• Asian-Australasian Journal of Animal Sciences
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• v.20 no.4
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• pp.550-555
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• 2007

The aim of this study was to determine the effect of two lighting programs (continuous lighting (CL) 24L:0D and intermittent lighting (IL) 1L:3D) on the broiler performance, carcass traits, incidence of tibial dyschondroplasia (TD), relative asymmetry (RA), duration of induced tonic immobility (TI), heterophils-lymphocytes ratio (H/L), serum glucose, cholesterol and triglyceride levels. The chicks were randomly divided into 2 treatment groups consisting of 100 chicks per treatment, continuous lighting (CL) 24L:0D or intermittent lighting (IL) 1L:3D. Each treatment consists of 5 replicates of 20 chicks. The experimental period was 6 weeks. Use of IL decreased feed to gain ratio, improved immune response and reduced fearful. Body weight, carcass traits, TD and stress parameters (organ weights, RA, H/L, glucose, cholesterol and triglyceride levels) were not significant in different lighting groups. As a result IL was beneficial for producers and chickens than CL.

• Korean Journal of Poultry Science
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• v.22 no.4
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• pp.213-221
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• 1995

Five experiments were conducted to evaluate the effect of dietary supplemental folic acid(FA) in starting broiler chicks. In the first two experiments, basal diets based on corn and soybean meal contained 0.6 mg/kg FA but no supplemental methionine or choline. At 18 d of age, chicks showed curvilinear responses to folic acid supplementation with maximum growth and feed efficiencies at 1.45 mg/kg FA diet. The liver FA response was also curvilinear but reached a plateau at 1.70 mg/kg FA diet. The basal diet for 3 additional experiments contained soybean meal that had been washed with methanol to remove most of the choline. The diet contained only 0.6 mg /kg folic acid and 754 mg /kg choline. Chicks exhibited a larger growth response to folic acid at low choline levels as evidenced by a significant FA x choline interaction. FA supplementation increased but then decreased valgus leg deformity. Choline supplementation also decreased the incidences of valgus and varus leg deformities and decreased bone ash and increased the incidence of tibial dyschondroplasia. It is concluded that chicks fed diets based on practical ingredients require from 1.45 to 1.70 mg /kg FA diet and also 1.60 mg/kg FA when choline is offered near the NRC recommended level of 1,300 mg/kg.

• Animal Bioscience
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• v.36 no.9
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• pp.1393-1402
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• 2023

Objective: In this study effects of three types of beddings on broiler leg health and bone biomechanics were evaluated. Methods: A total of 504 male chicks (Ross 308) were randomly placed on three beddings (4 replicates/group; 42 birds/pen), zeolite-added litter (ZL), plastic-grid flooring (PF), and wood shavings (WS). On day 42, chickens were weighed, slaughtered, and samples (bone, muscle, and drumstick) were collected. Bones were subjected to leg health tests, morphometric measurements, biomechanical testing, and ash analysis. Results: Broilers in PF and WS groups showed higher live weight than the ZL group (p<0.001), and the incidence of tibial dyschondroplasia (TD) and varus valgus deformity due to distal bending was significantly higher in PF (p<0.001). Multinomial logistic regression showed that bedding has a significant (p = 0.038) contribution toward the development of TD. Tibial strength (p = 0.040), drumstick width (p = 0.001), and total femur and epiphyseal ash contents (p = 0.044, 0.016) were higher in the ZL group. Chicken live weight was correlated with tibial length and weight (r = 0.762, 0.725). Conclusion: Flooring and the type of bedding material directly affect broiler bone length, strength and leg health. Plastic bedding improves the slaughter weight of chickens on the expense of leg deformities, and zeolite litter improves leg health and bone strength.

• Korean Journal of Poultry Science
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• v.22 no.3
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• pp.179-188
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• 1995

In Experiment 1, microbial assays were conducted on 57 feed ingredient samples to determine the content of total folic acid using Lactobacillus casei(ATCC 7469). Folic acid contents of feed samples pretreated with conjugase, ${\alpha}$-amylase, and a mixture of protease(Pronase)were corn, 09${\pm}$1.18($\pi$g${\pm}$SD); fish meal, 23.05${\pm}$1.27; milo, 29.34${\pm}$0.55; bakery meal, 25.80${\pm}$6.93; meat and bone meal, 56.76${\pm}$4.97; wheat middlings, 85.14${\pm}$2.56; and soybean meal, 193.97${\pm}$3.98. Experiments 2 and 3 were conducted to determine the effects of dietary supplemental folic acid and methionine on the performance of starting broiler chicks for 18 days. Four levels of dietary folic acid(0.24. 0.54,1.14 and 2.34mg/kg) and four levels of dietary methionine(0.45, 0.53,0.61, and 0.69%) were fed in a factorial design. The basal diet was based on corn, isolated soybean protein, meat and bone meal, and fish meal. It contained adequate amounts of all nutrients except methionine and folic acid in both experiments. Increased growth rate was observed in chicks fed the basal diet supplemented with either folic acid or methionine. Total dietary folic acid and methionine plus cysteine requirements for optimum growth were estimated to be 1.80 mg/kg and 0.89% in Experiment 2, and 1.47 mg/kg and 0.91% in Experiment 3, respectively. There were interactions between dietary folic acid and methionine on weight gain in both experiments. Chicks fed diets containing 2.34 mg folic acid /kg tended to display slow growth rate in both experiments. There was a significant linear feed conversion response to folic acid in Experiment 2, and a significant quadratic feed conversion resuonse to methionine in Experiment 3. There were both linear and quadratic liver folic acid responses to dietary folic acid in both experiments. There was no indication that dietary methionine had any effect on liver folic acid content. The incidence of tibial dyschondroplasia increased with increasing supplemental methionine, but were no significant differences detected at 5% level.