Phosphorus on performance, hematological, biochemical, and bone parameters of growing pigs

ABSTRACT: The purpose of this study was to assess the levels of available phosphorus (AP) in the diet of growing pigs selected for lean deposition on the hematological, biochemical, and bone performance parameters. A total of 64 commercial hybrid pigs (32 castrated males and 32 females; mean initial weight: 23.31±2.4kg; age: 55-90 days) were used. Animals were distributed into a randomized block design with four treatments, eight replicates, and two animals (one male and one female) per experimental unit. The treatments consisted of a basal diet and another three diets, which were obtained by supplementing the basal diet with dicalcium phosphate replacing the inert phosphate, resulting in four diets with 0.100, 0.180, 0.260, and 0.340% of available phosphorus. The levels of available phosphorus quadratically influenced the daily weight gain, feed consumption, and feed conversion, which increased up to the estimated levels 0.331; 0.330, and 0.302% of available phosphorus. Levels of phosphorus showed no influence on the hematological parameters, which remained within the reference values. Levels of available phosphorus increased linearly the ash and phosphorus contents in the metacarpal bone and decreased linearly the alkaline phosphatase activity. Levels of available phosphorus (0.331 and 0.302%, corresponding to a daily intake of 5.73 and 5.18g d-1) provided respectively the best results for weight gain and feed conversion in pigs with high genetic potential, without change in hematological parameters

Níveis de fitase sobre o desempenho, parâmetros ósseos e bioquímicos de suínos alimentados com ração de origem vegetal sem inclusão de fosfato bicálcico

Este estudo foi conduzido com o objetivo de avaliar os níveis de fitase em rações para suínos em crescimento selecionados para deposição de carne. Foram utilizados 64 suínos mestiços (32 machos castrados e 32 fêmeas), híbridos comerciais, com peso médio inicial de 23,311±2,254 kg, distribuídos em delineamento de blocos casualizados, com quatro tratamentos, oito repetições e dois animais (um macho e uma fêmea) por unidade experimental. Os tratamentos foram constituídos por uma ração controle de origem vegetal, sem inclusão de fosfato bicálcico e fitase, contendo 0,100% de fósforo disponível; e de outras três rações obtidas pela inclusão de 300, 600 e 1200 unidades de fitase (UFT kg-1) à ração controle. Os níveis de fitase influenciaram de forma linear o ganho de peso diário e consumo de ração, aumentando até o nível de 293 e 307 UFT kg-1 de ração, respectivamente, a partir do qual permaneceram em um platô. A conversão alimentar diminuiu até 255 UFT kg-1 de ração, a qual permaneceu em um platô. Os níveis de fitase não influenciaram os teores de cinzas e fósforo no metacarpo dos animais. Houve efeito linear decrescente dos tratamentos sobre o resultado bioquímico de fosfatase alcalina. Os melhores resultados de ganho de peso, consumo de ração e conversão alimentar foram obtidos, respectivamente, com os níveis de 293, 307 e 255 UFT kg-1 de ração, em suínos de alto potencial genético para deposição de carne na fase dos 55 aos 90 dias de idade.This study was carried out to determine the phytase levels in diets for growing swine selected for meat deposition. Sixty-four crossbred swine (32 barrows and 32 females), with an average initial weight of 23.311±2.254 kg were distributed in a block design with four treatments and eight replications of two animals (one male and one female) each. The treatments consisted of a control diet with vegetables ingredients, without dicalcium phosphate and phytase inclusion, containing 0.100% available phosphorus and three other diets obtained by the inclusion of 300, 600 and 1200 phytase units (FTU kg-1) to the control diet. Levels of phytase influenced linearly the daily weight gain and feed intake, increasing to the level of 293 and 307 FTU kg-1 diet, respectively, from which remained on a plateau. Feed conversion ratio decreased to 255 FTU kg-1 diet, and remained on a plateau. Levels of phytase did not affect the levels of ash and phosphorus in animal bone. There was decreasing linear effect of treatments on the biochemical results of alkaline phosphatase. The best results in weight gain, feed intake and feed conversion were obtained, respectively, with levels of 293, 307 and 255 FTU kg-1 of feed for pigs of high genetic potential for lean deposition during the 55 to 90 days of age