Effects of dietary red yeast (Sporidiobolus pararoseus) on production performance and egg quality of laying hens

The purpose of this study was to evaluate the effect of dietary red yeast (Sporidiobolus pararoseus) on production performance and egg quality of laying hens. A total of 200 Esa Brown laying hens (23 weeks of age) were allocated equally to negative control group (no yeast supplement); positive control group (2 g/kg of Saccharomyces cerevisiae); 0.5, 1, 2 g/kg red yeast respectively. The experiment was lasted for 12 weeks. Feed intake, hen‐day egg production and egg weight were not different between control and supplemented groups. However, yeast‐supplemented groups were significantly improved feed efficiency (p < .05). Incremental levels of red yeast increased the colour score of egg yolk (p < .05). The cholesterol and triglyceride of serum and yolk were significantly (p < .05) lower in the laying hens fed dietary administration red yeast compared to the control diet; however, no significant (p > .05) differences among yeast‐supplemented groups were observed. The hepatic hydroxymethylglutaryl‐coenzymeA (HMG‐CoA) reductase activity was significantly lower (p < .05) in the 2 g/kg red yeast‐supplemented group compared to the control and other red yeast‐supplemented groups. Concentrations of caecal short‐chain fatty acids was increased (p < .05) in laying hens fed 1 and 2 g/kg red yeast as compared to the control group. Dietary administration of 2 g/kg red yeast (S. pararoceus) significantly improved egg yolk colour, decrease serum and egg yolk cholesterol levels.     

Effects of main cereal type and feed form on production performance,egg quality and egg sanitary indices of laying hens

ABSTRACT

1. The experiment was conducted to evaluate the effects of cereal types (maize or wheat) and feed forms (pelleted or mash feed) on production performance, egg quality and egg sanitary indices in laying hens.

2. Three hundred and sixty hens (Jinghong No. 1) at 18 weeks of age were randomly assigned to four treatments with six replicates of 15 hens per replicate according to a 2 × 2 factorial design with two cereal types (maize or wheat) and two feed forms (pelleted or mash feed).

3. Compared with the wheat-based diet, the maize-based diet improved (P < 0.05) average egg weight of laying hens. Yolk colour of hens fed with the maize-based diet was higher (P < 0.05) in comparison to those fed the wheat-based diet, while Haugh units were lower (P < 0.05) for the maize-based treatment. Egg mass and average daily feed intake of hens fed the pelleted diet were higher (P < 0.05) than of those fed the mash diet. However, the mash diet improved (P < 0.05) yolk colour compared with the pelleted diet. The percentage of dirty eggs for the wheat-based diet was higher (P < 0.05) than for the maize-based diet. The percentage of dirty eggs was higher (P < 0.05) in birds fed the pelleted diet compared with those fed the mash diet. There were interactions (P < 0.05) between cereal type and feed form, with regard to average egg weight and shell thickness.

4. In conclusion, dietary cereal type affected average egg weight, yolk colour and Haugh units in eggs, while feed form influenced egg mass, average daily feed intake and yolk colour.     

Tea polyphenols increase the antioxidant status of laying hens fed diets with different levels of ageing corn

