Digestibilidade de fósforo de alimentos e exigência de fósforo digestível de aves e suínos

• Ano de defesa: 2009
• Autor(a) principal: Bünzen, Silvano
• Orientador(a): Rostagno, Horácio Santiago
• Banca de defesa: Teixeira, Alexandre de Oliveira , Kiefer, Charles
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Zootecnia
• Departamento: Genética e Melhoramento de Animais Domésticos; Nutrição e Alimentação Animal; Pastagens e Forragicul
• País: BR
• Palavras-chave em Português: Fósforo digestível; Fósforo endógeno; Monogástricos
• Palavras-chave em Inglês: Digestible phosphorus; Phosphorus endogenous; Monogastric
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::NUTRICAO E ALIMENTACAO ANIMAL::AVALIACAO DE ALIMENTOS PARA ANIMAIS
• Link de acesso: http://locus.ufv.br/handle/123456789/1735

Nine experiments were carried out to determine the phosphorus endogenous losses, the true digestibility coefficients of phosphorus of feeds and the digestible phosphorus requirements for broilers and growing pigs. In a first moment, 15-d 50 broilers were fed a free- phosphorus purified diet to determine the phosphorus endogenous losses by the total feces collection and ileal digesta collection using chromium oxide as marker. No differences were detected between the methodologies. The phosphorus endogenous losses for growing broilers were estimated in 138,43 mg of P/kg of dry matter intake (DMI). The second trial was conducted to determine the true digestibility coefficients of phosphorus of soybean meal and dicalcium phosphate of 52.54 and 75.01%, respectively. The methodologies were the same as experiment 1. The third experiment aimed to evaluate the true digestibility coefficients of phosphorus for broilers. Two hundred and forty 21-d broilers were assigned to eight treatments (six feeds and two rations), six replicates and five birds by experimental unit, and evaluated by the total feces collection and ileal digesta collection using chromium oxide as marker. The values of phosphorus true digestibility were: corn, 44.49%; soybean meal, 57.74%; wheat bran and middlings, 46.21%; meat and bone meal, 57.39%; dicalcium phosphate, 57.28% and monocalcium phosphate, 56.86%. No differences among both methodologies occurred. A fourth experiment was carried out to evaluate the phosphorus digestible requirement for broilers chickens from 22 to 35 days old. One thousand and four hundred and forty broilers (half male and half female) were assigned to a factorial design, with six levels of digestible phosphorus (0.22; 0.26; 0.30; 0.34; 0.37 and 0.41%), eight replicates and 15 broilers per experimental unit. No treatment effect on feed intake was observed, but effect on weight gain, feed:gain ratio and bone parameters occurred. The value of digestible phosphorus that maximizes the performance and bone quality was estimated in 0.35% for females 0.41% for males. Four metabolism trials were carried out with growing and finishing pigs. Forty-eight barrows (24 growing and 24 finishing) were divided in two trials of each phase, one to evaluate the phosphorus endogenous losses of barrows fed a free-phosphorus purified diet (four animals assigned to a 2 x 6 factorial, both methodologies for all animals and six days of collection) and another to determine true digestibility coefficients of phosphorus of feeds for 20 animals allotted to a 2 x 5 factorial (two methodologies - total feces collection and chromium oxide as marker - and five treatments, with four feeds and a reference diet). Both trials had four replicates. No differences between the methodologies were observed. The phosphorus endogenous losses was estimated as 275.75 mg P/kg DMI for growing barrows and 434.80 mg of P/kg DMI for finishing barrows. The true digestibility coefficients of phosphorus were: corn, 53.19 and 63.20; soybean meal, 48.51 and 56.60; meat and bone meal, 63.40 and 83.70; dicalcium phosphate 74.79 and 82.43 in the growing and finishing phases, respectively. A ninth experiment was carried out to evaluate the digestible phosphorus requirements in growing pigs. Seventy crossbred pigs, 35 barrows and 35 females, from 30 to 50 kg were assigned to a randomized block design, with five treatments, seven replicates and two pigs (a male and a female) per experimental unit. The treatments consisted of corn-soybean meal based diets, supplemented with dicalcium phosphate to obtain five levels of digestible phosphorus (0.19; 0.25; 0.30; 0.35 and 0.40%). The increasing digestible phosphorus levels resulted in quadratic effect on the feed intake and weight gain, with maximum values of 0.32 and 0.31%, respectively. No treatment effect on feed: gain ratio was observed, but linear effect on the phosphorus percentage in the bones occurred.