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.     

The effect of graded inclusions of waxy starch hull-less barley and a multi-component exogenous carbohydrase on the growth performance,nutrient digestibility and intestinal morphometry of broiler chickens

ABSTRACT

1. A 21-d experiment was conducted to investigate the effect of graded inclusions of waxy starch hull-less (WSHL) barley and a multi-component exogenous carbohydrase on the growth performance, nutrient digestibility and intestinal morphometry of broiler chickens. Five levels of WSHL barley inclusion (0, 65, 130, 195 and 260 g/kg) in a wheat-based diet, and two levels of enzyme supplementation (0 and 150 g/tonne of feed) were evaluated in a 5 × 2 factorial arrangement of 10 dietary treatments. All diets were equivalent in metabolisable energy and digestible amino acid content. A total of 400, one-d-old male broilers (five cages/treatment; eight birds/cage) were used in the experiment.

2. Regardless of enzyme supplementation, feed intake declined (P < 0.001) with increasing inclusion of WSHL barley. Increasing levels of WSHL barley (P < 0.001) and supplemental enzyme (P < 0.01) increased gain to feed ratio.

3. Birds fed diets with 0 g/kg WSHL barley showed the lowest (P < 0.001 to 0.01) digestibility for all nutrients except starch. Only starch digestibility was improved (P < 0.05) by enzyme supplementation. The nitrogen-corrected apparent metabolisable energy improved with increasing inclusion of WSHL barley (P < 0.001) and supplemental enzyme (P < 0.001). Increasing inclusion of WSHL barley increased the relative weight of gizzard (P < 0.001) and reduced jejunal digesta viscosity (P < 0.01). Supplemental enzyme (P < 0.001) reduced digesta viscosity.

4. All levels of WSHL barley inclusion improved digestibility of dry matter, nitrogen and fat, whilst energy utilisation improved at inclusions of 130 g/kg WSHL and above, probably due to lowered digesta viscosity and better development of the gizzard. Gain to feed ratio, starch digestibility, energy utilisation and jejunal digesta viscosity can benefit from carbohydrase supplementation in wheat-based diets, regardless of barley inclusion level.     

Digestibility,productive performance,and egg quality of laying hens as affected by dried cassava pulp replacement with corn and enzyme supplementation

Two experiments were conducted to investigate the potential use of dried cassava pulp (DCP) supplemented with enzymes as an alternative feed ingredient in laying hen diets. In experiment 1, 45 laying hens (Isa Brown) aged 45 weeks were placed in individual cages to measure nutrient digestibility for 10 days. Nine dietary treatments were control and DCP as a replacement for corn at 20, 25, 30, and 35% supplemented with mixed enzymes (cellulase, glucanase, and xylanase) at 0.10 and 0.15%. Results showed that the use of DCP at 20–35% added with mixed enzymes had no negative effects on dry matter digestibility, while organic matter digestibility and nitrogen retention decreased with increased DCP up to 30–35% in diets. Both enzyme levels (0.10 and 0.15%) showed similar results on nutrient digestibility and retention. In experiment 2, a total of 336 laying hens aged 32 weeks were randomly allocated to seven dietary treatments (control and DCP-substituted diets at 20, 25, and 30%) supplemented with mixed enzymes (0.10 and 0.15%). Diets incorporated with 20–30% of DCP and supplemented with mixed enzymes at both levels had no significant effects on egg production, egg weight, feed intake, egg mass, feed conversion ratio, protein efficiency ratio, or egg quality, except for egg yolk color being decreased with an increase of DCP in diets (P?<?0.05). In conclusion, it is suggested that DCP supplemented with enzymes can be used as an energy source in laying hen diets up to 30% without showing negative effects on nutrient digestibility, productive performance, or egg quality.     

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.     

Pasture,multi-enzymes,benzoic acid and essential oils positively influence performance,intestinal organ weight and egg quality in free-range laying hens

1. The objective of this study was to investigate the effect of range type, multi-enzyme applications, and a combination of benzoic acid (BA) and essential oils (EO) on the productive performance, organ weight and egg quality of free-range laying hens.

