The Effects of Dietary Protein and Lysine Levels on Broiler Performance, Carcass Characteristics and N Excretion (original) (raw)
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Animal Research, 2005
The effects of two dietary crude protein levels (H = 22.5 and L = 17% on average) and four lysine levels (0.56, 0.66, 0.76 and 0.86%) were compared in a 2 × 4 factorial design, on growth and carcass composition of slow growing broilers (Label) during the finishing period (42-77 days). There were six pens of 28 male chickens per treatment. In each pen, 14 chicks received a stimulating starter diet (13 MJ•kg-1 , 1.4% lysine) and the other 14 chicks a poor starter diet (12.1 MJ•kg-1 , 1.1% lysine) from 0 to 6 days of age. The starter regime had no significant effect on subsequent performances and no interaction with the other traits. During the finishing period, lysine deficiency at 0.56% induced feather pecking and cannibalism resulting in more severe mortality with the H (33.9%) than the L diet (5.4%). Growth, feed conversion and breast meat yield were significantly improved by lysine supplementation up to 0.76% in the diet whatever the protein level. However, the deterioration of growth and feed conversion for lower lysine levels was more severe for the H diet compared to the L diet (interaction P < 0.001). The H fed chickens had less abdominal fat (3.3%) than the L fed chickens (4.3%) without a significant effect of the lysine level. The lysine requirement measured by regression (exponential and ascending line with a plateau) was close to 0.68%. High dietary protein levels associated with subdeficiency in lysine might favour cannibalism in label chickens during the finishing stage. meat chicken / growth / protein / lysine / body composition / cannibalism
African journal of agricultural research
An experiment was conducted to evaluate crude protein level on lysine requirements and performance of male broiler chickens. From 21 to 42 day old chicks were fed one combination of dietary lysine and CP (18, 20 and 22% crude protein and 0.08, 0.9, 1 and 1.1% lysine) in a diet containing 3.200 kcal/kg ME. Variables measured consisted of feed intake, body weight gain, feed conversion ratio, percentage of fat pad carcass, breast and thigh weight. The lysine requirement was estimated by broken line methodology based on body weight gain, feed conversion ratio, carcass and breast weight recorded in the grower period. There were significant effects of crude protein level on body weight gain, feed intake, feed conversion ratio and percentage of fat pad that existed. The body weight gain and feed intake increased and percentage of fat pad decreased as crude protein increased in the diet. However, increasing lysine in the diets significantly increased body weight gain, breast meat, thigh and...
Trakia Journal of Science
One hundred and fifty day-old Abor-acre strain broilers chicks were used to evaluate the blood parameters, carcass yield, organ weight and villi morphometrics of broilers fed low protein diet in excess of dietary lysine. The chicks were weighed on the eight day and then randomly assigned to five experimental diets in such a way that each dietary treatment had 30 birds replicated thrice. Diet 1 was the control with 22.22% crude protein (CP) while diets 2, 3, 4 and 5 contained 16.6% CP each at both starter and finisher phases with varying levels of lysine ranging from 0.50 to 0.90%. They all had the same level of methionine. Results showed that the birds fed diet 4 (16.6% CP and 0.8% lysine inclusion level) had a significantly (p<0.05) higher breast, villi height, crypt depth and muscle thickness while the lymphocyte count, total protein, abdominal fat and back size increased linearly with lysine inclusion unlike decreases in heterophil among birds fed LCP diets. It can be concluded that increased villi morphology enhanced breast yield due to enhanced absorption with increased abdominal fat as observed in birds fed 16.6% CP and 0.8% lysine inclusion level.
