• 농업과학연구
• /
• 제44권4호
• /
• pp.531-540
• /
• 2017

A study was conducted to compare growth performance of six female commercial Korean native chicken (KNC) crossbreeds from hatching to twelve weeks of age. Three hundred and twelve, 1-day-old female commercial KNC were used within 1 paternal line and 6 maternal lines. The chickens were allocated to 24 battery cages to give 4 replicates per strain with 13 chickens per cage. The chickens were reared under continuous lighting (24 h) and water was available at all times. Ad-libitum feeding was practiced throughout the experimental period. Among the six different strains, 2A had the greatest bodyweight (BW) at 42 days after hatching (p < 0.05). No BW difference between six crossbreed strains (p > 0.05) was found thereafter. Crossbreed 1A had the higher average daily gain (ADG) than crossbreed 2A and 3A chickens (p < 0.05), whereas crossbreed 4A, 5A, and 6A had similar ADGs to that of crossbreed 1A (p > 0.05) at 84 days after hatching. Furthermore, crossbreed 4A had a great average daily feed intake (ADFI) from hatching to 84 days (p < 0.05). Nonetheless, there was no difference in the feed conversion ratio (FCR) and uniformity between six crossbreed strains for the experimental period (p > 0.05). Despite that 1A, 4A, and 6A had the higher viability (p < 0.05) than crossbreed 2A and 5A, they had a similar viability than crossbreed 3A (p > 0.05). With this in mind, crossbreed 2A had greater BW, ADG, and FCR than other chicken crossbreeds from hatching to 84 days, although they had a lower viability than others.

• 한국양식학회지
• /
• 제20권2호
• /
• pp.85-89
• /
• 2007

무지개송어 품종개량의 일환으로 국내에 이식 양식되고 있는 미국산 무지개송어 발안난의 부화와 자치어 성장에서 얻어진 초기사육에 관한 기초적 시험을 실시하고 그 결과는 다음과 같다. 무지개송어 발안란의 난경은 $4.95{\pm}0.34\;mm$, 중량은 $0.07{\pm}0.003\;g$였다. 발안란은 8일째인 11월 25일에 전량 부화되었으며, 부화율은 평균 87.8%였다. 무지개송어 치어를 56일간 사육한 결과 전장 $4.0{\pm}0.7\;cm$로 매우 완만한 성장을 보였으며, 전장의 사육 경과일수에 따른 성장식은 TL=0.0366ED+1.8645 ($r^2=0.9285$, n=350)로 표시되었다. 부화된 치어의 평균 체중은 0.09 g였으며, 사육 $14{\sim}20$일째 $0.11{\sim}0.14\;g$로 서서히 증가되어 사육 41일째 0.33 g, 사육 48일째 0.45 g, 56일째 0.62 g로 급증되었으며, 체중의 사육 경과 일수에 따른 성장식은 $BW=0.0638e^{0.0408ED}\;(r^2=0.9917,\;n=350)$로 표시되었다. 치어의 56일간 사육 시 생존율은 $64.5{\pm}1.3%$였다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제31권6호
• /
• pp.899-904
• /
• 2018

Objective: This experiment studied the effects of first feed intake time post-hatch on growth performance, nutrient apparent metabolic rate and intestinal digestive enzyme activities in broilers. Methods: Two thousand five hundred and twenty LingNan Yellow broilers were randomly allotted to seven treatments with six replicates of 60 each. The only experimental factor was the first feed intake time which was 18, 24, 30, 36, 42, 48, and 54 hours after hatching. The whole experiment lasted for 21 days. Results: During the whole period, the 30 h treatment had the best body weight and average daily gain (p<0.05), followed by the 24 h group performance optimization. Also, the 30 h group was observed to have the best apparent metabolic rate for ether extract (p<0.05) and crude protein (p<0.05) and the highest activities of amylase, lipase and trypsin in small intestine. And the 24 h group was second only to the 30 h group in terms of the above two measures. Conclusion: These results indicated that the appropriate first feeding time of LingNan Yellow broilers was 24 to 30 hours after hatching.

• 농업과학연구
• /
• 제48권4호
• /
• pp.719-727
• /
• 2021

This study was conducted to evaluate the effects of mixed and separate gender feeding on the growth performance and carcass traits of Korean native chickens (KNC) compared to white semi-broilers (WSB) and a commercial broiler (CB) from hatching to 35 days. Here, 240 chicks were used with eight birds per cage in a randomized design with six replicates per breed. For the KNC lines, three groups of males (KNC-M), mixed-gender birds (KNC-FM) and females (KNC-F) were used. The two-phase feeding program used here consisted of a starter phase (days 1 - 21: crude protein [CP] 20% and metabolizable energy [ME], 3,050 kcal·kg^-1) and a grower phase (days 22 - 35: CP 18%, 3,100 kcal·kg^-1) for a commercial broiler. The WSB and CB were fed the only starter commercial diet. Fresh water and feed were provided ad-libitum. The results revealed that the KNC group had a lower (p < 0.05) body weight (BW) from day 7 and day 35 compared to that of the CB. Furthermore, the KNC group showed a lower (p > 0.05) average daily gain (ADG) relative to that of the CB during the entire experimental period. No difference (p > 0.05) was observed in the shank length among the treatments. There were also no significant differences in the growth performance or carcass traits between the KNC-M and WSB groups or in the genders of the KNC group.

