• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.16-16
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• 2002

The egg productivity of the chick is represented by the number of egg produced, egg weight, and sexual maturity, which are regulated by various endocrine factors. Although there were some reports that insulin-like growth factor-I (IGF-Ⅰ) affected egg production, studies on any correlation between IGFs and egg productivity were not reported in poultry. The objectives of the present study were to examine the IGFs profile and egg productivity in both KNOC and laying hen (Saver) and to investigate the relationship of IGFs with egg productivity. Whole blood was collected every 10 wk until 60 wks. (omitted)

• Korean Journal of Poultry Science
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• v.32 no.1
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• pp.67-72
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• 2005

Forty-wk-old 480 ISA Brown layers were used in a 10-wk feeding trial to investigate the effects of additional various levels of limestone to a low calcium diet without any calcium additives on the performance of laying hens. There were significant differences in average egg weight (P<0.05) without any specific trend among treatments and hen-day egg production was not influenced by the dietary treatments. Daily intake and conversion per kg egg of feed excluded the calcium supplement were significantly reduced (p<0.05) as the level of additional calcium supplement increased in both types of layer diet, while those of feed included the calcium source were significantly increased (P<0.05) as the level of additional calcium supplement increased. Egg specific gravity, eggshell breaking strength and thickness were increased as the level of additional calcium supplement increased, however the significant differences were found only in egg specific gravity It would be possible to reduce the daily feed intake and feed conversion and to improve the eggshell quality by feed the low calcium diet devoid of calcium supplement from the conventional laying hen diet and by supply the additional calcium source at 3 to 4 p.m. instead of the continuous feeding of conventional high calcium diet.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.8
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• pp.1043-1048
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• 2010

This study investigated the effects of Fe-soy proteinate (Fe-SP) and magnesium oxide (MgO) dietary supplements on eggshell quality in laying hens. A total of 800 26-wk-old Hy-Line Brown hens were assigned to four dietary treatments: control (C), Fe-SP 100 (100 ppm Fe-soy proteinate), MgO (3 g MgO/kg diet), and Fe-SP 100+MgO. Each treatment had five replicates of 40 hens. The FT-IR (Fourier transform infrared) and XRD (X-ray diffraction) spectra of Fe-soy proteinate were different from those of $FeSO_4$ and soy digest. There were no significant differences among treatments in hen-day egg production, hen-house egg production, broken and soft egg rate, feed intake, or feed conversion. The MgO and Fe-SP 100+MgO treatments showed significantly (p<0.05) higher egg weights than the control group. Eggshell strength and thickness were significantly (p<0.05) higher in the MgO supplemented groups. The lightness and yellowness of the eggshells decreased, and the redness increased significantly in the Fe-SP treated groups. There were no significant differences among treatments in leukocyte level, but hemoglobin (Hb) concentrations were higher with Fe-SP treatments. In conclusion, supplementation with Fe-SP significantly affects eggshell color and hemoglobin concentration, whereas MgO supplementation increases eggshell strength and thickness. Egg weight and egg shell quality can be improved by supplementation of 100 ppm Fe in the form of Fe-SP and 3 g MgO/kg diet.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.6
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• pp.702-707
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• 1998

An experiment was conducted to evaluate the effect of a microbial enzyme (Roxazyme-$G^{(R)}$), a multicarbohydrases preparation, supplementation to the wheat-based layer diets. Diets were formulated to include different levels of wheat replacing yellow corn on isocaloric and isonitrogenous basis. The energy value of wheat in the enzyme supplemented diets was adjusted (spec-modified) to have 5% more ME than the wheat in diets without enzyme. A total of 864 Hy-$Line^{(R)}$ brown layers were assigned to 4 dietary treatments: 10% wheat (T1), 25% wheat (T2), 25% wheat (spec-modified)+ 0.01 % Roxazyme-$G^{(R)}$ (T3), and all wheat (spec-modified)+0.01% Roxazyme-$G^{(R)}$ (T4). Hen-day egg productions of T1 and T4 were significantly (p < 0.05) greater than that of T2 but not different from T3. Hen-housed egg production of T4 was significantly (p < 0.01) greater than those of T1 and T3 but not different from T2. Egg weights of T1 and T2 were significantly (p < 0.0 1) greater than that of T4. Feed consumption of T2 was significantly (p < 0.01) lower than other treatments. Feed conversion ratio (feed/egg mass) was not significantly different among treatments. Eggshell thickness of T1 was significantly (p < 0.01) greater than other treatments but ratio of broken eggs was not significantly different among treatments. Haugh unit of T4 was significantly greater (p < 0.05) than that of T2. Egg yolk color was significantly (p < 0.01) influenced by treatments in which enzyme treatment potentiated the yolk pigmentation. It was concluded that a multi-carbohydrases supplementation enables complete replacement of yellow com with wheat without loss of productivity and major egg quality parameters.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.7
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• pp.930-938
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• 2019

