• Korean Journal of Poultry Science
• /
• v.24 no.3
• /
• pp.117-126
• /
• 1997

This study was conducted to estimate the hatching and growing performance, and heterosis of Korean Native Chicken(KNC), Rhode Island Red(RIR) and KNC XRIR crossbred. A total of 1,274 female pullets were produced from KNC, RIR and KNC x RIR crossbred kept in National Live-stock Research Institute, Korea. The experiment was conducted for 20 weeks from Sep. 2, 1995 to Jan. 20,1996. Hatchabilities of KNC dark brown strain x RlR(DR), KNC light brown strain x RlR (LR) and KNC dark black strain x RlR(BR) were 77.3%, 73.6% and 72.5%, respectively. Viabilities up to 20 weeks of age were not significantly (P>0.05) different among purebreds and crossbred. Body weights of DR, LR and BR were 1,890 g, 1,849 g and 1,967 g, respectively, at 20 weeks of age. The feed conversion ratio(feed /gain) of DR, LR, and BR were 5.88, 6.07 and 5.87, respectively, up to 20 weeks of age. Average shank lengths of DR, LR and BR were 97.1 mm, 98.9 mm and 99.4 mm, respectively, at 20 weeks of age. The heterosis effects were estimated to be -0. 48%, and 12.58%, respectively, in fertility and hatchability. Up to 20 weeks of age, the heterosis effects were estimated to be 0.07%, 13.49%, -5.77%, and 3.52% in viability, body weight, feed conversion ratio, and shank length, respectively.

• Journal of Animal Science and Technology
• /
• v.62 no.5
• /
• pp.628-637
• /
• 2020

In poultry diets, a requirement of crude protein is one of the most important factors in poultry productivity. Besides, the Pekin duck requirement of crude protein is still not clear. This experiment was conducted to determine the crude protein requirement of Pekin duck on diet formulation by investigation of growth performance, carcass trait, and analysis of blood parameter for a hatch to 21-day (d) of age. A total of 432 male White Pekin ducks were randomly allocated to six levels of crude protein (i.e., 15%, 17%, 19%, 21%, 23%, and 25%) to give six replicate pens per treatment with 12 ducklings per each pen. Body weight and feed intake were measured weekly by calculating feed conversion ratio and protein intake. Two ducklings each pen was euthanized via cervical dislocation for analysis of carcass trait and plasma blood on 21-d of age. Data were applied on both prediction linear-plateau and quadratic-plateau models by estimation of the crude protein requirements. Data were applied on both prediction linear-plateau and quadratic-plateau models by estimation of the crude protein requirements. The level of crude protein requirements of Pekin ducks for 21 days after the hatch was estimated to be 20.63% and 23.25% diet for maximum daily gain, and minimum feed conversion ratio, respectively.

• Korean Journal of Poultry Science
• /
• v.44 no.3
• /
• pp.161-172
• /
• 2017

This study was conducted to determine the effect of Saccharomyces cerevisiae (SC) as a dietary probiotic and evaluated the most suitable feeding interval for this probiotic on growth performance, carcass yield, and meat quality parameters in broiler chickens. In total, 1,050 one-day-old Cobb 500 chicks were randomly assigned to one of seven dietary treatment groups, in a $2{\times}3$ factorial arrangement with 3 SC dosages (0.6%, 1%, and 1.4%) and two feeding intervals [long term (LT) for 35 days and short term (ST) for 28 days after hatching], with a negative control diet (NC; 0% SC). Triplicate experiments were performed with 50 birds per cage. Broilers fed a diet including SC showed increased (p<0.01) daily gain and feed efficiency compared to the control. Further, broilers fed the 1.4% SC supplemented diet showed a significantly increased (p<0.01) average daily gain (ADG) and feed conversion ratio (FCR) compared to broilers fed the 0.6% and 1% SC incorporated diets. Similarly, broilers fed an LT SC diet showed a greater (p<0.01) increase in ADG and FCR compared to broilers fed an ST SC diet. Moreover, broilers fed an LT SC diet displayed a reduced (p<0.05) meat pH, gizzard weight, and increased (p<0.05) meat water-holding capacity compared to broilers fed an ST SC diet. Broilers fed the 1.4% SC supplemented diet showed increased (p<0.05) thigh muscle weight compared to broilers fed the 0.6% and 1% SC supplemented diets. In conclusion, broilers fed LT SC diets showed improved growth performance and carcass quality parameters compared to broilers fed ST SC diets, and the NC diet, from hatching to day 35.