This study was conducted to evaluate the effects of ageing corn levels (stored for 4 years) with or without the supplementation of tea polyphenols (TPP) on the performance, egg quality and antioxidant status of laying hens. A total of 288 Lohmann commercial laying hens (63-week-old) were used under a 2 × 4 factorial arrangement with 4 levels of dietary ageing corn (0%, 25%, 50%, or 100%) and 2 levels of TPP (0 and 600 mg/kg) for 8 wk. Dietary ageing corn linearly decreased (P < 0.05) the egg production, serum total antioxidant capacity (T-AOC), liver glutathione peroxidase (GSH-Px) of laying hens, yolk index, yolk colour, 1,1-diphenyl-2-picrylhydrazyl (DPPH) value and the reducing power value of egg yolk, but it linearly increased (P < 0.05) the feed conversion rate, ovary malondialdehyde (MDA) content of laying hens, and the protein carbonyl content of egg yolk. Tea polyphenol supplementation increased (P < 0.05) the serum T-AOC, serum superoxide dismutase (SOD), liver SOD, liver GSH-Px, ovary SOD, GSH-Px, the expression of antioxidant-related genes of laying hens, albumen height, Haugh unit, DPPH value and the majority free amino acids of egg yolk, but it decreased (P < 0.05) the serum MDA content of laying hens, MDA and protein carbonyl of egg yolk. In conclusion, the ageing corn significantly reduced the performance, egg quality, antioxidant status and egg antioxidant capacity of laying hens, while TPP supplementation partially counteracted the adverse effects, especially antioxidant status and egg antioxidant capacity of laying hens.     

Effects of δ-aminolevulinic acid and vitamin C supplementation on iron status, production performance, blood characteristics and egg quality of laying hens

An experiment was conducted to evaluate the effects of laying hen diets supplemented with δ-aminolevulinic acid (ALA) and vitamin C (VC) on productive performance, iron status and egg quality. A total of 252 Hy-line brown commercial laying hens were fed two levels of VC (0 and 500 mg/kg) and three levels of ALA (0, 5 and 10 mg/kg) in a 2 × 3 factorial arrangement from 57 to 63 weeks of age. Each treatment contained seven replicates with six hens in each replicate. Supplementation of the diet with both ALA and VC resulted in a significant increase in egg production during 4-6 weeks (p < 0.05). The haematocrit (HCT), total iron-binding capacity (TIBC), white blood cell (WBC), total protein and albumin concentrations were not affected by the dietary treatments. However, ALA and interactive effect of ALA and VC were observed to increase the RBC, haemoglobin and serum iron concentrations (p < 0.05). In addition, inclusion of both ALA and VC increased blood lymphocyte percentage in relation to hens not supplemented with ALA (p < 0.05). Moreover, single effect of ALA or VC improved (p < 0.05) the yolk colour unit and albumin height from 3 to 6 weeks. The egg shell colour was increased (p < 0.05) by the effect of ALA. The addition of VC also led to an increase (p < 0.05) of the Haugh unit at the end of the experiment. However, neither ALA, nor VC exerted an effect on egg weight, egg shell breaking strength or egg shell thickness. The results demonstrate that dietary ALA and VC supplementation can improve the iron status and egg quality of laying hens.     

不同来源色素对蛋黄颜色及叶黄素沉积的影响

为研究不同蛋鸡日粮类型中添加不同来源色素对蛋黄着色及叶黄素沉积的影响,试验1在玉米-豆粕日粮中添加天然或合成虾青素,测定蛋黄色度值(RYCF)和蛋黄中叶黄素含量;试验2在玉米-豆粕和小麦-豆粕日粮中添加混合天然色素(橙黄素∶辣椒红素=1∶1),测定RYCF及叶黄素含量。结果显示:天然虾青素对蛋黄着色无显著影响(P>0.05);合成虾青素可以显著提高RYCF(P<0.05)。不同来源虾青素对叶黄素的沉积无显著影响(P>0.05)。小麦日粮中添加混合天然色素可以显著提高蛋黄叶黄素含量和RYCF(P<0.05),且RYCF与蛋黄叶黄素含量有极显著的相关关系(P<0.01)。对混合色素添加量与RYCF进行拟合,预测RYCF达到8时,需添加混合天然色素2 340 mg/kg。结果表明:合成色素不会增加蛋黄叶黄素含量。在小麦-豆粕基础中添加1.2 g/kg的天然色素可以改善蛋黄色泽,若使RYCF达到8则需添加混合色素2 662 mg/kg。     

Effect of dietary inclusion of cumin seed oil on the performance,egg quality,immune response and ovarian development in laying hens under high ambient temperature

