Impact of ß-glucan dietary supplementation on productive, reproductive performance and physiological response of laying hens under heat stress conditions.

The exploration for effective in-feed additives is growing owing to the global climatic change trend to alleviate the negative effects of heat stress in laying hens. This research assessed the potential of using B-glucan (G) as an antiheat stress agent in Matrouh laying hens subjected to early heat shock programs during the growing period. Factorial design (3 × 3) was used, including 3 levels of heat stress (control, heat shock at 3 d and at 3 d and 8 wk of age) and 3 levels of ß-glucan (0, 100, and 200 mg ß-glucan /kg diet). During the first 12 wk of egg production (EP), treatments were exposed to heat challenge. The results revealed that heat shock program applications at 3 d and 8 wk of age significantly decreased body weight at 36 wk of age (P < 0.05) and reduced (P < 0.05) feed intake (FI). While significantly (P < 0.05) improved feed conversion ratio (FCR), hemoglobin, RBCs, WBCs, immunoglobulin M (IgM), immunoglobulin G (IgG), and Heat shock protein (HSP70) of the Liver (P < 0.01) as compared with the control group. At the same time, there was a decrease in lymphocyte%, H/L ratio, cortisol, and T3 compared to the thermo-neutral control. When compared to the control group, hens fed a diet containing 200 mg of ßG significantly (P < 0.05) improved body weight at 16 wk and final weight at 36 wk, feed conversion (FCR) (g. feed/g. egg mass), hen-day egg production, and egg mass, as well as the digestibility coefficients of crude protein (CP), dry matter (DM), metabolizable energy (ME), and cortisol. The interactions between heat chock programs and ßG levels were nonsignificant for the most studied traits except daily feed intake. Therefore, the early heat shock exposure 2 times and supplementation of Β-glucan (ßG) at 200 mg/kg diet during the growth period for laying hens that are exposed to heat stress during the reproductive period could improve productive, reproductive performance, HSP70 level and enhance immunity responses.

Intermittent light program impacts on reproductive performance, health and welfare of breeding hens.

The lighting regime significantly impacts poultry production, reproductive performance, health and welfare. This study aimed to test the effect of the intermittent light (IL) regime on reproductive organs and hormones, semen quality, and behavioral performance. Thus, 270 Rhode Island Red hens aged 20 weeks were distributed among three groups of six replicates and 15 birds each, housed in floor pens. The first group was used as a control (C) and was exposed to constant light for 16 h d-1, while birds in other groups were exposed to IL for 20 min h-1 (T20) and 40 min h-1 (T40) during the 16 h light period. The outcomes were that follicle number was higher for T20 compared to T40 but not the controls, while T40 is different from T20 but not the controls. The same is true for testosterone. The sperm concentration is lower for T40 compared to the controls, with no difference between T20 and the controls. Body temperature was not different among groups. Conversely, differences were not noticed for leg alterations; plumage conditions; and relative ovary, oviduct, and/or testes weight and hatchability. Thus, the IL T20 program should be further investigated as a lighting regimen for managing Rhode Island Red laying hens for stimulating follicle number and testosterone without negatively impacting the physiological response and health traits. From a practical point of view, the IL schedule of 20 min h-1 during 20-36 weeks of age can be economically viable due to saving 66 % of the light cost.

Growth performance of broiler chickens fed diets supplemented with amylase and protease enzymes individually or combined.

Background: Feed additives that increase nutrient availability in feeds have gained a lot of interest. Aim: An experiment was conducted to determine whether amylase, protease, and their combined supplementation affected broiler performance. Methods: Two hundred eighty broiler chicks were selected and distributed randomly into 28 replicate pens with four treatment groups and seven replicates under a completely randomized design. A total of four diets were developed, having 0, 100, 100, and 100 + 100 g of control (AP0), amylase (A1), protease (P1), and amylase + protease (AP1)/ton of feed, respectively. Four replicates of each treatment were fed each diet. Each diet was randomly allotted to each group. Ad-libitum feeding was provided to the birds. The feeding program had starter and finisher diets. Upon completion of the experiment, three birds from each pen were slaughtered to analyze the carcass characteristics and organ weight. Results: Differences were insignificant between 100 g/ton of amylase supplementation and FI, body weight gain (BWG), or feed conversion ratio (FCR) (p > 0.05). Supplementation with 10 0g/ton of protease did not significantly affect FI, BWG, and FCR (p > 0.05). Similarly, 100 + 100 g/ton of amylase + protease addition had no significant effect on FI, BWG, and FCR (p > 0.05). None of the treatments significantly affected carcass weight, abdominal fat percentage, dressing percentage, drumstick, wings, breast, and thigh weights (p > 0.05). In addition, there were no significant effects (p > 0.05) on the weight of the heart, liver, gizzard, and spleen. Conclusion: In conclusion, amylase, protease, and their combined supplementation at a rate of 100 g/ton of feed did not influence BWG, FI, FCR, carcass characteristics, or organ weight.

