• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.8
• /
• pp.1164-1170
• /
• 2008

In this study, the effects of propolis and vitamin C (L-ascorbic acid) supplementation in diets were investigated on feed intake (FI), body weight (BW), body weight gain (BWG), feed conversion rate (FCR) and digestibility and on egg production and qualities (weight, mortality, shell thickness) in laying hens exposed to heat stress. A total of 150 Hyline White Leghorn, aged 42 weeks, hens was divided into five groups of 30 hens. Chicks were randomly divided into 1 positive control, 1 control and 3 treatment groups. The chicks were kept in cages in temperature-controlled rooms at $22^{\circ}C$ for 24 h/d (positive control, Thermoneutral, TN group) or $34^{\circ}C$ for 9 h/d from 08.00-17.00 h followed by $22^{\circ}C$ for 15 h (control, heat stress, HS group) and fed a basal diet or basal diet supplemented with vitamin C (250 mg/kg of L- ascorbic acid/kg of diet) or two levels of propolis (2 and 5 g of ethanol extracted propolis/kg of diet). Increased FI (p<0.05) and improvement in FCR (p<0.05), hen day egg (p<0.05) and egg weight (p<0.05) were found in Vitamin C and propolis-supplemented laying hens reared under heat stress conditions. Mortality rate was higher in the control group than TN, vitamin C and propolis groups (p<0.05). Digestibility of dry matter, organic matter, crude protein and ether extract improved with increasing of both dietary vitamin C and propolis (p<0.05). Vitamin C or propolis supplementation did not affect either the percentage shape index, yolk index or haugh unit and albumen index (p>0.05). However, the egg shell thickness and egg shell weight appeared to be increased in Vitamin C and propolis groups in comparison to HS group birds (p<0.05). In conclusion, dietary supplementation of laying hens with anti-oxidants (vitamin C and propolis) can attenuate heat stress-induced oxidative damage. These positive effects were evidenced by increased growth performance and digestibility, improvement of egg shell thickness and egg weight in comparison to non-supplemented birds. Moreover, supplementation with propolis (5 g/kg diet) was the most efficient treatment.

• Asian-Australasian Journal of Animal Sciences
• /
• v.28 no.7
• /
• pp.1006-1013
• /
• 2015

Heat-stress remains a costly issue for animal production, especially for poultry as they lack sweat glands, and alleviating heat-stress is necessary for ensuring animal production in hot environment. A high ${\gamma}$-aminobutyric acid (GABA)-producer Lactobacillus strain was used to investigate the effect of dietary GABA-producer on laying performance and egg quality in heat-stressed Hy-line brown hens. Hy-Line brown hens (n = 1,164) at 280 days of age were randomly divided into 4 groups based on the amount of freeze-dried GABA-producer added to the basal diet as follows: i) 0 mg/kg, ii) 25 mg/kg, iii) 50 mg/kg, and iv) 100 mg/kg. All hens were subjected to heat-stress treatment through maintaining the temperature and the relative humidity at $28.83{\pm}3.85^{\circ}C$ and 37% to 53.9%, respectively. During the experiment, laying rate, egg weight and feed intake of hens were recorded daily. At the 30th and 60th day after the start of the experiment, biochemical parameters, enzyme activity and immune activity in serum were measured. Egg production, average egg weight, average daily feed intake, feed conversion ratio and percentage of speckled egg, soft shell egg and misshaped egg were significantly improved (p<0.05) by the increasing supplementation of the dietary GABA-producer. Shape index, eggshell thickness, strength and weight were increased linearly with increasing GABA-producer supplementation. The level of calcium, phosphorus, glucose, total protein and albumin in serum of the hens fed GABA-producing strain supplemented diet was significantly higher (p<0.05) than that of the hens fed the basal diet, whereas cholesterol level was decreased. Compared with the basal diet, GABA-producer strain supplementation increased serum level of glutathione peroxidase (p = 0.009) and superoxide dismutase. In conclusion, GABA-producer played an important role in alleviating heat-stress, the isolated GABA-producer strain might be a potential natural and safe probiotic to use to improve laying performance and egg quality in heat-stressed hens.

