Eggshell Breaking Strength Research Articles

Fatty acid composition, physicochemical and sensory properties of eggs from laying hens fed diets containing blue lupine seeds

Summary This study was undertaken to determine the effect of partial replacement of soybean meal with 10% and 20% of blue lupine ( Lupinus angustifolius) seeds in layer diets on laying performance, the fatty acid profile, physicochemical and sensory properties of eggs. A 20-week study was performed on 150 Lohman Brown hens with 50 birds in each group. Diet supplementation with blue lupine seeds contributed to an increase in the content of neutral detergent fiber (NDF), acid detergent fiber (ADF) and raffinose family oligosaccharides (RFOs) without compromising laying performance. Feed intake was lower (P = 0.004) in groups fed blue lupine seeds. Eggshell weight as a percentage of total egg weight, and eggshell breaking strength were higher in groups fed lupine-supplemented diets (P = 0.002 and P = 0.036, respectively). Eggs from hens fed blue lupine seeds were characterized by lower albumen quality expressed as albumen height (P = 0.001) and Haugh units (P = 0.001). Diet supplementation with blue lupine seeds contributed to an increase in the concentrations of C18:2 n-6 (P = 0.001) and C18:3 n-3 (P = 0.001) fatty acids and total polyunsaturated fatty acids (PUFAs) (P = 0.001) in yolk lipids. Higher dietary inclusion levels of blue lupine increased the levels of C22:6 n-3 fatty acid (P = 0.004) in the egg yolk, thus significantly (P = 0.035) improving the n-6/n-3 PUFA ratio. Dietary treatments had no influence on the sensory properties of eggs, except for yolk color which was most intense (P ≤ 0.05) in eggs from hens fed 20% blue lupine seeds. Our results indicate that blue lupine seeds can be added to layer diets at 20% without compromising laying performance. Blue lupine seeds improved yolk color and the fatty acid profile of yolk lipids.

Effects of inorganic and organic manganese supplementation on gonadotropin-releasing hormone-I and follicle-stimulating hormone expression and reproductive performance of broiler breeder hens

Manganese is an essential microelement. Manganese deficiency affects reproduction performance and reproductive hormones in layers. However, little is known about its effects and the possible mechanism in regulating reproduction in broiler breeder hens. In the current study, broiler breeder hens at peak production were fed with diets supplemented with 0, 120, or 240 mg of Mn/kg as MnSO4 or Mn proteinate for 13 wk. Manganese supplementation did not alter egg laying rate, egg weight, fertility, hatchability, or hatchling weight over a 13-wk trial period. However, 240 mg of Mn/kg supplementation significantly increased serum Mn (P < 0.05). Manganese supplements increased the eggshell breaking strength (P < 0.05) without affecting the eggshell thickness. There was no difference in serum cholesterol and estradiol. Expression of follicle-stimulating hormone) and gonadotropin-releasing hormone-I (GnRH-I) genes was significantly elevated by 240 mg of Mn/kg (P < 0.05). Furthermore, inorganic Mn supplementation doubled GnRH-I expression compared with supplementation with the organic form (P < 0.05), although serum Mn was comparable between these 2 supplements. No obvious difference was shown in gene expression of luteinizing hormone, prolactin, GnRH-I receptor, inducible NO synthase, and dopamine receptor D1 in the pituitary as well as tyrosine hydroxylase and inducible NO synthase in the hypothalamus. This suggests that dietary Mn supplementation could improve eggshell quality in the long term. The central mechanism of nontoxic high doses of Mn suggested the transcriptional activation of GnRH-I and follicle-stimulating hormone genes. The central effect of inorganic Mn activating GnRH-I genes compared with the reduced effect by organic Mn could possibly be due to a decreased capacity of the latter passing through the blood-brain barrier.

Feed type for induced molting of commercial layer hens

An experiment employing three hundred and twenty 81-week-old Lohmann LSL commercial-breed hens was conducted to compare alternative induced-molting methods with the conventional method (fasting). Induced molting lasted 28 days at most, production and quality being monitored for four periods of 28 days thereafter. A completely randomized experimental design with five treatments, eight replicates of eight birds each per plot was adopted. The following experimental treatments were applied until a loss of 26% of body weight was reached: T1 - fasting, T2 - wheat bran ad libitum, T3 - rice bran ad libitum, T4 - cracked rice ad libitum, T5 - ground alfalfa ad libitum. Birds were then fed production diet ad libitum, except for those on treatment T1 (fasting) which received 30, 60 and 100 g/bird/day and then feed ad libitum. During induced molting the birds were exposed to a natural photoperiod and at day 28 that period was increased by 30 minutes/week until reaching 16 hours of light/day. The characteristics evaluated during induced molting were: feed intake, body weight changes and laying percentage. In the post-molt period, performance (feed intake, laying percentage, egg weight, egg mass, feed conversion ratio per dozen and per egg mass and percentage of broken eggs) and egg quality (specific gravity, eggshell breaking strength, percentages of eggshell, yolk, and albumen, eggshell thickness, yolk color and Haugh unit) were evaluated. Every 28 days one egg was collected from each repetition for three consecutive days for quality assessment. The use of rice bran and wheat bran is viable as molting inducers since the birds given those treatments display performance and egg quality similar to those fasted during the induced molting and also because these ingredients promote easier handling, eliminates the need for grinding and feed-mixing equipment and, being less aggressive, provide greater bird welfare.