Rice gluten meal as a substitute for soybean meal in the diets for growing rabbits.

The impacts of different dietary levels of rice gluten meal (RGM) on growth performance, digestibility, carcass characteristics, and blood traits of growing New Zealand White (NZW) rabbits were studied. One hundred and twenty, 6 weeks old weaned male rabbits (body weight; 682 [g] ± 23) were randomly allotted into four groups. The control diet contained 160 [g/kg] soybean meal (SBM), while the other three diets were obtained by replacing 40, 80, and 120 [g/kg] SBM with RGM (RGM40, RGM80, and RGM120, respectively). The results showed that RGM contained higher levels of dry matter (DM), crude protein (CP), ether extract (EE), ash, and gross energy than SBM. RGM contained a high level of arginine followed by leucine and valine as essential amino acids and high levels of glutamic, aspartic acid, and alanine as non-essential amino acids. The obtained results showed that the final body weight of rabbits fed diets containing 40, 80, and 120 [g/kg] RGM was higher than those fed the control diet. The daily weight gain of rabbits fed RGM diets increased (p < 0.05) by 10.50%, 6.50%, and 10.00%, respectively, compared to the control group. Rabbits fed RGM80 showed the highest (p < 0.05) digestibility of DM, organic matter (OM), EE, neutral detergent fibre (NDF), and acid detergent fibre (ADF) compared to the other tested levels. Rabbits fed RGM120 had the highest (p < 0.05) digestible energy (DE) and digestible crude protein (DCP) values. RGM inclusion levels of 40 and 80 [g/kg] increased (p < 0.05) plasma total protein and albumin compared to the control group. Rabbits fed a diet containing RGM40 had the highest (p < 0.05) globulin level. The highest (p < 0.05) plasma urea concentration level was measured in the rabbit group fed the RGM120 diet. Conclusively, RGM could be a valuable ingredient for growing rabbits, as at all the tested levels improved growth performance, digestibility, and nutritional values.

Restricted feeding could enhance feed conversion ratio and egg quality of laying Japanese quail kept under different stocking densities.

Impacts of different stocking densities and feed restriction on egg production and quality and blood biochemicals of laying Japanese quail (Coturnix coturnix Japonica) were studied. A total number of 360 adult Japanese quails were used in an experiment, including two stocking densities (300 and 200 cm2/bird) and four feed restriction levels (ad libitum, 25, 30 and 35 g/day/bird). As a result of this study, feed restriction (30 g/bird/day) enhanced most of egg production traits and improved hatchability. Albumen and egg shell thickness showed the highest values when birds fed ad libitum and 35 g/bird/day. Blood total protein, albumin, Aspartate Aminotransferase (AST) and cholesterol were higher in quails housed at 200 cm2/bird than those kept at 300 cm2/bird. The highest values of blood total protein, albumin, AST and cholesterol were found in quails fed ad libitum. Activity of superoxide dismutase was the highest estimate when birds stocked at 300 cm2/bird and fed ad libitum or 25 g/day. Conclusively, decreasing space per bird had a negative effect on performance. Feed restriction can achieve a better feed conversion ratio (FCR).

Influences of vitamin A, L-carnitine, and folic acid in ovo feeding on embryo and hatchling characteristics and general health status in ducks.