• Journal of Animal Science and Technology
• /
• 제64권1호
• /
• pp.84-96
• /
• 2022

The current study was conducted to evaluate the effect of calcium-enriched fatty acid supplementation on the growth performance, blood metabolites, intestinal morphology, carcass traits, and nutrient digestibility of broilers subjected to chronic heat stress. A total of 210 one-day-old broiler chicks (40.12 ± 0.25 g) were randomly allocated to one of five dietary treatments, to obtain six replicates per treatment. Broilers were subjected to chronic heat stress from day 21 to day 35, post-hatching, at 34℃ for 9 h per day. The body weight (BW) and feed intake of the experimental broilers were recorded weekly, and the average daily gain (ADG) and feed conversion ratio (FCR) were calculated accordingly. Rectal temperature was measured to compare the basal body temperatures between individuals, and blood samples were collected on days 21 and 35 to evaluate basal body temperature, serum total cholesterol, and the triglyceride content of the broilers. On days 21 and 35, one broiler from each cage (n=6) was euthanized to measure carcass trait parameters, nutrient digestibility in digesta, and intestinal morphology. On days 14, 28, and 35, the broilers fed 2.0% calcium-enriched fatty acids had higher BW (p < 0.05) than those fed the other diets. However, no differences (p > 0.05) were found in the average daily feed intake (ADFI) between dietary treatments over the 35 experimental days. On the other hand, on day 21, post-hatching, the broilers fed the 2.0% calcium-enriched fatty acid diet had improved (p < 0.05) dietary feed efficiencies compared to the other treatments. On day 28, the broilers fed the 5.0% of calcium-enriched fatty acid diet also had higher (p < 0.05) dietary feed efficiencies than those fed with the other dietary treatments. No effects (p > 0.05) on carcass weight, nutrient digestibility, intestinal morphology, or blood parameters were found between broilers fed with dietary treatments. This study demonstrated that the inclusion of an additive, containing 2.0% calcium-enriched fatty acid, to broiler diet could ameliorate the negative growth performance of broilers; and no interaction (p > 0.05) was observed between the calcium-enriched fatty acid and nutrient digestibility, digestive anatomy, blood metabolism, and carcass traits of broilers subjected to chronic heat stress conditions for 35 days post-hatching.

• 농업과학연구
• /
• 제44권4호
• /
• pp.566-573
• /
• 2017

The study was conducted to evaluate the growth performance, viability, and uniformity of female crossbred Korean native chickens (KNC) for the first twelve weeks after hatching. Six crossbreed lines of chickens (1B, 2B, 3B, 4B, 5B, and 6B) bred from 1 paternal line and 6 maternal lines of KNC were compared in this study. Sixty newly hatched 1-day old chicks from each crossbreed, for a total of 360 chickens, were allocated into 6 replicates (10 birds per replicate) in a complete randomized design. Experimental diets used in this study consisted of 3 phases: 1) week 0 to 5, crude protein 20.3% and metabolizable energy 3,059 kcal/kg; 2) week 5 to 8, crude protein 18.6% and metabolizable energy 3,123 kcal/kg; and 3) week 8 to 12, crude protein 16.7% and metabolizable energy 3,187 kcal/kg. Body weight and feed intake were measured bi-weekly during the experiment. The 4B crossbreed had a higher body weight, average daily gain, and average daily feed intake on week 12 (p < 0.05) than the other groups. The 4B crossbreed had a lower (p < 0.05) uniformity during weeks 10 to 12 than crossbreeds 1B and 5B. However, a lower viability was observed (p > 0.05) in 4B in weeks 2 to 12 than those in the other groups. Results of the current study indicate that the 4B crossbreed had a higher growth performance in week 12 but had a lower viability for weeks 2 to 12 than the other crossbreeds.