2. Three hundred laying hens were evaluated for the short-term (6 weeks) and long-term (12 weeks) effects of range type (G = no pasture, P = pasture) and feed additives (T1 = control; T2 = betaglucanase/pectinase/protease; T3 = BA/EO). Body weight, feed intake (FI), feed conversion ratio (FCR), egg production (EP), digestive organ weight, and egg quality (EQ) were evaluated. Data were analysed using SPSS 2.2 in a 2×2×3 factorial arrangement.

3. Hens that ranged on pasture were significantly heavier (2043 g vs. 1996 g; p < 0.001), laid heavier eggs (61.9 g vs. 60.3 g; p < 0.001) and produced darker yolk colour (4.3 vs. 7.0; p < 0.001) compared to hens ranged on gravel. Hens fed T2 were significantly heavier (2050 g) compared to hens fed T1 (2005 g) or T3 (2008 g). Organ weights (gizzard, liver and pancreas) were significantly heavier in hens ranged on pasture (16.8 g/kg BW, 22.3 g/kg BW and 1.89 g/kg BW, respectively) compared to hens ranged on gravel (14.2 g/kg BW, 21.7 g/kg BW and 1.83 g/kg BW, respectively). Over time, body weight (1970–2070 g; p < 0.001) and egg weight (59.5–62.8 g; p < 0.001) increased, FI (123–120 g; p = 0.024) was reduced and FCR (2.36–2.10; p = 0.002) improved

4. In conclusion, hens housed on pasture and fed multi-enzyme supplemented diets had significantly heavier body weight and produced heavier eggs with darker yolk colour. Pasture intake and enzyme supplementation increased digestive organ weight significantly.     

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.     

Nutrient content and digestibility of different batches of wheat distillers dried grains with solubles for laying hens

ABSTRACT

1. Four batches of wheat distillers dried grains with solubles (DDGS) produced by a single production plant were used to investigate variation in digestible energy (DE) and nutrient digestibility for laying hens.

2. A total of 144 Hy-Line Brown laying hens were allocated to eight treatment groups in replicates of six. Experimental diets were prepared by replacing the basal feed with either 150 g/kg or 300 g/kg of each batch of DDGS.

3. Chemical analysis of the DDGS showed variation between the different batches. Largest coefficients of variation were observed for starch (0.546) and total soluble non-starch polysaccharides (NSP; 0.276).

4. Digestible energy and the nutrient digestibility of each diet was measured using the ileal collection technique. Data were statistically analysed as a blocked 2 × 4 factorial design analysis of variance (ANOVA).

5. Variability between the different diets were observed for digestible energy and the digestibility of certain nutrients (P < 0.05).

6. The observed differences in energy utilisation and nutrient digestibility in laying hens suggested that the feeding quality of diets containing different wheat DDGS batches produced by a single production plant may still have large variation.     

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.

     

Potential of dried cassava pulp as an alternative energy source for laying hens

Two experiments were conducted to evaluate the potential use of dried cassava pulp (DCP) with reference to productive performance, nutrient digestibility, egg quality, egg yolk cholesterol, cecal microbial populations, and volatile fatty acids production in laying hens. In experiment 1, a total of 48 laying hens (Isa Brown) were placed in individual cages and assigned randomly to one of 6 dietary treatment groups consisting of a control and 5, 10, 15, 20, and 25% DCP for 10 d. Feeding laying hens with diets containing up to 20% DCP did not affect the dry matter (DM) and organic matter (OM) digestibility and nitrogen (N) retention (P > 0.05). In experiment 2, a total of 288 laying hens (Isa Brown) were randomly distributed to 6 dietary groups (one control and 5 DCP: 5, 10, 15, 20, and 25%) for 12 wk. The results show that diets containing up to 20% DCP had no significant effects on productive performance or egg quality (P > 0.05). The inclusion of DCP at levels of 20 to 25% showed a positive effect on decreased egg yolk cholesterol (P < 0.05). In addition, DCP also increased the cecal Lactobacillus and Bifidobacterium populations, acetic acid, and propionic acid production. In conclusion, DCP can be used as part of the energy source in laying hen diets at up to 20% inclusion, without showing negative effects on productive performance, nutrient digestibility, and egg quality. Feeding DCP can potentially modulate egg yolk cholesterol and cecal microbial populations and alter volatile fatty acids production.     

