scholarly journals Crude protein and supplemental dietary tryptophan effects on growth and tissue neurotransmitterlevels in the broiler chicken

1996 ◽  
Vol 76 (1) ◽  
pp. 87-96 ◽  
Author(s):  
R.W Rosebrough

Indian River male broiler chickens growing from 7 to 28 d of age were fed on diets containing 120,210 and 300 g crude protein/kg diet and 0, 1–67 or 16·7 g added tryptophan (TRP)/kg diet. The hypothesis tested was that crude protein levels and TRP would affect both growth and neurotransmitter metabolism. Heart, brain and pancreatic neurotransmitter (noradrenaline (NA), dopamine(DA), serotonin (5-HT) and 5-hydroxy-indole-3-acetic acid (5-HIAA) concentrations were determined by HPLC separation and electrochemical detection. Malate dehydrogenase (2-oxoglntarate decarboxylating) (NADP+) (MDH(NADP+); EC 1.1.1.40), isocitrate dehydrogenase (NADP+) (ICD(NADP+); EC 1.1.1.42) and aspartate aminotransferase (AAT; EC 2.6.1.1) activities were also measured. Supplemental TRP decreased growth and feed intake. Increasing dietary crude protein decreased MDH(NADP+), but increased (ICD(NADP+) and AAT activities. Additional dietary TRP decreased MDH(NADP+) activity, but had no effect on other enzyme activities. Cardiac NA concentrations were directly related to dietary crude protein levels while pancreatic levels were inversely related. An increase in dietary crude protein decreased both brain NA and DA. Supplemental dietary TRP increased both 5- HIAA and 5-HT. Changes in feed intake caused by different levels of botb dietary crude protein and TRP are accompanied by altered levels of neurotransmitters. The present study indicates that much arger amounts of TRP are required to make simultaneous changes in feed intake and neurotransmitters.

1993 ◽  
Vol 70 (3) ◽  
pp. 667-678 ◽  
Author(s):  
R. W. Rosebrough ◽  
J. P. McMurtry

Male broiler chickens growing from 7 to 35d were fed on a diet containing 150g crude protein (N × 6·25)/kg diet supplemented with lysine to equal that in diets containing 166, 183 and 200g crude protein/kg diet (Expt 1). A second group of male broiler chickens growing over the same period were fed on a diet containing 120g crude protein/kg supplemented with lysine, arginine, tryptophan, threonine and isoleucine equal to that in diets containing 144, 172 and 200g crude protein/kg diet (Expt 2). Growth was improved by lysine supplementation but not to the level attained by feeding 200g crude protein/kg (Expt 1). Lysine, arginine, tryptophan, threonine and isoleucine supplementation of a low-protein diet also improved growth, but growth again fell short of that attained by feeding a diet containing 200g crude protein/kg. Plasma insulin-like growth factor-1 and thyroxine concentrations increased and triiodothyronine decreased as the crude protein level increased from 150 to 200g/kg diet. Supplemental lysine did not affect plasma levels of these hormones. Although dietary crude protein levels noticeably changed rates ofin vitrolipogenesis, changing either the level of a single limiting amino acid or the levels of several limiting amino acids did not change lipogenesis.


2021 ◽  
Vol 24 (2) ◽  
pp. 116-123
Author(s):  
S. O. O. Oyewole ◽  
R. I. Salami

An experiment was conducted to evaluate the replacement value of poultry visceral offal meal (PVOM) substituting for fish meal (FM) on an equal protein basis in the diets of unsexed Ross-strain broiler chickens from day-old to 8 weeks of age. One hundred and fifty birds were allotted in groups of 10 into 15 equidimensional floor pens with floor space of 0.189m2 per bird. There were three replicates per treatment diet, with 10 birds per pen serving as a replicate. Five treatment diets, each for the starter and finisher phases of 5 and 3-week duration respectively were fed ad libitum. Diet A (control) contained 8% FM which was gradually replaced with PVOM at 2,3,4,6,6,90 and 9.20% in diets B, C, D and E respectively for both phases. All the diets were isocaloric (ca 12MJ   ME/kg) for both phases and isonitrogenous with 23 and 20% dietary crude protein contents for the starter and finisher diets respectively. Feed intake and feed conversion rations (FCR) were similar (P >0.05) on all diets in support of complete substitution. However , weight gain for 8 weeks on the control diet was better (P <0.05) than those on FM/PVOM- and PVOM-diets whose weight gains were similar (P < 0.05). The mean feed intake values of 4.031, 3.936, 3.760, 3.870 and 3.715 kg/bird were obtained for birds receiving diets A,B,C,D and E respectively while the equivalent FCRs were 2.326, 2.352, 2.233, 2.326 and 2.340. The mean weight gains for birds on diets A,B,C,D and E for 8weeks were 1.824, 1.688, 1.689, 1.676 and 1.590 kg/bird respectively. The dressed weight and weight of back, drumsticks, things and wings were similar (P >0.05) for all diets in favour of complete substitution of FM with PVOM. Mean dressing percentages were 58.24 to 69.07% . It is concluded that PVOM could replace FM completely in broiler diets.   


PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0260285
Author(s):  
Shemil P. Macelline ◽  
Peter V. Chrystal ◽  
Shiva Greenhalgh ◽  
Mehdi Toghyani ◽  
Peter H. Selle ◽  
...  

The objective of this study was to investigate the impacts of dietary crude protein (CP), fishmeal and sorghum on nutrient utilisation, digestibility coefficients and disappearance rates of starch and protein, amino acid concentrations in systemic plasma and their relevance to growth performance of broiler chickens using the Box-Behnken response surface design. The design consisted of three factors at three levels including dietary CP (190, 210, 230 g/kg), fishmeal (0, 50, 100 g/kg), and sorghum (0, 150, 300 g/kg). A total of 390 male, off-sex Ross 308 chicks were offered experimental diets from 14 to 35 days post-hatch. Growth performance, nutrient utilisation, starch and protein digestibilities and plasma free amino acids were determined. Dietary CP had a negative linear impact on weight gain where the transition from 230 to 190 g/kg CP increased weight gain by 9.43% (1835 versus 2008 g/bird, P = 0.006). Moreover, dietary CP linearly depressed feed intake (r = -0.486. P < 0.001). Fishmeal inclusions had negative linear impacts on weight gain (r = -0.751, P < 0.001) and feed intake (r = -0.495, P < 0.001). There was an interaction between dietary CP and fishmeal for FCR. However, growth performance was not influenced by dietary inclusions of sorghum. Total plasma amino acid concentrations were negatively related to weight gain (r = -0.519, P < 0.0001). The dietary transition from 0 to 100 g/kg fishmeal increased total amino acid concentrations in systemic plasma by 35% (771 versus 1037 μg/mL, P < 0.001). It may be deduced that optimal weight gain (2157 g/bird), optimal feed intake (3330 g/bird) and minimal FCR (1.544) were found in birds offered 190 g/kg CP diets without fishmeal inclusion, irrespective of sorghum inclusions. Both fishmeal and sorghum inclusions did not alter protein and starch digestion rate in broiler chickens; however, moderate reductions in dietary CP could advantage broiler growth performance.


Nova Scientia ◽  
2020 ◽  
Vol 12 (25) ◽  
Author(s):  
Fidel Infante-Rodríguez ◽  
Miguel Ángel Domínguez-Muñoz ◽  
Martín Francisco Montaño-Gómez ◽  
Michael E. Hume ◽  
Robin C. Anderson ◽  
...  

Introduction: Current diets of broiler chickens tend to increase protein levels to obtain high productive variables that are achieved in combination with genetic, management, and sanitary improvements, among others. An increase in dietary crude protein levels does not always accompany an increase in broiler productive efficiency due to multiple factors involved in the production system. The objective of this study was to evaluate the effect of increasing levels of dietary crude protein (CP) on productive performance, carcass characteristics, and chemical composition of breast and thigh meat in broiler chickens raised in the dry subtropics of northeastern Mexico.Method: The study used 200, 1-day-old male Ross broiler chicks. In a completely randomized design, birds were allocated to the four treatments with five replicates (floor pens) of ten birds each. The trial was divided in two phases (starter and finisher) of 21 days each (42 days total). Treatment diets (T) for starter and finisher phases had crude protein concentrations (CP; %) of 21 and 18.1 (T1), 21.4 and 18.5 (T2), 21.8 and 18.9 (T3), and 22.2 and 19.3 (T4), respectively. Within each feeding phase, the four treatment diets were formulated to similar levels of apparent metabolizable energy.Results: Protein concentrations had no effect (P > 0.05) on weight gain, while feed intake was greater in T1 (P < 0.05) than in T2 and T3. Feed conversion was better in T2 and T4 (P < 0.05) than in T1. There was no influence of treatment on carcass weight or carcass cuts (P > 0.05). Carcass yield was greater in T1 than in T3 (P < 0.05). Breast and thigh dry matter and ether extracts were similar (P > 0.05) between treatments. Breast crude protein was greater (P < 0.05) in T2 than in T3. The lowest (P < 0.05) CP concentration in thigh meat was in T3.Discussion or Conclusion: These results indicated that in the dry subtropics area of northeastern Mexico increases in CP above the level of T2 (21.4% and 18.5% CP in starter and finisher diets, respectively) did not improve broiler chicken productive performance, carcass characteristics or meat chemical composition.


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