Interactive effect of exogenous protease enzyme and dietary crude protein levels on growth and digestibility indices in broiler chickens during the starter phase

2020 ◽  
Vol 53 (1) ◽  
Author(s):  
Abdul Jabbar ◽  
Muhammad Tahir ◽  
Rifat Ullah Khan ◽  
Nazir Ahmad
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.


2016 ◽  
Vol 32 (4) ◽  
pp. 353-360 ◽  
Author(s):  
Vladimir Doskovic ◽  
Snezana Bogosavljevic-Boskovic ◽  
Lidija Peric ◽  
Milos Lukic ◽  
Zdenka Skrbic ◽  
...  

This study evaluates the effect of different crude protein levels in broiler diets supplemented with 0.2% and 0.3% protease enzyme (Ronozyme Pro Act) on dressed carcass weight and dressing percentage during two fattening periods (49 and 63 days). The fast-growing strain Cobb 500 was used. At the end of the fattening trial i.e. at 49 and 63 days, 10 male and 10 female birds were randomly sacrificed from each experimental group to determine body weights and conventionally dressed, ready-to-roast and ready-to-grill carcass weights. The data obtained were used to calculate the dressing percentages of the differently dressed carcasses. Results indicated that carcass weights and dressing percentages were not affected by diet (P>0.05), but also showed that the increase in the length of the fattening period by two weeks (from 7 to 9 weeks) led to increased carcass weights, while dressing percentages decreased (P<0.05).


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.


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.


Animals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2499
Author(s):  
Abdul Jabbar ◽  
Muhammad Tahir ◽  
Ibrahim A. Alhidary ◽  
Mutassim A. Abdelrahman ◽  
Hani Albadani ◽  
...  

In this trial, a 3 × 2 factorial design with different dietary crude protein levels (CP, 17, 19 and 21%) and two levels of exogenous protease (0 and 30,000 IU/kg) was used. A total of 540 two-week old broilers (Ross-308) was randomly allocated to experimental diets over 15–28 days of age. The interaction between dietary protein levels and enzyme supplementation showed that body weight gain was significantly (p < 0.05) higher in birds fed CP-19 (1114.7 g) and CP-21 (1108.8 g) with enzymes supplementation. Feed intake was higher (p < 0.05) in broilers fed with CP-17 than CP-19 with supplementation of the protease enzyme. Results also revealed that the feed conversion ratio (FCR) was significantly (p < 0.05) improved in birds fed with CP-19 and CP-21 and protease supplementation. Total tract N retention was lower (p < 0.05) in birds fed CP-17 with no enzyme than the other dietary groups. Similarly, the gross energy (GE) was significantly (p < 0.05) lower in birds fed CP-17 with or without the protease enzyme. Abdominal fat was higher (p < 0.05) in CP-17 (0.96%) without the protease enzyme. It was concluded that a diet at 19% CP with the protease enzyme improved the performance and nutrient digestibility in broilers over 15–28 days.


2020 ◽  
Vol 6 (6) ◽  
pp. 94-100
Author(s):  
Serge-Olivier Konan KOUASSI ◽  
◽  
Yves Bénarèce Tra DJE BI ◽  
Soualio KAMAGATE ◽  
Mathieu Nahounou BLEYERE ◽  
...  

The study aims to determine the impact of dietary crude protein levels on the hematological parameters of Japanese quail from growth to ovipositor. To this end, five feeds with different crude protein levels (18, 20, 22, 24 and 26%) were supplied to 700 quails of three weeks of age. These were subdivided into six batches, including three batches of females and three batches of males for each feed group. After subjecting the quails to diets containing the different protein levels, four samples were taken at the fourth, fifth, sixth and seventh week of age. The samples taken were analyzed using an SYSMEX XN 350 automated hematological analyzer. The results of this investigation indicated that non-significant differences (P > 0.05) were observed in hematological parameters in both female and male quails. This study showed that dietary crude protein levels had no impact on the health status of Japanese quails. Keywords: Japanese quails, Crude protein, Hematological parameters.


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