Yolk Fatty Acid Research Articles

옥수수 주정박이 산란계의 생산성 및 경제성에 미치는 효과

A 10-wk layer feeding trial was conducted to investigate the effects of high quality corn distiller's dried grains with solubles (DDGS) on performance, egg qualities, and yolk fatty acid composition. The economics of using DDGS in the Korean situation was also analyzed. A total of 216 Hy-line Brown layers, 23-wk of age, were employed in this trial consisting of three dietary treatments (0%, 10%, and 20% DDGS), and six replicates per treatment. All experimental diets were prepared as iso-protein (17%) and iso-calorie (2,780 kcal/kg). The use of DDGS up to 20% in layer diets did not affect the feed intake, laying rate, egg weight, and feed conversion ratio (P>0.05). At 5th and 10th wk of the trial, the eggshell color, albumen height, and Haugh unit were not influenced by the DDGS supplementation. At 5th wk of the trial, the eggshell qualities, like eggshell weight, eggshell thickness, and eggshell strength, were not affected by the DDGS feeding; however, these eggshell qualities were decreased at 10th wk due to the 20% DDGS feeding (P<0.05). Yolk color of DDGS 20% increased compared to DDGS 0% at 5th and 10th wk of the trial (P<0.05). At 10th wk, yolk/egg ratio of DDGS 20% decreased compared to DDGS 0% (P<0.05). The yolk fat content was not changed due to DDGS feeding. The monounsaturated fatty acid content of yolk decreased linearly by feeding DDGS (P<0.05). The yolk polyunsaturated fatty acid content of DDGS 20% increased significantly compared to DDGS 0%. The DDGS feeding was not found to affect the degree of yolk fat unsaturation. The cost of feed ( /kg feed) decreased as the level of DDGS increased. The production costs of egg ( /kg egg) were cheap in the order of DDGS 10%, DDGS 20%, and DDGS 0%, indicating that DDGS is a viable alternative feed ingredient to corn and soybean meal. In conclusion, high quality DDGS (L * 61.72) could be used economically up to 20% level without any harmful effect on laying performance: however, the use of DDGS up to 10%

Quality characteristics of &lt;i&gt;n&lt;/i&gt;-3 polyunsaturated fatty acid-enriched eggs

The aim of this work was to develop a diet suitable for obtaining eggs enriched in omega-3 fatty acids at a suffi cient level with minimum disadvantages affecting egg quality parameters or laying hen health and yield. A trial was conducted to study the effects of two previously designed experimental diets on egg quality and fatty acid composition; these effects were compared with those of a standard diet for laying hens. Yolk fatty acid composition was determined and typical egg quality parameters were measured, in particular rheological measurements were carried out to evaluate structural yolk quality. Sensorial quality of eggs was also analysed and necropsies of laying hens were performed. The results show that a diet containing 1.5% Cantabrian blue fi sh oil and 5% linseed achieved commercially acceptable levels of omega-3 fatty acids in egg yolk avoiding most of the drawbacks reported by many authors.

The relationship among age, yolk fatty acids content, and incubation results of broiler breeders

This research was carried out to investigate the correlations among age, yolk fatty acids content, and incubation results of broiler breeders. Egg samples were obtained from Ross 308 broiler breeder parent stock at 28, 45, and 65 wk of age. A total of 1,800 eggs were used for incubation results of each age period. The mean values of hatchability of fertile eggs (H/F) were 94.04 +/- 0.42, 91.36 +/- 1.08, 85.97 +/- 0.96%, values for hatchability of total eggs (H) were 92.00 +/- 0.47, 83.61 +/- 1.23, 62.78 +/- 1.57%, and fertility ratios (F) were 97.83 +/- 0.30, 91.50 +/- 0.54, and 73.00 +/- 1.55% at 28, 45, and 65 wk of age, respectively (P < 0.01). The mean values of early embryonic mortality and hatched chick weight were 2.73 +/- 0.27, 4.01 +/- 0.56, 8.93 +/- 0.89% and 36.58 +/- 0.51, 42.47 +/- 0.48, 45.31 +/- 0.96 g, at 28, 45, and 65 wk of age, respectively (P < 0.01). Myristic acid and linoleic acid contents of yolk significantly decreased with increasing age of broiler breeder (P < 0.01). The mean yolk myristic acid contents were 0.34 +/- 0.02, 0.29 +/- 0.06, and 0.24 +/- 0.01 mg/g, and linoleic acid contents were 21.60 +/- 1.26, 16.05 +/- 3.04, and 13.87 +/- 0.49 mg/g at 28, 45, and 65 wk of age, respectively (P < 0.01). Correlations between breeder age and myristic acid and linoleic acid (r = -0.317 and -0.435, respectively) were significant when data were pooled from 28 to 65 wk of age. Significant correlations between H/F and myristic acid and linoleic acid were determined. The correlation between F and linoleic acid (r = 0.364; P < 0.05) was found to be significant with the change of breeder age. There were negative correlations between late embryonic mortality and myristic acid (r = -0.432; P < 0.05), stearic acid (r = -0.437; P < 0.05), and linoleic acid (r = -0.469; P < 0.5) at 28 to 65 wk of age. The findings from this study will contribute to the hatcheries of the poultry sector and the new studies that are going to be carried out..

