Utilização do metabólito 1,25-dihidroxicolecalciferol proveniente da Solanum glaucophyllum na alimentação de frangos de corte

Abstract

The vitamin and mineral nutrition interferes with the production performance and bone characteristics of birds. The vitamin D supplement used without restriction in the feed for broilers is inactive cholecalciferol and 25-hydroxycholecalciferol. The objective of this study was to evaluate the performance, and yields of carcass and commercial cuts and bone parameters of male broilers supplemented with 1,25-dihydroxycholecalciferol and reduction of calcium and available phosphorus in feed. A total of six hundred and forty-eight males, was used in a randomized-block design, with six treatments: control diet - meeting nutritional requirement; negative control diet - with 15% reduction in the levels of calcium and available phosphorus; negative control diet supplemented with: 0.5; 1.0; 1.5 and 2.0 μg of vitamin D3 active/kg diet respectively, with six replicates (boxes). The performance was evaluated by weight gain (kg), feed intake (kg/bird) and feed conversion. The broilers were weighed one day and at 42 days of age, for obtaining the weight gain. Feed intake was calculated as the difference between the amount of feed, discounting the leftovers at each stage of creation. The ratio between feed intake and weight gain corrected feed conversion originated. Later, four broilers of each experimental unit were sampled, weighed and slaughtered by cervical dislocation to evaluate carcass yield and commercial cuts yield at 42 days of age. Later, a one bird of each experimental unit was sampled, weighed and sacrificed for removal of tibiotarsos for the assessment of bone parameters at 21 and 33 days of age. The bones were identified and cleaned of all adhering tissue and frozen (-20°C) until analysis begins. The bone parameters were evaluated weight (mg) and length (mg) of the bone Seedor index (mg/mm) bone ash (%) and breaking strength (kgf). The active vitamin D3 supplement with reduced calcium and available phosphorus in the diets did not influence performance and carcass and commercial cuts (breast, thigh + drumsticks and wing) of poultry. A 15% reduction in the levels of calcium and available phosphorus and vitamin D3 supplement active in the diets did not affect the weight and length of the bone, the index Seedor and resistance to breakage. The percentage of bone ash deposition in bones of broilers at 21 and 33 days of age was different between treatments. The lowest values for ash, without interference in breaking resistance force of tibiotarsos, demonstrates the possibility of reducing in the 15% levels of calcium and available phosphorus in diets without compromising the bone structure of birds.