Body composition and requirements for calcium and phosphorus for gain and maintenance of Santa Ines lambs from 15 to 25 kg of body weight

[摘要] - The research was carried out to determine body composition and calcium and phosphorus requirements of Santa Ines lambs. Eighteen entire male lambs with average initial live weight of 15 kg were used. The animals were allotted to three groups: six animals were slaughtered at the beginning of the experiment, to access the amount of calcium and phosphorus present in the body, as reference animals for the comparative slaughter technique. Six animals were ad libitum fed and six were restrict fed (maintenance level plus 20%). The animals ad libitum and restrict fed started the experimental period by pairs and they were both slaughtered when the first reached 25 kg body weight. The body composition was estimated through the prediction equations obtained by regression of the logarithm of the amount of calcium and phosphorus in the empty body on the logarithm of the empty body weight. Net requirements for calcium and phosphorus for maintenance and the absorption coefficient were obtained through the correlation between the amount of each mineral consumed and retained in the animal body. The net requirements maintenance for live weight gain were obtained by means of derivation of the prediction of body composition equations. The net requirements maintainance of calcium and phosphorus for animals from 15 to 25 kg body weight were: 305 mg Ca/day and 325 mg P/day and net requirements for kg of the body weight gain for animals with 15 and 25 kg LW were 11.41 and 10.33 g Ca and 5.72 and 4.94 g P, respectively. The absorption coefficients were estimated to be .44 and 0.55 for Ca and P, respectively.

[学科分类] 兽医学

[关键词] body composition;calcium;nutritional requirements;phosphorus;lambs;Santa Inês     IntroduçãoAs concentrações de cálcio e fósforo corporais são reflexo;principalmente;da proporção de ossos e gordura da carcaça; portanto;fatores como idade;raça;grupo genético;sexo;manejo alimentar e condições climáticas a que o animal são submetidos influem na concentração desses minerais