Apparent digestibility of diets with different concentrations of lysine and energy in piglets with different body weights and post-weaning age

Abstract

-The effects of body weight or age and dietary digestible lysine and metabolizable energy on apparent digestibility of energy and dry matter were evaluated in piglets after weaning. The animals were weaned at 21 days of age and distributed in two groups: 8.68 ± 0.76 kg at 28 days of age (weaned 7 days earlier); and 12.73 ± 0.99 kg at 35 days of age (weaned 14 days earlier). The pigs were allotted in digestibility cages in a completely randomized block design with the following factorial arrangements: 2 × 4 composed of two weight categories and four levels of digestible lysine (1.222; 1.305; 1.390 and 1.497%); and 2 × 3 composed of two weight categories and three levels of metabolizable energy (3,510; 3,700 and 3,830 kcal/kg rations).Digestible lysine was evaluated in six replications and metabolizable energy in eight replications and each animal constituted an experimental unit. Piglets with higher body weight and age were more efficient in nitrogen retention and energetic balance, compared to lighter and younger piglets, particularly those given lower concentration of lysine in the diet. The energy increase favored nitrogen retention by the heavier and older piglets. However, coefficients of dry matter and energy apparent digestibility did not differ among weight categories. Older and heavier piglets were more efficient in nitrogen retention, although this efficacy depended on concentration of the energy in the diet. This better use of protein and energy suggest differences on nutritional requirements.

Efeito da adição de enzimas na digestibilidade total aparente de dietas para leitões desmamados

“…Coeficiente de digestibilidade (CD) da matéria seca (CDMS), matéria orgânica (CDMO), proteína bruta (CDPB), matéria mineral (CDMM), amido (CDAM) e energia bruta (CDEB) de ração para leitões na creche em dois períodos. AHERNE, 1996;VENTE-SPREEUWENBERG et al, 2003;MONTAGNE et al, 2007). O principal motivo parece ser a necessidade de adaptação dos leitões ao consumo de uma dieta com características químicas e físicas diferentes do leite materno.…”

“…Dietas de menor complexidade, contendo quantias elevadas de milho e farelo de soja, podem ser mais influenciadas pelo efeito da idade dos suínos em comparação com dietas possuindo maior proporção de ingredientes altamente digestíveis (TRINDADE NETO et al, 2010). Não foram encontrados experimentos que pudessem confirmar a veracidade dessas suposições, de forma a realização de estudos para esclarecer essa questão seria importante.…”