Effect of dietary lysine to crude protein ratio on performance of male Ross 308 broiler chickens
Tropical Animal Health and Production, 2008
Two experiments were conducted to determine the effect of dietary lysine to crude protein ratio on performance of male Ross 308 broiler chickens. In each experiment the diets were isocaloric and isonitrogenous but with different lysine to crude protein ratios. A complete randomized design was used in both experiments, the starter (1-21 days) and grower (22-42 days) experiments. The three starter diets, based on lysine to crude protein ratios, were L 0 (0.055), L 1 (0.066) and L 2 (0.077), while grower diets were L 3 (0.047), L 4 (0.061) and L 5 (0.074). A quadratic type equation was used to determine ratios for optimum growth rate, feed conversion ratio, breast meat yield and breast meat nitrogen content. Dietary lysine to crude protein ratios of 0.066 and 0.077 supported optimum growth rate and feed conversion ratio, respectively, during the starter period. Dietary lysine to crude protein ratios of 0.073, 0.073, 0.069 and 0.079 supported optimum growth rate, feed conversion and breast meat yield and nitrogen content during the grower phase. Dietary lysine to crude protein ratio had no effect on diet intake and digestibility. The results indicate that at each phase a single dietary lysine to crude protein optimized both growth rate and feed conversion ratio. However, the ratio for optimum breast meat yield was lower than that for optimum growth rate and feed conversion ratio. These findings have implications on ration formulation for broiler chickens.
Kafrelsheikh Veterinary Medical Journal
Two hundred day-old unsexed broiler (Cobb 500) chicks were randomly distributed to four groups. The first (control) group was fed on starter (22% CP, 3100 Kcal/kg ME, 1.10% Lysine, and 0.48% Methionine) and finisher (20% CP, 3200 Kcal/Kg ME, 0.90% Lysine, and 0.35% Methionine) diets. The other three groups were fed on three starter and finisher isocaloric isonitrogenou diets with 2% lower protein content than the diets of control group with addition of graded levels of L-lysine HCl and DL-methionine to give 120%, 140%, and 160% of the NRC (2000), At the end of starting period, the increased Lysine and Methionine content of the low-protein starter's rations didn't affect body weight and gain but increased the feed consumption and decreased the feed conversion ratio of the birds. At the end of finishing period, body weight, body gain, feed intake, and breast meat yield increased significantly with the increasing of synthetic amino acids in the diets, while the best feed conversion ratio was obtained with 120% amino acids level. Plasma uric acid level increased with Effect Of Feeding Low-Protein, L-Lysine And Dl-Methionine-… Gaafar, K et al., 339 feeding broiler on low protein diets and with increasing of synthetic amino acids supplementation to the diets. Plasma Creatinine increased in the birds fed on low-protein diet supplemented with the highest synthetic amino acids level (160%). Plasma Calcium wasn't affected by the treatment while phosphorus increased in the birds fed on low-protein, DL-Methionine and L-lysine supplemented diets compared with the control group, which might be as indicator for enhanced growth of these groups. It could be concluded that the minimum levels of protein (20% and 18% for starting and finishing periods, respectively) in the broiler's diets supplemented with 120% of NRC requirements for Lysine and Methionine requirements ensure an optimum body weights, body gains, and feed conversion ratios with reduced plasma level of Uric acid but were inadequate to produce the highest breast meat yield.
Revista Brasileira de Zootecnia, 2011
One thousand and fifty (1,050) Ross male broilers from 23 to 36 days of age were used to evaluate the dietary effects of levels of lysine. It was used a random block design with 5 levels of digestible lysine (0.95; 1.00; 1.05; 1.10 and 1.15%). Each level was applied to seven replicates and the experimental unit was composed of 30 birds. Diets were offered in seven replicates and the experimental unit was represented by 30 birds. Weight gain, feed intake, feed conversion, carcass traits, cut yields, composition and deposition of body nutrients were evaluated. The concentration of 1.09% of digestible lysine optimized performance without significant effects on feed intake. Carcass traits and cut yields had no significant differences among levels of lysine. On the other hand, there was a quadratic effect on carcass weight, which was the best at the level of 1.07% of digestible lysine. On crude protein content of the empty body, the best response was observed at the level of 1.10% of die...