The current investigation was conducted to test the potential effects of in ovo feeding of vitamin A, L-carnitine, and folic acid on embryonic growth and post-hatch performance. A total of 450 fertile duck eggs were randomly distributed into two experiments of five groups/experiment (255 eggs/experiment and 45 egg/group). The experimental groups were: negative control (non-injected eggs), positive control (eggs were injected with 0.1 ml sterile deionized; DI water/egg), and three other treatments in which vitamin A, L-carnitine, and folic acid were injected (1 mg of each nutrient dissolved in 0.1 ml sterile DI water/egg). All-in ovo injected groups with vitamin A, L-carnitine, and folic acid increased the embryo weight, residual yolk weight, heart weight, hatchability percentage, and embryo length at the 25th day of incubation. At hatching, all micronutrients-in ovo injected treatments increased the duckling's weight, levels of blood hemoglobulin, plasma triiodothyronine, and thyroxin, insulin-like growth factor1, total protein, albumin, and globulin, compared with the controls in both experiments. Conclusively, the in ovo feeding of the present micronutrients showed positive impacts on embryonic development, hatchling health status of ducklings.

Effects of lighting source as an environmental strategy for heat stress amelioration in growing Californian rabbits during summer season.

The current work investigated the influences of different light sources on growth performance, carcass characteristics, blood biochemicals, physiological status and health aspects. One hundred and twenty growing California rabbits were assigned into four empirical collections in an experiment of completely randomized design. Rabbits of the first collection were reared under incandescent light bulbs (control), while the second, third and fourth collections were reared under fluorescent, saving light and LED light bulbs, respectively. The results indicated that rabbits reared under incandescent and LED had the heaviest body weight at 16-weeks-old. Rabbits reared under LED recorded the greatest gain during 14-16 weeks of age and 6-16 weeks of age. The lowest feed conversion ratio was observed in rabbits reared under LED lighting, during 14-16 weeks of age, and during the whole period without significant variations. Fat percentage (%) was low in rabbits exposed to fluorescent and LED. Rabbits grown under LED showed the lowest albumin/globulin and the highest glucose concentration. Rabbits kept under LED showed the lowest rectal temperature, mortality and health risks %. Conclusively, LED lighting source might be appropriate for alteration of incandescent and fluorescent light sources in rabbit farms to improve growth performance without compromising rabbit's carcass and welfare.

Efficacy of dietary inclusion of biologically treated pruning peach trees by-products on growth performance, blood biochemicals and economic efficiency of New Zealand White rabbits.

This work examined the influences of partial replacement of clover hay with 15 or 30% of untreated pruning peach trees by-products (UPPT) or those biologically treated (BTPPT) with effective microorganisms (EM1) on growing rabbit performance. Seventy-five NZW weaned rabbits (6-weeks-old; average body weight 657 g) were assigned randomly into five groups. Five pelleted diets were used, control and other four diets (15 or 30% UPPT or BTPPT were replaced of clover hay). The biological treatments improved the chemical composition of pruning peach trees by-product, in terms of increasing crude protein and decreasing crude fiber as compared to UPPT. Final body weight, body weight gain, feed conversion ratio and performance index values were enhanced when rabbits fed either 15 or 30% BTPPT. Digestibilities of crude protein, crude fiber, nitrogen free extract, total digestible nutrients and digestible energy were increased with rabbits fed diets containing BTPPT. Carcass traits studied, moisture, crude protein (CP), ash, ether extract (EE) of rabbits meat, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities, total cholesterol, creatinine and urea were not different between the applied treatments. Net revenue and economic efficiency were increased with the biological treatment. Conclusively, BTPPT could be used up to 30% with positive effects on growth performance, physiological functions and economic efficiency in NZW growing rabbits.

Role of clay in detoxification of aflatoxin B1 in growing Japanese quail with reference to gender.

