• Asian-Australasian Journal of Animal Sciences
• /
• v.8 no.6
• /
• pp.627-633
• /
• 1995

This experiment was designed to evaluate the effect of various dietary vitamin $B_6$ levels on conversion from linoleic acid to arachidonic acid in various tissues in growing chicks. Growing chicks were fed the purified diet containing 7% safflower oil with different levels of vitamin $B_6$ (0, 4, 8, 40, 80 mg per kg diet) for 14 days. Feed intake and weight gain in chicks fed the vitamin $B_6$-free diet were markedly depressed. Esterified and free cholesterol concentrations in serum were significantly higher, while the serum triglyceride concentration was significantly lover in chicks fed the vitamin $B_6$-free diet compared to that fed diets with vitamin $B_6$. The liver triglyceride content was also lower in chicks fed the vitamin $B_6$-free diet. The liver and serum cholesterol ester fractions in chicks fed the vitamin $B_6$-free diet showed higher rate of $C_{18:2n6}$ and lower rates of $C_{18:3n6}$, $C_{20:3n6}$ and $C_{20:4n6}$ as compared with vitamin $B_6$ fed groups. In serum phospholipid fraction of chicks fed the vitamin $B_6$-free diet, rates of $C_{20:3n6}$ and $C_{20:4n6}$ were markedly lower. As dietary vitamin $B_6$ level was increased, the rate of $C_{20:4n6}$ was slightly increased, although it was statistically not significant. The fatty acid compositions of adipose tissue showed almost the same pattern as those in liver and serum. This result suggests that the desaturation of $C_{18:2n6}$ to $C_{18:3n6}$, elongation to $C_{20:3n6}$ or both steps might be impaired by vitamin $B_6$ deficiency in growing chicks.

• Asian-Australasian Journal of Animal Sciences
• /
• v.5 no.1
• /
• pp.123-128
• /
• 1992

In Experiment 1, when fasted chicks were fed diets containing various sources of protein for 3 days, the activities of lipogenic enzymes (acetyl-CoA carboxylase, fatty acid synthetase, citrate cleavage enzyme and malic enzyme) in the liver of growing chicks were significantly lower in the soybean protein or gluten diet than in the casein or fish protein diet. Triglycride contents of the liver and plasma of chicks fed the casein or fish protein diet were significantly lower than that of those fed soybean protein or gluten diet. In Experiment 2, the effects of dietary amino acid mixture simulating casein or protein on the activities of hepatic lipogenic enzymes were examined. The activities of acetyl-CoA carboxylase and fatty acid synthetase in the liver of chicks fed the casein diet were significantly higher than that of those fed the soybean protein diet or two diets of amino acid mixtures. Furthermore, there were no significant differences between the two diets of amino acid mixture based on casein or soybean protein. However, the activities of malic enzyme and citrate cleavage enzyme tended to be lower in the soybean-type amino acid diet than in the casein-type amino acid diet. Thus, some effects can be ascribed to the protein itself and some to the amino acid composition of the protein sources.

• Asian-Australasian Journal of Animal Sciences
• /
• v.25 no.8
• /
• pp.1145-1152
• /
• 2012

This experiment was conducted with male chicks to investigate the influence of hormones and nutrients on the development of fatty liver syndrome (FLS) as well as the effects of dietary lipotropic factors on hepatic fat accumulation and lipogenic enzyme gene expression. A total of two-hundred sixteen 4-wk-old Hy-Line male chicks were divided into six groups and fed an experimental diet (T1, low-energy diet with low levels of lipotropic factors; T2, high-energy diet with low levels of lipotropic factors; T3 and T5, low-energy diet with high levels of lipotropic factors; T4 and T6, high-energy diet with high levels of lipotropic factors) for six weeks. The chicks in T5 and T6 groups were treated with intramuscular injections of estradiol benzoate for three days prior to biopsy and clinical analysis of FLS. Chicks treated with estrogen had significantly greater liver weights than untreated chicks. The abdominal fat contents were increased in chicks consuming high-energy diets as compared to those consuming low-energy diets. Treatment with estrogen significantly increased the concentrations of serum cholesterol, triacylglycerol and phospholipid (p<0.05). The hepatic triacylglycerol levels were tenfold higher in the estrogen treated chicks than in the untreated chicks. There were no significant differences in malondialdehyde levels between the treatment groups. Estrogen treatment dramatically increased the levels of fatty acid synthetase, acetyl-CoA carboxylase and ApoB mRNA. The results indicated that treatment with exogenous estrogen in growing male chicks induced hepatic fat accumulation, which might be partially due to increased lipogenic enzyme gene expression.