Effects of dietary supplementation of palm fatty acid powders on performance, internal egg quality and yolk oxidation stability in laying hens during early egg production

The present study was conducted with Hy-Line W-36 Leghorn hens to investigate the effects of dietary substitution of soybean oil (SO) with 2 commercial palm fatty acid powders (PFAP) on performance, egg quality measurements and oxidative stability of yolk lipids. Laying hens (225) were fed with a basal diet containing 3.5% soybean oil in which SO was replaced with PFAP (either energizer A or B) by 25, 50, 75 or 100%. Dietary treatments had no significant effect on egg production during 27 to 32 wk of age, but incremental levels of both PFAP sources reduced hen-day egg production during 32 to 37 wk of age. Energizer B was associated with more egg production and egg mass compared with energizer A. Dietary supplementation with PFAP increased feed intake compared with control group during 32 to 37 wk of age. Although feed conversion ratio (FCR) was not affected by experimental diets from 27 to 32 wk of age, the best FCR values assigned to the birds on control diet in the second 35 d, and birds on energizer B improved FCR compared with those on energizer A-diets. PFAP improved Haugh unit during both recording periods. All dietary replacement levels of PFAP were associated with higher standing-up quality of egg yolks. Diets supplemented with energizer B improved shell thickness and subsequently eggshell breaking strength compared with energizer A or control diets. Yolk cholesterol content was higher in eggs laid by hens fed on A- and B-containing diets compared with control birds. Dietary inclusion of PFAP partially or completely in place of SO reduced egg yolk malondialdehyde. The present findings suggested that one can replace 75% of SO with PFAP without any detrimental effect on performance and egg quality. In addition, yolk oxidative stability could be improved with PFAP.

Manganese supplementation enhances the synthesis of glycosaminoglycan in eggshell membrane: A strategy to improve eggshell quality in laying hens

This study investigated the effect of dietary Mn supplementation on eggshell quality, ultrastructure, glycosaminoglycan (GAG), and uronic acid content, and mRNA and protein expression of Galβ1,3-glucuronosyltransferase (GlcAT-I). A total of 216 layers (Hy-Line Grey) at age of 50 wk were divided into 3 groups. In the first 8 wk of the 12-wk feeding trial, all groups were fed a basal diet that met all layer nutrient requirements except for Mn. In the last 4 wk, each group was fed 1 of 3 diets supplemented with Mn levels at 0, 25, or 100 mg Mn/kg. Dietary Mn deficiency did not affect the egg performance of layers. Dietary Mn supplementation significantly improved the breaking strength, thickness, and fracture toughness of eggshells (P < 0.05). In photographs of eggshell ultrastructure, the size of mammillary cones and cracks in the outer surface were decreased by dietary Mn supplementation. The contents of GAG and uronic acids in eggshell membrane were significantly increased by dietary Mn addition (P < 0.05). This result was further confirmed by increased mRNA expression and protein expression of GlcAT-I when Mn was added to the diet. This study suggests that dietary Mn supplementation can improve eggshell quality by enhancing the GAG and uronic acid synthesis in the eggshell glands, which can affect the ultrastructure of eggshells.

Eggshell Quality, Eggshell Structure and Small Intestinal Histology in Laying Hens Fed Dietary Pantoea-6® and Plant Extracts

The present study aims to investigate the effects of dietary Pantoea-6® (extract of fermented wheat flour with Pantoea agglomerans) and plant extracts (red clover and garlic) on eggshell quality and structure and intestinal histology. Sixty-six Boris Brown laying hens (30 weeks old) were allotted to 3 groups, each with eleven replicates of two chickens. The control group was fed a basal diet (18% crude protein, 2850 kcal/kg ME) and the other groups were fed the basal diet supplemented with 0.1% Pantoea-6® (including 0.06 g/kg lipopolysaccharide) and 0.1% plant extracts, respectively. There were no significant differences in laying performance and egg quality. However, these adverse effects occurred in the egg and albumen weight and eggshell breaking strength of the Pantoea-6® and plant extracts groups (P<0.05). Shell weight of the Pantoea-6® group was significantly higher than the other groups (P<0.05). Compared with the control, eggshell structure tended to have greater thickness in both dietary Pantoea-6® and plant extracts groups. The duodenum and jejunum of both Pantoea-6® and plant extracts groups showed higher values for cell area than those of the control (P<0.05). Moreover, cells on the villus tip surface were protuberated in both dietary Pantoea-6® and plant extracts groups, resulting in a rough surface. This study shows that Pantoea-6® and plant extracts at a 0.1% level might have a beneficial effect on egg and albumen weight, eggshell quality and structure parameters, as well as on small intestine histological parameters.