• 농업과학연구
• /
• 제46권3호
• /
• pp.591-599
• /
• 2019

The study was conducted to investigate the growth performance of two strains of Korean domestic chickens (KDC, i.e., 1A, and 2A). A total of 600, one-day-old female chicks were allocated in a completely randomized design to give 15 replicates for each strain (10 birds per pen). The chickens were fed (week 0 to 6: ad libitum; week 6 to 12: restricted feeding) commercial diets (week 0 to 5: crude protein 20.3% and metabolizable energy 3,059 kcal/kg; week 5 to 8: crude protein 18.6% and metabolizable energy 3,123 kcal/kg, and week 8 to 12: crude protein 16.7% and metabolizable energy 3,187 kcal/kg) together with fresh water. Body weight (BW) and feed intake were measured bi-weekly to calculate the average daily feed intake (ADFI), average daily gain (ADG), and subsequently the feed conversion ratio (FCR). The results indicate that the 1A crossbreed had a higher (p < 0.05) BW compared to the 2A crossbreed from week 6 to 10. A higher ADG (p < 0.05) was seen in the 1A crossbreed on week 6 and in the 2A crossbreed on week 8. Moreover, no difference (p > 0.05) was observed in the FCR between crossbreed 1A and 2A during the 12 weeks with the exception of week 8. Crossbreed 1A had (p < 0.05) an improved FCR compared to the 2A crossbreed on week 8. In conclusion, the 1A crossbreed had a higher growth performance compared to the 2A crossbreed for 12 weeks after hatching. This data can contribute by helping the KDC market.

• 농업과학연구
• /
• 제48권1호
• /
• pp.133-140
• /
• 2021

The aim of this study was to evaluate the growth performance between two different crossbred strains of Korean native chickens denoted as 1A and 2A compared to white semi broilers and Ross (RR) from hatching to 40 days. In total, 576 one-day-old chicks were allocated in a completely randomized design to give 18 replicate cages each (eight chicks per cage). The two-phase feeding program consisted of the starter (day 1 - 21: Crude protein [CP] 20% and metabolizable energy [ME], 3,050 kcal·kg^-1) and the grower (day 22 - 40: CP 18%, 3,100 kcal·kg^-1). The results revealed that 1A and 2A had a lower (p < 0.05) body weight (BW) from day 1 to day 40 compared with the other groups. A lower (p < 0.05) average daily gain (ADG) was observed in 1A and 2A during the entire period when compared with the other groups. The 1A and 2A groups had the minimum (p < 0.05) average daily feed intake (ADFI) compared with the other groups for the whole period. The RR had an improved (p < 0.05) FCR compared with the other groups during the whole period. The 1A and 2A groups were observed to have the lowest (p < 0.05) shank length compared with the other groups during the entire period.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제9권2호
• /
• pp.269-272
• /
• 2004

Different methods of cold storing of bivoltine eggs are in practice to postpone hatching. Bivoltine eggs undergo hibernation if they are not acid treated within 20 - 24 hrs of oviposition, which depends on race, ambient temperature and humidity. The schedules adopted for cold storing include hibernation schedule (Hib), ordinary chilling (OC), short term chilling (STC) and acid treated layings (AT). Peanut cocooning race ${NB_4}{D_2}$ has been subjected for the present assessment. Cocoons harvested from the crop pertaining to all the four methods of cold storing have been used for producing different combinations and acid treated followed by rearing. The performance in respect of chawki loss, maximum larval weight 4({5^th} age)$, yield/ 10,000 larvae (no), cocoon and shell weight showed maximum values for hibernation ${\times}$ hibernation combination followed hibernation with OC and hibernation with AT. Lowest performance was recorded when STC batch source females were used.

• Fisheries and Aquatic Sciences
• /
• 제26권7호
• /
• pp.447-454
• /
• 2023

Fast somatic growth is important considerations for successful and competitive aquaculture industry. In rainbow trout reared in South Korea, triploid induction was used to suppress negative influence of reproductive maturation to body growth. However, the effects of triploidy are visible in both mature fish and developing juvenile fish. Thus, it is also important to explicate the effect of triploid induction on growth during the early-life stages of rainbow trout-alevins and fry. Rainbow trout fertilized eggs were subjected to triploid induction and polyploidy was checked by flow cytometry. Diploid and triploid alevins and fry were reared separately in tanks with constant flow of freshwater through flow-through water system and growth measurements were done from zero days after hatching (DAH 0) until DAH 134. The egg-yolk morphometrics of alevins-yolk length, yolk height, yolk volume and yolk weight-were statistically similar (p > 0.05) in both genotypes from DAH 0 to DAH 22. The total length, body height, and body weight of alevins and fry were statistically better (p > 0.05) in both genotypes until DAH 92 but thereafter, triploid had a significantly better growth performance (p < 0.05) over diploid fish until the completion of study at DAH 134. With that, triploid induction did not influence alevin yolk regions and body growth and fry somatic growth until around 3 months after hatching, but considerable growth enhancement was subsequently apparent.