Effects of dietary humate supplementation on performance, egg quality and egg yolk fatty acid composition in layers

AbstractBACKGROUND: The objective of this study was to determine the effects of humate on performance, egg quality and egg yolk fatty acid (FA) composition in laying hens.RESULTS: Six hundred and thirty White Lohmann layers at 46 weeks of age were assigned randomly to seven groups, each with 18 replicate cages of five hens. Control diet (C) and C supplemented with 0.10 (H1), 0.15 (H2), 0.20 (H3), 0.25 (H4), 0.30 (H5) and 0.35 (H6) wt% humate were offered for 25 weeks. Humate supplementation improved performance variables and egg quality indices including shape index, yolk colour, albumen index, yolk index and Haugh unit, but not specific gravity, shell strength and shell thickness. Average feed intake (g), egg production (%), egg weight (g) and feed efficiency for the groups were 118.9, 87.2, 68.1 and 2.07 (C), 118.8, 87.7, 66.3 and 2.08 (H1), 119.3, 89.8, 66.6 and 2.03 (H2), 119.5, 88.9, 66.9 and 2.05 (H3), 118.3, 86.5, 66.9 and 2.11 (H4), 119.3, 90.6, 66.9 and 2.02 (H5) and 123.6, 88.5, 66.1 and 2.16 (H6) respectively. Palmitoleic acid concentration increased from 4.34% (C) to 7.65% (H5) and stearic acid concentration decreased from 7.39% (C) to 5.39% (H6) of total FA.CONCLUSION: Dietary humate supplementation improved performance, inner egg quality parameters and egg yolk fatty acid composition. Copyright © 2008 Society of Chemical Industry

Effects of Corn Distiller's Dried Grains with Solubles on Production and Egg Quality in Laying Hens

Corn distiller's dried grains with solubles (DDGS) is a completely new feed ingredient in the Korean feed market. There is an ever increasing need for the Korean feed industry to import and make the best of it as a high protein and high energy feed ingredient. A layer feeding trial was conducted for 10 weeks to investigate the effects of addition of light-colored DDGS to layer diets on laying performance, egg qualities and yolk fatty acid composition. Also, the economics of using DDGS in the Korean situation was analyzed. Nine hundred Hy-line Brown layers, 24 weeks of age, were employed in a feeding trial consisting of four dietary treatments (0, 10, 15, and 20% DDGS), and five replicates per treatment. All experimental diets were prepared as iso-protein (17%) and iso-calorie (TMEn 2,780 kcal/kg). The use of DDGS up to 20% in layer diets did not exert any influence on feed intake, laying rate, total egg mass, mean egg weight and feed conversion ratio (p>0.05). The color and breaking strength of eggshell, as well as the albumin height and Haugh unit were not affected by the addition of DDGS up to 20% in the diet. The yolk color was significantly increased by DDGS supplementation (p<0.05). As the DDGS level increased, the oleic acid content decreased, and the linoleic acid increased (p<0.05) in egg yolk. The degree of saturation of yolk fatty acids was not affected by DDGS supplementation. The inclusion of light-colored DDGS up to 20% in layer diets resulted in a decrease of feed cost per kg without any undesirable effect on laying performance. In conclusion, the light-colored DDGS (L* 56.65) could be used up to 20% in layer diets without any harmful effect on laying performance, and possibly provide economic benefits to the Korean poultry industry.

