Jong Hwangbo

Effects of Dietary Supplementation of Vitamin C and Sea Buckthorn on the Performance and Meat Quality in Old Laying Hens

The objective of this study was to investigate the effect of dietary supplementation of vitamin C and Sea buckthorn on the performance, blood biochemistry and meat quality in old laying hens. A total 200 Hy-Line Brown laying hens (101 weeks old) were randomly allotted to 1 of 5 dietary treatments : (1) Basal : basal diet, (2) Vit. C : basal diet + 0.1% vitamin C, (3) SB 0.1 : basal diet + 0.1% Sea buckthorn, (4) SB 0.5 : basal diet + 0.5% Sea buckthorn, and (5) SB 1.0 : basal diet + 1.0% Sea buckthorn. Each treatment was replicated 4 times with 10 birds units were arranged according to randomized block design. Feeding trial lasted 4 weeks under 16L:8D lighting regimen. The diets were fed to hens on an ad libitum basis for 4 weeks. Result indicated that during feeding trial of the experiment, hen-day egg production and feed conversion ratio were not significantly influenced by treatments. However, feed intake was significantly (P<0.05) higher in Vit. C and SB treated groups than the basal during 1 wks and 3 wks. Egg weight was significantly (P<0.05) higher in basal and Vit. C than the SB 1.0 treatment. There were no differences in carcass yield during feeding trials. However, partial ratio (breast and neck) was significantly (P<0.05) higher in SB 0.5 than other treatment. There were no differences in the level of leukocytes and erythrocytes. There were no significant differences on proximate analysis (DM, crude protein, crude fat, and crude ash), meat color, water holding capacity, cooking loss, and fatty acids concentrations. In conclusion, dietary supplementation of vitamin C and Sea buckthorn to the diet of old laying hens might be a potential ingredient for increasing partial weight (breast) in old laying hens.

Dietary Effects of Herbal Mixture on the Laying Performance, Blood Parameters and Immune Response in Laying Hens

Poultry Science Division, National Institute of Animal Science, RDA, Seonghwan 331-808, KoreaABSTRACT The objective of this experiment was to investigate the effect of dietary supplementation of herbal medication (HM) on laying performance, blood parameter, and immune response in laying hens. A total of 800 Hy-Line Brown laying hens of 60 weeks of age were randomly allotted to one of four dietary treatments with four replicates per treatment. Three additional diets were prepared by adding 0.5, 1.0 or 1.5 % of HM to the basal diet. Feeding trial lasted 7 weeks under 16L:8D lighting regimen. The diet and water were available ad libitum. Hen-day egg production in groups fed diets with 0.5% and 1.5% HM was significantly (P<0.05) higher than that of control. Feed conversion ratio in group fed diet with 0.5% HM showed the lowest value (P<0.05). Egg weight, feed intake, broken and shell-less egg production were not affected HM supplementation levels. Egg yolk color was significantly greater in all HM supplemented groups than basal treatment. However, eggshell strength, eggshell thickness, eggshell color, and Haugh units were not affected by HM supplementation level. There were no differences in leukocyte counts among the treatments. Plamsa IgM concentration was (P<0.05) higher in all HM treated groups. In conclusion, dietary HM improved egg production, and IgM of laying hens.(Key words : Glycyrrhiza uralensis, immune response, laying hens, laying performance, Lycii fructus)

Effect of Dietary Fermented Earthworm Cast Additives on Odor Reduction of Poultry House and Egg Production

This study was carried out to investigate the effect of feeding fermented earthworm cast additives (FEC) on egg production, egg yolk fatty acids, blood lipid, cecal microorganism and fecal odor. The completely randomized experiment was applied, and the treatments were designed as 2 feeding regimens (control vs. FEC feeding), and FEC contained 3.5% top dressing to common diet. Egg production and egg weight of FEC group were significantly higher than that of control (p<0.05). Ratios of n-6/n-3 fatty acids in the egg yolk of FEC group were significantly higher than those in control group (p<0.05). Concentrations of HDL-C in FEC group was significantly higher than control group (p<0.05), but not triglyceride and total cholesterol. The caecal Lactobacillus of FEC group was significantly higher in FEC group than control group (p<0.05). NH3 concentrations from poultry house were significantly lower in FEC group than control (p<0.05). In conclusion, these study results showed that the addition of FEC at 3.5% to the diet has reduced odor of poultry house and improved the n-6/n-3 fatty acid of egg yolk and egg production in laying hens.

