An experiment was conducted to determine the possibility of using various levels of crude protein (CP) by providing laying hens with constant levels of digestible sulfur amino acid, threonine and lysine to improve performance and egg quality. The experiment was conducted as a completely randomized block design in a factorial arrangement (4×2) with 8 replicates of 10 hens in each. Factors included 4 levels of CP (18.5%, 17.5%, 16.5% and 15.5%) and 2 strains (LSL and Hy-Line W-36) of laying hens. Hens were fed experimental diets from 25 to 33 weeks of age. Production performance was measured for eight weeks and egg quality characteristics were determined at 29 and 33 weeks of age. Protein reduction decreased egg weight, egg mass and hen body weight linearly (P≤0.01). Egg production was not affected by protein reduction but feed efficiency, and average daily feed intake increased significantly (P≤0.01). Lohmann Selected Leghorn laying hens showed significantly higher egg production, egg weight, egg mass, weight gain, feed efficiency and feed intake compared to the W-36 laying hens (P≤0.01). Shell thickness increased linearly as protein levels decreased (P≤0.05). There were significant differences between two strains on the egg quality characteristics (P≤0.01). Significant (P≤0.05) CP × strain interactions were observed for hen weight, albumen height, Haugh units, yolk and shell percentage. Based on the results of this experiment, a reduction in dietary protein level (from 18.5% to 15.5%), without any alteration in digestible TSAA and Thr: Lys ratio, led to inferior egg mass and feed conversion ratio during the peak production period.

This study was designed to investigate the effects of Sangrovit on performance, small intestinal morphology, and immune response of 300 commercial hybrid broilers, Ross 308. The study was conducted in the Agricultural Research Station of Islamic Azad University, Varamin, in the spring 2010 for 42 days. The broilers were kept in a completely randomized design with 3 treatments, 4 replicates, 12 experimental units each containing 25 broilers. Treatments used in this experiment included controls, 0.05 % and 0.1 % Sangrovit of total ration. The test results showed no significant difference between different treatments during the breeding period on feed intake, feed conversion, and small intestinal morphology. However, treatments containing 0.1% Sangrovit showed significant differences on weight gain in the early rounds between the other treatments (P<0.05). Statistically, these differences were not significant during the breeding period. Regarding the effects of different treatments on the carcass components, the diet containing 0.05% Sangrovit could significantly increase the weight of the thigh (P<0.05) than the other diets. In this treatment, the mean serum antibody titers against Newcastle disease by HI method showed significant differences at 35 and 42 days of the breeding period (P<0.05). Based on the results of this experiment, Sangrovit can obtain the desired results in improving immune system, performance and carcass yield.

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Nowadays, aquaculture produces approximately half of the utilized fish globally (Galkanda-arachchige, Wilson, & Davis, 2019). In this regard, fishmeal is the main source of protein in aquaculture nutrition, especially for carnivorous species. Fishmeal not only has high palatability, digestibility and well-adjusted amino acid profile, but also it has some unique properties such as high levels of essential n-3 fatty acids, nucleotides, minerals, phospholipids, vitamins and free of antinutrient factors (Gatlin et al.

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