Effects of supplementing layer hen diets with selenium and vitamin E on egg quality, lipid oxidation and fatty acid composition during storage

A 7-wk trial was carried out to investigate the effect of vitamin E and inorganic and organic selenium added to hens' diet on quality and lipid stability of eggs during storage. One hundred forty-four Hy-Line W-36 hens (63-wk of age) were divided into six equal groups. Five groups received a basal diet supplemented with 0.4 mg kg-1 sodium selenite or selenium yeast, 200 mg kg-1 vitamin E or a combination of selenium and vitamin E; whereas the control group received no supplementation. Hen production was assessed daily and fresh egg quality parameters were determined every 2 wk. Eggs were stored under different conditions (4°C, 23–27°C or 31°C) for 14 d. Eggs were analyzed for quality characteristics, egg component weight, Malondialdehyde values as a secondary oxidation product and yolk fatty acid (FA) composition. The performance of the hens and egg weights were not affected either by the source of the selenium or by the vitamin E. The inclusion of selenium or vitamin E in the diet significantly increased their concentrations in the egg. The supplemented diets also improved egg quality, oxidative stability and fatty acid composition during storage. Key words: Vitamin E, selenium, lipid peroxidation, egg fatty acid composition, storage

Acclimation to Heat During Incubation. 2. Embryo Composition and Residual Egg Yolk Sac Fatty Acid Profiles in Chicks

The aim of the research was to evaluate embryo composition and changes in egg yolk fatty acid composition during embryonic development as a function of incubation temperature and age of breeders. Eggs obtained from a common breeder stock at 3 ages: 32 (younger), 42 (mid age), and 65 (older) wk were divided into 2 groups and placed into 2 incubators: the control and the second where eggs were heat-acclimated (HA) at 38.5°C for 6 h daily from d 10 to 18 of incubation. Body composition of embryos and chicks were measured on d 14, 18, and at hatch, respectively. Fatty acid profiles of yolk and residual egg yolk sac of chicks were analyzed before incubation and at hatch, respectively. Moisture content of embryos was highest on d 14 and then decreased regardless of parental age and incubation temperature. Moisture content of chicks at hatch from 42- and 65-wk parents were lower than those of chicks from 32-wk parents, whereas the trend in chick fat content was opposite. Incubation temperature had no effect on composition of chicks. Consistently lower cis-4,7,10,13,16,19-eicosapentaenoic (docosahexaenoic acid, DHA; 22:6n-3) and cis-11,14,17-eicosatrienoic (20:3n-3) fatty acids in the residual yolk sac of chicks than in egg yolks before incubation may have resulted from preferential uptake from the yolk. The DHA content in the residual yolk sac was considerably higher in chicks from older parents incubated at HA, whereas, in contrast, levels of 18:3n-3 were lower. Also, chicks from younger parents in the HA treatment had lower transported 18:3n-3 and higher levels of transported DHA. It may be concluded that this process observed during the high incubation temperature may be related to a protective strategy and thus contributes to postnatal heat adaptation.

Effects of a Prelay 6/85-Strain Mycoplasma gallisepticum Inoculation Alone or in Conjunction with Subsequent F-Strain M. gallisepticum Inoculations During Lay on the Internal Egg Characteristics of Commercial Egg-Laying Hens

The effects of a prelay 6/85-strain Mycoplasma gallisepticum (6/85MG) inoculation alone or in conjunction with subsequent F-strain M. gallisepticum (FMG) inoculations during lay on the internal egg characteristics of commercial egg-laying hens were investigated. In the first 2 treatment groups, birds were sham inoculated or were inoculated with 6/85MG at 10 wk of age. In a third treatment group, birds were inoculated with 6/85MG at 10 wk in conjunction with a subsequent inoculation of FMG at 22 wk, and in a fourth treatment group, birds were inoculated with 6/85MG at 10 wk in conjunction with a subsequent inoculation of FMG at 45 wk. Percentage yolk weight, albumen weight, yolk moisture, and yolk lipid were determined at 24, 32, 43, 47, and 58 wk of hen age. The data from wk 24, 32, and 43 were analyzed separately from those at wk 47 and 58. Furthermore, yolk fatty acid profiles were determined at wk 58. The applied treatments affected yolk moisture and fatty acid profiles. Across wk 24, 32, and 43, yolk moisture content was higher in birds inoculated with 6/85MG at 10 wk and FMG at 22 wk when compared with control birds and those inoculated with 6/85MG at 10 wk alone. In addition, at wk 58, yolk palmitic, oleic, and linolenic acid concentrations were affected differently by treatment. A 22-wk FMG inoculation in birds previously inoculated with 6/85MG at 10 wk may increase yolk moisture content, and alterations in yolk palmitic, oleic, and linolenic acid levels with treatment may be manifested by disturbances in fatty acid synthesis.

