• Asian-Australasian Journal of Animal Sciences
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• v.17 no.11
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• pp.1570-1574
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• 2004

A flock of AA breed chickens were reared in peterstme brood-vait chamber and were provided with high energy pelleted feed. At 14 d of age, a total of 350 birds were randomly divided into 3 groups as follows: 100 birds were exposed to normal ambient temperature of 20$^{\circ}C$ for control group; 150 birds were exposed to lower ambient temperature of 11$^{\circ}C$ to induce ascites (treatment I); and another group of 100 birds were exposed to lower ambient temperature of 11$^{\circ}C$ and fed diet containing 1% L-arginine for ascitic prophylactic treatment (treatment II). Samples were collected from blood and abdominal fluid of chicken at 3, 4, 5, 6 and 7 wk of age subsequently, to analysis the contents of plasma endothelin (ET-1), angiotensin II (Ang II), cyclic adenosine monophosphate (cAMP), cyclic guanosine monophosphate (cGMP). The results indicated that the contents of cAMP, cGMP, and Ang II in reatment I and ascitic broilers were higher than the corresponding control group (p<0.01, p<0.05), ET-1 of preascitic broilers were control group (p<0.05), while there was an insignificant difference with later ascitic broilers. The contents of cAMP and cGMP in treatment II were higher than the treatment I and control groups (p<0.01, p<0.05), whereas, the contents of Ang II were gradually decreased compared to the control group (p<0.05), the contents of ET-1 were insignificantly different. On further analysis, the increased plasma Ang II at low ambient temperature condition in broilers made endothelium cell secretion of increased ET-1, cAMP, cGMP and decreased NO. Therefore, low temperature accelerated ascites syndrome in broilers. Supplemently L-arginine can decrease ET-1, and increase cAMP and cGMP. It is concluded that cAMP mediated in broilers pulmonary hypertension syndrome.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.9
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• pp.1319-1325
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• 2002

Two experiments were conducted to evaluate the effect of early feed restriction on growth, feed conversion ratio (FCR) and mortality in unsexed broiler chickens. In Experiment 1, 350 one-day-old broiler chickens were divided into 7 groups. Each treatment group was represented by five replicates of ten broilers each. One group was fed ad libitum as the control group and the other six groups were fed 25% ad libitum (25% multiplied by amount of feed intake of ad libitum chickens at the previous day) for 4 or 6 days, 50% ad libitum for 4 or 6 days, and 75% ad libitum for 4 or 6 days. In experiment 2, 500 broiler chickens were divided into 10 groups. Each treatment group was represented by five replicates of ten broilers each. One group was fed ad libitum as the control group. Three ages of feed restriction initial timing (2, 4 or 6 days of age) and three types of feed restriction (physical restriction, meal feeding and diet dilution) were used ($3{\times}3$) in both experiments. They were feed-restricted for 6 days. Results showed that restricted broilers exhibited compensatory growth in both experiments except for diet dilution groups. In both experiments, FCR of restricted broilers was higher, whereas feed intake of them was lower during restriction period. FCR of restricted broilers was lower upon refeeding. Mortality was inconsistently affected by early feed restriction. Leg abnormality was lower in restricted broilers in both experiments. Level of feed restriction significantly influenced body weight, FCR and feed intake of restricted broilers (p<0.05), but duration of feed restriction had no effect. Type of restriction significantly affected body weight, feed intake and FCR (p<0.05). It appeared that to achieve the best result (complete compensatory growth and better FCR), broilers should be restricted at 25% ad libitum for 6 days (Experiment 1). Meal feeding started at 2 days of age would show the best performance (Experiment 2).

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.12
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• pp.1757-1762
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• 2011

Aflatoxins are natural contaminants of poultry feeds and feed ingredients and cause liver damage, immunosuppression, reduction in performance and mortality in broilers. A number of studies have been carried out to study the effects of aflatoxin on feed conversion ratio in broilers. The results on feed conversion ratio of 10 research articles in broilers fed with aflatoxin from first day of age to six weeks of age were compiled and were subjected to meta-analysis. Chi-square test and $Tau^2$ (heterogeneity co-efficient) were applied to test for significance of heterogeneity of studies. To integrate results, fixed effect model by Inverse Variance method (IV method) was used when heterogeneity was insignificant and otherwise random effect model by DerSimonian and Laird Method (DL method) was used. The results of meta-analysis showed that the adverse effect of aflatoxin on feed conversion ratio at the end of first week was negligible, second week was medium and third to six weeks was very large.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.4
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• pp.359-362
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• 1996