• Asian-Australasian Journal of Animal Sciences
• /
• v.10 no.2
• /
• pp.185-191
• /
• 1997

This experiment was conducted to determine the effects of a low-protein diet supplemented with DL-methionine plus L-cystine (Met + Cys) on the growth performance and fat accumulation of female broiler chicks during the growing period (3-6 wks old). A low-protein diet (17% CP; 3,200 ME kcal/kg) was supplemented with Met + Cys (1.1 : 1.0) at levels 0.75, 0.94, 1.25, 1.31 or 1.50% of diet, respectively. Another diet with 21% CP and 3,200 ME kcal/kg served as the control group. All essential amino acids were adjusted to meet the National Research Council (1984) requirement for chicks. Feed and water were given ad libitum. Body weight of the chicks fed the low-CP diets supplemented with Met + Cys were heavier than those of the control birds. Feed conversion ratio and feed intakes were not significantly different between and among the treatment groups. Similary, abdominal fat content was not significantly different among the various treatments except that of the chicks fed the low CP diet with 1.25% Met + Cys which was higher than that of the control group. Fatty acid synthetase (FAS), acetyl-CoA carboxylase (ACC) activities and carcass protein content were not influenced by dietary treatments. Carcass fat content was lowest in chicks fed low CP diet with 0.75% Met + Cys and highest in the group that received 1.50% Met + Cys supplementation. Liver triglyceride increased as Met + Cys supplementation level increased. Various lipid fraction concentrations (cholesterol ester, free cholesterol, and phospholipid) in the serum went up as Met + Cys increased up to 1.25% after which it levelled off. Results of this experiment suggest that it is possible to reduce dietary protein level from 21% to 17% for growing broiler chicks by the supplementation of Met + Cys when other EAA were sufficient.

• Asian-Australasian Journal of Animal Sciences
• /
• v.5 no.4
• /
• pp.647-651
• /
• 1992

Two experiments involving comparative slaughter procedures were conducted to see if the decrease in total energy retention (ER) resulted from the decreased food intake in growing chicks fed on a diet containing tryptophan less than the requirement. Ad libitum-feeding a diet containing 50% of tryptophan of a control diet (1.5 g/kg) decreased body weight gain, apparent metabolizable energy intake (AMEI), ER and ER : AMEI ratio. When both the control diet and the 0.75 g/kg tryptophan diet were tube-fed at the two levels of food intake, body weight gain was significantly lower in chicks on the low tryptophan diet than in the control chicks at each level of intake. AME : gross-energy ratio decreased only when the low tryptophan diet was tube-fed at the higher level of intake. Energy retained as protein was significantly decreased by the low tryptophan level and reduction of food intake. Energy retained as fat was affected by food intake. ER and ER : AMEI ratio were unaffected by dietary tryptophan level and were proportional to AMEI. Heat increment of feeding was affected by neither tryptophan nor food intake. These results indicate that the decreased ER in chicks fed on the low tryptophan diet was due mainly to the decreased food intake and not to the decreased efficiency of ME utilization.