The objective of the present study was to find the effect of cumin seed oil (CSO, Cuminum cyminum L.) on the laying performance, ovarian follicular development and immune response in laying hens under high ambient temperature. A total of 162 Boven hens were randomly divided into three treatments and were fed, ad libitum, diets containing 0 (control), 250 or 500 g CSO per ton from 24 to 30 weeks of age. The experiment was done during summer season where the average temperate was 30 to 36°C. Feed intake and egg mass were recorded. Egg quality characteristics and egg‐yolk cholesterol content were evaluated. Ovary and oviduct samples were immediately weighted, and ovarian follicles were classified. Plasma total protein, albumin, total cholesterol, LDL‐cholesterol, HDL‐cholesterol glutamic oxalacetic transaminase (GOT), and glutamate pyruvate transaminase (GPT) were measured. Yolk width, yolk weight, yolk colour, shell weight and shell thickness were increased by feeding CSO. Egg production rate was not affected. However, dietary 500 g CSO per ton had a significantly positive impact on egg weight in comparison with control. The FCR was improved by feeding 500 g CSO per ton; however, feed intake and egg mass were not affected by CSO treatments. Plasma GOT, GPT and triglycerides were significantly decreased, while, plasma HDL‐cholesterol was significantly (p < .05) increased due to CSO treatments. Yolk cholesterol content was significantly decreased; however, liver malondialdehyde (MDA) concentration was insignificantly decreased due to dietary treatments. Interestingly, the inclusion of CSO in laying hens’ diets improved the antibody titres against Newcastle disease (ND, p < .05) and against avian influenza H9N1 (p > .05) when compared with the control diet. It could be concluded that dietary inclusion of CSO improved egg weight, FCR, yolk and shell quality characteristics and did not have a negative effect on the reproductive morphology parameters in laying hens.     

Influence of sumac (Rhus Coriaria L.) and ginger (Zingiber officinale) on egg yolk fatty acid,cholesterol and blood parameters in laying hens

The aim of the study was to evaluate the potential effect of different levels of sumac (Rhus coriaria L.) seed powder and ginger (Zingiber officinale) root powder on egg yolk fatty acid composition, blood/yolk cholesterol in laying hen. A total of 63 (ATAK‐S: Domestic Turkish Laying Hens) laying hens (average weight: 1470 g each hen, 25‐weeks of age) were assigned to seven treatment diets including sumac seed (S) and ginger root powder (G) at 0 g/kg (control), 10 g/kg (S1), 20 g/kg (S2), and 30 g/kg (S3); 10 g/kg (G1), 20 g/kg (G2), or 30 g/kg in rations respectively, for 8 weeks. After a two‐week adaptation period to cages, the hens were allocated to 7 groups with 9 replicates of 1 hen in per cage each. The replications were allotted equally into the upper and lower cages to minimize the effects of cage level. In this study, egg yolk cholesterol had a decrease (p <0.05) in supplemented diet( sumac seed and ginger root powder). Fatty acid content in yolk; saturated fatty acid, monounsaturated fatty acids, polyunsaturated fatty acids and rate of n6/n3 were not significant (p <0.05). However, dietary supplementation with sumac and ginger powder reduced and yolk/blood cholesterol concentrations in laying hens. Supplementation of sumac and ginger affected on HDL, there was found a significant effect (p < 0.05) in treatment groups. Moreover, LDL positively decreased in all treatment groups compared with the control group. The findings of this study suggested that feeding sumac and ginger tend to be decreasing cholesterol levels in both yolk and blood on laying hens. It can be concluded that ginger root and sumac seed powder can be used as an effective feed additive to improve fatty acid composition and yolk and blood cholesterol in ATAK‐S laying hens.     