Effects of dietary olive oil on egg quality, serum cholesterol characteristics, and yolk fatty acid concentrations in laying hens

A total of 252 Hy-Line laying hens were used to evaluate the effects of dietary olive oil on egg production, egg quality, serum cholesterol characteristics, and yolk fatty acid (FA) concentrations. Layers were randomly allocated into three treatments with seven replications for 4 weeks. Dietary treatments were: CON (control diet, 5% tallow), OLO2 (3% tallow + 2% olive oil), and OLO5 (5% olive oil). Throughout the experimental period, yolk color was greater in OLO5 group than CON group (P < 0.05). The OLO2 and OLO5 groups showed greater egg shell breaking strength than CON group (P < 0.05). Egg shell thickness was increased in OLO2 and OLO5 groups compared with CON group (P < 0.05). The total serum cholesterol concentrations in OLO2 and OLO5 groups were lower than CON group (P < 0.05). Serum high-density lipoprotein cholesterol was elevated in OLO2 and OLO5 treatments compared with CON group (P < 0.05). Layers fed OLO2 diet had greater serum low-density lipoprotein cholesterol concentration than those fed CON and OLO5 diets (P < 0.05). Total yolk unsaturated fatty acids (UFA) were greater in OLO2 treatment compared with CON group (P < 0.05). In conclusion, 2% or 5% olive oil could improve yolk color, increase total yolk UFA, and decrease serum cholesterol concentration in laying hens.

Effect of extruded amaranth grains on performance, egg traits, fatty acids composition, and selected blood characteristics of laying hens

The aim of the study was to evaluate the effect of extruded amaranth grains (AMG) in laying hen diets on performance, egg traits, egg yolk fatty acids composition, as well as selected blood characteristics. A total of 60 Lohmann Brown laying hens, 24wk of age, were randomly distributed into 3 dietary treatments and fed for 10wk. The AMG was used at the levels of 0%, 5%, and 10% in the diets of the control and 2 treatment groups, respectively. Each dietary treatment was divided into 4 replicates, comprising of 5 hens each. Hens were housed in a 3-tier battery system. Feed and water were provided ad libitum. Blood samples and eggs were collected after 5wk and at the end of the experiment. Amaranth grain supplementation increased body weight (1.64, 1.66, and 1.72kg for diets containing 0%, 5%, and 10% AMG, respectively; linear, P<0.01). Although hens responded to AMG supplementation linear and quadratically (P<0.01), the greatest egg production and the lowest feed conversion ratio were observed with 5% AMG. No differences in the mean egg weight, eggshell weight, yolk and albumen weight, thick albumen height, Haugh units and breaking strength of eggshells were observed in hens fed AMG-supplemented diets. Also, sensory analysis of eggs did not reveal any differences among hens fed different diets. Fatty acids content of egg yolk was similar in all treatments, although in hens fed 5% AMG, the polyunsaturated fatty acid (n-6), especially linoleic acid, level was slightly greater and the n-6/n-3 acid ratio was decreased. The concentrations of alanine aminotransferase, aspartate aminotransferase, and glucose level were reduced linearly after 5wk (P=0.01–0.03) by increasing AMG supplementation. The quadratic effect on alanine aminotransferase at wk 5 (P=0.02) and 10 (P<0.01) was also observed. The results showed that dietary inclusion of AMG at the level of 5% increased hen performance and did not negatively influence the hens' health conditions and also quality and sensory traits of eggs.

Effects of dietary rosemary and oregano volatile oil mixture on quail performance, egg traits and egg oxidative stability