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 dietary energy,protein, and a versatile enzyme on hen performance,egg solids,egg composition,and egg quality of Hy-Line W-36 hens during second cycle,phase two

This study was conducted to evaluate the effect of Rovabio, dietary energy, and protein on performance, egg composition, egg solids, and egg quality of commercial Leghorns in phase 2, second cycle. A 4 × 2 × 2 factorial arrangement of treatments comprising 4 dietary energy levels (2,791, 2,857, 2,923, and 2,989 kcal of ME/kg) and 2 protein levels (15.5 and 16.1%) with and without Rovabio was used. Hy-Line W-36 hens (n = 1,920, 87 wk old) were randomly divided into 16 dietary treatments (8 replicates of 15 hens per treatment). The trial lasted 12 wk. Dietary protein significantly increased feed consumption but decreased yolk color. As dietary energy increased from 2,791 to 2,989 kcal of ME/kg, feed consumption decreased from 98.0 to 94.9 g per hen daily, and yolk color increased from 5.27 to 5.56. There was a significant interaction among dietary protein, energy, and Rovabio on egg production, BW, egg mass, feed conversion, and yolk solids. Egg weight of hens fed the diets supplemented with Rovabio was significantly greater than that of hens fed the diets without Rovabio during wk 3 and 4. However, Rovabio did not significantly influence average egg weight (87 to 98 wk of age). Rovabio supplementation significantly increased BW of hens. These results suggest Rovabio had a small but significant influence on nutrient utilization of commercial Leghorns during phase 2 of the second cycle.     

Effects of dietary red pepper on egg yolk colour and histological intestinal morphology in laying hens

To evaluate the effect of three kinds of red pepper supplementation ‘Kagawa Hontaka’ produced at Shiwaku Islands (KHS), Miki (KHM) and Takanotsume (TKT) on production performance, egg quality and intestinal histology in laying hens. A total of 32 laying hens (39 weeks of age) were randomly allotted to four groups, each comprising eight hens. Birds were fed a basal diet supplemented with red pepper at 0% (control), 0.5% KHS, 0.5% KHM and 0.5% TKT, respectively. Compared with the control group, no significant difference (p > 0.05) in feed consumption, final body weight, hen‐day production, egg mass, feed efficiency, shell‐breaking strength, shell thickness, shell ratio, albumen ratio, yolk ratio and Haugh units was observed among the experimental groups. Roche yolk colour fan (RYCF) value increased significantly in all experimental groups (p < 0.05). Furthermore, the KHS and KHM groups showed higher RYCF values than the TKT group (p < 0.05). Spectrophotometric measurements of yolk colour, redness (a*) and yellow index (YI) values were higher in the KHS and KHM groups (p < 0.0001). The yellowness (b*) value was lower in the TKT group (p < 0.05). The lightness (L*) value was lower in the KHS and KHM groups (p < 0.05). Villus height, villus area, cell area and cell mitosis in all intestinal segments tended to be higher in all experimental groups. Jejunal cell area and cell mitosis were higher in experimental groups than in the control group (p < 0.05). The cells on the villus tip surface were protuberated in all experimental groups. In conclusion, the KHS, KHM and TKT groups showed hypertrophied intestinal villi and epithelial cell functions. These results indicate that dietary red pepper has stimulating effect on intestinal villi and the structure of epithelial cells, and the 0.5% KHS and KHM groups improved in egg yolk colour.     

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.     

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.     