Astragalus polysaccharide supplementation improves production performance,egg quality,serum biochemical index and gut microbiota in Chongren hens

This research aimed to determine whether the astragalus polysaccharide (AP) can improve the production performance and gut microbiota in Chongren hens.120 Chongren hens (240-d old) were randomly allocated into 4 treatments with 30 hens and fed with a control basal diet (CON) or CON supplemented with the different levels of AP (100, 200, and 400 mg/kg) for 56 d. The egg production and feed conversion ratio were decreased (p < .05) with the levels of AP. The yolk weight, yolk color, eggshell thickness, eggshell redness index and egg shell yellowness were increased (p < .05). AP supplementation increased CAT and T-AOC and SOD, and decreased MDA (p < .05). Supplementation of AP decreased IL-2, IL-6 and TNF-α levels (p < .05), but increased the IL-4 level in the liver (p < .05). The villus heights of duodenum, jejunum ileum, the crypt depth and V/C in the jejunum were increased (p < .05). Dietary supplementation of 200 mg/kg AP increased (P relative abundances of Firmicutes and Lactobacteriaceae in the cecum of Chongren hens. In conclusion, addition of AP improved the production performance, egg quality, antioxidant function, and intestinal morphology in hens, which might be associated with the gut microbiota.     

Effect of feeding broccoli floret residues on leghorn layer performance and egg quality and nutrient digestibility

1. A study was conducted to determine the effects of dried broccoli floret (DBF) on egg production parameters, egg quality and apparent nutrient digestibility of laying hens. It was hypothesised that feeding DBF can improve egg quality without adversely affecting layer performance.2. Seventy-two White Leghorn layers aged 62 weeks were randomly allotted to 4 dietary treatments (6 cage replicates with 3 hens each) and fed diets containing 0, 40, 80 and 120 g/kg DBF in feed for 56 d.3. Inclusion of DBF had no effect on feed intake, egg production, feed conversion ratio or egg components. However, egg weight increased (linear effect, P < 0.05) as the level of DBF in the diet increased. Egg breakage strength, eggshell strength and Haugh unit were not influenced by dietary treatments. Egg yolk colour (quadratic effect, P = 0.002) and α-tocopherol concentration (quadratic effect, P < 0.0001) improved as a result of DBF inclusion. Egg yolk cholesterol concentration was not altered by DBF inclusion. Apparent total tract nutrient (dry matter, organic matter and crude protein) digestibility coefficients decreased (linear effect, P < 0.05) as the level of DBF increased.4. Feeding DBF to layers up to 120 g/kg of the diet had no negative effects on feed intake, egg production and feed efficiency and improved egg yolk colour and α-tocopherol concentration. However, total tract nutrient digestibility coefficients were negatively decreased as a result of DBF inclusion.     

Organic trace minerals on productive performance,egg quality and immune response in Bovans White laying hens

This study was performed in 360 laying Bovans White hens and aimed to evaluate the effect of Carbo‐Amino‐Phosphate‐Chelates (CAFQ) as a mineral premix and its 30% reduction by compared to inorganic trace minerals (ITM) concerning its performance, egg quality, tibia breaking strength and immunity. Sixty‐week‐old hens were assigned into three treatments with 10 replicates of 12 birds each. Treatments were as follows: (a) (100% ITM), (b) (100% CAFQ) and (c) (70% CAFQ). Based on the results obtained during 12 weeks, under the current test conditions, improved yolk colour (p < 0.05); shell breaking strength (p < 0.05); and storage time (p < 0.05) were observed in hens fed with a diet reduced by 70% in CAFQ inclusion showed similar performance behaviour and better egg breaking strength regarding with ITM, suggesting the possibility of minimizing the inclusion of trace minerals in laying hen diets improving environmental impact, in contrast to the use of inorganic sources of minerals.     