• Asian-Australasian Journal of Animal Sciences
• /
• v.18 no.4
• /
• pp.545-551
• /
• 2005

A feeding trial was conducted to determine whether dietary vitamin C (200 mg/kg) and vitamin E (250 mg/kg) prevent any drops in egg shell quality under heat stress in broiler breeder hens. One hundred and sixty molted Ross broiler breeders were housed randomly in an individual cage at 83 weeks of age. Four dietary treatments with forty hens and four replications per treatment were control (no additional vitamins), vitamin C-, or vitamin E-supplemented and combined supplementation of the two vitamins. After a tenday-adaptation period at 25$^{\circ}C$, the ambient temperature was kept at 32$^{\circ}C$ for a three-week-testing period. Egg production dropped dramatically over week but it did not show a significant change among treatments (p<0.05). However, egg quality parameters such as egg weight, specific gravity, shell thickness, SWUSA, puncture force and shell breaking strength from the birds fed the diet with the combined vitamins C and E were significantly improved over those of the control group during the heat stress period (p<0.05). The hens fed the vitamin C diet improved tibia breaking strength (37.16 kg), statistically higher than the birds fed the control and the vitamin E diets (p<0.05). The hens fed the control diet showed higher serum corticosterone levels, a mean of 5.97 ng/ml, than those of the other treatments (p<0.05). The heat stress resulted in elevated heterophils and decreased lymphocytes in serum, increasing the H/L ratios for all the treatments. However, the increases in H/L ratios were alleviated by feeding the diets containing vitamin C alone or together with vitamin E, although there were no significant differences in the ratio between the two groups (p<0.05). In conclusion, vitamins C (200 mg/kg) and/or E (250 mg/kg) supplemented to the diets for broiler breeder hens could prevent drops in egg shell quality and tibia bone strength under highly stressful environmental temperatures.

• Journal of the Korean Applied Science and Technology
• /
• v.35 no.3
• /
• pp.787-796
• /
• 2018

This study was conducted to investigate the effects of probiotic mixture on fecal ammonia, caecal microorganism, immune response, egg quality and production in layer under heat stress (HS).A total of four hundred 50 week olds Hy-Line Brown layers were randomly divided into four groups of 100 heads each: C (control, room temperature $25^{\circ}C$), HS (heat stress $33^{\circ}C$), PM (HS plus probiotic mixture 500, 750 mg/kg of diets). Egg production, egg quality, spleen weight, blood IgG and lymphocyte concentrations were increased in the PM group compared to the HS group, while mortality, the heterophil:lymphocyte (H:L) ratio, and corticosterone levelswere significantly decreased. Lactobacillus was increased in the PM group compared to the HS group, but E. coli, coliform bacteria and aerobic bacteria were significantly reduced. Fecal ammonia production was significantly increased in the HS group compared to the PM group. In conclusion, the results of this study that these mixed probiotics can reduce the heat damage of the summer laying hens and can be an effective nutritional strategy to reduce odor generation from feces, and to improve egg quality and laying production through immune response and caecal microbial balance.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.2
• /
• pp.252-256
• /
• 2007

This study was carried out to determine the effect of vitamin E and vitamin C on the performance of Japanese quails (Coturnix coturnix japonica) reared under heat stress during the growth and egg production period. A total of 810 seven-day-old Japanese quails were used in the trial. The birds received a diet with either three levels of vitamin E (DL-${\alpha}$Tocopheryl acetate) (60, 120 and 240 mg/kg of diet) and vitamin C (ROVIMIX STAY-C 35) (60, 120 and 240 mg/kg of diet). Live weight on day 35 and weight gain were the lowest in the group of chicks on a combination of 60 mg of vitamin E and 60 mg of vitamin C, whereas the highest live weight was demonstrated in chicks on a combination of 240 mg of vitamin E and 240 mg of vitamin C (p<0.01). The effects of treatments on cumulative feed consumption, feed conversion ratio, age at 5% lay, sexual maturity weight, rate of lay and mean egg weight values were found to be significant (p<0.01). The highest feed consumption, feed conversion ratio, age at 5% lay, sexual maturity weight, rate of lay and mean egg weight values were found in the group on a combination of 240 mg of vitamin E and 240 mg of vitamin C. The effect of treatments on the mortality ratio was found to be insignificant (p>0.01). The cost of supplementing diets with vitamin E and vitamin C is very low. Therefore such a combination of supplement can offer a potential protective management practice in preventing heat stress related losses in performance of Japanese quails.

