scholarly journals Effects of dietary crude protein on the growth performance, carcass characteristics and serum biochemical indexes of Lueyang black-boned chickens from seven to twelve weeks of age

2015 ◽  
Vol 17 (1) ◽  
pp. 103-108 ◽  
Author(s):  
SK Liu ◽  
ZY Niu ◽  
YN Min ◽  
ZP Wang ◽  
J Zhang ◽  
...  
Author(s):  
T. Srilatha ◽  
V. Ravinder Reddy ◽  
V. Chinni Preetam ◽  
S.V. Rama Rao ◽  
Y. Ramana Reddy

An experiment was conducted to find out the effect of different levels of crude protein in broiler diets during different phases. i.e., pre starter (0-11d), starter (12-21d) and finisher (22-42d). 360 day-old broilers (Vencobb) were procured from a commercial hatchery and fed either high or low dietary CP diets during pre-starter (23 and 21%) , starter (21 and 19%) and high, moderate or low CP diets during finisher ( 18.5, 17.5 and 16.5%) phases, for a total of 12 possible treatment combinations at d 42. The results showed that the broilers fed low levels of CP ( 21 and 19 %) had significantly(P less than 0.05) higher body weight gain (BWG) and feed intake (FI), and better feed efficiency over the diets with high levels of CP during pre-starter and starter phases (23 and 21%, respectively). The higher (18.5%) level of protein in the finisher phase showed higher BWG and best FCR compared to the lower levels (17.5 and 16.5%). Carcass characters were not influenced by the variation in dietary CP level tested except the abdominal fat weight which was significantly higher in broiler fed low CP diet compared to those fed higher levels of CP during all three phases. The results indicated that the broilers fed low CP diets supplemented with critical amino acids (21 and 19%) had beneficial effect on the growth performance during pre-starter and starter phase. The broilers showed an ability to respond to increase in dietary CP levels during finisher phase.


Author(s):  
Beena C. Joseph ◽  
Jayanaik T. Munegowda ◽  
Chandrapal . ◽  
K. Singh ◽  
V. Malathi

A six-week trial was conducted to determine the effect of lowering dietary crude protein levels with supplementation of limiting amino acid on growth performance, and carcass characteristics in one of the Indian improved crossbred Swarnadhara chicks in a completely randomized design having five treatments and four replications of 20 birds in each. Five isocaloric (2800 ME Kcal//kg) experimental diets based on corn-soy bean meal were formulated in a gradual crude protein decline from 21 % (control T1) to 19% by 0.5% interval. The levels of limiting amino acids namely methionine, lysine, threonine and tryptophan were met as that of control (T1) by adding synthetic preparations. Highest body weight was recorded in 2% crude protein reduced group (T5) which was comparable with control (T1). However, cumulative feed intake and feed conversion ratio of different treatments were not significantly different. Moreover, carcass parameters like dressing percentage, breast meat yield, liver and heart weights remained unaffected by the dietary treatments. Relative gizzard weight and abdominal fat weights showed variations and lower dietary protein diets were comparable with control diet (T1). In summary, crude protein content of Swarnadhara chick diet can be reduced to 19% with essential AA fortification without any adverse effect on growth performance and carcass characteristics during 0-6 weeks of age.


2013 ◽  
Vol 40 (4) ◽  
pp. 351-359
Author(s):  
Hyung Joo Kwon ◽  
Yun Kyung Choo ◽  
Sung Taek Oh ◽  
Hak Kyu Kim ◽  
Chang Won Kang ◽  
...  

Animals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 151 ◽  
Author(s):  
Wen Zhu ◽  
Wei Xu ◽  
Congcong Wei ◽  
Zijun Zhang ◽  
Chunchao Jiang ◽  
...  

The effects of decreasing dietary crude protein (CP) level on growth performance, nutrient digestion, serum metabolites, and nitrogen utilization in growing goat kids were investigated in the current study. Thirty-six male Anhui white goat kids were randomly assigned to one of three CP content diets: 14.8% (control), 13.4%, and 12.0% of dry matter, respectively. Diets were isoenergetic. The experiment lasted for 14 weeks, with the first two weeks being for adaptation. Results showed that the low-CP diet decreased average daily gain, feed efficiency, digestibility of dry matter, organic matter, crude protein, and fiber. No significant changes were observed in dry-matter intake. With a decrease in dietary CP level, fecal nitrogen excretion (% of nitrogen intake) increased linearly, whereas CP intake, blood urea nitrogen, urinary nitrogen excretion (% of nitrogen intake), and total nitrogen excretion (% of nitrogen intake) decreased. Serum glucose concentration decreased, while concentrations of low-density lipoproteins and non-esterified fatty acids increased with the low-CP diet. In conclusion, decreasing the dietary CP level decreased goats’ nitrogen excretion, but with restrictive effects on growth performance. A diet containing 13.4% CP is optimal for reducing nitrogen excretion without any adverse effect on growth performance of Anhui white goat kids. This concentration is 1.4% points lower than the NRC recommendations and thus is also environmentally beneficial on the input side because it decreases the use of feed (soy) protein.


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