Effects of supplemental L-carnitine in drinking water on performance and egg quality of laying hens exposed to a high ambient temperature

The present study was conducted to investigate effects of L-carnitine supplied with drinking water on performance and egg quality of laying hens under high environmental temperature. In the study, 47-week-old laying hens (Brown hisex) were divided into two groups (control and treatment) and fed with a standard layer diet. Treatment group was received 50 p.p.m L-carnitine with drinking water for an 8-week period. Throughout the study, 8 h hot (35-37 degrees C) and 16 h thermoneutral (20-22 degrees C) environmental temperature regime was employed daily. The results showed that L-carnitine supplementation affected some egg quality characteristics of layers under high environmental temperature. Relative albumen weight and height were increased (p < 0.05) by supplemental L-carnitine. Live weight gain, feed intake, egg mass, egg weight, yolk weight, shell weight, yolk index, egg-shape index, yolk colour score and shell thickness were not affected (p < 0.05) by L-carnitine. It is concluded that L-carnitine supplementation in laying hens could have potential to improve albumen quality under high environmental temperature.     

Effect of expanded cottonseed meal on laying performance,egg quality,concentrations of free gossypol in tissue,serum and egg of laying hens

Three hundred and sixty Hy‐Line Brown hens, 40 week of age, were allocated to five treatments, each of which included four replicates of 18 hens. After an expanded process of cottonseed meal (CSM), free gossypol content in CSM was decreased from 1.24 to 0.40 g/kg. The dietary treatments were corn‐soybean meal based diets including 6% CSM and 6%, 8% and 10% expanded cottonseed meal (ECSM). Hens fed 8% ECSM had higher (P < 0.05) laying rate and average egg weight than those fed 6% CSM. The albumen height and Haugh unit in the control group, 6% and 8% ECSM groups were superior (P < 0.05) to other treatments. Hens fed 6% CSM resulted in severe (P < 0.05) egg yolk discoloration. Free gossypol (FG) concentrations in yolk and albumen and tissues of the 6% CSM group were greater (P < 0.05) than those in any ECSM treatments. Hens fed 6% CSM and 10% ECSM had the highest (P < 0.05) FG concentrations in the liver compared with those in the kidney and muscle, and higher (P < 0.05) FG residues in yolk than those in albumen. In conclusion, FG in CSM can be reduced by 68% through an expanded process and ECSM can be available in laying hens at up to 10% of the total diet and an appropriate replacement of soybean meal with ECSM may improve performance in laying hens.     

Effects of vitamin E supplementation on performance,serum biochemical parameters and fatty acid composition of egg yolk in laying hens fed a diet containing ageing corn

This study investigated whether dietary vitamin E (VE) supplementation could alleviate any detrimental effects of ageing corn in the diet for laying hens on egg performance, egg quality, serum biochemical parameters, cholesterol content and the fatty acid (FA) profile of egg yolks. The experiment consisted of a 2 × 3 factorial design with two corn types (normal corn and ageing corn) and three concentrations of VE (0, 20 and 100 IU/kg). A total of 216 Lohmann laying hens (50‐week‐old) were randomly allocated into six treatment diets for 12 week. Each treatment had six replicates with six hens. The results showed that ageing corn significantly reduced average daily feed intake (ADFI; p < 0.01) and egg weight (p < 0.05). Dietary VE supplementation had no significant influences on egg production performance (p > 0.05). Egg yolk colour was decreased in ageing corn diets (p < 0.01), while 20 and 100 IU/kg VE significantly improved vitelline membrane strength (p < 0.01) compared with feeding of 0 IU/kg VE. Ageing corn also significantly decreased the content of cholesterol including total cholesterol (TC; p < 0.05), low density lipoprotein cholesterol (LDL‐C; p < 0.01) and very low density lipoprotein cholesterol (VLDL‐C; p < 0.05) in the serum. Feeding 100 IU/kg VE significantly increased the content of LDL‐C (p < 0.01) and VLDL‐C (p < 0.05) in the serum. Furthermore, the content of the oleic acid, docosahexaenoic acid and total monounsaturated fatty acid (MUFA) was lower (p < 0.05) and stearic acid and total saturated fatty acid (SFA) was higher (p < 0.05) in egg yolks in ageing corn diets. Ageing corn resulted in reduced feed intake, egg weights and yolk colour, but the effects of VE supplementation were independent of those of age of corn and were unable to counteract the negative effects of feeding ageing corn.     