Laying hen performance,egg quality improved and yolk 5-methyltetrahydrofolate content increased by dietary supplementation of folic acid

This study was performed to evaluate the effect of folic acid (FA) on performance, egg quality and yolk 5-methyltetrahydrofolate (5-MTHF) content. A total of 384 Hy-line W36 strain hens from 52 to 58 weeks of age were randomly assigned to 4 groups, and each group received one of following dietary treatments: 0, 5, 10 and 15 mg FA/kg diet. A completely randomized design was used. Egg production percentage, egg mass and egg weight were increased significantly (P < 0.05) and feed conversion ratio (FCR) was reduced significantly (P < 0.05) by increasing FA content in diets. No significant differences were detected among treatments on egg quality except for shell thickness. The dietary supplementations of laying hens diets with FA significantly increased yolk 5-MTHF content (P = 0.02). Overall, these data demonstrate that dietary supplementation with FA raised 5-MTHF content of yolk and productivity of egg production 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.     

Comparison of single- and multi-strain probiotics effects on broiler breeder performance,egg production,egg quality and hatchability

ABSTRACT

1. This study was conducted to investigate the effect of multi-strain probiotic (containing Lactobacillus acidophilus 2.5 × 10⁷ cfu/g, Lactobacillus casei 2.5 × 10⁷ cfu/g, Bifidobacterium thermophilum 2.5 × 10⁷ cfu/g and Enterococcus faecium 2.5 × 10⁷ cfu/g) and single-strain probiotic (Pediococcus acidilactici 1 × 10¹⁰ cfu/g) on broiler breeder performance and gastrointestinal health.

2. A completely randomised trial was conducted using 300 broiler breeder hens (Ross 308) aged 51 weeks old which were randomly allocated to 1 of 5 dietary treatments with 6 replicates per treatment in a 10 week trial. Treatments included (1) the basal diet a negative control, (2) basal diet supplemented with 0.1 g/kg multi-strain probiotic (MS), (3) basal diet supplemented with 0.1 g/kg single-strain probiotic (SS), (4) basal diet supplemented with 0.1 g/kg of both of probiotics (MS+ SS) and (5) positive control basal diet supplemented with 0.5 g/kg oxytetracycline antibiotic (OX).

3. Body weight, egg production, yolk weight, eggshell thickness and weight, Haugh unit, fertility and hatchability were determined. Results showed that dietary treatments had no significant effect on total hen house or total hatching egg production, egg weight, yolk colour index, shell weight, mortality, body weight, fertility, hatchability, oviduct and stroma weight or number of large and small yellow follicles (P > 0.05). None of the jejunum morphological parameters, apparent ileal digestibility of protein and ileal Lactobacillus population were influenced by supplemental probiotics (P > 0.05), although ileum Escherichia coli count was reduced by inclusion of dietary probiotics (P < 0.05).

4. It was concluded that although both probiotic treatments reduced coliforms, they did not improve broiler breeder performance or gastrointestinal tract (GIT) function.     

Thermostable xylanase derived from Trichoderma citrinoviride increases growth performance and non-starch polysaccharide degradation in broiler chickens

ABSTRACT

1. The aim of this trial was to determine the optimal supplementation level of a xylanase enzyme from Trichoderma citrinoviride on growth performance, apparent ileal and total tract nutrient retention, intestinal morphology, and intestinal concentration of volatile fatty acids in broiler chickens.

2. A total of 600 broiler chickens (Ross 308) of mixed sex were randomly allotted to four treatments, on the basis of similar body weight. The dietary treatments were made from a corn-wheat-soy based diet supplemented with either 0, 3750, 7500, or 11 250 XU/kg xylanase and were fed to 32 d of age.

3. A linear response to increasing dietary xylanase was demonstrated for overall weight gain (P < 0.05) and feed conversion ratio (P < 0.05). The apparent total tract digestibility of dry matter and gross energy, and the coefficient of apparent ileal digestibility (CIAD) of N and soluble non-starch polysaccharides were linearly improved when xylanase was added to the diet (P < 0.05). Moreover, a linear increase (P < 0.05) was observed in the CIAD of Arg, Lys, and Try with increasing dietary levels of xylanase.