The present study investigated the influence of the quail diet polluted with aflatoxin B1 (AFB1) and its detoxification by using clay as a feed additive on the growth performance and some blood biochemical components of growing Japanese quail with reference to sex. A total number of 120 Japanese quail chicks (1 week old), was randomly divided into 10 groups (24 chicks/ group). A 5 × 2 factorial arrangement experiment was performed and included five levels of AFB1 (0 ppm, 1 mg/kg AFB1, 1 mg/kg AFB1 + 1% clay, 2 mg/kg AFB1 and 2 mg/kg AFB1 + 1% clay) and two sexes. Birds fed with aflatoxin free diet had significantly (P ≤ 0.05 and 0.01) higher final live body weight, weight gain and lower mortality rate than the other groups. Addition of 1% clay significantly (P ≤ 0.05 and 0.01) improved the growth performance traits and diminished aflatoxin effect when compared to groups without the addition of clay. Obtained results indicated significant (P ≤ 0.05) differences between the two sexes in their response to aflatoxicosis in the final live body weight and weight gain. Our results showed significant (P ≤ 0.01) changes in all blood biochemicals (total protein, albumin, globulin, total cholesterol, creatinine, uric acid) and activities of serum enzymes studied due to the toxicity of AFB1. Conclusively, the consumption of polluted diets with AFB1 caused deleterious effects on the growth performance and blood biochemicals components of Japanese quail, while dietary addition of natural clay to the diet of growing Japanese quail caused beneficial effects.

Yeast as growth promoter in two breeds of growing rabbits with special reference to its economic implications.

The present study investigated the effects of dietary supplementation of Saccharomyces cerevisiae (SC) on growth performance, carcass traits, blood biochemical parameters, histological changes in intestinal wall and economic indices in two breeds of weanling rabbits (V-Line and Rex). One-hundred and twenty weaned male rabbits were allotted randomly into four groups in factorial arrangement. The results could be summarized as follows: dietary supplementation of SC significantly accelerated body weight gain (BWG), reduced feed conversion ratio (FCR) and increased profit. The highest BWG and the lowest FCR were noticed in each breed when interacted with SC. There were non-significant differences in carcass traits due to the studied factors, except in loin and dressing percentages. The highest percentages of loin and dressing were obtained from V-line when fed diet supplemented with SC. The treated rabbits with yeast were characterized by an increase in Brunner`s gland and villi. Dietary Supplementation of SC decreased blood total glycerides and cholesterol and increased blood total protein, albumin and A/G ratio. The treated group showed higher profitability than the control. Conclusively, dietary supplementation of SC provided beneficial effects in growth performance and profitability of rabbits. Finally, dietary supplementation of SC is highly recommended in growing rabbits.

Effects of ecofriendly synthesized calcium nanoparticles with biocompatible Sargassum latifolium algae extract supplementation on egg quality and scanning electron microscopy images of the eggshell of aged laying hens.

In the present study, 200 Brown commercial egg-type layers (60 wk old) were used to study the effects of different levels of ecofriendly synthesis of calcium (Ca) nanoparticles (0.0, 0.50, 1.0, and 1.5 g/kg diet) with biocompatible Sargassum latifolium algae extract (SL-CaNps) on exterior egg quality traits, electronic microscopic view of eggshells, Ca and phosphorus (P) retention, serum Ca and P concentrations, and the histology of the uterus. Hens fed with dietary SL-CaNps powder had higher egg weight and shell weight % values than those of the control group. All SL-CaNps treatment groups had the greatest values of shell weight per unit surface area and shell thickness. Dietary supplementation of SL-CaNps at graded levels up to 1.5 g/kg diet had higher serum Ca and inorganic P levels than that of the control. Laying hens fed with SL-CaNps-added diets had beneficial effects on shell ultrastructure in terms of well-developed palisade and mammillary layers. The numbers of apical cells along the branched tubular gland were greater in SL-CaNps-treated groups than those of control. Conclusively, supplementing SL-CaNps powder up to 1.5 g/kg to the diet of laying hens improved eggshell thickness, shell weight% and shell weight per unit surface and has no adverse effect on their eggshell quality or electronic microscopic view of their eggshell.

Influence of dietary graded levels of lycopene on the growth performance, muscle cholesterol level and oxidative status of Japanese quail fed high-fat diet.