The impact of phytoestrogen source supplementation on reproductive performance,plasma profile,yolk fatty acids and antioxidative status in aged laying hens

The objectives of this study were to investigate the effects of flaxseeds and/or fenugreek seeds as a source of phytoestrogens in laying feed on productive performance, egg quality, yolk fatty acids, plasma profile and antioxidative status in aged laying hens. A total of 120 Bovans Brown hens at 65 weeks of age were housed individually in laying cages in an open‐sided building under a 16‐hr light: 8‐hr dark lighting schedule. Hens were randomly divided into four experimental treatments (n = 30 each): (a) control (basal diet without any supplementation); (b) 1 g/kg of flaxseeds; (c) 1 g/kg of fenugreek seeds; and (d) combination of 1 g/kg flaxseeds and 1 g/kg fenugreek seeds from 65 to 71 weeks of age. Hen‐day egg production and egg mass were significantly increased by dietary supplementation of flaxseeds and/or fenugreek seeds, while feed intake was not affected; thus, feed conversion ratio was improved (p < 0.05). Weights of egg, albumen, yolk and shell were increased by the dietary treatments. Shell thickness and yolk colour were improved by supplementation of flaxseeds and/or fenugreek seeds. Yolk crude protein was not significantly affected by treatments; however, crude fat and calcium contents in yolk were increased and egg yolk cholesterol content was decreased. Interestingly, dietary supplementation of flaxseeds, fenugreek seeds and their combination had a significant positive effect on plasma luteinizing hormone, follicle‐stimulating hormone, oestradiol‐17β and triglycerides. Inclusion of flaxseeds and/or fenugreek seeds in the diets enhanced the serum glutathione peroxidase and superoxide dismutase activities and reduced the malondialdehyde and total cholesterol concentrations in plasma. Dietary supplementation of flaxseeds and/or fenugreek seeds increased α‐linolenic and linoleic acids in egg yolk. It could be concluded that inclusion of mixed sources of phytoestrogens in diets improved laying performance, egg quality, the antioxidative status, hormonal profile and steroidogenesis in aged laying hens.     

Supplemental defatted microalgae affects egg and tissue fatty acid composition differently in laying hens fed diets containing corn and flaxseed oil

Effects of defatted microalgae (DFA) on fatty acid composition of eggs and tissues of hens have not been well studied. This experiment was to determine how low concentrations of supplemental DFA in the presence or absence of flaxseed oil (FO) altered fatty acid profiles of egg yolk, liver, adipose tissue, and plasma of layers. A total of 60 Shaver Leghorn layer hens (individually caged, 20-wk old) were allotted into 6 groups (n = 10) and fed a corn/soybean meal basal diet containing 0, 3, or 5% DFA and 0 (1.5% corn oil, CO) or 1.5% FO for 6 wk. BW, ADFI, egg production rate, and egg component weights were not affected by any of the dietary treatments at various time points, but egg yolk color was changed (P < 0.05) with increasing concentrations of DFA. The concentration of n-3 fatty acids in egg yolk and plasma were elevated by FO up to 9-fold (P < 0.05) starting at wk 1 or 2, and 39 to 83% (P < 0.05) by DFA. Supplemental DFA improved (P < 0.05) n-6/n-3 fatty acid ratios in egg yolk and plasma from 13 to 23 and 7 to 13, respectively, only in hens fed diets without FO. Fatty acid profiles of liver and adipose tissue (at wk 6) displayed responses to supplemental DFA and FO similar to those of egg yolk or plasma. In conclusion, supplemental 3 or 5% DFA caused moderate enrichments of n-3 fatty acids and decreased the n6/n3 fatty acid ratios of egg yolk and tissues in hens fed diets without FO.     

