No abstract

eventy two New Zealand White rabbits (NZW) at 25 days of age were used to study the effect of of different dietary starch and protein levels on productive performance, nutrients digestibility coefficients, carcass characteristics, digestive tract measurements, blood constituents, enzymes activity and economical evaluation. The rabbits were fed on six experimental diets containing 3 levels of starch {16 (LS), 19 (MS) and 22% (HS)} and 2 levels of protein {14 (LP) and 16% (OP)} in a factorial arrangement design. The results obtained are summarized as follows:-Best results for live body weight (LBW) were obtained for rabbits fed 16% starch and 14% protein diet at the end of growth period (81 days of age). Decreasing of dietary starch and protein levels had a positive effect on average daily body weight gain (DBWG) in overall growth period (25-81 d.). Daily feed consumption (DFC) was affected by different levels of starch, but no protein level. Feed conversion ratio (FCR) was improved at moderate dietary starch and low dietary protein levels. Mortality rate of growing rabbits improved due to decreasing dietary protein levels. However, dietary starch levels had no effect.-Rabbits fed low levels of starch and protein in their rations significantly increased DM, OM, CP, NFE, starch and sugar digestibility coefficients and nutritive values (TDN and DCP). Neither dietary starch nor protein levels had impact on CF, neutral detergent fiber (NDF), acid detergent fiber (ADF) and EE digestibility.-There were not significant effects of starch and protein levels on dressing percentage, hot carcass weights (%), blood total protein, albumin, globulin, albumin/globulin ratio, liver activity enzymes (GOT and GPT). While, high starch level in the diet increased significantly liver weight (%) regardless of protein content.-Blood glucose, triglycerides and total protein content, amylase and protease enzymes activity in the stomach, ileum and cecum were significantly increased, while degree of pH for stomach, ileum and cecum contents was decreased by decreasing starch and protein levels in the diet. In addition, non-significant was observed in the cellulase and carboxymethylcellulase as affected by the different levels of protein and starch in all segents of the digestive tract. The results show that, total VFAs in the cecum and blood were high with 16% starch and 14% protein.-Economic efficiency and performance index were improved for rabbits fed (MS-LP) diet. However, production efficiency factor was improved for rabbits fed (LS-LP) diet. In growing rabbits, it was concluded that high correlation exists between dietary starch and protein levels which was reflected on productive performance, digestibility coefficients, digestive tract measurements and economic efficiency.

Animal production and its industrial investment is overwhelmed with various problems due to the insufficient animal feeding requirements and the competition with the human crop requirements. Therefore, about third of the total cultivated area of the world is covered with the animal feeding crops. In this regard, efforts have to be carried out to develop new techniques to face this competition. The aims of this study are to: 1) establish a hydroponic unit for intensive grass fodder production; 2) study the engineering parameters affecting the efficiency of the suggested unit such as light intensity and duration of aeration, nutrient solution and its characteristics and applied amounts of water, and 3) determine the total energy requirements for improving the unit production capacity.

he current study was designed to investigate the effects of dietary Spirulina inclusion at different levels on growth performance, antioxidant status, carcass traits and blood hematology of broilers subjected to cyclic heat stress. A total of 150 one-day-old Ross broiler chicks were randomly divided into three experimental groups with 5 replicates with 10 birds for each. The first group was provided with a basal diet and served as a control. Meanwhile, others were fed a basal diet supplemented with Spirulina at a concentration of 1 or 2 g/kg diet, respectively. The experiment was conducted during hot climate of July with ambient temperature of 30 ± 1 •C, Spirulina supplementation to heat-stressed broilers was able to alleviate the negative impacts of heat stress on the final average daily gain, body weight and feed conversion ratio, with the best impacts on the chickens fed Spirulina at level of 2 gm/kg diet. Further, Spirulina supplementation significantly affected blood lipid profile by reducing serum total cholesterol, low-density lipoprotein (LDL) and increasing high-density lipoprotein (HDL) levels. While the thyroid hormones T3 and T4 were increased by Spirulina supplementation. In addition, spirulina supplementation at 1 or 2 g improved carcass dressing percentages. It concluded that dietary Spirulina supplementation at 1 or 2 g/kg diet to broilers reared under heat stress conditions can effectively improve broiler production performance, blood constituents and physiological status.

A study was conducted to investigate the effects of feeding different levels of threonine and tryptophan on growth performance, some serum parameters and carcass traits of broiler chicks under Egyptian summer conditions. Three hundred and sixty Ross 308, one-day-old broiler chicks were randomly allocated into nine treatments with 4 replicates of 10 chicks each. Three levels of threonine (100, 150 or 200 %) and three levels of tryptophan (100, 150 or 200%) according to dietary requirements for Ross 308 chick's guidebook were used in a factorial design arrangement to obtain nine experimental treatments. Two periodical diets were used (starter phase 1-21 days and grower phase 22-35 days). Growth performance traits including live body weight (LBW), Body weight gain (BWG), feed consumption (FC) and feed conversion ratio (FCR) were recorded at the end of each week. Carcasses were manually eviscerated and weighed. Components of total protein, albumin, cholesterol, and triglycerides were analyzed by using commercial kits. The results showed that chicks fed diet containing 200 % threonine had an improvement in live body weight, body weight gain and feed conversion ratio. The performance index increased with the addition of threonine and tryptophan in the broiler diets. Serum total protein and globulin concentrations were affected by supplemental threonine and tryptophan. Dietary threonine, tryptophan did not affect serum albumin and triglycerides. Total cholesterol was increased with supplementation of threonine, tryptophan and interaction between them. Chicks fed 100% dietary threonine had the significantly better results in terms of the relative weights of carcass, edible parts and bursa compared to the chicks fed other dietary threonine levels, although tryptophan amino acid had not any significant effect on the above-mentioned traits. Giblets, liver, and heart weights percentage increase with increasing tryptophan level in the broiler diets. The relative weight of gizzard reduced with increasing level of both amino acids in the diets. In this study, it concluded that supplementation of threonine and tryptophan improves productive performance and health status of broiler chicks without imposing any toxicity as all blood components were in normal range.