This study investigated the impact of supplementing normal and high-fat diets with graded levels of lycopene on the growth performance, cholesterol level of the muscle, and antioxidant markers in Japanese quail. A total of 192, 14 day-old unsexed Japanese quail were part of a 2 x 4 factorial arrangement consisting of a control group; birds that were fed a normal fat diet (NFD), another control group; birds that were fed a high-fat diet (HFD) with four levels of lycopene for NFD and HFD (0, 100, 200 and 300mg lycopene/kg diet). Lycopene level of 300mg/kg gave the greatest body weight, body weight gain, and relative growth rate when added to the NFD, but this level showed non-significant improvement in growth performance when supplemented to an HFD. Superoxide dismutase in the muscle and liver was noted to be high in NFD+ 300mgL, HFD+ 200mgL, and HFD+ 300mgL groups, while malondialdehyde level in the muscle and liver and cholesterol level in the muscle was found to be low in the same groups. Lycopene slightly improved growth performance, but significantly improved the antioxidant status and lowered cholesterol concentration in the muscle. A diet supplemented with 300 mg lycopene/kg could be recommended for Japanese quail.

Lighting programs as an appliance to improve growing New Zealand white rabbit's performance.

Lighting regimes are possibly used as a strategy to improve rabbit production in tropical regions; on this background, this study was conducted to assess the possible role of different light (L):dark (D) regimes in improving growing New Zealand white rabbit's performance. Sixty-four growing rabbits were randomly divided into four groups. Rabbits of the first group (C) were exposed to 12 h of light (from 10.00 to 22.00 h). Rabbits of the second group (T1) were exposed to 12 h of light (from 22.00 to 10.00 h). The third group (T2) was exposed to 8 h of light (from 10.00 to 18.00 h), while the fourth group (T3) was exposed to 8 h of light (from 22.00 to 06.00 h). Temperature-humidity index values ranged between 27.00 and 28.87, indicating exposure of growing rabbits to very severe heat stress. Body weight (BW), body weight gain (BWG), feed consumption (FC), feed conversion ratio (FCR), carcass traits, blood parameters, and some physiological (rectum temperature, respiration rate) and health aspects (morbidity, mortality, and health risks %) were investigated. Rabbits of T1 showed the highest (P < 0.05) averages of BW and BWG in comparison with their counterparts. There were no significant differences in FC; however, rabbits of T1 had the lowest value of FCR at marketing. The percentages of dressed carcass, liver, and kidney in T1 and T3 were the highest. Non-significant changes were observed among the groups in most of the metabolic and hematology parameters of blood, except for ALT and N/L ratio. Further, rabbits of T1 showed the lowest rectal temperature and respiration rate in comparison with their counterparts. Conclusively, the utilization of photoperiod of afternoon program for over a short period of time in rabbitry brought in beneficial effects on growth performance and other productive and physiological parameters of growing rabbits.

Response of duck breeders to dietary L-Carnitine supplementation during summer season.

A total number of 300 (225 ducks and 75 drakes) Sudani ducks, 28-wk-old were divided into five groups to investigate the effects of dietary L-carnitine (LC) supplementation on productive, hatching and physiological performance as well as nutrients digestibility coefficients. The results indicated that the productive performance and Semen quality parameters (ejaculate volume, sperms concentration and advanced motility) were significantly improved by LC supplementation (150-450 mg /kg diet) as compared to the control. Hatchability of fertile eggs (%) was significantly improved, while total embryonic mortality was significantly decreased by supplementing 300 and 450 mg LC/kg diet. Supplementing different dietary LC levels resulted in significantly high values of hemoglobin, red and white blood cells count and lymphocyte (L) cells percentage, while it decreased heterophils (H) cells and H/L ratio. Serum albumin, total cholesterol and AST enzyme values were significantly low in ducks fed diets supplemented with LC. Serum triglycerides were significantly the lowest by feeding 300 and 450 mg LC/kg diet. Nutrients digestibility coefficients were significantly improved in drakes fed diet supplemented with 450 mg LC/kg diet. Conclusively, dietary LC supplementation at 300 or 450 mg/kg for duck breeders in summer could improve productive, hatching and physiological performance and nutrients digestibility coefficients.

Influences of stocking density and dietary probiotic supplementation on growing Japanese quail performance.