Influence of citrus flavonoids on laying hen performance,inflammatory immune response,egg quality and yolk oxidative stability

1. The objective of this study was to investigate the effects of dietary supplementation with natural flavonoids (naringin and hesperidin) on laying hens’ performance, cellular immunity and egg quality parameters.

2. A total of 72 individually caged laying hens were allocated into 1 of 6 treatment groups: a control (C) group that was fed with a basal diet and groups that were offered the same diet further supplemented with hesperidin at 0.75 g/kg (E1), or 1.5 g/kg (E2), or naringin at 0.75 g/kg (N1), or 1.5 g/kg (N2) or α-tocopheryl acetate at 0.2 mg/kg (VE) for 67 d.

3. Supplementation with naringin or hesperidin did not affect the performance and egg quality (P > 0.05) apart from an improvement in the yolk colour that was more orange in naringin and hesperidin groups in comparison to the controls (P-linear < 0.05). Egg yolk and plasma cholesterol levels were not affected by citrus flavonoids (P-linear > 0.05).

4. Inflammatory immune response, measured by phytohaemagglutinin skin test (PHA), was suppressed in laying hens that were fed with either naringin (P-linear < 0.05) or hesperidin (P < 0.05). Egg yolk oxidative stability was improved from the 4th d after naringin or hesperidin supplementation. This beneficial effect was comparable to that of α-tocopheryl acetate and was observed in eggs that were stored for up to 120 d.

5. In conclusion, naringin and hesperidin may favourably prolong the shelf life of eggs, appear to possess anti-inflammatory properties and could improve the yolk colour without any side effects on the performance or egg quality traits.     

Effect of different levels of dried citrus pulp on performance,egg quality,and blood parameters of laying hens in early phase of production

Utilization of agricultural wastes in animal nutrition is a matter of great concern. Dried citrus pulp (DCP) is a potential source of some valuable nutrients for animal and poultry. In an experiment with completely randomized design, the effect of different levels (0%, 4%, 8%, 12%, and 16%) of DCP was evaluated on performance, egg quality, and blood parameters of laying hens from 25 to 37 weeks of age. The birds were randomly allocated to five groups with six replicates and three birds in each replicate. The results showed that with increasing the level of DCP up to 12%, there were no significant differences among treatments for feed intake, egg production, egg mass, feed conversion ratio, final body weight, yolk index, and yolk color. There were no significant differences between treatments in shell thickness, eggshell index, egg score, and Haugh unit. Utilization of DCP up to 16% significantly increased serum glucose and high-density lipoprotein and reduced cholesterol, low-density lipoprotein, and triglycerides (P < 0.05). Results of the present study indicated that use of 12% DCP in laying hen diets had no adverse effect on performance and egg quality of laying hens in early phase of production.     

Comparison of marine algae (Spirulina platensis) and synthetic pigment in enhancing egg yolk colour of laying hens

1. The objective of this experiment was to determine the effects of dietary marine algae (Spirulina platensis) on egg yolk colour, and compare the effectiveness of Spirulina and synthetic pigment in enhancing egg yolk colour of laying hens fed on a wheat-based diet.

2. In total, 160 Hy-line W36 laying hens of 63 weeks of age were studied by dividing them into 5 groups, 32 birds in each. Except for the control group (based on wheat and soyabean meal), the feed for three other groups contained 1·5, 2·0 and 2·5% of Spirulina; while one group contained synthetic pigments (BASF Lucantin® yellow: 30?mg/kg, and BASF Lucantin® red: 35?mg/kg).

3. Egg production, feed intake, feed conversion ratio (FCR), egg weight and egg yolk colour were determined.

4. A significant increase in egg yolk colour was observed in the treatments that received the Spirulina and synthetic pigment, compared with the control diet.