A study was conducted to assess the influence of copper on the total sulphur amino acid requirements of broiler chickens reared under two growing periods. The TSAA levels used were 0.73, 0.83, 0.93% with copper levels of 0, 125, 250 and 375 mg/kg for the starter period and the TSAA levels of 0.72, 0.79 and 0.86% with copper levels of 0, 125, 250 and 375 mg/kg for the grower period. Total feed consumption, body weight gain and feed L gain ratio were used as the parameters for the assessment. The results showed that adding copper at 250 mg/kg to the diets improved feed : gain ratio of the starter broilers and resulted in small improvement of body weight gain and feed : gain ratio of the grower broilers. Growth was depressed in relation to the reduction of feed intake on the chicks fed diet containing 375 mg/kg copper. There was a significant interaction between dietary TSAA and copper levels for feed intake, hence, indicating that the supplementation of copper at the level of 375 mg/kg increased the TSAA requirement of the starter broilers, although no interference with the requirement of grower broilers.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.8
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• pp.1145-1149
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• 2004

Immunomodulatory feed additives might offer alternatives to antimicrobial growth promoters in poultry production. This experiment was carried out to test the effect of $\beta$-glucan supplementation on the growth performance and immune response in broilers. Total of 160 day-old broilers were randomly assigned to 4 treatment groups fed corn-soybean diets containing 0, 0.012, 0.025 or 0.05% of $\beta$-glucan supplement in a 6 week feeding experiment. Growth performance, antibody titer against New Castle vaccine, lymphocyte blastogensis, and peritoneal macrophage chemotaxis activity of broilers were evaluated. Results showed that there were no significant differences in weight gain and feed efficiency among the treatments, and no differences in antibody titer was observed. Supplementation of $\beta$-glucan did not elevate the lymphocyte blastogensis among treatments, following stimulation with different mitogens. However, supplementation with 0.025 and 0.05% $\beta$-glucan enhanced the macrophage chemotaxis activity of broilers. These results suggest that $\beta$-glucan may enhance some cell-mediated immune responses of chickens by modulate macrophages ability.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.1
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• pp.91-96
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• 2006

The experiment was conducted to study the effect of choice feeding on growth performance, carcass quality, gastrointestinal development and feed utilization of 22-49 days old broilers. One hundred and forty four 22-day-old broilers were randomly allocated to 3 treatments with 4 replicates per treatment and 12 birds per replicate. Three feeding regimes are complete diet (control), ground corn and protein concentrate (treatment I), and soybean meal and balancer (treatment II). Protein concentrate is the residue part of complete diet without corn, and balancer is the residue part of complete diet without soybean meal. Treatment I and II are designed for the broilers to freely choose the two parts of diet. The results showed that: (1) broilers under choice feeding (treatment I and II) had lower performances compared with the control; (2) gastrointestinal development and the efficiency ratios that broilers converted dietary crude protein and lysine to body weight gain were improved in treatment I (p<0.05); (3) there were no significant differences in the apparent metabolizabilities of dietary dry matter, crude protein and gross energy, and deposition ratios of dietary nitrogen and energy, and carcass quality among three feeding regimes (p>0.05).

• Korean Journal of Poultry Science
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• v.43 no.4
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• pp.213-218
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• 2016

This study was conducted to investigate the effect of taurine supplementation on heat shock protein 70 and in vitro protein turnover in broiler chicks under chronic heat stress. Chicks were allocated into 3 groups of 10 birds per group; the control group was maintained at a temperature of $24^{\circ}C$ without taurine (CO group), the heat-stressed group maintained at a temperature of $34^{\circ}C$ without taurine (HO group), and heat-stressed group maintained at a temperature of $34^{\circ}C$ with taurine (HT group). The final body and liver weights of broilers in the HO and HT groups were significantly lower than those of broilers in the CO group (P<0.05). However, these parameters of the broilers in the HT group were significantly higher than those of broilers in the HO group (P<0.05). The heat shock protein 70 (hsp70) concentration in the liver of broilers in the HO group was significantly higher than that of broilers in the CO and HT groups, but the hsp70 concentration in the liver of broilers in the HT group was not different from that of broilers in the CO group. Liver homogenates of 21 day-old broilers were incubated at temperatures of $37^{\circ}C$ and $45^{\circ}C$ to prove the effect of high temperature and taurine on total protein syntheses. Neither high temperature nor taurine supplementation affected protein syntheses in liver homogenates of the broilers. However, the more the temperature increased, the more the degradation rates of cytoplasmic protein in liver homogenates increased; however, taurine supplementation had no effects on the protein syntheses in the liver of the broiler. It is possible that taurine indirectly affected protein turnover via various physiological mechanisms.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.2
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• pp.227-232
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• 2013