• Korean Journal of Poultry Science
• /
• v.28 no.1
• /
• pp.55-59
• /
• 2001

The objective of these experiments gas to investigate the feeding of Powerfeel supplementation on performance and intestinal microflora of broiler chicks. Five treatments were allocated into 0, 0.025, 0.050, 0.075, 0.10% Powerfeel with four replications for five weeks. Diets contained 21.5% CP, 3,100 kcal/kg ME for the first three weeks and 19% CP, 3,100 kcal/kg ME for the rest two weeks. Weight gain, feed intake, feed conversion were weekly measured. E. coli and Salmonella were examined from cecum and ileum at the end of experiment. ND titer were also measured at five weeks old after first and booster vaccination at 14 and 21 days of age. In experiment 1, Weight gain of Powerfeef treatments was significantly higher for five weeks (P〈0.05). Feed intake increased on all Powerfeel treatments. Chicks fed Powerfeel improved feed conversion ratio(FCR) significantly compared to that of control (P〈0.05), but was not shown the consistency. In experiment 2, Weight gain and feed consumption of chicks fed Powerfeel were tended to increase, but were not statistically different from control. Powerfeel treatments showed significantly lower FCR than control(P〈0.05). The number of Salmonella and E. coli of chicks ileum fed Powerfeel were highly decreased, compared to those of control in both experiments. Powerfeel supplementation seemed to decrease the number of both Salmonella and E. coli in illeum, but was not consistency in cecum. Chicks fed Powerfeel showed significantly higher ND titer than control (P〈0.05). These results indicated that the optimum level of Powerfeel to maximize the performance of broiler chicks were estimated from 0.050 to 0.075% in broiler diets.

• Asian-Australasian Journal of Animal Sciences
• /
• v.9 no.3
• /
• pp.261-266
• /
• 1996

Carcass analysis of most economical parts of broilers were studied after they were fed with different protein levels of 16, 18, 20 and 23% for the starter period and 16, 18 and 20% for the grower period. The energy value of the feed was constant at 3,200 kcal ME/kg. The results for the starter and grower broilers showed similar pattern of responses. There were significant increased in weight gain, feed intake, protein intake, while there were significant decrease in the feed conversion ratio (FCR), abdominal fat and carcass fat when dietary protein increased. For the economical parts of the carcass, most of the fats were found in the thigh meat, while the lowest was found in the breast meat. The protein levels did not influence the meat production of the breast, drumstick and thigh portion. Increasing the protein intake, increased the broiler performance in relation to increased protein content of the breast, drumstick and thigh meat. The different fat contents of the meat might be due to differences in the rate of lipogenesis and fat deposition of the meat.

• Asian-Australasian Journal of Animal Sciences
• /
• v.16 no.9
• /
• pp.1360-1363
• /
• 2003

A feeding trial was conducted on pigs to study the effect of La on their growth performance. Sixty barrows were randomly assigned to two groups (each of which included three replicates) and they were fed same basal diet supplemented with 0 or 100 mg/kg lanthanum (La) respectively for 30 d. Blood samples were collected and analyzed to study the growth hormone secretion pattern. La residues in selected organs were analyzed to test the safety level. The results showed that average daily gain and feed conversion ratio of pigs were increased by 12.95% (p<0.05) and 6.78% (p<0.05) respectively with the supplementation of La. Blood samples analysis showed that peak amplitude, base-line level and mean level of growth hormone in serum were elevated by 80.42% (p<0.05), 70.99% (p<0.05) and 64.91% (p<0.05) respectively. No significant difference of La residues was found in selected organs between the control and La-treated group.

