Diets with reduced levels of nutrients supplemented with phytase and amino acids for broilers

Abstract

One performance experiment and another metabolism experiment were conducted simultaneously with broilers from 22 to 35 days of age, evaluating five diets in six replicates. The control diet, without phytase, contained 19% of crude protein (CP); 0.412% of available phosphorus (aP) and 0.824% of calcium (Ca). The other diets were supplemented with phytase and were formulated with 0.262% of aP and 0.524% of Ca, with the CP level ranging from 19 to 16%. In the performance assay, 750 birds were used, in which were evaluated the performance, the tibia ash content and yields of carcass, cuts, and abdominal fat at 35 days of age. The metabolism assay was conducted with 90 birds, evaluating the apparent metabolizable energy corrected by the nitrogen balance; the metabolizability coefficient of dry matter (MCDM) of the diets, and also the balance and retention of nitrogen (N) and phosphorus (P). Diets did not affect performance, tibia ash content and yields of carcass, breast and thigh + drumstick. However, birds fed diet containing 16% of CP showed greater abdominal fat. Diets containing 19% of CP had the smaller energetic value and MCDM. The retention of N and P was higher in birds fed diets formulated with reduced CP content and phytase. Therefore, when the broiler feed is supplemented with phytase and amino acids it is possible to reduce the CP, aP and Ca for up to 16; 0.262 and 0.524%, respectively.Index terms: Tibia ash, carcass yield, ideal protein, metabolism, performance. RESUMOUm experimento de desempenho e outro de metabolismo foram conduzidos simultaneamente com frangos de corte de 22 a 35 dias de idade, avaliando-se cinco dietas em seis repetições. A dieta controle, sem fitase, continha 19% de proteína bruta (PB); 0,412% de fósforo disponível (Pdisp) e 0,824% de cálcio (Ca). As demais dietas foram suplementadas com fitase e formuladas com 0,262% de Pdisp e 0,524% de Ca, tendo o teor de PB variado em 19 até 16%. No ensaio de desempenho, 750 aves foram utilizadas, avaliando-se o desempenho, o teor de cinzas na tíbia e rendimentos de carcaça, cortes e gordura abdominal, aos 35 dias de idade. O ensaio de metabolismo foi realizado com 90 aves, determinando-se a energia metabolizável aparente, corrigida pelo balanço de nitrogênio e o coeficiente de metabolizabilidade da matéria seca (CMMS) das rações, e também o balanço e retenção de nitrogênio (N) e fósforo (P). As dietas não influenciaram o desempenho, teor de cinzas na tíbia e os rendimentos de carcaça, peito e coxa + sobrecoxa. Entretanto, as aves alimentadas com a ração contendo 16% de PB apresentaram maior teor de gordura abdominal. As rações com 19% de PB apresentaram menor valor energético e CMMS. A retenção de N e P foi maior nas aves que receberam as rações com reduzidos teores de PB e fitase. Portanto, quando a ração de frangos de corte é suplementada com fitase e aminoácidos é possível reduzir a PB, Pdip e Ca em até 16; 0,262 e 0,524%, respectivamente.Termos para indexação: Cinza na tíbia, rendimento de carcaça, proteína ideal, metabolismo, dese...

Efficiency of microbial phytases in diets formulated with different calcium:phosphorus ratios supplied to broilers from 35 to 42 days of age

“…Finally, it was found that supplementing the diet with phytase did not change the AMEn or the DMDC of the diets, corroborating with the results of Gomide et al (2012) obtained for broilers reared in the period from 22 to 35 days of age.…”

“…In view of this situation, the diets that are currently in use have been formulated with low levels of available phosphorus (AP) and supplemented with phytase (Gomide et al 2012;Jalali & Babaei 2012;Rutherfurd et al 2012;Olukosi et al 2013;Naves et al 2014a). However, although the inorganic source of calcium (Ca) is relatively inexpensive, it is important to assess the optimal level of this nutrient when the feed is formulated with a specific P concentration and supplemented with a certain activity of phytase.…”

“…There are several studies about the utilization of phytases in feeds for broilers during initial rearing periods (Santos et al 2008;Gomide et al 2012;Rutherfurd et al 2012;Olukosi et al 2013), however it is important to consider that during the last week of rearing there is a high feed intake (Rostagno et al 2011). Therefore, an important nutritional strategy to reduce the cost of the feed and the P excretion in the environment is to evaluate the possibility of feeding broilers from 35 to 42 days of age with feed formulated without inorganic P, supplemented with phytase.…”

Efficiency of microbial phytase supplementation in diets formulated with different calcium:phosphorus ratios, supplied to broilers from 22 to 33 days old

“…Conversely, dietary phytase supplementation did not improve N utilization or the ADDM and AMEn of feeds, corroborating the results that Gomide et al. () obtained from 22‐ to 35‐day‐old broilers.…”

Increasing levels of phytase in diets formulated with reduced available phosphorus content supplied to male and female broilers

“…This improvement in the retention of total P can be explained by the action of phytase on the phytate of the diet, as reported by several authors (HAN et al, 2009;SANTOS et al, 2011;GOMIDE et al, 2012), who verifi ed gradual increase in the utilization of phy P in the function of the level of phytase in the diet.…”