scholarly journals Effect of protein concentrations in the diet on productive performance, carcass characteristics, and meat chemical composition of broiler chickens in the dry subtropics

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.

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.


2019 ◽  
Vol 24 (1) ◽  
Author(s):  
Cecep Hidayat ◽  
Sofjan Iskandar

<p class="Default"><span lang="EN-US">Sensi-1 Agrinak is a strain of the improved native chickens for meat production in Indonesia. The objective of </span><span lang="IN">this</span><span lang="EN-US"> study  was to investigate influence of different dietary energy and protein levels on </span><span lang="IN">p</span><span lang="EN-US">erformance, meat bone ratio</span><span lang="IN">,</span><span lang="EN-US"> and meat chemical composition of Sensi-1 Agrinak chicken, reared until 10 weeks of age. Two hundred and sixteen of unsexed day old chickens (DOC) of  Sensi-1 Agrinak were subjected to six experimental rations differed in dietary crude protein (CP) content,. </span><span lang="IN">Namely:</span><span lang="EN-US"> 21;19; and 17 % and dietary  metabolizable  energy (ME) (2800 and 3000 kcal/kg). Each treatment combination was replicated  four times and fed from day old to 10 weeks old. In each treatment combination there were nine unsexed-DOCs. The parameters observed were performance (i.e. live weight, feed intake, viability, FCR), economic index (European Production Efficiency Factor/EPEF), meat bone ratio, and meat chemical composition.  </span><span lang="IN">R</span><span lang="EN-US">esult showed that  </span><span lang="EN-US">increas</span><span lang="IN">ed</span><span lang="EN-US"> of dietary CP level increased live weight and EPEF (p&lt;0.05). Sensi-1 Agrinak chicken had the best FCR (2.59), when fed  diet containing 21% CP and 3000 kcal/kg. Increas</span><span lang="IN">ed</span><span lang="EN-US"> dietary CP level increased the  meat-bone ratio of breast, thighs, and drumsticks. Meanwhile, increas</span><span lang="IN">ed</span><span lang="EN-US"> levels of dietary CP and ME did not affect (p&gt;0.05) meat chemical composition. It </span><span lang="IN">is</span><span lang="EN-US"> concluded that optimal dietary levels of crude protein and energy for unsexed Sensi-1 Agrinak chicken  up to 10 weeks of age were 21% CP and 3000 kcal/kg.</span></p>


2021 ◽  
Vol 31 (1) ◽  
pp. 27-31 ◽  
Author(s):  
R. I. Salami ◽  
O. G. Longe ◽  
J. A. Oluyemi

A study was carried out to investigate the effect of dietary crude protein (CP) levels in diets of 2600kcal kg metabolisable energy content on the performance and carcass characteristics of cockerel finishers. The experimental diets A, B, C, D and E contained CP levels of 140, 160, 180, 200 and 200g kg and they were produced by modified diet dilution technique. Response criteria such as weight gain and feed conversion ratio, among others, and carcass characteristics were measured. Results on performance and carcass characteristics, with the exception of the neck, intestinal weights  and other visceral offals, revealed that these response criteria were optimized in the birds fed on 180g kg dietary CP level. Beyond this level, it was nor beneficial to feed higher CP levels. It is therefore, concluded that the CP requirement of finisher cockerels is 18% on the bases of their Performance and carcass characteristics.


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.


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