The study was carried out to evaluate the effect of quantitative feed restriction with or without enzyme supplementation on the bilateral body measurements, organ weights and serum biochemistry of broiler chickens. A total number of 100 healthy mashall breed of day old chickens were used for the study. The birds were all fed ad libitum for the first week. At the second week, the birds were divided into four (4) treatment groups consisting of three (3) replicates per group. The first group of the broiler chickens was considered as the control group and were fed ad libitum diet without enzyme supplementation. The 2nd, 3rd and 4th groups were fed with diets supplemented with enzyme (maxigrain) at restriction levels of 15, 30 and 45% of ad libitum respectively. After two weeks of feed restriction, birds in all groups were fed ad libitum to allow for re-alimentation. Starter diet comprising of 23% CP and 2966kcal/kg was fed for 0-4wks while finisher diet comprising of 18% CP and 2885 kcal/kg was fed from 5-7wks. At the 4th week, blood samples were collected in heparinised bottles for serum biochemical analysis. Similarly, birds were randomly selected for bilateral body measurements of the shank, thigh, wing and chest. At the 7th week, six broilers were randomly selected from each treatment group (i.e. 2 per replicate) and slaughtered for collection and evaluation of organs such as liver, kidney, heart, gizzard and intestine. The results obtained after analysis showed no significant effect (P>0.05) of feed restriction and enzyme supplementation on organ weights (i.e. liver, kidney, heart, gizzard and intestine). Also no significant effect (P>0.05) was seen on development of body parts (i.e shank length, thigh length, and chest girth). However, it had significant effect (P<0.05) on wing length. Furthermore, feed restriction and enzyme supplementation also significantly affected (P<0.05) the serum biochemical parameters of broiler chickens such as urea, sodium, potassium, globulin, cholesterol and aspartate transaminase. However, feed restriction did not have significant effect (P>0.05) on parameters such as chlorine, creatinine, total protein and albumin.
Poultry production has the potentials to contribute meaningfully to the economic growth of any country. In Nigeria for instance, the poultry subsector has contributed greatly to the improvement of the national economy in terms of job creation, Gross Domestic Products as well as food security. This is evident in as high as 10% of Nigerians directly engaged in the supply of poultry inputs, establishment of hatcheries, feed mills, farms and cottage industries producing egg, meat and their products. Broilers are known for their efficient feed conversion into essential nutrients required by man. According to Wilson (2005), broiler has the capability to attain table weight of 2.0kg in 33days. However, this depends on the genetic makeup of the strain, housing standard, feed quality and management strategy adopted.
Feed represents 70% of the total costs in poultry production(Willemsetal., 2013). Adlibitum feeding have led to the increase in growth rates in poultry; unfortunately this high growth rate is associated increased body fat deposition, high mortality and high incidence of metabolic and skeletal diseases which has negative impact on broilers (Zubaire tal, 2006). Therefore, there is a critical need to increase effort to reduce some of these problems and reduced feed cost (Sarvestani, 2006).
Quatitative feed restriction has been found to reduce body weight (Fattorietal., 1993) and delay sexual maturity (Krishnappa et al, 1992). Feed restriction, which is denying the fast growing bird a full access to nutrients that are required for their normal growth and development, is categorised into quantitative and qualitative feed restriction (Fanooci and Torki., 2010). The potential of feed restriction programs as management tool is related to decreasing the incidence of metabolic disease, carcass fat deposition, reduce maintenance requirements and improvement of feed efficiency in broiler chicken production (Johnson and Yamamoto., 2010).
Feed restriction is a conventional strategy employed in modern broiler breeder industry to lessen fat accretion and avoid reproduction and health complication but not in modern meat industry where feeding is ad libitum. However, ad libitum feeding has been implicated in mortality and health problems such as ascites, tiabialdyschondroplasia, necrosis of the femoral head, angular and torsional long bone deformities, perosis, spinal deformities, obesity and sudden death syndrome (Oyedeji and Atteh 2005).
To determine the effect of quantitative feed restriction with or without enzyme supplementation on bilateral body measurement, organ weight and serum biochemistry of broiler chicken.
- To determine the effect of quantitative feed restriction and enzyme supplementation on the bilateral body measurement of broiler chicken such as thigh length, shank length, wing length and chest girth.
- To determine the effect of quantitative feed restriction and enzyme supplementation on the organ weights of broiler chicken such as gizzard, liver, kidney, heart and intestine.
- To determine the effect of quantitative feed restriction and enzyme supplementation on serum biochemistry of broiler chicken such as urea, creatine, albumin, globulin, cholesterol, sodium, potassium and chlorine and aspartate transaminases.