• Asian-Australasian Journal of Animal Sciences
• /
• v.28 no.4
• /
• pp.538-543
• /
• 2015

This experiment was conducted to measure the effects of olive leaf powder on performance, egg yield, egg quality and yolk cholesterol level of laying hens. A total of 120 Lohmann Brown laying hens of 22 weeks old were used in this experiment. The birds were fed on standard layer diets containing 0, 1%, 2%, or 3% olive leaf powder for 8 weeks. Egg weight and yield were recorded daily; feed intake weekly; egg quality and cholesterol content at the end of the trial. Olive leaf powder had no effect on feed intake, egg weight, egg yield and feed conversion ratio (p>0.05) while olive leaf powder increased final body weight of hens (p<0.05). Dietary olive leaf powder increased yellowness in yolk color (p<0.01) without affecting other quality parameters. Yolk cholesterol content was tended to decrease about 10% (p>0.05). To conclude, olive leaf powder can be used for reducing egg yolk cholesterol content and egg yolk coloring agent in layer diets.

• Asian-Australasian Journal of Animal Sciences
• /
• v.18 no.10
• /
• pp.1445-1450
• /
• 2005

This experiment was conducted to evaluate the effect of feed withdrawal (F) and heat acclimatization (A) on malebroiler and -layer chickens responses to acute heat stress (AHS) at four weeks of age. Totals of ninety male chicks of broiler or layer type were randomly allocated into 30 pens of grower batteries with raised wire floors. Chicks were subjected to F and A three times a week through the first three weeks of age. At each time, feed withdrawal and heat acclimatization (T = $35^{\circ}C$) lasted for six and four hours, respectively. Feed consumption (FC), body weight (BW), and feed conversion ratio (FCR) were recorded weekly for broiler type chickens only. At four weeks of age, all groups of chickens were exposed to AHS (T = $39{\pm}1^{\circ}C$) for three hours. Before and after AHS challenge, body temperature (Tb), heterophil (H), and lymphocyte (L) counts were recorded, and H/L ratio was calculated. Antibody (Ab) response to sheep red blood cells (SRBC) was assessed from all treatments without being exposed to AHS. Group F of broiler-type chickens weighed less (p<0.05) compared to control group. Also, both A and F groups of broiler-type chickens consumed less (p<0.05) feed when compared to control group. Acute heat stress elevated Tb of all treatment groups, however the increase was more profound (p<0.001) in broiler chicks. Broiler chicks of both A and F groups showed a tendency to have higher (p = 0.08) Tb when compared to control group. Acute heat stress elevated (p<0.001) H/L ratio in both types of chickens. Broiler chicks maintained higher (p<0.001) H/L ratio. Both F and A groups reduced (p<0.01) the level of elevation in H/L ratio compared to control groups of both types of chickens. Neither A nor F group affected the Ab production in response to SRBC. However, there was a tendency towards higher Ab responses in F group when compared to other groups in both types of chickens. Results of the present study demonstrate that previous history of feed withdrawal or episodes of heat exposures improved chicks'physiological withstanding of AHS and a tendency to improved humoral immune response.