• Proceedings of the Korea Society of Poultry Science Conference
• /
• 2001.11a
• /
• pp.49-51
• /
• 2001

Betaine functions as an osmoregulators in the cells and its inclusion can spare the choline, carcass fat reduction. Thus, two hundred eighty eight of seventy eight weeks old laying hens were fed with 0, 500, 1,000, 2,000 ppm betaine addition during the environmentally high temperature stress. Basal diets contained 16% CP and 2,800 ME. Egg production, feed intake, feed conversion were examined for eight weeks. Egg qualities, liver betaine, blood osmolarity, AntiDiuretic Hormone(ADH) were measured at the end experiment. Egg production of hens fed 500, 2,000 ppm dietary betaine and showed significance between control and 2,000 ppm betaine treatment(P＜0.05). ADH of blood sera tended to increase as dietary supplemental betaine increased. The results of this experiments indicated that dietary supplemental betaine was able to improve the performance, eggshell breaking strength, liver betaine in this experiment.

• Korean Journal of Poultry Science
• /
• v.29 no.2
• /
• pp.117-124
• /
• 2002

Betaine functions as an osmoregulators in the cells and its inclusion in diet can spare the choline and carcass fat reduction in chicken. Thus, two hundred eighty eight laying hens were fed with 0, 500, 1,000, 2,000 ppm of betaine from seventy eight to eighty six weeks of age during the environmentally high temperature stress. Com and soybean basal diets contained 2,800 kcal/kg ME and 16% CP. Egg production, feed intake, and feed conversion were examined for eight weeks. Egg quality characters, serum cholesterol, liver betaine, and lower ileal osmolality were measured at the end of experiment. Egg Production rates of hens fed with 500 or 2,000 ppm of betaine were 75.06 and 75.02%, respectively and tended to increase compared to the control. The feed conversion(FCR) of these treatments was significantly(P<0.05) improved compared to that of control although it did not significantly differ in the e99 Production rates between 500 and 2,000 ppm of betain groups. Eggshell breaking strength of hens fed betaine was significantly(P<0.05) higher than those of control. However, betaine supplements did not influence to improving the albumen height and Haugh unit. Liver betaine in hens fed with betaine was linearly increased unto 2,000 ppm. The birds fed with 2,000 ppm betaine showed significantly(P<0.05) higher in the liver betaine than the control birds. Total cholesterol and triglyceride tended to be increased by dietary betaine supplement. The lower ileal osmolality in betaine supplement group tended to be slightly decreased. As a result, dietary betaine supplement tended to improve the egg Production and eggshell Quality in laying hens during heat stress.

• Proceedings of the Korea Society of Poultry Science Conference
• /
• 2004.11a
• /
• pp.69-79
• /
• 2004