1. This study was conducted to determine the effects of volatile oil mixture on quail laying performance, egg traits and egg malondialdehyde (MDA) concentration.2. A total of 260 Pharaoh quails (Coturnix coturnix Pharaoh) aged 6 weeks were equally divided into 5 groups of 65 (4 replicates of 13 quails each). The mixture of diets was as follows: a control treatment with 0 mg volatile oil/kg of diet; (1) 200 mg/kg rosemary volatile oil; (2) 200 mg/kg oregano volatile oil; (3) 40 mg/kg rosemary volatile oil plus 160 mg/kg oregano volatile oil (ratio 20:80) and (4) 160 mg/kg rosemary volatile oil plus 40 mg/kg oregano volatile oil (ratio 80:20). The diets were prepared fresh for each treatment. The experimental period lasted 10 weeks.3. At the end of the experiment, there were no significant differences amongst the groups in body weight, egg weight, egg mass, egg shape index, Haugh unit, egg shell thickness or egg shell–breaking strength.4. Diets containing rosemary volatile oil increased the egg production significantly. Feed intake significantly increased in the groups containing volatile oil mixture (groups 4 and 5). The inclusion of rosemary volatile oil at 200 mg/kg improved feed efficiency.5. Egg albumen and egg yolk index values showed significant increases in the group given diets containing rosemary volatile oil. Egg yolk colour became darker with the addition of rosemary and oregano volatile oil. The treatment group had lower egg yolk MDA concentration than the control group.6. It is concluded that, alone or in combination, rosemary and oregano volatile oil can be used in quail diets without adverse effects on the measured parameters. Inclusion of rosemary and oregano volatile oil in quail diets enhanced the antioxidant status of eggs.

안토시아닌의 함량을 달리한 보리의 급여가 산란계의 생산성과 계란품질에 미치는 영향

산란계 사료 내 유색보리 혹은 청보리의 10 또는 20% 첨가가 산란계의 생산성과 계란 품질에 미치는 영향을 조사하기 위하여 총 200 마리의 Brown nick을 5처리구에 5반복으로 배치하며 8주간 사양하였다. 시험군의 사료섭취량, 산란율, 난중과 일산란량은 대조구와 유의성 있게 달랐으며 특히 사료섭취량, 산란량과 일산란량은 보리의 함량이 증가할수록 유의적으로 감소하였다. 계란의 품질 중 난황색, 난각강도 또는 난각색은 사양 6주차까지의 보리 시험군에서 유의하였으나 보리를 8주차까지 급이한다면 난백고와 더불어 호우유닛에 긍정적인 영향을 나타내었다. 사양 6주까지에 대한 보리의 급이는 난각색과 난황색의 수치를 첨가량에 따라 유의적으로 높인 반면 난각강도에 대한 유의성은 없었다. 산란계 사료 내 보리의 함량을 20%로 증가시켜 급이한다면 난백고와 호우유닛은 유의적으로 증가하였으며 특히, 유색보리보다는 청보리의 첨가군에서 수치적으로 높은 9.10과 94.53의 난백고와 호우유닛을 나타내었다. 따라서 본 연구에서는 산란계의 생산성과 계란의 품질을 고려한 보리 첨가 산란계 사료를 생산하고자 한다면 생산성에서는 대조구와 유사하면서도 계란의 품질을 향상시킨 청보리 혹은 유색보리를 최대 10%까지 첨가한 산란계 사료의 생산을 고려해 볼 수 있을 것으로 판단된다. To evaluate the effects of anthocyanin-fortified barley (AFB) and whole crop barley (WCB) addition to diets, 200 Brown Nick hens were assigned to 5 treatments with 5 replicates for 8 weeks. All the treated groups differed in feed intake, egg production, egg weight, and egg mass compared to those of a control group. As the intake of barley was increased, feed intake, egg production, and egg mass decreased. In terms of egg quality, the yolk color (YC), the egg shell breaking strength (SBS), and the egg shell color (SC) differed up to 6 weeks of growth. Feeding the WCB and AFB to laying hens up to 8 weeks had a positive influence on albumin height (AH) and the haugh unit (HU). Up to 6 weeks of growth, increasing the amount of barley in the diets of the laying hens had a positive effect on the SC and the YC but had no effect on the SBS. Diets including 20% AFB and WCB increased the AH and HU to 9.10 and 94.53, respectively. The results suggest that the addition of AFB and WCB up to 10% to the diets of laying hens could improve the laying performance and the egg quality.

Effect of Different Housing System on the Performance, Bone Mineral Density and Yolk Fatty Acid Composition in Laying Hen

Different housing systems have considerable influence on performance in poultry production. Therefore, the present study was undertaken to investigate the impact of different housing systems on the performance, bone mineral density and egg yolk fatty acid composition in laying hen. Hy-line brown pullets (n=450) of 12 weeks age were randomly divided into 3 housing systems with 6 replicates of 25 birds in each room. A diet with 2,750 kcal/kg ME and 16.5% CP was assigned to all birds. The pullets provided free access to feed and water. Significantly (P<0.05) higher values for egg production, egg mass and feed conversion efficiency were found in battery cages, however egg weight, egg shell color and breaking strength was remarkably (P<0.05) higher in floor system. The albumin height and Haugh unit were significantly higher (P<0.05) in battery cages which was statistically similar to aviary housing system. The egg yolk fatty acids concentration of linoleic acid and linolenic acids were significantly higher in aviary and in floor system, respectively, however both values were lower in battery cages. Saturated and unsaturated fatty acid content (%) in egg yolk did not influence by any housing systems. Bone mineral density was significantly higher (P<0.05) in floor and aviary housing system than that of battery cage system. It was concluded that in battery cages the egg production and composition maximized, however higher bone mineral density and yolk fatty acids content can be improved in the laying hen reared on floor and aviary housing systems.