• Korean Journal of Organic Agriculture
• /
• v.17 no.2
• /
• pp.237-251
• /
• 2009

This study was carried out to evaluate the effect of replacing antibiotics by organic acid mixture on growth performances and blood metabolites in growing pigs. Twenty-five crossbred pigs (Large White${\times}$Landrace) at the age of 79 days were fed five different diets by supplementing organic acid mixture and chlortetracycline. The experimental diets were consisted of diets without antibiotics supplementation (control), diets added 100mg/kg of chlortetracycline to control diet (T1), diets added 100mg/kg of chlortetracycline and 0.1% of $Acidomix^{(R)}$ (comprising formic acid 25%, sorbic acid 10%, fumaric acid 10%) to control diet (T2), diets added 0.1% of $Acidomix^{(R)}$ to control diet (T3), and diets added 0.3% of $Acidomix^{(R)}$ to control diet (T4). The changes in feed conversion ratio, average daily gain and blood metabolites were investigated. Twenty-five pigs were allotted to five treatments with five replications of each and the experiment was conducted on the basis of complete randomized design for 6 weeks. Average daily gain was significantly (p<0.05) different between T4 and control diets. All treatments including diets added $Acidomix^{(R)}$ and chlortetracycline were slightly higher than control diets. The feed intakes did not show a significant difference between the control and other treatments, and did not give change in feed intake by the addition of $Acidomix^{(R)}$. No differences on feed conversion ratio among treatments were observed but T4 and T3 treatments showed lower value than other treatments. The concentrations of blood urea nitrogen, total cholesterol and triglyceride were significantly (p<0.05) different among treatments, but their values were within the normal range representing that effects on blood profile by organic acid or antibiotics supplementation were not found. The results from this study indicated that adding chlortetracycline or organic acid mixtures to diets showed tendency to improve average daily gain and feed conversion ratio in growing pigs. These results showed that antibiotics could be replaced by organic acid mixture in growing pig diets, leading to stimulated growth and improved feed conversion ratio.

• The Journal of Fisheries Business Administration
• /
• v.29 no.1
• /
• pp.121-137
• /
• 1998

This study was conducted to examine the economic evaluation of the newly developed fish meal analog (BAIFA-M) in Korean rockfish feed. A raw fish feed (MP) and two commercially formulated diets (EP) were employed to compare weight gain (WG), feed conversion ratio (FCR) and survival rate (SR) from the sea cage culture system. By using the economic model in the practical sea cage culture system, feed cost, production cost and gross profit per kg production, rate of profit to gross revenue (RPGR), and internal rate of return (IRR) were calculated based upon the results of the experiment and the information of the private aquaculture farm (Young Chang) in Tong young, Korean. IRR criteria is one of the popular economic feasibility analysis methods applicable far aquaculture industry. This is an economic evaluation method to compare the given interest rate or the discount rate with IRR which can be calculated by the difference between the present value of the benefit stream and of the cost stream. The benefits of using EP on WG, FCR, SR, and production cost will be emphasized in this study. Fish averaging 20$\pm$3.6g (Mean$\pm$SD) were randomly distributed in each small cage (6m$\times$6m) as groups of 2,000 fish. By using 3 large size cages (12m$\times$12m), 12 small cages were constructed, and only 9 small cages were employed for three replicates of each diet treatment. To compare with MP diet, two sinking EP diets were designed by our laboratory and produced by the local feed company who wanted to promote these EP diets for the mass cage culture of Korean rockfish in the future. Two EP diets contain white fish meal and/or BAIFA-M as the main animal protein sources : WFM diet, maximum 43% of white fish meal : BAIEA- M diet, 30% of white fish meal nab replaced by BAIFA- M from WFM diet. Results are summarized in Table 1. Fish fed MP diet showed significantly lower SR than does fish fed two EP diets(P<0.05). However, there Were no significant difference on FCR among fish fed three practical diets. Table 1. Average feed conversion ratio (FCR), accumulative average survival rate (SR) and economic evaluation data far three practical diets. As we expected, BAIFA-M diet is more economical than WFM diet as well as MP diet. Feed cost and production cost per kg production from BAIEA - M diet were lower than those from WFM and MP diets. Moreover, gross profit per Kg production, RPGR and IRR from BAIFA- M diet were higher than those from WFM and MP diets. This economic evaluation study clearly indicated that MP diet should be replaced by the commerical formulated EP diets as soon as possible in the near future because MP diet is not economical in the practical sea cage culture system.