• Korean Journal of Poultry Science
• /
• v.29 no.4
• /
• pp.249-253
• /
• 2002

A 2 ${\times}$ 2 factorial experiment was conducted to determine the effect of cecectomy and urea supplementation on nitrogen utilization In growing chicks. Birds were either cecectomized or shamoperated and fed a 19% protein diet with or without 1% urea supplementation. All chicks were provided ad libitum access to feed and water throughout the six-day experimental period. In the cecectomized chicks, fred efficiency was significantly decreased when fed a 19% protein diet supplemented with 1% urea (P<0.05). When chicks were fed a 19% protein diet, cecectomy significantly shortened gastrointestinal passage time (GPT) of food (P<0.05). However, the GPT was significantly lengthened in chicks fed a 19% protein diet supplemented with urea (P<0.05). Regardless of diets, cecectomized chicks increased the moisture contents of the excreta (P<0.05) and feeding a 1% dietary urea also significantly increased (P<0.05). Cecectomy significantly decreased uric acid N excretion by about 30 mg per 100 g body weight per day (P<0.05) and uric acid N/ total N excretion when fed both diets (P<0.05). The present study suggests that cecectomy improves nitrogen utilization rate by decreasing uric acid excretion in growing chicks. These results are in good agreement with those obtained previously in a cecectomy study of adult chickens.

• Asian-Australasian Journal of Animal Sciences
• /
• v.16 no.6
• /
• pp.903-909
• /
• 2003

For the last two decades, energy utilization of growing chicks has been studied more and more. This paper focuses on the energy utilization estimated by the metabolizable energy (ME) values and the efficiency at which ME is used for growth of chicks under various nutritional environment. Degree of saturation of dietary fats is responsible for nitrogen-corrected apparent metabolizable energy (AMEn) of fats. The effect of dietary fat sources on heat production depends on the kind of unsaturated fatty acids as well as the degree of saturation. Medium chain triglyceride shows lower AME and net energy than long chain triglyceride. Phytase as feed additives increases the AME values of the diet along with improvement of the phosphorous utilization. Ostriches have higher ability to metabolize the energy of fiber-rich foodstuffs than fowls. Their higher ability seems to be associated with fermentation of fiber in the hindgut. Proportions of macronutrients in the diets have influenced not only the gain of body protein and energy but also the oxidative phosphorylation of the chicken liver. Essential amino acids deficiency reduces ME/GE (energy metabolizability) little, if any. Growing chicks respond to a deficiency of single essential amino acids with the reduction of energy retained as protein and increased energy retained as fat. Thus, energy retention is proportional to ME intake despite deficiency, and efficiency of ME utilization is not affected by deficiency of amino acids. Effect of oral administration of clenbuterol, a beta-adrenergic agonist, on the utilization of ME varies with the dose of the agents. Although the heat production related to eating behavior has been estimated less than 5% of ME, tube-feeding diets decreases HI by about 30%.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.10
• /
• pp.1502-1506
• /
• 2002

This experiment was conducted to evaluate the effects of the broiler's genotype ($G_t$) and ambient temperature ($T_a$) on performance and core body temperature ($T_core$) of broiler chicks. A factorial arrangement of two $G_t$ (Hubbard and ISA J57 chicks) and two $T_a$ (moderate, $23{\pm}0.5^{\circ}C$ and hot, $33{\pm}0.5^{\circ}C$) were used in this study. Performance data (body weight gain, feed intake and feed:gain ratio) were determined weekly for six weeks. Chicks' $T_core$ was measured using a biotelemetric system between Weeks five and six. Results showed that body weight gain and feed intake were significantly high, and feed:gain ratio was significantly low for Hubbard chicks compared to those of ISA J57 chicks. High $T_a$ significantly reduced weight gain and feed intake. Furthermore, the reduction in body weight gain and feed intake under the hot $T_a$ was more pronounced for Hubbard chicks than those of the ISA J57 chicks resulting in significant $G_t$ by $T_a$ interaction. Chicks grown under moderate $T_a$ had significantly lower $T_core$ than those grown under hot $T_a$. The $T_core$ of the Hubbard chicks was significantly lower than that of the ISA J57 at the moderate $T_a$ while under the hot $T_a$, the magnitude of the change in $T_core$ was more pronounced in Hubbard chicks than that of ISA J57; this resulted in a significant $G_t$ by $T_a$ interaction. The results of this study indicate that chicks with higher potential for growth under thermo-neutral temperature are more susceptible to heat stress than chicks with lower potential for growth. This maybe due, at least in part, to their lower body $T_core$ under moderate temperature and to the lesser ability of these fast growing chicks to regulate their $T_core$ when exposed to heat stress, as was clearly shown on these birds' performance.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.2
• /
• pp.254-265
• /
• 2002