Phytate is not only an unavailable source of phosphorus (P) for broilers but it also acts as an anti-nutrient, reducing protein and mineral absorption, increasing endogenous losses and reducing broiler performance. The objective of this study was to investigate the anti-nutritional effects of phytate by including high levels of phytase in diets not severely limited in available P. A total of 768 male Arbor Acres broilers were distributed in six treatments of eight replicate pens of 16 birds each consisting of a positive control diet (PC), positive control with 500 FTU/kg phytase, negative control (NC) diet with lower available P and calcium (Ca) levels and the same NC diet with 500, 1,000 or 1,500 FTU/kg phytase. Body weight gain (BWG), feed intake (FI), feed conversion ratio (FCR) and mortality were determined at 21 and 35 d of age while foot ash was determined in four birds per pen at 21 d of age. FI, FCR and foot ash where not affected by the lower mineral diets at 21 d of age nor by the enzyme inclusion but broilers fed lower Ca and available P diets had lower BWG. At 35 d of age no difference was observed between broilers fed the positive or NC diets but broilers fed 500, 1,000 and 1,500 FTU/kg on top of the NC diet had better FCR than broilers fed the positive control diet. When compared to birds fed a diet adequate in P, birds fed the same diet included with 500, 1,000 and 1,500 FTU/kg of phytase in marginally deficient available P and Ca diets had an improvement of performance. These results support the concept that hydrolysing phytate and reducing the anti-nutritional effects of phytate improves bird performance on marginally deficient diets that were not covering the P requirement of birds.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.6
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• pp.843-848
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• 2009

This experiment was conducted to compare the effects of oak acorns and corn on broilers growth performance, carcass characteristics and meat fatty acid (FA) composition according to different ages of broilers. Two separate groups of 400 male broilers, reared for six weeks, were fed diets containing 33.5% green oak acorns (GO) and 67% of corn (C), respectively. At day 35, the body weight of the chickens fed the GO diet was 12% lower (p<0.05) compared with controls (C). However, at day 56 birds reached similar final weights. Abdominal adipose tissue (AAT) was 78% higher in the controls compared to those fed the oak acorn-based diet. The total lipids (TL) of thigh muscle were higher in the controls compared to dietary treatment GO (3.1 against 2.5 g/100 g of muscle). There were significant differences in fatty acid (FA) composition of the muscle between two groups. The broilers fed oak acorn exhibited more C18:2, as well as a higher proportion of polyunsaturated fatty acid (PUFA) and PUFA:SFA (saturated fatty acid) ratio than those on the control diet, but no significant differences were observed among groups for the age of birds. There was a higher proportion of linolenic acid in broilers fed the oak acorn compared to the controls (0.8 vs. 0.6%). Furthermore, linolenic acid content decreased with age (p<0.001) in both groups. The results indicated no significant differences in FA with the age of birds. In conclusion, the meat fatty acids provided by the GO diet appeared to improve the nutritional quality preferred by the consumer.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.7
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• pp.993-1000
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• 2011

The aim of this study was to evaluate the potential of fermented red ginseng extract (FRGE) as feed additive in broilers and laying hens. In broilers, 480 Arbor Acre male broilers were randomly allotted to 4 treatments with 6 replications per treatment and 20 chicks per pen. The experiment lasted 5 weeks and dietary treatments were as follows: i) CON, basal diet; ii) FRGE1, basal diet+1 g/kg fermented red ginseng extract; iii) FRGE2, basal diet+2 g/kg fermented red ginseng extract and iv) FRGE3 basal diet+4 g/kg fermented red ginseng extract. Throughout the experiment, no effects were observed (p>0.05) in performance in response to FRGE. At the end of the experiment, FRGE administration improved (p<0.05) the lymphocyte level compared with CON. The relative weight of bursa of fabricius and spleen were increased (p<0.05) by the inclusion of FRGE3. Besides, redness ($a^*$) value for the breast meat was higher (p<0.05) in FRGE1 and FRGE3 treatments than that in CON. In laying hens, 240 ISA brown layers at 35 weeks of age were used in this 8-week trial. Dietary treatments were the same as in the broilers trial with 10 replicates per treatment and 6 layers per replicate. During the entire experiment, there were no significant differences (p>0.05) in performance or egg quality among all the treatments. However, the layers fed diets supplemented with FRGE had higher lymphocyte level (p<0.05) compared with those fed CON. In conclusion, the dietary supplementation with FRGE did not influence performance but improved the lymphocyte level in both broilers and laying hens.