Efeito da utilização de dietas simplificadas, à base de forragem, sobre a digestibilidade e o desempenho de coelhos Nova Zelândia

Abstract

RESUMO -Dois experimentos foram conduzidos para avaliar a digestibilidade da matéria seca, proteína bruta e energia bruta e o desempenho de coelhos alimentados com dietas simplificadas, à base de forragem. No ensaio de digestibilidade, foram utilizados 45 coelhos Nova Zelândia brancos com 1.550 kg de peso inicial e 50 dias de idade distribuídos em delineamento inteiramente casualizado com 3 dietas e 15 repetições. Foram utilizadas uma dieta-referência e duas dietas simplificadas (uma contendo feno de alfafa e outra contendo feno do terço superior da rama de mandioca). Os coeficientes de digestibilidade da matéria seca, proteína bruta e energia bruta foram de 50,06; 73,29; e 50,59% para a dieta contendo feno de alfafa e de 29,64; 46,96; e 24,52% para dieta simplificada contendo feno de rama de mandioca. No experimento de desempenho, foram utilizados 90 coelhos Nova Zelândia brancos no período de 35 a 70 dias de idade distribuídos em delineamento experimental inteiramente casualizado com as três dietas especificadas e 30 repetições. Os resultados obtidos com as dietas simplificadas no período total do experimento (35 a 70 dias) foram inferiores aos obtidos com a dietareferência, contudo, mais estudos devem ser realizados com dietas simplificadas com o objetivo de se obter máximo aproveitamento da utilização de forragens para o animal. Palavras-chave: feno de alfafa, feno de mandioca, utilização digestivaEffect of the use of simplified diets based on forages on digestibility and performance of New Zealand rabbits ABSTRACT -Two experiments were carried out to evaluate the dry matter, crude protein and gross energy digestibilities and the performance of rabbits fed simplified diets based on forages. In digestibility assay, 45 New Zealand white rabbits with 1,550 kg of initial weight and 50 days old were distributed to a completely randomized design with 3 diets and 15 replications. Three diets were used: a reference-diet and two simplified diets (one with alfalfa hay and other with upper third part of foliage cassava hay). Coefficients of digestibility of dry matter, crude protein and gross energy were 50.06, 73.29 and 50.59% for the diet with alfalfa hay and 29.64, 46.96 and 24.52% for simplified diet with upper third part of foliage cassava hay. In performance experiment, 90 New Zealand white rabbits from 35 to 70 days old were distributed to a completely randomized design with three diets, above specified, and 30 replications. The results obtained with simplified diets in the total experimental period of (35 to 70 days) were lower than those obtained with the referencediet; however, more studies should be conducted with simplified diets to obtain maximum incorporation use of forages for the animal.

Apparent digestibility of simplified and semi-simplified diets, with and without addition of enzymes, and nutritional value of fibrous sources for rabbits

“…These values are close to the ones obtained in this experiment for the semi-simplified diet based on alfalfa hay. Faria et al (2008) observed coefficients of 0.500, 0.733 and 0.506 kg/kg for dry matter, crude protein and gross energy for simplified diet based on alfalfa hay and 0.296, 0.469 and 0.245 kg/kg for the respective nutritional principles of the simplified diet based on hay from the upper third of the cassava foliage. The author reinforced the hypothesis of low digestibility of the last diet, due to the presence of tannins, as proposed by Scapinello et al (1999).…”

“…Fernandez-Carmona et al (1998), evaluated simplified diets based on alfalfa hay, and found values of digestibility coefficients for dry matter, organic matter and crude protein in the order of 0.530; 0.545 and 0.645 kg/kg, respectively, for a diet of 960 g of alfalfa hay per kg of natural matter. For a similar diet with inclusion of 89.0 g of oil per kg of natural matter, values of 0.540; 0.550 and 0.660 kg/kg were found for digestibility of the respective nutritional principles.…”

“…During formulation, all diets had levels of lysine, methionine + cystine, threonine, tryptophan and arginine balanced in the form of total amino acids. Oil was added to increase the energy density of the diet, and because of the positive contribution to the digestibility of other nutrients (Fernandez-Carmona et al, 1998;Bertechini, 2006); dried molasses were used to improve the quality and palatability of the pellet, and bentonite to improve its quality. At least 50 g/kg of source of starch and small amounts of soybean meal were added to the semisimplified diets, to improve the digestive process.…”

“…As quoted by Cheek et al (1986) and Gidenne (2000) the rabbit has a low utilization of the fiber fraction due to the rapid passage of feed through the gastrointestinal tract. Through the caecotrophic activity, the digestibility of nutrients, especially protein, is incremented (Carabaño et al, 1988;Carabaño & Piquer, 1998;Machado et al, 2007;Faria et al, 2008).…”

“…In this methodology, the nutritional value of the feed tested (with high inclusion) is obtained by the difference between total nutrient content in the diet tested and the nutrient content in the feed pre-determined in the literature. The methodology employed by Fernandez-Carmona et al (1998) was also used, in which 100% of digestibility was adopted for lysine; the digestible energy of 4.901 kcal/kg of natural matter and 858.0 g/kg of natural matter for digestible protein (Rostagno et al, 2005) were considered. The values of digestible energy considered for soybean oil, dried molasses, corn and soybean meal were 8,517; 2,780; 3,134; and 3,182 kcal/kg of natural matter (Villamide et al, 1998), respectively.…”