Soybean meal (SBM) is a major protein source in poultry feeds and one of the best quality ingredients because of the relatively high protein content, good amino acid profile and bioavailability. But soybean meal quality is largely dependent on the processing technology and origins. In this experiment, effects of three different soybean meals were evaluated in layer (experiment 1) and broiler (experiment 2). Soybean meal sources used in the experiments were the US-originated dehulled soybean meal (USDHSBM), India-originated non-dehulled soybean meal (India SBM) and Brazil-originated non-dehulled soybean meal (Brazil SBM). Experiment 1 was conducted during growing and laying periods and evaluated the interactive effects of soybean meal sources according to feeding periods on growth performance and egg quality. Experiment 2 was conducted during growing period (day 1-35) and finishing period (day 35-42). The growth performance was measured for the same periods and any possible interaction between soybean meal origins and crude protein levels was also studied. In experiment 1, chicks fed India SBM utilized feed more efficiently (p<0.05) than those fed Brazil SBM from day 29 to day 42. The body weights of layers during the laying period had no relation to egg production. But egg weights were significantly heavier in all the USDHSBM fed groups than other groups (p<0.001) and depended on feed protein source during growing period (p<0.001). The average egg weight of the USDHSBM fed group scored the highest value (65.4 g), followed by the Brazil SBM fed group (62.1 g) and India SBM fed group (62.1 g). There was an effect of interaction between origins of soybean meal fed group in growing and laying period on eggshell color (p<0.01). Eggshell was significantly stronger in the USDHSBM fed (for growing period) groups than other groups (p<0.05) on $31^{st}$ week. Haugh's unit (HU), albumin index and yolk index of the USDHSBM fed group in growing stage were significantly superior (p<0.001) to other groups. In experiment 2, for the 7-week, chicks on the India SBM group gained less (p<0.001) weight than other groups. While daily gain of India SBM chicks was not affected by dietary crude protein level, those of the USDHSBM and Brazil SBM chicks were linearly increased as dietary crude protein level increased from 18% to 20%. The gain per feed ratio of the USDHSBM group was the highest (0.585), followed by the Brazil SBM group (0.568) and India SBM group (0.550) (p<0.01). Therefore, in this experiment, the use of USDHSBM with excellent protein quality and amino acid digestibility could be of advantage to the economic production of layer and broiler.

• Korean Journal of Poultry Science
• /
• v.26 no.4
• /
• pp.261-265
• /
• 1999

The objective of this experiment was to investigate the effect of feeding Angelica gigas Nakai by-products on performance and meat quality of Korean native chicks(KNC). Five hundred forty KNC were placed into 0, 0.2, and 0.4% Angelica gigas supplements with four replications between males and females. Weight gain, feed conversion ratio(FCR), breast meat lipid, fatty acid and protein contents were measured from 17 to 20 weeks old. Egg production, feed intake and FCR were examined from 22 to 29 weeks at four weeks at four weeks intervals. Basal diets based on corn and soybean meal contained 15% crude protein and 2,850㎉/kg ME for the growing period, 16.5% and 2,800㎉/kg for the laying period. Experiments were designed in a one way analysis. Weight gain of female chicks fed 0.2% Angelica gigas by-products increased significantly compared to that of other treatments for the growing period, but was not consistency in male groups. Moisture, protein, fat content were not statistically different among all treatments. Fatty acid composition(C16:0, C18:0) of chicks fed 0.2% Angelica gigas by-products was higher than other treatments. In laying period, hens fed 0.2 or 0.4% Angelica gigas Nakai by-products seemed to increase the egg production and significantly improved FCR compared to that of control(P〈0.05). Birds fed 0.4% treatment showed significantly the lowest feed intake and FCR of all treatments(P〈0.05). The results of these studies indicated that dietary supplemental Angelica gigas by-products may have a role to improve the performance of KNC.