The Effect of Male and Female Supplementation of l-Carnitine on Reproductive Traits of White Leghorns

Previous work in our laboratory showed that including 125 ppm of l-carnitine in the diets of roosters increased sperm concentration. The objective of this experiment was to determine whether reproductive efficiency could be improved by feeding l-carnitine to both parents over that of feeding l-carnitine to only the male or female. Diets formulated to contain 0 or 125 ppm of l-carnitine were fed to male and female birds from hatch until 37 wk of age. Eighty-four roosters were used, with the semen of 2 roosters constituting an experimental unit. Pools of semen from either l-carnitine-supplemented or control roosters were artificially inseminated into each of 288 hens with 23.5 μL of semen at weekly intervals, in a 2 × 2 factorial arrangement, resulting in a mean insemination dose of 1.2 and 1.1 × 108 sperm/hen for l-carnitine and control hens, respectively. Dietary l-carnitine, as compared with the control diet, increased egg yolk l-carnitine concentration (P = 0.001), decreased hatchling yolk sac weights (P = 0.0001), decreased yolk sac lipid content at hatch (P = 0.01), and culminated in compositional changes of yolk fatty acids, but it did not affect hatch rate, egg production, and egg traits. Although supplementing diets with l-carnitine improved sperm concentration, it did not result in a subsequent improvement in hatch rate, most likely because of the high numbers of sperm that were inseminated artificially in both the control and l-carnitine-supplemented hens. The higher concentrations of l-carnitine in the yolk of hatching eggs obtained from hens consuming l-carnitine as compared with controls may have encouraged the utilization of fat by developing embryos, as indicated by the decreased hatchling yolk sac weights and yolk sac lipid content, perhaps leading to the selective utilization of linoleic (C18:2n-6) and α-linolenic (C18:3n-3) acids for growth and development over myristic (C14:0) and oleic (C18:1n-9) acids.

The influence of diet on fatty acids in the egg yolk of green sea turtles, Chelonia mydas

Fatty acid concentrations found in the yolk of green sea turtles reflect differences in the diet of the mothers. All of the 12 fatty acids measured in yolk samples were significantly different between eggs produced from the pellet and wild-type diets. However, the relative pattern of yolk fatty acids in the green turtle mirrored those of other reptiles. Yolk samples contained mostly (63-67%) 14:0. 16:0, 16:1n-7 and 18:1n-9. Yolks from captive animals on pellet diet contained an additional 17.64% of the total yolk lipid as 12:0 and 18:2n-6. Wild yolks contained an extra 11.41% of lipid as 18:0 and 18:1n-7. Selection of fatty acids for the yolk should balance the energetic and anabolic needs of the embryo. Eggs are provisioned based on maternal metabolism of available nutrients and subtle differences between natural foods and those available in captivity could affect the viability of future eggs.

Long-Term Feeding of Conjugated Linoleic Acid and Fish Oil to Laying Hens: Effects on Hepatic Histopathology, Egg Quality, and Lipid Components

The present study was conducted to investigate the effect of long-term feeding of conjugated linoleic acid (CLA) and fish oil on egg quality characteristics, production performance, liver pathology, and egg fatty acid content of laying hens. Single Comb White Leghorn laying hens (n = 112), 21 wk old, were placed in cages and randomly assigned to 4 diets (28 hens/diet, 4 replicates of 7 hens) containing 3.0% yellow grease (control), 2.75% yellow grease + 0.25% CLA (YG-CLA), 2.5% yellow grease + 0.25% CLA + 0.25% fish oil (YG-CLA-FO), and 2.75% yellow grease + 0.25% fish oil (YG-FO). The experimental diets were fed for 12 mo. Eggs were collected daily for 12 mo. Feed consumption, hen-day egg production, and feed efficiency were monitored. At the end of the trial, hepatic tissue was collected for histopathology. No effect of diet was found on feed consumption, hen-day egg production, feed efficiency, egg weight, yolk weight, shell weight, or Haugh unit. The YG-CLA and YG-CLA-FO diets produced an increase in CLA and saturated fatty acids in the egg and liver tissue with a concomitant reduction in monounsaturated fatty acids (P < 0.05). Feeding YG-CLA-FO and YG-FO increased the n-3 fatty acids in egg yolk and liver of hens (P < 0.05). No difference was observed in the number of fat vacuoles in the liver tissue. The total fat content of hepatic and abdominal fat pads did not differ among treatments (P > 0.05). Regardless of the diet, as the hens aged, egg weight, yolk weight, and egg total fat increased, and shell weight decreased (P < 0.05). These data demonstrate that eggs with increased n-3 fatty acids and CLA can be generated by minor diet modifications without affecting the production performance or health of birds.