Effects of Early Heat Conditioning on Performance in Broilers exposed to Heat Stress

Department of Animal Biotechnology, Kangwon National University, Chooncheon 200-701, KoreaABSTRACT Heat manipulation at early age has been known to help chickens cope with heat stress later in life. The present study was conducted to determine the effects of early heat conditioning at 5 days of age on performance in broilers when re-exposed to heat stress later in life. Day-old, 256 Arbor Acre boiler chicks were housed in two identical rooms where all broilers were exposed to a 23-h light: 1-h dark cycle throughout the study and provided with feed and water ad libitum. At the age of 5 days, one group was exposed to 37for 24 hours and then returned to the temperature at which control birds were maintained (early heat condition group) while the other was maintained without heat modulation (Control). On 21 days, broilers were regrouped into 4 groups (CON+CON: control+control; CON+HS: control+heat stress; HC+CON: heat conditioning+control; HC+HS: heat conditioning+heat stress), and given 7 days for adaptation. On 28 days, birds in one room were exposed to heat stress (2131) for 3 days whereas those in the other were at room temperature. Heat stress resulted in decreased feed intake, water intake, and body weight gain (P<0.05), but increased rectal temperature and mortality (P<0.05). No beneficial effects of heat conditioning were detected when broilers were exposed to heat stress again at later in life. The present results were discussed together with other studies regarding possible differences in methods such as ages of breeders and strains, which may have resulted in the failure of heat conditioning to help broilers resist heat stress.(Key Words : broilers, early heat conditioning, heat stress)

Effects of Repeated High Ambient Temperature on Performance in Broilers Heat-Conditioned at an Early Age

Heat conditioning at an early age has been known to help chickens cope with heat stress later in life. The present study was conducted to determine the effects of heat conditioning at 5 days of age in broilers repeatedly exposed to high ambient temperature later in life. A total of 256 day-old Arbor Acre boiler chicks were housed in two identical rooms with a 23-h light/1-h dark cycle and provided with feed and water ad libitum. At 5 days of age, the birds in one room were exposed to for 24 hours, while those in the other room served as controls. On day 21, half of the birds in each room were moved into the other room so that each room contained both control and heat-conditioned birds. After a 7-day adaptation period, the birds in one room were exposed to high ambient temperature () for 3 days, whereas those in the other room were kept at normal temperature. The same 3-day exposure to high ambient temperature was repeated two weeks later. Hence, there were four treatment groups (CON+CON: control+control; CON+HS: control+high ambient temperature; HC+CON: heat conditioning+control; and HC+HS: heat conditioning+high ambient temperature). Repeated heat stress resulted in decreased feed intake, water intake, body weight gain, and spleen weight (p

Effect of Various Forms of Floor System on Performance of Meat-type Duck and Environments of Duck House

This experiment was conducted to investigate the effects of floor type and heating system on performance, housing environment and health status of ducks reared in three types of duck house (OD : Open floor house-Direct heating system, OF : Open floor house-Floor heating system and LD : Loft type house-Direct heating system). In OF treatment, PVC pipes were installed for heating under concrete floor and covered with litter. In LD treatment, plastic mesh was installed 50 cm above the floor so that ducks droppings can pass through it. Each treatment had four replicates of 25 birds (Cherry Valley duck breed) per pen. There were no significant differences in weight gain and feed intake of ducks for 6 weeks among all treatments. However, feed conversion ratio in LD was significantly higher (p<0.05) than that in OF. No differences were found in carcass charac- teristics, with the exception of abdominal fat weight where OF were higher than the others. Concentrations of CO2 and NH3 gas in OD were higher than those of OF and LD at 3, 4 and 5 weeks. Moisture content in litter of OF was lower than that of OD. In contrast, the amount of dust in the air was higher in OF than in OD. The amount of fuel used for 6 weeks in LD was lower about 21% than that in OD. Some of unusual symptoms were observed in open floor house and loft type house, such as lying, spraddle legged, twisted ankle and legs, wounded sole, or etc. No components of leukocyte and erythrocyte of blood were significantly different among all treatments. The results of this experiment showed that OF and LD systems had no positive effects on performance of meat type commercial duck. However, there were some positive effects of certain house type for the improvement of environmental condition in duck house for hygienic production. In the future, more research on the effect of various facilities and systems for duck house is needed.