4. The viscosity of digesta in ileum was linearly decreased when dietary xylanase level increased (P < 0.05).

5. An increase in villus height of the duodenum and jejunum were observed with increasing dietary levels of xylanase (linear, P < 0.05).

6. Overall, the results showed that the effects of dietary xylanase supplementation on broiler performance was determined through effects on nutrient availability and intestinal morphology.     

Superdosing phytase reduces real-time gastric pH in broilers and weaned piglets

1. The current study was conducted to investigate the effect of high phytase doses on growth performance and real-time gastric pH measurements in broiler chickens and pigs.

2. In the first experiment, 576 male Ross 308 broilers were fed in two phases (0–21 and 21–42 d) with 4 treatment groups, with diets meeting nutrient requirements containing 0, 500, 1500 or 2500 FTU/kg phytase. In the second, 64 Landrace weaners were fed on diets meeting nutrient requirements with or without phytase (0 or 2500 FTU/kg) in two phases (0–21 and 21–42 d). Heidelberg pH capsules were administered to 7 broilers and approximately 13 pigs per treatment group, pre- and post-phase change, with readings monitored over several hours.

3. Addition of phytase into an adequate Ca and P diet had no significant effect on broiler performance although phytase tended (P < 0.07) to improve feed conversion in pigs over the entire experimental period. Real-time pH capsule readings in broilers demonstrated an increase (P < 0.05) in gizzard pH when phytase was dosed at 500 or 1500 FTU/kg, while higher doses of 2500 FTU/kg phytase lowered pH to a level comparable to control birds. Gastric pH increased (P < 0.01) when animals were exposed to dietary phase change, signifying a potential challenge period for nutrient digestibility. However, pigs fed 2500 FTU/kg were able to maintain gastric pH levels through diet phase change. In contrast, spear-tip probe measurements showed no treatment effect on gastric pH.

4. These findings demonstrate dietary manipulation of gastric pH and the value of real-time pH capsule technology as a means of determining phytase dose response.     

Effect of nutrient density on production performance, egg quality and humoral immune response of brown laying (Dahlem Red) hens in the tropics

A study was conducted to evaluate the effect of various concentrations of metabolizable energy (ME) with graded incremental levels of crude protein (CP) and essential amino acids (lysine and methionine) on production performance, egg quality and humoral immune response of Dahlem Red laying hens. Four experimental diets based on maize–soybean meal-deoiled rice bran were prepared. Diet 1 was fed as a control diet containing 2,600 kcal ME/kg, 15% CP, 0.75% Lys and 0.36% Met, and in the other three diets (D2, D3 and D4), concentrations of the above nutrients were increased by 2.5%, 5.0% and 7.5%, respectively. The levels of Ca (3.5%) and available P (0.32) were constant in all the diets. Each diet was offered ad libitum from 28 to 40 weeks of age to eight replicates containing six birds in each replicate. The egg production, egg weight and egg mass (in grams of egg per hen per day) were not affected by increasing the nutrient density up to 7.5% (2,795 kcal ME/kg diet) compared to the control group (2,600 ME/kg diet). However, feed consumption and feed efficiency (in grams of egg per gram of feed) were influenced by the variation in the nutrient density of diets. As the nutrient density increased by 5% (2,730 ME/kg diet), birds consumed significantly (P < 0.001) less feed. The birds in the 7.5% higher density group produced significantly (P < 0.05) higher egg mass per unit feed consumption compared to the control diet. Increasing nutrient density up to 7.5% had no effect on relative weight of albumen, yolk or shell. The Haugh unit, yolk colour and shell thickness were also not affected due to variation in the nutrient density. The humoral immune response measured at 34 and 40 weeks was progressively improved by increasing the nutrient density up to 5%. Increasing the nutrient density beyond 5% in the diet had no further influence on the humoral immune response. Based on the results of the present study, it can be concluded that Dahlem Red laying hens required 2,795 kcal/kg ME, 16% CP, 0.8% lysine and 0.4% methionine for eliciting optimum performance and immune response during 28 to 40 weeks of age.