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

Abstract

This study was undertaken to assess dietary crude protein (CP) concentration for optimum growth performance and carcass characteristics of Lueyang black-boned chicken. In total, six hundred 42-day-old Lueyang black-boned chicks were randomly assigned to five treatments, each with six replicate pens with ten males and ten females. The birds fed experimental diets with different levels of protein concentration of 120, 140, 160, 180 and 200 g kg -1 from seven to twelve weeks of age respectively. On day of 84, weight gain, feed intake, and feed:gain ratio were measured, and two chickens (one male and one female) close to the average weight of all birds in each treatment were selected from each pen and sacrificed to evaluate carcass traits and selected serum biochemical indexes. Dietary CP concentration did not have any significant influence on feed intake (p>0.05). The birds fed the diet with 180 or 160 g kg -1 CP concentration exhibited greater (p<0.05) growth rate, better feed conversion ratio, relative breast weight and albumin concentration in serum than that of those fed other dietary CP concentrations. According to the results of regression analysis, the CP requirements of Lueyang black-boned chicken from seven to twelve weeks of age for optimal weight gain and feed:gain ratio were 174 and 170 g kg -1, respectively.

Effects of dietary enzymolysis products of wheat gluten on the growth performance, serum biochemical, immune, and antioxidant status of broilers

“…Expelled with feces, it is the bird's main waste product and is also closely related to BUN (Mowrer, Sedlacek, Kim, Ritz, & Kim, 2016). Studies have shown that excess protein feeding during the late growing/prebreeder stage can increase the level of plasma uric acid (Liu, Niu, et al, 2015). Thus, a decrease in uric acid in poultry could indicate a higher utilization of the true protein and/or a higher expulsion of the product of excretion.…”

Effect of Diet Containing Palm Kernel Cake and Coconut Meal Cake on Growth Performance and Carcass Quality of Free-Range Chicken in Malaysia

“…The CP of the FFD diet (14.73%) was relatively similar to that of CFD diet (13.40%). Previous studies indicated the strong relationship between CP and chicken growth performance, which showed chicken that had been fed with high CP tends to grow faster (Liu et al 2015). This similar trend was observed in this study.…”

Faba beans and peas in poultry feed: economic assessment

“…It is known that the productivity of broilers has been developed as a genetic feature, 20 and an increase in production efficiency and a low production cost of poultry meat are achieved by a short production cycle and crosses of fast-growing broilers; yet feedstuffs used as well as the content of protein in the feed significantly affect the productivity of broilers. 8,21 The key focus in the composition of broiler feed is placed on CP, as it comprises most of any broiler diet, which, together with the other nutrients, considerably affects the health and productivity of the poultry. 22 If a diet is deficient in CP, broilers lose their appetite, poorly absorb their feed, their live weight decreases and their meat quality deteriorates.…”

“…Change in live weight and daily live weight gain for broilers ± 21.4 268.1 ± 24.0 S 276.2 ± 23.2 276.3 ± 16.1 285.0 ± 29.1 290.9 ± 27.2 288.2 ± 19.2 271.5 ± 22.1 S GBW (g) ± SD 1503.9 ± 171.5 1647.6 ± 162.3 S 1632.7 ± 168.2 S 1463.9 ± 159.2 1735.6 ± 181.5 S 1725.1 ± 237.1 S 1706.2 ± 173.6 S 1657.8 ± 185.3 S FBW (g) ± SD 2508.9 ± 284.7 2685.7 ± 283.4 2747.3 ± 335.8 S 2652.8 ± 302.3 2808.7 ± 410.3 S 2690.6 ± 298.1 2725.1 ± 299.5 2660.5 ± 312.2 Data are presented as means ± standard deviation (SD). IBW, initial body weight at day 10; GBW, grower body weight at day 27; FBW, final body weight at day 42; P-value A , to define differences in comparison of control group at 28 days of age; P-value B , to define differences in comparison of control group at 42 days of age; S, significant differences (P < 0.05) between control group (1) and experimental groups(2)(3)(4)(5)(6)(7)(8).…”