This study investigated the effects of stocking density and dietary supplementation of probiotic (Lactobacillus) on growth, traits of carcass, lymphoid organs and intestinal microbial count of Japanese quail. Quail chicks (one week old) were randomly allotted to 6 groups in a 2×3 factorial experiment included 2 levels of stocking density (100, and 75 cm2/bird) and 3 levels of probiotic (0.00, 0.02 and 0.04 g/kg diet). Quail reared at 100 cm2/ bird showed significantly the highest body weight and daily gain. Quail reared at 75 cm2/ bird had significantly the lower average of feed consumption and the best ratio of feed conversion. Increasing level of probiotic up to 0.04 g/kg led to a significant decrease in dressing percentage by about 2.7 % compared to the control. Interaction effect was insignificant on carcass traits studied except for liver percentage which was significantly higher for birds fed diet supplemented with probiotic at 0.04 g/kg of diet and reared at 100 cm2/bird. Rearing quail at 100 cm2/bird stocking density significantly increased bursa weight. Birds fed diet supplemented with probiotic at 0.02 g/kg of diet and reared at 100 cm2/bird showed significantly the highest (p = 0.043) spleen weight when compared with the other groups. In conclusion, the low (100 cm2/bird) stocking density was sufficient to give better performance of Japanese quail than the other group. Probiotic supplementation diminished the stressful effect of crowding on growing Japanese quail.

Laying Performance, Physical, and Internal Egg Quality Criteria of Hens Fed Distillers Dried Grains with Solubles and Exogenous Enzyme Mixture.

: The effects of dietary inclusion of distillers dried grains with solubles in laying hen diets with and without exogenous enzyme mixture (EEM) on performance and egg characteristics were evaluated. One of the main objectives of this study was to examine the effects of distillers dried grains with solubles (DDGS) and enzyme cocktail on egg yolk fatty acids. The study used total of 144 Hisex Brown laying hens in a 4 × 2 factorial arrangement, including four levels of DDGS (0, 6, 12, and 18% of diet) and two levels of enzyme cocktail (0 or 250 mg EEM/kg of diet) through 32⁻42 weeks of the age. The inclusion of 18% DDGS was associated with the worst (p ≤ 0.001) egg production and the lowest daily feed intake. Numerically, hens fed 6% DDGS diet consumed more feed and had the greatest egg production. The best feed conversion ratio (FCR) was recorded in the control, while the worst was recorded in the 18% DDGS group. Compared with EEM-free diets, EEM supplementation improved FCR by about 2.79%, but the difference was not significant. Shell thickness and shell percentage were significantly increased in hens fed 6% DDGS diet compared to other groups. Egg weights in the 6% and 12% DDGS groups were significantly higher than those in the control and 18% DDGS groups. Non-significant increases in shell and albumin percentages were recorded in groups fed EEM-supplemented diets. The interaction effect of DDGS and EEM was significant (p ≤ 0.01) for the majority of egg characteristics. As dietary DDGS level increased, yolk color density increased. Elevating DDGS level up to 18% increased yolk cholesterol, total fat, and total unsaturated fatty acids. The effects of EEM supplementation on egg yolk fatty acid composition and the interaction effects between DDGS and EEM were not significant. Considering these results, it could be concluded that DDGS is an acceptable feed ingredient in layer diets and that the maximum inclusion level of DDGS should not exceed 12% of the whole diet.

Influences of dietary crude protein and stocking density on growth performance and body measurements of ostrich chicks.

Thirty-six African Black ostrich chicks were used to investigate the effects of dietary crude protein (CP) levels (180, 210 and 240 g/kg), stocking density (4.5 and 3 m2/bird) and their interactions. A factorial arrangement was used to examine the impact of treatments on growth performance and body measurements of ostrich chicks during 2 to 10 weeks of the age. Results indicated that factors studied did not change growth performance traits. The highest value of protein efficiency ratio was observed in ostrich chicks fed diet contained 240 g/kg diet. Birds fed diet contained 240 g CP /kg diet and kept at stocking density of 3 m2 per bird had numerically the highest protein efficiency ratio. Shank girth and tibiotarsus length decreased with increasing dietary CP level. Stocking density did not change values of body measurements, except tibiotarsus length at 6 weeks of age, which increased in birds kept at the lower density than the higher. Body height at 10 weeks of age was significantly affected by the interactions between dietary CP and stocking density. In conclusion, results affirmed that ostrich chicks can grow on diets containing low levels of CP (180-210 g/kg). Our results provide a comprehensive set of morphometric data for ostrich chicks as affected by the factors studied.

Productive performance, egg quality, hematological parameters and serum chemistry of laying hens fed diets supplemented with certain fat-soluble vitamins, individually or combined, during summer season.

