Cambios en la velocidad de crecimiento e indicadores nutricionales de Caiman yacare alimentados con diferentes dietas

Abstract

The efficiency of a diet can be evaluated by means of liveweight and corporal dimension increments, as well as the optimization of nutritional biochemical indicators. The objective of this trial was to compare the effects of two different diets on the growth of C. yacare sub-adult specimens, housed in a hatchery from northeastern Argentina. Forty clinically healthy yearling animals were used. Reptiles liveweight and length from muzzle to anus averages were initially 1.41±0.22 kg y 37.88±4.87 cm. Animals were divided aleatorily into two groups and housed in separate tanks. During 105 days, both groups consumed a basal diet (70% of the ration) consistent in balanced pellets (88% of dry matter) with 30% of crude protein, 11% of ether extract and 4.5% of total ashes. For diet A, remaining 30% of the ration was beef without bone, in which values of parameters mentioned above were 33.3%, 17.2%, 13.5% and 1.1%, respectively. For diet B, remaining 30% was chicken meat with bone (37.6%, 18.4%, 11.6% and 7.7%, respectively). Weight, size, and blood analysis were carried out at the beginning and the end of the assay. A totally randomized design and a statistical covariance analysis (ANCOVA) were applied for the statistic analysis. Diet A, which contained a higher proportion of fat, produced significant increments (p<0.05) of triglycerides, magnesium and potassium. Diet B, with a higher proportion of proteins and minerals, caused significant increments of liveweight, length from muzzle to anus, length of head, mean corpuscular hemoglobin concentration, sodium, total cholesterol, HDL-C and LDL-C. It can be concluded that the minimum changes registered in this assay suggest the use of both diets indistinctly. When considering selection of one of them, economic factors should be taken into account.