Objective: Estimate genetic parameters, the rate of inbreeding, and the effect of inbreeding on growth and egg production traits of a Thai native chicken breed Lueng Hang Kao Kabinburi housed under intensive management under a tropical climate. Methods: Genetic parameters were estimated for weight measured at four weekly intervals from body weight at day 1 (BW1D) to body weight at 24 weeks (BW24) of age, as well as weight at first egg, age at first egg (AFE), egg weight at first egg, and total number of eggs (EN) produced during the first 17 weeks of lay using restricted maximum likelihood. Inbreeding depression was estimated using a linear regression of individual phenotype on inbreeding coefficient. Results: Direct additive genetic effect was significant for all traits. Maternal genetic effect and permanent environmental hen effects were significant for all early growth traits, expect for BW24. For BW24, maternal genetic effect was also significant. Permanent environmental hen effect was significant for AFE. Direct heritabilities ranged from 0.10 to 0.47 for growth traits and ranged from 0.15 to 0.16 for egg production traits. Early growth traits had high genetic correlations between them. The EN was lowly negatively correlated with other traits. The average rate of inbreeding for the population was 0.09% per year. Overall, the inbreeding had no effect on body weight traits, except for BW1D. An increase in inbreeding coefficient by 1% reduced BWID by 0.09 g (0.29% of the mean). Conclusion: Improvement in body weight gain can be achieved by selecting for early growth traits. Selection for higher body weight traits is expected to increase the weight of first egg. Due to low but unfavorable correlations with body weight traits, selection on EN needs to be combined with other traits via multi-trait index selection to improve body weight and EN simultaneously.

• Food Science of Animal Resources
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• v.43 no.2
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• pp.282-304
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• 2023

This study aimed to investigate the effectiveness of carotenoid supplementation on the performance, egg quality, and immunity of laying hens using a meta-analysis approach. The database was searched using Google Scholar and Scopus, from 2012 to 2022. The literature was published in English. 47 Articles were selected for meta-analysis. Analyses were performed using the Open Meta-analyst for Ecology and Evolution (OpenMEE) software. The heterogeneity and data validation against publication bias were analyzed using JASP 0.16.2 software. Overall, the results showed that carotenoid supplementation improved feed intake by 0.32 g/day/hen [95% confidence interval (CI)=0.02 to 0.61], final body weight by 0.33 g/hen (95% CI=0.05 to 0.60), egg production by 0.38% (95% CI=0.14 to 0.63), egg weight by 0.29 g (95% CI=0.09 to 0.5), yolk colour by 2.11 (95% CI=1.71 to 2.51), Haugh unit (HU) by 0.26 (95% CI=0.11 to 0.42), yolk carotenoids by 1.17 ㎍/kg (95% CI=0.59 to 1.75), immunoglobulin A (IgA) by 0.74 mg/L (95% CI=0.18 to 1.29), and lower yolk cholesterol by -0.38 mg/g (95% CI=-0.59 to -0.16). Feed conversion ratio (FCR), eggshell thickness, and white blood cells were unaffected by the application of carotenoids. The heterogeneity analysis showed variability in all studies (<0.05). In conclusion, carotenoid supplementation can elevate productivity, enhance egg quality, and improve immunity. However, based on Kendall's test, there was a publication bias in several parameters, namely FCR, egg weight, HU, yolk carotenoids, and IgA.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.10
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• pp.1495-1499
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• 2017