Instrumental measurement of the texture of hard-boiled egg yolks enriched with different levels of conjugated linoleic acid

There is increased interest in enhancing the conjugated linoleic acid (CLA) content of food products because of its potential health benefits. Inclusion of CLA in the diets of laying hens has led to the incorporation of CLA into eggs, changes in yolk fatty acid (FA) composition and non-acceptable greater firmness of hard-boiled egg yolks. This study was designed to develop instrumental tests to determine the texture characteristics of hard-boiled egg yolks obtained from hens fed diets supplemented with different levels of CLA and other fat sources. Two compression tests have established relationship between some FA levels added to diets and the firmness of boiled egg yolks. There were significant differences in the compression parameters among egg yolks from laying hens fed diets supplemented with 3 and 5 g/kg of CLA (without other fats in diet) and commercial egg yolks. Supplementations with 30 and 35 g/kg of high oleic sunflower oil (HOSO) in diets which included 3 g/kg of CLA, decreased compression parameters to levels similar to commercial eggs.

Association of the FADS2 Gene with ω-6 and ω-3 PUFA Concentration in the Egg Yolk of Japanese Quail

This study focused on the association of polymorphisms of the FADS2 gene with fatty acid profiles in egg yolk of eight Japanese quail lines selected for high and low ω-6:ω-3 PUFA ratio (h2 = 0.36–0.38). For the identification of polymorphisms within the FADS2 gene 1350 bp of cDNA sequence were obtained encoding 404 amino acids. Five synonymous SNPs were found by comparative sequencing of animals of the high and low lines. These SNPs were genotyped by single base extension on 160 Japanese quail. The association analysis, comprising analysis of variance and family based association test (FBAT), revealed significant effects of SNP3 and SNP4 genotypes on the egg yolk fatty acid profiles, especially the ω-6 and ω-3 PUFAs (P < 0.05). No effects of the other SNPs were found—indicating that these are not in linkage disequilibrium with the causal polymorphism. The results of this study promote FADS2 as a functional candidate gene for traits related to ω-6 and ω-3 PUFA concentration in the egg yolk.

Efeito do nível de ácido linoléico na ração de matrizes pesadas sobre o peso, composição e eclosão dos ovos

Avaliaram-se os efeitos dos níveis de ácido linoléico na dieta de matrizes pesadas, de 27 a 40 semanas de idade, sobre o peso e composição dos ovos, porcentagem de eclosão, peso do pinto, porcentagem de saco vitelino em relação ao peso do pinto e composição de ácidos graxos da gema. Os tratamentos foram definidos pelo nível de ácido linoléico na dieta. O peso dos ovos e a composição de ácidos linoléico na gema foram mais altos com a inclusão de 1,93% de ácido linoléico que a de 1,48% (59,5g vs 59,0g e 19,5% vs 15,5%, respectivamente). Não houve diferença entre os tratamentos quanto às porcentagens de gema, albúmen, casca, saco vitelino, eclosão e peso do pinto.

Effect of the combined supplementation of diets with increasing levels of fish and linseed oils on yolk fat composition and sensorial quality of eggs in laying hens

