 116583 Revista Veterinaria 1668-4834 v. 18 n. 1 (2007) 217547 ART (AGROP)40868 217577 217577 217577 AR-ReUNN spa AR-ReUNN aacr2