산란계 사료에 뽕잎 분말 첨가 급여가 산란율, 계란 품질 및 혈액 성상에 미치는 영향

본 시험은 산란계에 뽕잎 분말의 급여량(0, 1, 2 및 5%)과 급여 기간에 따라 사육한 산란계의 계란 품질, 혈액 생화화적 분석 및 혈액학적 지표 분석를 조사하였다. 실험구는 뽕잎 분말을 첨가 급여하지 않은 처리구를 대조구, 뽕잎 분말 1% 급여구는 T1, 뽕잎 분말 2% 급여구는 T2 그리고 뽕잎 분말 5% 급여구를 T3 등 4개 처리구로 나누어 실시하였다. 산란계의 산란율과 계란의 난황, 난각 무게는 뽕잎 분말의 급여량과 급여 기간에 의한 유의적인 변화는 없었다. 그러나 난백 무게는 뽕잎 분말의 급여량과 급여 기간이 지남에 따라 감소하였다(P<0.05). 그리고 난백 높이, 난황 색, 난각 두께 및 난각 강도는 뽕잎 분말의 급여에 의한 차이는 없었다. 산란계의 혈액 콜레스테롤 성상 중 HDL-cholesterol은 뽕잎 급여량이 많고 급여기간이 길어질수록 증가하였고, 총콜레스테롤과 triglyceride는 낮아지는 결과였으며(P<0.05), 뽕잎분말을 5% 급여할 경우 유의한 변화를 보였다. 또한, 혈액 내 WBC 함량이 뽕잎 분말 급여구에서 높아지는 결과이었다. 결론적으로 뽕잎 분말 5%를 급여하면 총콜레스테롤과 triglyceride는 감소하고, HDL-cholesterol, glucose 및 WBC 함량이 증가되어 혈액 성상을 개선할 가능성이 있는 것으로 판단된다. This study was conducted to investigate the effects of supplementation diets of powdered mulberry leaves on egg production, egg quality and blood characteristics in laying hens. Laying hens were fed diets for 30 days containing 0% powdered mulberry leaves (Control), 1% powdered mulberry leaves (T1), 2% powdered mulberry leaves (T2), and 5% powdered mulberry leaves (T3). The egg production, yolk weight and albumen weight were no significant difference among treatment groups. The albumen weight was significantly decreased by the supplementation of powdered mulberry leaves in all treatment groups (P<0.05). The albumen high, yolk color score, egg sell thickness and egg shell breaking strength were no significant difference. The total cholesterol and triglyceride concentration of control was higher than T3, and the high density lipoprotein (HDL)-cholesterol concentration and glucose of control were lower than treatment groups (P<0.05). The white blood cell (WBC) was significantly increased by the supplementation of powdered mulberry leaves compared to the control (P<0.05). In conclusion, these data indicate that 5% powdered mulberry leaves supplementation was most effective in decreasing total cholesterol and triglyceride and increasing HDL-cholesterol, glucose and WBC.

Performance, egg quality, and immune response of laying hens fed diets supplemented with mannan-oligosaccharide or an essential oil mixture under moderate and hot environmental conditions

In total, 432 thirty-six-week-old laying hens were fed a basal diet supplemented with mannan-oligosaccharide (MOS) or an essential oil mixture (EOM) from 36 to 51 wk of age. Hens were divided into 3 equal groups replicated 6 times with 24 hens per replicate. No significant difference was observed among the dietary treatments in terms of performance indices. Different from the dietary manipulation, high environmental temperatures negatively influenced all of the laying performance traits except the feed conversion ratio in association with the diminished feed consumption. The MOS, and particularly the EOM, tended to alleviate the deleterious effect of heat stress on BW gain. Mortality was higher in MOS-fed hens than with other treatments. A supplementation diet with MOS or EOM provided increments in eggshell weight (P < 0.01). Relative albumen weight was significantly decreased (P < 0.05) in response to EOM or MOS supplementation; however, this was not the case in the yolk weight rate. The MOS decreased albumen height and Haugh unit (P < 0.05). High environmental temperatures hampered entire egg quality characteristics except for the eggshell breaking strength and egg yolk weight. These results indicated that heat stress adversely affected both productive performance and egg quality. As for the results of this study, neither MOS nor EOM was efficacious in improving efficiency of egg production and stimulating humoral immune response in laying hens reared under moderate and hot climatic conditions. However, the ameliorative effect exerted by MOS and EOM on eggshell characteristics is conclusive.