A feeding trial was conducted to determine whether dietary vitamin C (200 mg/kg) and vitamin E (250 mg/kg) prevent any drops in egg shell quality under heat stress in broiler breeder hens. One hundred and sixty molted Ross broiler breeders were housed randomly in an individual cage at 83 weeks of age. Four dietary treatments with forty hens and four replications per treatment were control (no additional vitamins). vitamin C-. or vitamin E-supplemented. and combined supplementation of the two vitamins. After a ten-day-adaptation period at 25 $^{\circ}C$. the ambient temperature was kept at 32 $^{\circ}C$ for a three-week-testing period. Egg production dropped dramatically over week but it did not show a significant change among treatments (P<0.05). However. egg weight. SG. shell thickness. SWUSA. puncture force and shell breaking strength of the birds fed the diet with the combined vitamins C and E were significantly improved than those fed the basal diet during the heat stress period (P<0.05). The hens fed the vitamin C supplemented diet showed a tibia breaking strength of 37.16 kg statistically higher than those of the basal and the vitamin E supplemented groups (P<0.05). The hens fed the basal diet showed higher serum corticosterone levels. a mean of 5.97 ng/ml. than those of the rest of treatments (P<0.05). The heat stress elevated heterophils but decreased lymphocytes in serum. and it changed H/L ratios of all the treatments. The increases in H/L ratios were alleviated in the bird by feeding vitamin C and/or vitamin E supplemented diets. but they did not differ significantly (P<0.05). In conclusion. vitamins C (200 mg/kg) and/or E (250 mg/kg) supplementation to diets could prevent drops in egg shell quality and tibia bone strength by alleviating stressful effects from high temperature in broiler breeder hens.

• Korean Journal of Poultry Science
• /
• v.46 no.2
• /
• pp.77-86
• /
• 2019

This study was conducted to compare the heat stress response and production performance of chicks hatched in winter and summer. Among the 2,090 Korean native chickens examined, 1,156 hatched in winter and 934 hatched in summer. The amount of telomeric DNA, the expression of heat shock protein (HSP) genes, survival rate, egg production, and body weight were analyzed to evaluate the stress response and production performance of chickens. The results showed that the expression of HSP-70, $HSP-90{\alpha}$, and $HSP-90{\beta}$ genes in the winter-hatched chickens were significantly higher than those in the summer-hatched chickens during the growing and laying period (P<0.05). There was no significant difference in the amount of telomeric DNA between summer- and winter-hatched chickens. The survival rate was significantly higher in the summer-hatched chickens than in the winter-hatched chickens at the laying period (P<0.01). The hen-day egg production and egg weight in the summer-hatched chickens were also significantly higher than those in the winter-hatched chickens (P<0.05). In contrast, age of sexual maturity of winter-hatched chickens was significantly earlier than that of summer-hatched chickens (P<0.01). The body weights from birth to 24 weeks were significantly lighter in the summer-hatched chickens than in the winter-hatched chickens, however, it was reversed after 28 weeks (P<0.05). In conclusion, the chicks hatched in the summer are more resistant to heat stress, with better productivity than the chicks hatched in the winter. These results suggest that the chicks grown at high temperatures have greater adaptability to the thermal environment.

• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.5
• /
• pp.694-699
• /
• 2009

The present study was conducted to evaluate the effect of chilled drinking water on the productivity of laying hens under constant high ambient temperature. A total of seventy-two, 123-day-old Hy-line brown layers was divided into two equal groups. The first group (UDWG) was given unchilled water ($23.0{\pm}2.5^{\circ}C$) as a control, and the second group (CDWG) was given chilled water ($16.0{\pm}0.5^{\circ}C$). The laying hens were kept at $30^{\circ}C$ constant temperature with 50% relative humidity and were exposed to 17 h of light per day. Feed intake, egg production, egg quality (egg weight, shell weight, shell thickness, egg color, yolk color, and Haugh unit), and blood samples were collected and analyzed. The results showed that the feed intake of CDWG laying hens was significantly higher (11.64%) than the UDWG counterparts (p<0.01). Egg production of CDWG was also significantly higher (11.27%) than the UDWG counterparts (p<0.001). Furthermore, we observed that the CDWG laying hens had significantly higher (11.72%) levels (p<0.10) of blood calcium, with a corresponding value of 21.92 mg/dl compared to the UDWG hens (19.62 mg/dl). The higher calcium concentration in the CDWG animals may contribute to increased egg production. The CDWG laying hens also contained higher (12.53%) phosphorus concentrations in blood compared to the UDWG (4.22 mg/dl vs. 3.75 mg/dl), although not statistically different (p>0.10). Egg weight and egg quality were not affected by chilled drinking water. In conclusion, providing chilled drinking for laying hens under high ambient temperature improved feed intake and egg production.