دانلود رایگان ترجمه مقاله تاثیر مکمل فیتاز میکروبی در رژیم های غذایی جوجه های گوشتی (سال 2018)

اثر افزودن مکمل فیتاز میکروبی روی جوجه های گوشتی تغذیه شده از رژیم غذایی فسفات دی کلسیم پایین

Effect of Supplementing Microbial Phytase on Broiler Chicks Fed Low Di-calcium Phosphate Diets

Abstract

For this study 195 day-old broiler chicks were randomly divided into three treatment groups with five replicates in each treatment group having 13 chicks per replicate per pen. Three iso-nitrogenous and iso-caloric rations were prepared as: R-I served as control with 0.83% di-calcium phosphate (DCP); R-II contained 50% less DCP (0.41%) than R-I and R-III contained R-II plus phytase Quantum® Blue @ 100 g/ton feed. Daily feed intake and weekly body weight gain per replicate were recorded for 35 days. On 35th day, blood and tibia bone samples from 5 birds per treatment were collected. Total weight gain and dry matter intake in chicks fed rations I, II and III were 1861, 1736 and 2023 gm/bird and 3242, 3284 and 3265 gm/bird, respectively. The chicks fed R-III got 16.00 and 8.00% higher weight gain compared to chicks fed R-II and R-I, respectively. Feed: gain ratio (gm/gm) was found best (P<0.05) in chicks fed R-III (1.61) and poorer in chicks on R-II (1.89). The concentration of Ca and P were 10.60, 9.47 and 11.43 mg/dL and 5.76, 4.91 and 7.11 mg/dL in blood serum and 32.61, 31.36 and 32.83% and 16.57, 15.92 and 16.60% in tibia bone of chicks fed rations I, II and III, respectively. The total feed cost per unit weight gain of broilers fed R-III diet was numerically 14% and 9% less than the broilers fed R-II and R-I, respectively. Results suggested that exogenous microbial phytase supplementation to rations having low DCP had positive effects on weight gain, feed: gain ratio and economic efficiency in broiler chicks. 

1 Introduction

After calcium (Ca) the second abundant mineral in animal body is phosphorus (P) and majority (80%) of the P is found in bones and teeth (NRC, 1994). The P is not only essential for bone development, growth, health, production and reproduction but it also aids in energy metabolism, synthesis of sugars and maintenance of acid-base balance in the body. However, the quantity and availability of dietary P is vital for growing animals. It is well established that phytate is the major source of P in plant based feedstuffs. Since birds are unable to produce any endogenous phytase, therefore their capability to utilize P from phytate is very limited (Woyengo et al., 2010).

Phytate is a ubiquitous component of plant sourced feed ingredients which encompasses approximately twothirds of total plant P (Hughes et al., 2009). In poultry, phytate P is normally utilized with availability from 0 to 50%, depending on age and metabolic adaptation in critical circumstances. Therefore, to meet the P requirement, generally expensive inorganic P sources are added to poultry diets. This practice leads to non-utilization of a large portion of dietary P from feedstuff and its excretion in faeces (Hughes et al., 2008; Woyengo et al., 2010) which ultimately pollutes environment. Recently, microbial phytase supplementation in poultry diets has got remarkable attention to reduce negative impact of phytate P on environment and performance of birds (Ceylan et al., 2003; Francesch and Geraert, 2009). Since phytase efficiency in the digestive tract is influenced by various factors like phytase origin, type of birds and ambient temperature etc. Therefore, each phytase preparation for poultry must be tested on broilers/layers to ensure its efficacy (Hughes et al., 2008; Onyango et al., 2005). Information regarding effect of microbial phytase addition in broiler chicks’ diet having low DCP is limited. Therefore, current study was designed to asses the effect of microbial phytase supplementation in broiler chicks fed low DCP diets on growth, economic efficiency and P contents in serum and tibia bones.