English

&nbsp; Inulin is reported to improve the egg quality and production of laying hens. In the present study, we investigated the dietary effects of microcapsulated inulin oligosaccharide (INO) which is manufactured from Jerusalem artichoke&nbsp;(Helianthus tuberosus&nbsp;L.) on the cecum bacteria, egg quality and production of laying hens. 400 laying hens were randomly allocated to one of the following four treatment groups for 10 weeks: T1 (control without INO or inulin), T2 (200 mg INO/kg diet), T3 (250 mg INO/kg diet) and T4 (300 mg INO/kg diet). Egg production, Haugh unit, egg shell thickness and breaking strength were significantly higher in the T3 and T4 groups than in the T1 and T2 groups (P&lt;0.05). The level of egg cholesterol was highest in the T1 group and decreased in the INO addition groups from 5.68 to 8.46% (P&lt;0.05). When compared with the T1, triglycerides in the blood and total cholesterol decreased significantly in the T2, T3 and T4 groups by 11.75 to 13.45% and 9.41 to 9.85%, respectively (P&lt;0.05). The growth of cecum&nbsp;Bifidobacterium&nbsp;and&nbsp;Lactobacillus&nbsp;was stimulated in the T2, T3 and T4 when groups compared with the T1 group, while the growth of&nbsp;Escheria coli&nbsp;and&nbsp;Salmonella&nbsp;was clearly inhibited (P&lt;0.05). The results of this study demonstrate that the addition of microcapsulated inulin oligosaccharide (250 mg/kg) into a laying hen&rsquo;s diet can promote the multiplication of beneficial cecum bacteria and simultaneously improve egg production and quality. &nbsp; Key words: Jerusalem artichoke, inulin oligosaccharides, egg quality, cecum bacteria.

맥섬석과 한방제재 첨가급여가 재래닭 교잡종의 계란생산 및 품질에 미치는 영향

본 시험은 산란계에 대한 맥섬석과 한방제재의 첨가급여가 계란의 생산성과 품질에 미치는 영향을 알아보기 위하여 산란초기에 있는 재래닭교잡종(재래닭<TEX>${\times}$</TEX>레드브로교잡종) 360수를 공시하여 4처리로 임의 배치하였다(각 처리구당 30수<TEX>${\times}$</TEX>3반복), 대조구(무첨가), 시험 1구(맥섬석 0.3% 첨가), 시험 2구(한방제재 0.3% 첨가), 시험 3구(맥섬석 0.3%+한방제재 0.3%)로 나누어 8주간 시험한 결과는 다음과 같다. 사료섭취량과 난중 및 평균 산란율은 처리구간에는 차이가 없었으나(P>0.05), 그러나 파란율은 대조구(3.41%)가 시험구보다 크게 높았으며, 그 중에서도 시험 3구가 가장 낮은 파란율을 나타내었다(P<0.05). 전란 중에서 조지방의 경우는 대조구(11.20%)가 시험구(9.67 - 10.01%) 보다 크게 높게 나타났다(P<0.05). 계란품질에서 호우유니트 계수, 난황색, 난각 두께 및 난각 강도는 시험구가 더 높은 경향을 보였으나 통계적인 유의차는 나타나지 않았다(P>0.05). 그러나 난각 강도는 시험구(36.98 - 37.52)가 대조구(35.56) 보다 유의적으로 높았고(p<0.05), 난황 중의 콜레스테롤 함량은 시험 3구(14.91 mg/g)가 다른 처리구보다 크게 낮았다(P<0.05). 지방산 조성에서 포화지방산 함량은 대조구가 시험구보다 더 높았으나, 불포화 지방산은 시험구(66.82 - 67.00%)가 대조구(64.58%) 보다 더 높게 나타났다(P<0.05). 결론적으로, 맥섬석과 한방제재 혼합첨가제는 난황중의 콜레스테롤 함량을 낮추고, 계란의 품질을 개선시킬 수 있을 것으로 사료된다. The study was conducted to investigate the effects of dietary supplementation of Macsumsuk and herb resources on the egg performance and quality in Korean native crossbred chickens. A total of three hundred sixty improved Korean native crossbred chickens in primary laying period were randomly allocated to four treatments (30 birds/treatment <TEX>${\times}$</TEX> 3 replications) for eight weeks. Dietary treatments included CON (basal diets), T1 (basal diets + 0.3% Macsumsuk), T2 (basal diets + 0.3% herb resources) and T3 (basal diets + 0.3% Macsumsuk + 0.3% herb resources). No significant differences were found for feed intake, egg weight and average egg production (P>0.05), however, cracked egg rate was higher in CON than in T1-T3, especially T3 was the lowest (P<0.05). The crude fat content of whole eggs, CON (11.20%) was higher (P<0.05) than the experimental treatments (9.67%-10.01%). Haugh unit, yolk color, eggshell thickness, and eggshell breaking strength tended to be higher in T1 and T2, but there were no significant differences (P>0.05). However, the experimental treatments were significantly higher than CON (P<0.05) for eggshell breaking strength, and T3 (14.91 mg/g) contained lower (P<0.05) cholesterol in egg yolk than other treatments. For fatty acid composition in egg yolk, CON group showed higher saturated fatty acid contents than the experimental treatments, but T1 (67.00%), T2 (66.78%) and T3 (66.82%) were higher than CON for unsaturated fatty acids (P<0.05). In conclusion, supplementating Macsumsuk and herb resources together in diets of Korean native crossbred chickens could decrease egg yolk cholesterol and improve egg quality.