5. There were no significant differences between the treatments with 2·5% Spirulina and synthetic pigment in enhancing egg yolk colour. Finally, the results indicated that the diet containing 2·5% Spirulina could be as effective as the diet with synthetic pigment in producing an agreeable egg yolk colour.     

Effects of Chinese herbal mixture on performance,egg quality and blood biochemical parameters of laying hens

The aim of the study was to evaluate the effect of Chinese herbal mixture (CHM) in laying hen diets on performance, egg quality and egg nutrition components, as well as selected blood biochemical parameters. A total of 270 Lohmann Brown laying hens, 24 week of age, were randomly distributed into three dietary treatments and fed for 6 week. The CHM was used at the levels of 0%, 0.5% and 1.0% in the diets of the control and two treatment groups respectively. Each dietary treatment was divided into five replicates, comprising of 18 hens each. Hens were housed in a 3‐tier battery system. Feed and water were provided ad libitum. Blood samples and eggs were collected at the end of the experiment. The results showed that dietary treatments did not affect egg weight, mortality, eggshell thickness, albumen height, Haugh units, eggshell‐breaking strength and egg‐shape index. Dietary supplementation of CHM significantly improved (p < 0.05) laying rate and the lowest feed conversion ratio were observed with 1.0% CHM supplementation diets. CHM supplementation decreased (p < 0.05) cracked‐egg rate, egg yolk cholesterol, blood serum levels of cholesterol, triglyceride, low‐density lipoprotein cholesterol (LDL‐C) and alanine aminotransferase (ALT) and increased blood serum levels of high‐density lipoprotein cholesterol (HDL‐C). No differences in serum total protein, serum albumen, serum glucose and aspartate amino transferase (AST) were observed in hens fed CHM. In conclusion, dietary supplementation with CHM improved egg production and egg quality and reduced serum cholesterol concentrations in laying hens. Dietary supplementation of 1.0% CHM in layer diets may be a feasible means of producing eggs with lower cholesterol and higher egg yolk phospholipid contents for health conscious consumers.     

Feeding value of rice distiller’s dried grains with solubles as protein supplement in diet of laying hens

A feeding trial of 10 weeks duration was undertaken on laying hens (n = 240) to evaluate feeding value of rice distiller’s dried grains with soluble (rDDGS) with or without enzyme supplementation (α-amylase, β-glucanase, xylanase, carboxymethylcellulase, pectinase, proteinase, α-galactosidase, β-galactosidase, lipase, and phytase), following 4 × 2 factorial design, on egg production, nutrient utilization, and cost economics of egg production. The birds were randomly assigned to eight dietary treatments with 30 birds/treatment. The birds were housed individually in layer cages and each bird was taken as an experimental unit. Eight experimental diets were prepared by incorporating four levels (0, 50, 75, and 100 g/kg) of rDDGS with and without enzyme supplementation. The results revealed a significant (P < 0.01) increase of egg mass, feed intake, egg production, and body weight gain in dietary treatments with up to 75 g rDDGS though the values were statistically similar to the hens fed 100 g rDDGS. Enzyme supplementation resulted in significant (P < 0.01) improvement of egg mass, egg production, feed conversion ratio (FCR) per dozen eggs, FCR per kilogramme egg mass, and net FCR. The significantly (P < 0.01) higher yolk index was observed at 100 g rDDGS level, while shell thickness improved significantly (P < 0.01) up to 75 g rDDGS level. No significant effect of rDDGS inclusion was observed on shape index, albumin index, and Haugh unit. Enzyme supplementation significantly improved the shell thickness and yolk colour of eggs. Nitrogen, calcium, and phosphorus retention and dry matter metabolizability did not show any significant treatment effects. There was significant (P < 0.01) reduction in feed-cost per kilogramme egg mass or per dozen eggs with the increased DDGS levels and dietary enzyme supplementation. It was concluded that rDDGS can be used up to 100 g/kg diet of laying hens along with enzyme supplementation for better productivity of layer hens.