Effect of dietary phytase suplementation on the performance, bone densitometry, and phosphorus and nitrogen excretion of broilers

Abstract

This experiment was carried out to evaluate the effects of the inclusion of different levels of phytase on broiler performance, bone densitometry, and phosphorus and nitrogen excretion. Nine hundred and sixty one-day old broilers, 50% males and 50% females, were distributed in a completely randomized experimental design into five treatments and six replicates 32 birds each. The treatments consisted of a control diet and four diets with the addition 25, 50, 75, and 100 g/ ton of phytase (250, 500, 750 and 1000 FTU of phytase/kg fed). Diets were formulated to contain equal nutritional levels, and considered the phytase product nutritional levels. In general, the addition of phytase resulted in a linear decrease in broiler performance. However, the performance results obtained with the level of 250 FTU phytase/kg feed were not different from the control treatment. The best bone density results were observed in the control treatment, with no phytase. The results of this experiment indicate that the nutritional matrix of the phytase product needs to be reviewed when added in levels higher 250 FTU/kg to broiler diets. INTRODUCTIONAiming at lowering production costs, many current research studies have focused on improving the efficiency of feedstuff utilization and to reduce the impact of animal production on the environment (Payne et al., 2005).Phosphorus is one of the most expensive nutrient of poultry and swine feeds, second only to energy and protein (Borges, 1997). It is nutritionally essential, as shown by its several roles in the body, and it is particularly important during growth. However, two thirds of the phosphorus contained in cereal grains and oil seeds are in the form of phytate, which can bind to other nutrients, rendering them unavailable for poultry and pigs, thereby, requiring dietary inorganic phosphorus supplementation (Denbow et al., 1995).The production of industrial phytase is based on microorganisms, using DNA recombination techniques. This enzyme increases phosphorus (P) availability in plant feed ingredients, where P is usually present as phytate. The dietary supplementation of phytase allows poultry and pigs to more efficiently absorb phosphorus, reducing the amount of inorganic phosphorus supplementation, and promoting better weight gain, feed conversion ratio, feed intake, and bone mineralization, as well as reducing mortality (Qian et al., 1996).Along with calcium, phosphorus has an essential role in bone formation. In the animal, phosphorus comprises about 1% of live weight, and it is carefully considered when feeds and supplements are formulated. About 80% of phosphorus in the animal body is deposited 26in bones and teeth. Therefore, the inclusion of phytase in broiler diets may enhance their bone development. The objectives of the present study were to evaluate the effects of the inclusion of different levels of phytase on broiler performance, bone densitometry, and phosphorus and nitrogen excretion in the litter during the starter (1 to 21 days), grower (22 to 42 days), and t...

Effect of ph and temperature on the activity of phytase products used in broiler nutrition

“…Several studies have been conducted to evaluate the performance and other parameters of broilers fed diets supplemented with phytase (Singh, 2008;Assuena et al, 2009;Nagata et al, 2009). However, few scientific studies evaluating the effect of pH and temperature on the activity of different phytases were published (Wyss et al, 1999;Igbasan et al, 2000).…”

“…However, in addition to the increasing number of broilers produced per year, modern commercial broiler strains present rapid growth, and consequently, diet formulation needs to follow up the changes in their nutritional requirements (Brandão et al, 2007). Phosphorus is nutritionally essential, as evidenced by the different roles it plays in metabolism, and it is particularly important for broiler growth (Assuena et al, 2009).…”

Níveis de cálcio e fósforo disponível em rações com fitase para frangos de corte nas fases pré-inicial e inicial

“…Além disso, o fitato pode atuar como fator antinutricional, pois pode complexar-se com nutrientes da dieta formando complexos insolúveis e, consequentemente, diminuir a biodisponibilidade dos nutrientes (Ravindran et al, 1999). Diante disso, fitases têm sido adicionadas às rações de frangos de corte com o propósito de disponibilizar parte do fósforo fítico e aumentar o aproveitamento de nutrientes da dieta (Selle & Ravindran, 2007), melhoria relatada por Assuena et al (2009), Nagata et al (2009 e Lelis et al (2010).…”

Energy and protein levels in diets containing phytase for broilers from 22 to 42 days of age: performance and nutrient excretion

“…Laurentiz et al (2009), working with normal levels of crude protein for growing broilers found no effect of phytase on the excretion of copper or zinc but significant reduction of phosphorus using 500 or 1,000 PTU/kg. Assuena et al (2009) also observed reduction of phosphorus excretion but not nitrogen when using phytase for broiler growth. According to Mroz et al (1994), phytic acid may inactivate enzymes such as trypsin and pepsin, interfering with the nutrient digestibility, especially protein in this case.…”