Performance and egg quality of aged laying hens fed diets supplemented with meat and bone meal or oyster shell meal

Meat and bone meal (MBM) and oyster shell meal (OSM) were supplemented to a basal diet (LMS), either alone or in combination, in order to assess the dietary influences of those complementary Ca sources on performance and egg quality of laying hens. Four hundred and thirty-two Brown-Nick hens, at the beginning of their second production period, were divided into four treatment groups with six replicates each. The final body weight of OSM-fed hens was highest, whereas others did not differ significantly. Hens receiving OSM produced more eggs and egg mass along with considerably greater feed intake than those on all the other treatments. Egg weight was not affected by the treatments except for the lower egg weight of the MBM+OSM treatment. Hens fed a diet supplemented with MBM laid at a rate of 1.14%, 3.66% points lower than those on the control and OSM treatments, respectively. Feed efficiency was not influenced by origin of calcium source. Egg shape index and eggshell weight did not differ among treatments. Eggshell thickness and eggshell breaking strength were higher in hens fed with MBM as compared to control and OSM fed birds. Similar to the tendency in shell quality, MBM inclusion in the diet tended to enhance albumen height and Haugh unit. Dietary treatment with OSM resulted in the highest serum Ca and P concentrations. These results indicate that partially replacing limestone with OSM in the laying hen diet provided significant improvements in egg production performance, whereas most of the egg quality traits were enhanced by dietary supplementation with MBM at 4%.

The effect of dietary calcium concentration and particle size on performance, eggshell quality, bone mechanical properties and tibia mineral contents in moulted laying hens

1. A total of 72 H&N Brown Nick laying hens, 76 weeks of age (moulted at 60 weeks of age), were randomly assigned into a 3 × 3 factorial arrangement with three limestone particle sizes and three dietary Ca concentrations (30, 36 and 42 g/kg Ca); with 8 replicates per treatments, and one hen (individual) per experimental unit. 2. Particle sizes of the limestone were: distributions smaller than 2 mm (Fine), between 2 to 5 mm (Medium), and larger than 5 mm (Large). The fine, medium and large limestone particles were all obtained from the same source, and sieve sizes used had screen sizes 2 mm and 5 mm. 3. The different concentrations of dietary Ca, particle size or interactions had no significant effect on egg production, egg weight, egg mass, feed intake or feed conversion ratio. 4. The concentrations of dietary Ca and particle sizes had no significant effect on egg breaking strength, eggshell as % by weight of whole egg or eggshell thickness. The interactions between Ca concentrations and particle sizes had a significant effect on eggshell breaking strength, but not on other parameters. 5. Different dietary particle sizes had no significant effect on the Ca, P and Mg mineral contents of eggshell. While the different concentrations of Ca in diets had a significant effect on the P content of eggshell, they had no significant effect on Ca and Mg contents. 6. Different dietary concentrations of Ca had a significant effect on shear stress, and Ca and Mg contents of tibiae, but not other parameters. Also, dietary particle sizes had a significant effect on shear stress and Ca contents of tibiae. The interaction between Ca concentrations and particle sizes had a significant effect on tibia shear force and Ca content. 7. According to the results of this study, moulted brown laying hens should be fed 36 g/kg Ca and a medium limestone particle size (2–5 mm) in the diet to maintain performance, eggshell and bone quality.