Yolk fatty acid (FA) concentrations and egg quality were evaluated with respect to the inclusion of different levels of marine fish oil (MFO) and linseed oil (LO) in a basal diet. Ten diets were arranged factorially with two levels of MFO addition (15 and 17 g/kg) and five levels of linseed oil (1, 2, 3, 4 and 5 g/kg). Two commercial feeds with no n-3 FA sources added, or containing 15 g MFO/kg served as controls for egg sensorial quality traits. Type of diet did not affect egg production traits, nor total fat content in yolk or saturated and monounsaturated FA concentration in yolk fat. An increase in the inclusion of MFO from 15 to 17 g/kg increased (P<0.05) egg yolk content of total n-3 FA, C 20:5 n-3 and C 22:6 n-3 by 3.3, 9.8 and 3.5%, respectively. Linseed oil addition increased linearly (P<0.001) the level of total n-3 FA and the proportion of C 18:3 n-3, C 20:5 n-3, C 22:5 n-3 and C 22:6 n-3 retained in yolk fat by respectively 131, 12.0, 6.9 and 20.7% between extreme diets. Efficiency of retention of n-3 FA decreased (P<0.001) with dietary level of n-3 FA, and with the dietary ratio of MFO to LO. Both MFO and LO addition decreased (P<0.001) C 20:4 n-6 to C 18:2 n-6 ratio in yolk. Sensorial quality of eggs was not affected by treatments and did not differ with respect of that obtained in commercial n-3 FA enriched eggs. No interaction was found between LO and MFO addition for any of the traits studied. Regression equations have been calculated in order to predict efficiency of retention and yolk fat content of LC n-3 and n-6 FA from dietary characteristics.

Validation of Two Methods for Fatty Acids Analysis in Eggs

A comparative study between two methods (lipid extraction followed by saponification and methylation, and direct methylation) to determine the fatty acids in egg yolk was evaluated. Direct methylation of the samples resulted in lower fatty acid content and greater variation in the results than the lipid extraction followed by saponification and methylation. The low repeatability observed for the direct HCl methylation method was probably due to a less efficient extraction and conversion of the fatty acids into their methyl esters as compared to the same procedure starting with the lipid extract. As the lipid extraction followed by esterification method was shown to be more precise it was validated using powdered egg certified as reference material (RM 8415, NIST) and applied to samples of egg, egg enriched with polyunsaturated omega-3 fatty acids (n-3 PUFA), and commercial spray-dried whole egg powder.

Metabolic fates of yolk lipid and individual fatty acids during embryonic development of the coot and moorhen

There is currently little information regarding the metabolic fates of yolk lipid and individual fatty acids during embryonic development of free-living avian species. Here we report the pattern of lipid utilization during embryonic development of the coot ( Fulica atra) and the moorhen ( Gallinula chloropus), two related species producing precocial offspring from eggs with a distinctive fatty acid composition and with an incubation period similar to that of the chicken. By the time of hatching, the proportions of the initial yolk lipid that had been transferred to the embryo were 88.2% and 79.8% for the coot and moorhen respectively. During the whole incubation period, 42.9% and 40.0% of the initial yolk lipid of the coot and moorhen respectively were lost from the system due to oxidation for energy, equating to 47.8% and 50.0% respectively of the actual amount of lipid transferred over this time. Thus, the lipid received by the embryos of both species is partitioned almost equally between the alternative fates of energy metabolism and incorporation into tissue lipids. In the coot, this 50:50 split between oxidation and tissue formation was maintained during the hatching process. The proportions of arachidonic (20:4n-6) and docosahexaenoic (22:6n-3) in the yolk lipids of these species were 2.5-3.5 times higher than in eggs of domestic poultry. In contrast to the situation in the chicken, there was no preferential uptake of 22:6n-3 from the yolk during coot and moorhen development. The fatty acid compositions of the whole body lipids of the coot and moorhen hatchlings were almost identical to those of the initial yolks indicating that, unlike the chicken, these species display relatively little overall biomagnification of 20:4n-6 and 22:6n-6 during development. It is suggested that the yolk fatty acid profiles of the coot and moorhen are particularly well matched to the requirements of the embryo, reducing the need for selective uptake of 22:6n-3 and for the overall biomagnification of 22:6n-3 and 20:4n-6.