Asian Australasian Journal of Animal Sciences 24, 1623-1628, 2011
An experiment was conducted to evaluate the effect of dietary replacement of normal maize (NM) with quality protein maize (QPM) on performance, immune response and carcass characteristics of broiler (Krishibro) chickens. Six experimental diets were prepared separately for starter and finisher phases. Diet 1 was a control diet formulated with NM and soybean meal. In diets 2-5, the NM was replaced with QPM at 25, 50, 75 and 100%, respectively. Diet 6 was the same as the control diet, but supplemented with synthetic lysine similar to the industry standard. Each test diet was fed to 8 replicates, each of 5 chicks, reared in stainless steel battery brooders. The AME content of QPM (3382 kcal/kg) was similar to that of NM (3,352 kcal/kg), but protein (9.91 vs. 8.94%), lysine (0.40 vs. 0.26%) and tryptophan (0.09 vs. 0.07%) contents of QPM were higher than NM. Dietary replacement of NM with 50% QPM significantly (p<0.05) improved body weight gain, feed conversion ratio, humoral immune response, relative bursa weight, and breast muscle yield and lowered abdominal fat content. No further improvement in these parameters was recorded by increasing the level of replacement of NM with QPM to either 75% or 100%. Further, the improvement noticed in the 50% QPM group was similar to the group fed the NM diet with lysine supplementation, and thus dietary replacement of NM with QPM at 50% did not need extra synthetic lysine supplementation. It is concluded that dietary replacement of NM with QPM at the 50% level resulted in optimum performance, higher breast muscle yield and higher immune response in broiler chickens. (
Revista Brasileira de Zootecnia, 2014
The objective of this study was to evaluate the effect of digestible lysine levels in diets with or without supplementation of industrial amino acids on performance, carcass characteristics and nitrogen excretion in broilers of 22 to 42 days of age. Birds were distributed in a completely randomized experimental design in a 4 × 2 factorial arrangement, with four digestible lysine levels (9.0, 10.0, 11.0 and 12.0 g/kg) and two methods to obtain the lysine levels (variation in the proportion of corn and soybean meal, without supplementation; or supplementation of industrial amino acids), eight replicates and 20 birds per replicate. There was an interaction effect on the performance characteristics and on the weights and yields of prime cuts. In both diets, feed conversion improved linearly as the lysine levels were increased. Feed intake; weight gain; carcass, thigh and drumstick weights; and boneless breast yield increased and abdominal fat reduced linearly as the lysine levels were increased in the unsupplemented diet. The lysine levels of the supplemented diets linearly reduced the yield of drumstick and quadratically reduced the yields of bone-in and boneless breast up to the estimated levels of 10.4 and 10.7 g/kg, respectively. Diets without supplementation increased the excretion and retention of nitrogen. The levels of 9.0 and 12.0 g/kg digestible lysine obtained with supplementation of industrial amino acids and without it, respectively, provide the best performance and yield of prime cuts in the birds. Diets in which the digestible lysine levels are obtained without supplementation provide better performance responses and carcass characteristics compared with supplemented diets.
2021
Simple Summary In the past, many studies have been carried out to investigate the effect of lysine supplementation on broilers’ growth performances and feed efficiency. However, the knowledge concerning the reduction of the dietary content of this essential amino acid is limited and mainly restricted to the production performances of the birds. Within this context, the present study aimed at assessing the impact of lysine restriction during grower I (10–20 d) and grower I and II (10–20 and 21–34 d) feeding phases on live performances, breast meat quality traits and technological properties, as well as on the incidence and severity of abnormalities affecting the pectoral muscles (i.e., white striping, wooden breast and spaghetti meat). Lysine restriction during different feeding phases exerts negligible effects on the production performances of the broilers due to their compensatory growth. In addition, the increased anserine content following lysine depletion might have exerted a pr...