밀기울 위주의 환우용 사료가 산란계의 환우 후 생산성에 미치는 영향

Milltech, Co., Ltd. Seongnam 463-010, KoreaABSTRACT This work was carried out to investigate the effect of the induced molting diet based on wheat bran on the postmolt performance of layers. Two hundred White Leghorn layers (65-old-wk) with over 80% egg production were used for 8 weeks in this work. Treatments were non-molt control (CO), fasting treatment for 10 days (FW), molt treatment with used molting diet for 4 wk (UM), molt treatment with molting diet based on corn-wheat bran for 4 wk (CW), and molt treatment with molting diet based on wheat bran for 4 wk (WM) as 5 treatments (4 replications/treatment and 10 birds/replication). Feed intake decreased at molting treatments at first weeks and increased after the 3rd week compared to control (P<0.05). Body weight (BW) loss were 18.6% of initial BW at first week in FW treatment, and were 11.4, 14.2 and 17.4% in UM, CW and WM treatments at 4th weeks (P<0.05). Egg production decreased at 1 week in molt treatment and stopped at 2 week in FW, whereas, other molting treatments didn't stop laying eggs. The birds started to lay egg at 4 week in FW and recovered at 5 week in other molting treatments. Egg quality (eggshell thickness, eggshell breaking strength, haugh unit) was high in molting treatments compared with control at 8th weeks (P<0.05). Finally, molting diet based on wheat bran affected BW loss and egg quality such as eggshell thickness, eggshell breaking strength and haugh unit.(Key words : induced molt, wheat bran, feed intake, body weight, egg production, egg quality)

Effects of phytase B on laying performance, eggshell quality and on phosphorus and calcium balance in laying hens fed phosphorus-deficient maize-soybean meal diets

A study was conducted to evaluate the effects of dietary supplementation of phytase B (product of the Aspergillus niger phyB gene expressed in Trichoderma reesei) on feed intake, laying performance, eggshell quality, and on phosphorus and calcium balance in laying hens. Seventy-two, 40 weeks old Hy Line Brown hens were fed for 14 weeks the following four phosphorus-deficient (0.12% nonphytate phosphorus, NPP), maize-soybean meal-based diets: (1) calcium-deficient (2.8% Ca) control diet; (2) diet 1 + phytase B at the activity of 2.5&amp;nbsp;acid phosphatase units (AcPU/kg); (3) control diet (3.8% Ca); (4) diet 3 + phytase B at the activity of 2.5 AcPU/ kg. Each dietary treatment was fed to 18 cages of hens, 1 hen/cage kept in individual cages. Hens fed the NPP- and Ca-deficient diets consumed more feed (P &amp;lt; 0.01) and excreted less calcium (P &amp;lt; 0.01) than those receiving P-deficient diets with the standard calcium level. There were no effects of calcium level on feed utilization, egg mass, egg weight, and eggshell breaking strength. Egg production, although numerically higher in hens fed low Ca diets with no enzyme added, failed to be significantly different due to the low number of hens investigated and therefore the measurement should be considered as preliminary and supplementary. Phytase B increased mean egg weight by about 7% in layers fed the NPP- and Ca-deficient diet (Ca &amp;times; phytase B interaction, P &amp;lt; 0.05), increased shell breaking strength, particularly at the standard calcium level, significantly enhanced amounts of calcium retained by layers and amounts of&amp;nbsp; phosphorus retained by hens fed the Ca-deficient diets. Additionally, phytase B improved Ca retention at both dietary Ca levels and phosphorus retention in hens fed the Ca-deficient diets. Results of the study indicate that the efficacy of phytase B in NPP-deficient diets is strongly influenced by the dietary calcium level and the enzyme may modulate egg weight, eggshell quality, phosphorus and calcium retention in laying hens fed low-NPP, maize-soybean meal-based diets.

Limestone and oyster shell for brown layers in their second egg production cycle

This study aimed at evaluating the effect of dietary calcium levels and the replacement of calcium sources with different particle size compositions on the performance and egg quality of brown layers in their second egg production cycle. A randomized block experimental design was applied with 12 treatments in a 3x4 factorial arrangement: three calcium levels (2.6, 3.2, 3.8 %) and four combinations of calcium sources (1- 100% fine limestone (FL), 2- 50% FL + 50% coarse limestone (CL), 3- 50% FL and 50% oyster shell (OS), 4- 50% FL and 25% CL+ 25 %OS), with six replicates of eight birds each. Calcium sources were analyzed for geometric mean diameter (GMD) and in-vitro solubility. The following performance and egg quality parameters were evaluated: egg weight (EW, g), egg production (% Eggs), egg mass (EM %), feed intake (FI g), feed conversion ratio (FCR kg/dz and FCR kg/kg), mortality (% Mort.), specific egg gravity (SG), percentages of yolk (Y%), albumen (Alb%) and eggshell (ES%), eggshell thickness (EST), eggshell breaking strength (BS), eggshell weight per surface area (EWSA), Haugh unit (HU), yolk index (YI) and yolk color. Performance and internal egg quality were not affected by the treatments (p>0.05). Blocks had a significant effect on (p<0.05) FI and FCR (kg/dz and kg/kg). Treatments significantly influenced external egg quality, which improved as dietary calcium levels increases and when up to 50% fine limestone was replaced by combinations of coarse limestone with oyster shell.