Objective: This study aimed to investigate the effects of enrichment resources (a perch, dustbath, and nest) layout in furnished laying-hen cages (FC) on exterior quality of eggs. Methods: One hundred and sixty-eight (168) Hy-Line Brown laying hens at 16 weeks of age were randomly distributed to four treatments: small furnished cages (SFC), medium furnished cages type I (MFC-I), medium furnished cages type II (MFC-II), and medium furnished cages type III (MFC-III). Each treatment had 4 replicates or cages with 6 hens for SFC (24 birds for each SFC) and 12 hen/cage for MFC-I, -II, and -III (48 birds for each MFC-I, -II and -III). Following a 2-week acclimation, data collection started at 18 weeks of age and continued till 52 weeks of age. Dirtiness of egg surface or cracked shell as indicators of the exterior egg quality were recorded each week. Results: The results showed that the proportion of cracked or dirty eggs was significantly affected by the FC type (p<0.01) in that the highest proportion of cracked or dirty eggs was found in MFC-I and the lowest proportion of dirty eggs in SFC. The results of this showed that furnished cage types affected both dirty eggs and cracked eggs (p<0.01). The results also indicated that not nest but dustbath lead to more dirty eggs. Only MFC-I had higher dirty eggs at nest than other FC (p<0.01). The results of dirty eggs in MFC-I and MFC-II compared with SFC and MFC-III seemed suggest that a low position of dustbath led to more dirty eggs. Conclusion: SFC design affected exterior egg quality and the low position of dustbath in FC resulted in higher proportion of dirty eggs.

• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.4
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• pp.391-395
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• 1985

The Retionl Equivalent value and the composition of carotenoids in hen, quail and duck eggs were investigated by thin-layer chromatography. Total carotenoid contents per gram yolk were great in order of hen＞duck＞quail and retinol contents, quail＞duck＞hen. In Retinol Equivalent value, quail showed the highest level and hen showed the lowest level. In hen and quail, the contents of lutein and zeaxanthin of egg yolk were about 75% of their total carotenoid contents and they were about 60% in duck. In all cases, the sum of the concentration of lutein and zeaxantin accounted for more than 60% of the total carotenoid.

• Korean Journal of Poultry Science
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• v.23 no.1
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• pp.27-37
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• 1996

This experiment was carried out to study the effects of feeding split diets for a.m. and p.m. on laying hen performance and feed cost with 480 ISA Brown layers for three periods during 32∼36, 52∼56 and 72∼76 wk of age, respectively. The control group(C) was fed a conventional single diet throughout the day and split diet groups (T$_1$, T$_2$, T$_3$, T$_4$ and T$\_$5/) were offered high energy-high protein-low Ca diets, and low energy-low protein-high Ca diets in a.m. and p.m., respectively. In split diet groups, feed intake, ME and CP consumption, and feed cost were significantly reduced(P<0.05) compared to the C, while the hen-day egg production was significantly improved. However, the average egg weight was not influenced by the feeding system. Due to the reduced daily feed, ME, and CP intakes, and the improved egg production, the conversions of feed, ME, CP, and feed cost required per kg egg mass were also significantly improved (P<0.05) in splits diet groups. Among split diet groups, the T$_2$ group fed the diet devoid of Ca supplement from the conventional laying hen diet in a.m., and the diet containing the Ca supplement 2 times the conventional diet in p.m., was superior in conversion of nutrients and feed cost per kg egg mass to the other split diet groups. It was concluded that daily feed and nutrients cousumption and daily feed cost could be reduced 5∼6％ while hen-day egg production could be improved about 4％, so that about 10％ of the feed and nutrients and feed cost per kg egg mass could be spared by introducing the split diet feeding for a.m. and p.m. based on T$_2$ treatment in laying hens.

• Korean Journal of Poultry Science
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• v.38 no.3
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• pp.165-171
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• 2011

This study was conducted to investigate the effects of dietary supplementation of copper-soy proteinate (Cu-SP) on the performance of laying hens. A total of 1,000 Hy-Line Brown laying hens of 32 wks old were assigned to one of the following 5 dietary treatments: Control, Cu-SP 50, 100, 150, 200 (50, 100, 150, 200 ppm Cu supplementation as Cu-soy proteinate). Each treatment was replicated 4 times with fifty birds per replication, housed in 2 birds cages. Fifty birds units were arranged according to randomized block design. Feeding trial lasted 5 wks under 16L : 8D lighting regimen. There were no significant differences among treatments in hen-day and hen-house egg production, egg weight, broken & soft egg production. Feed intake and feed conversion rate (FCR) were significantly (P<0.01) lower in Cu-SP treated groups than Control. Eggshell thickness was significantly (P<0.01) higher in Control than Cu-SP 100, 150 and 200. Egg yolk color index was significantly (P<0.01) higher in Cu-SP 200 than other treatments. Egg shell color index was significantly (P<0.05) higher in Cu-SP 150 and Cu-SP 200 than Cu-SP 100. Concentration of copper, iron and zinc of the egg yolk were not significantly influenced by treatment. There were no significant differences in the level of leukocytes and erythrocytes in the chicken blood. The result of this experiment showed that dietary supplementation of Cu-SP at the level of 50ppm of Cu can reduce feed intake and FCR.