• Korean Journal of Poultry Science
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• v.48 no.4
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• pp.161-168
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• 2021

The present study investigated production traits, including body weight, egg production, egg weight, and egg quality in Korean indigenous parent stocks. Parent stocks produced from a nine-combination association from five pure line strains (C, D, F, K, and Y) were used. The body weight analyses results showed that the CY combination had the highest body weight (1,604.9 g) and the DK combination had the lowest (1,424.4 g). The average age at first egg of the nine combinations was 118.6 days; however, that of the YD combination was 111.6 days, making it the fastest growing combination, whereas the DK combination was the slowest, at 126 days. Hen-day egg production was 74% or more for the CF, CK, and DK combinations. The DK combination hens showed excellent persistence in egg laying. Hen-housed egg production exhibited results similar to those of hen-day egg production. Egg weight was significantly higher in the DK combination than in the other combinations and was observed to increase from 20 (43.9 g) to 40 (58.1 g) weeks. The egg quality analyses results showed that the combinations based on the F and K strains had a bright eggshell color, with relatively high egg weights. Eggshell strength and thickness were the highest in the DK combination (3.8 kg/cm², 0.38 mm). In summary, the CF and DK combinations showed excellent egg production ability and egg quality, while the YC, YD, and YK combinations with the Y strain as the paternal strain exhibited poor performance.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.11
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• pp.1619-1637
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• 2000

A review was undertaken to obtain information on the range of beak-trimming methods available or under development. Beak-trimming of commercial layer replacement pullets is a common yet critical management tool that can affect the performance for the life of the flock. The most obvious advantage of beak-trimming is a reduction in cannibalism although the extent of the reduction in cannibalism depends on the strain, season, and type of housing, flock health and other factors. Beak-trimming also improves feed conversion by reducing food wastage. A further advantage of beak-trimming is a reduction in the chronic stress associated with dominance interactions in the flock. Beak-trimming of birds at 7-10 days is favoured by Industry but research over last 10 years has shown that beak-trimming at day-old causes the least stress on birds and efforts are needed to encourage Industry to adopt the practice of beak-trimming birds at day-old. Proper beak-trimming can result in greatly improved layer performance but improper beak-trimming can ruin an other wise good flock of hens. Re-trimming is practiced in most flocks, although there are some flocks that only need one trimming. Given the continuing welfare scrutiny of using a hot blade to cut the beak, attempts have been made to develop more welfare friendly methods of beak-trimming. Despite the developments in design of hot blade beak-trimmers the process has remained largely unchanged. That is, a red-hot blade cuts and cauterises the beak. The variables in the process are blade temperature, cauterisation time, operator ability, severity of trimming, age of trimming, strain of bird and beak length. This method of beak-trimming is still overwhelmingly favoured in Industry and there appears to be no other alternative procedures that are more effective. Sharp secateurs have been used trim the upper beak of both layers and turkeys. Bleeding from the upper mandible ceases shortly after the operation, and despite the regrowth of the beak a reduction of cannibalism has been reported. Very few differences have been noted between behaviour and production of the hot blade and cold blade cut chickens. This method has not been used on a large scale in Industry. There are anecdotal reports of cannibalism outbreaks in birds with regrown beaks. A robotic beak-trimming machine was developed in France, which permitted simultaneous, automated beak-trimming and vaccination of day-old chicks of up to 4,500 chickens per hour. Use of the machine was not successful because if the chicks were not loaded correctly they could drop off the line, receive excessive beak-trimming or very light trimming. Robotic beak-trimming was not effective if there was a variation in the weight or size of chickens. Capsaicin can cause degeneration of sensory nerves in mammals and decreases the rate of beak regrowth by its action on the sensory nerves. Capsaicin is a cheap, non-toxic substance that can be readily applied at the time of less severe beak-trimming. It suffers the disadvantage of causing an extreme burning sensation in operators who come in contact with the substance during its application to the bird. Methods of applying the substance to minimise the risk to operators of coming in contact with capsaicin need to be explored. A method was reported which cuts the beaks with a laser beam in day-old chickens. No details were provided on the type of laser used, or the severity of beak-trimming, but by 16 weeks the beaks of laser trimmed birds resembled the untrimmed beaks, but without the bill tip. Feather pecking and cannibalism during the laying period were highest among the laser trimmed hens. Currently laser machines are available that are transportable and research to investigate the effectiveness of beak-trimming using ablasive and coagulative lasers used in human medicine should be explored. Liquid nitrogen was used to declaw emu toes but was not effective. There was regrowth of the claws and the time and cost involved in the procedure limit the potential of using this process to beak-trim birds.

• Korean Journal of Poultry Science
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• v.21 no.1
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• pp.41-48
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• 1994

In order to get information for the improvement of feeding systems of egg-type layers, a dietary self-selection study was conducted. Corn diet, soybean meal diet, wheat bran diet, soybean meal+fish meal diet, and limestone diet were individually prepared for self-selection regime. Forty brown layers were offered either a control laying diet (C) or one of the 3 self-selection regime consisted of corn-soybean meal-limestone diet ($T_1$), corn-soybean meal-wheat bran-limestone diet ($T_2$) and corn-soybean meal+fish meal-wheat bran-limestone diet ($T_3$) for one wk each at 31 wk and 41 wk of age. In all dietary treatments, most of the eggs were laid from 0700 h 1300 h and hens consumed more feed, energy and protein on egg forming days than on non-forming days. On egg forming days, hens fed self-selection regime consumed less energy and protein than those fed control diet. On egg forming days, the consumption of feed, energy and protein increased continuously from 1000 h 2200 h in the control diet group but they decreased during the last 3 hours from 1900 h to 2200 h in self-selection regime groups. Up to 1600 h, calcium intake of the self-selection regime groups were much less than that of the control group but after that time, they increased markedly and were much more than that of the control group. The results of the study suggest that the practical self-selection regime for layers should be developed to meet the daily cyclic requirement for nutrients without consuming an excess energy and protein at certain times of the day.

• Korean Journal of Poultry Science
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• v.36 no.2
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• pp.103-110
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• 2009

This experiment was conducted using 350 Lohmann Brown layers (67 weeks of age) to evaluate the dietary effect of organic or inorganic Se and Cu on their contents in chicken eggs. The layers were divided into seven groups and fed a commercial diet or one of the six experimental diets containing different levels of Se and Cu (T1, 0.3ppm organic Se; T2, 1.0ppm organic Se; T3, 1.0ppm inorganic Se; T4, 125ppm organic Cu; T5, 250ppm organic Cu; and T6, 250ppm inorganic Cu) for 5 weeks. No significant differences were observed in egg production and its qualities among groups. The contents of blood cholesterol in the birds fed various levels of Se and Cu were not significantly different as compared to control. Se contents in eggs were linearly increased as dietary Se levels increased for both sources, but Se contents from the groups fed organic Se were slightly higher than those fed inorganic Se. Sensory characteristics of eggs were not influenced by dietary treatments. In conclusion, Se contents in eggs were linearly increased as dietary levels of organic or inorganic Se increased, but eggs in layers fed the diet containing organic Se did not show higher Se contents than those in birds fed dietary inorganic Se.