title: Net requirements of calcium, phosphorus, magnesium, and sulphur for growth of non-descript breed hair lambs of different sex classes in the Brazilian semiarid conditions.
abstract: The aim of this study was to determine the net requirements of calcium (Ca), phosphorus (P), magnesium (Mg), and sulphur (S) for weight gain of non-descript breed hair lambs (NDBL) of different sex classes reared under Brazilian semiarid conditions. Sixty NDBL (20 intact males, 20 castrated males, and 20 females), with an average initial body weight of 18.1 ± 0.4 kg and average age of 5 months were used. The macromineral requirements were determined by the differences in body composition through comparative slaughter direct method. The animals were confined for 58 days, and the average fasting body weight (FBW) and average daily gain (ADG) of lambs fed ad libitum were 29.2 ± 0.6 and 0.19 ± 0.01 kg, respectively. The net requirements of macrominerals for gain of NDBL did not differ between sex classes (P > 0.05), and ranged from 1.83 to 1.46 g/day of Ca, 1.21 to 1.01 g/day of P, 37 to 30 mg/day of Mg, and 0.31 to 0.28 g/day of S, for lambs with an ADG of 0.200 kg and 15 or 30 kg of FBW, respectively (P < 0.05). The N to S net ratio reduced and increased, respectively, as the body weight and ADG increase. The net requirements of Ca, P, Mg, and S for gain of NDBL slaughtered young and at the same age did not differ between sex classes and decreased as the body weight increased. The net requirements for gain of Ca and P were similar to those recommended by NRC (2007).
authors.affiliation: Department of Animal Science, Universidade Federal do Vale do São Francisco-UNIVASF, Petrolina, Pernambuco, 56300-990, Brazil.
authors.forename: Ivonete Ferreira
authors.initials: IF
authors.lastname: da Silva
authors.affiliation: Department of Animal Science, Universidade Federal de Lavras-UFLA, P.O. Box 3037, Lavras, Minas Gerais, 37200-000, Brazil. rafael.nutricao@hotmail.com.
authors.forename: Rafael Torres
authors.initials: RT
authors.lastname: de Souza Rodrigues
authors.affiliation: Department of Animal Science, Universidade Federal do Vale do São Francisco-UNIVASF, Petrolina, Pernambuco, 56300-990, Brazil.
authors.forename: Mário Adriano Ávila
authors.initials: MA
authors.lastname: Queiroz
authors.affiliation: Department of Animal Science, Universidade Federal de Viçosa-UFV, Viçosa, Minas Gerais, 36570-900, Brazil.
authors.forename: Mario Luiz
authors.initials: ML
authors.lastname: Chizzotti
authors.affiliation: Department of Animal Science and Food Engineering, Universidade de São Paulo-USP, Pirassununga, São Paulo, 13635-900, Brazil.
authors.forename: Marcus Antonio
authors.initials: MA
authors.lastname: Zanetti
authors.affiliation: Department of Animal Science and Food Engineering, Universidade de São Paulo-USP, Pirassununga, São Paulo, 13635-900, Brazil.
authors.forename: José Aparecido
authors.initials: JA
authors.lastname: da Cunha
authors.affiliation: Department of Animal Science, Universidade Federal de Lavras-UFLA, P.O. Box 3037, Lavras, Minas Gerais, 37200-000, Brazil.
authors.forename: Karina Costa
authors.initials: KC
authors.lastname: Busato
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000822:Animal Husbandry; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001823:Body Composition; D001835:Body Weight; D001938:Brazil; D002118:Calcium / Q000008:administration & dosage; D003889:Desert Climate; D004032:Diet / Q000662:veterinary*; D005260:Female; D008274:Magnesium / Q000008:administration & dosage; D008297:Male; D010758:Phosphorus / Q000008:administration & dosage; D012756:Sheep / Q000254:growth & development*; D013455:Sulfur / Q000008:administration & dosage; D015430:Weight Gain
chemical_list: D010758:Phosphorus; D013455:Sulfur; D008274:Magnesium; D002118:Calcium
keywords: Gender; Mineral; Nutrient balance; Semiarid; Sheep