Ácidos graxos da gema e composição do ovo de poedeiras alimentadas com rações com farelo de coco

O objetivo deste trabalho foi avaliar o efeito da inclusão do farelo de coco (FC) na ração e do tempo de alimentação de poedeiras comerciais, sobre os ácidos graxos da gema e os componentes do ovo. O delineamento foi em esquema fatorial 5x2, com cinco níveis de inclusão do FC (0, 5, 10, 15 e 20%) e dois tempos de alimentação (14 e 28 dias). Foram avaliados o peso e as porcentagens de albúmen, gema e casca dos ovos, bem como os sólidos e lipídios totais e o perfil de ácidos graxos das gemas. A inclusão do FC e o tempo de alimentação influenciaram apenas a proporção de ácido mirístico na gema, que aumentou com a inclusão do FC aos 28 dias de alimentação. Os ácidos esteárico e oléico variaram somente com o tempo de alimentação, e as maiores concentrações foram obtidas aos 28 dias. A relação de ácidos graxos poliinsaturados para ácidos graxos saturados da gema diminuiu a partir de 10% de inclusão e aumentou com o tempo de alimentação das aves. O uso de farelo de coco, na ração de poedeiras comerciais, não influencia a proporção dos componentes do ovo, apenas altera a concentração do ácido mirístico da gema.

Effects of Lacquer (Rhus verniciflua) Meal Supplementation on Layer Performance

Two experiments were conducted to see the effects of lacquer meal (Rhus verniciflua) on layer performance. In Exp. 1, seventy-two Hy-Line brown layers, 46 wk of age were fed 0, 1.5% and 3.0% lacquer added diets for 6 weeks. Diets contained 2,650 kcal/kg ME and 16.50% CP. In Exp. 2, high-energy diets were fed to 72 Hy-line brown layers of 46 wk age for 6 wk. The diets were: control (3,000 kcal/kg ME and 16.50% CP); Tl and T2 contained 1.5 and 3.0% lacquer respectively, in addition to high energy levels. Each treatment had four replicates with 6 birds each in both the experiments. During Exp.l, there was no effect on average daily feed intake, egg production and feed efficiency, however, egg weight was linearly (p = 0.0128) decreased with the addition of lacquer in diets. The egg quality parameters measured at bi-weekly intervals did not reveal any particular trend. In Exp 2., high-energy diets have decreased the feed intake and egg production in all groups. However, feeding lacquer at 1.5% increased the egg production by 9% than control. The yolk fat content was increased due to treatments showing quadratic trend (p = 0.0683). The liver fat content was decreased by 40-43% than control in lacquer added diets. Except palmitic, oleic and arachidonic acids, some yolk fatty acids showed a linear decreasing trend in lacquer diets. The serum triglycerides and total cholesterol levels were not influenced with lacquer in the diets; however, the serum glucose level was linearly decreased with the addition of lacquer. In conclusion, lacquer meal supplementation significantly affected the performance of layers fed high-energy diets.

Effects of S6-Strain Mycoplasma gallisepticum Inoculation at Ten, Twenty-Two, or Forty-Five Weeks of Age on the Egg Yolk Composition of Commercial Egg-Laying Hens

Commercial laying hens maintained under controlled conditions were experimentally inoculated with the S6 strain of Mycoplasma gallisepticum (S6MG) at 45 wk of age. This resulted in depressed liver lipid concentration, and inoculations at 20 and 45 wk affected the size of various portions of the reproductive tract. In 2 consecutive trials of the current study, the effect of age of application of S6MG inoculation on the egg yolk characteristics of commercial layers similarly housed and maintained under controlled conditions was determined. The ages of inoculation compared were prior to lay at 10 wk of age, during onset of lay at 22 wk of age, and during postpeak lay at 45 wk of age. In each trial, yolk moisture and total lipid content were determined at 24, 32, 43, 47, and 58 wk of age. Yolk cholesterol concentration and yolk fatty acid profiles at wk 47 and 58 were also examined. Data from wk 24, 32, and 43 (effects of S6MG inoculations at 10 and 22 wk) and data from wk 47 and 58 (effects of S6MG inoculations at 10, 22, and 45 wk) were analyzed separately. The data of both trials were pooled then analyzed together. Across wk 47 and 58, percentage yolk lipid was significantly lower in eggs laid by birds inoculated at 10 wk compared with those inoculated at 45 wk. Sham-inoculated control and 22-wk inoculated groups had intermediate percentage yolk lipids. Compared with sham-control and 10-wk S6MG inoculation groups across wk 47 and 58, yolk myristic, oleic, and linolenic acid concentrations were reduced, whereas yolk stearic and arachidonic acid levels were increased by either 22- or 45-wk S6MG inoculations. In comparison with all other treatment groups at wk 47, yolk linoleic acid concentration was reduced by S6MG inoculation at 45 wk. Variable postpeak alterations in yolk total lipid and fatty acid content occur in response to the timing of S6MG inoculation in layers housed under controlled conditions.