This present study aimed to determine the efficacy of supplementing layer diets with vitamin A (0, 8,000 and 16,000 IU/kg diet) and vitamin E (0, 250 and 500 mg/kg diet) either individually or in combination on egg production and quality, and blood hematology and chemistry of birds reared under summer conditions. A total of 135 Bovans Brown laying hens were distributed to 9 treatment groups with 5 replicates of 3 hens/pen in a 3 × 3 factorial design. A significant improvement in feed conversion ratio (FCR) was observed as supplementary vitamin A or E increased (P ≤ 0.01). Hens fed diets supplemented with 16,000 IU vitamin A plus 500 mg vitamin E/kg diet had the best FCR among all groups. Egg quality traits were not significantly affected by the interaction of vitamin A and vitamin E levels. There was a significant increase in monocytes (P ≤ 0.01) and a decrease in basophils counts (P ≤ 0.05) in response to vitamin E. Significant decreases were observed in packed cell volume (PCV), thyroxine (T4), alanine transferase (ALT), albumin, total cholesterol and total lipids ( (P ≤ 0.05 or P ≤ 0.01) P ≤ 0.01) , and increases were observed in serum concentrations of globulin (P ≤ 0.05) and calcium (P ≤ 0.01) due to vitamin A. The combination of 0 IU vitamin A and 500 mg vitamin E/kg diet had the highest values of PCV (40.09%) and hemoglobin (Hb) (10.33 mg/100 mL) among all groups. Vitamin E raised serum values of total protein, total cholesterol and total lipids (P ≤ 0.05 or P ≤ 0.01). Feed intake, FCR, PCV, Hb, lymphocytes, monocytes, eosinophils, T4, ALT and total protein were significantly affected by the interaction of vitamins A and E (P ≤ 0.05 or P ≤ 0.01). The interaction of vitamins A and E was only significant with respect to serum total protein (P ≤ 0.05). It can be concluded that layer diets supplemented with vitamins A and E had good results in alleviating the harmful impacts of high ambient temperature. The combination of 16,000 IU vitamin A and 500 mg vitamin E per kilogram diet is preferable for obtaining better production of laying hens reared under hot summer conditions.

Intermittent lighting regime as a tool to enhance egg production and eggshell thickness in Rhode Island Red laying hens.

Influences of intermittent light regime as a tool to enhance egg production, egg quality, and blood parameters of laying hens were investigated. A total of 270 hens of Rhode Island Red (during 20 to 36 wk of age) were used to investigate the effects of intermittent light regime in completely randomized design. The birds were divided into 3 equal groups (6 replicates of 15 birds each) and housed in floor pens. The first group was served as non-treated control (C) and was exposed to continuous and constant light for 16 h light/day throughout the experimental period. Whereas, birds of the other groups were exposed to intermittent lights for 20 min/h + 40 min of constant light (T1; FLASH20) and 40 min/h + 20 min of constant light (T2; FLASH40) during the 16 h of light period. Hens of T1 group showed significantly (P ≤ 0.05) the highest concentration of total antioxidant capacity and the lowest one of malondialdehyde in comparison with the other groups. Hens of T1 group had significantly (P ≤ 0.05) the greatest egg laying rate and egg mass in comparison with the other counterparts. Feed consumption was similar in the groups under study. Hens exposed to FLASH20 had the lowest (P ≤ 0.05) FCR when compared with the other treatments. Eggs produced from hens exposed to FLASH20 had the highest value of shell thickness followed by the control and then that of those exposed to FLASH40. There were insignificant differences among the treatments in body weight of hens and all of other egg quality and egg problem traits. In conclusion, intermittent light regime of 20 min/h was the most efficient in comparison with the other ones. Finally, intermittent light regime of 20 min/h during laying period (during 20 to 36 wk of age) is highly recommended.

Implementation of different feeding regimes and flashing light in broiler chicks.

A 3 × 2 factorial arrangement was implemented to determine the performance of 450 Cobb broilers subjected to different feeding regimes with and without lighting programs. The chicks were divided into 3 groups according to the feeding regime (ad libitum, restricted, or intermittent), and each group was reared under one of two lighting programs (100% continuous light or 50% continuous light and 50% flashing light). The results showed that the broilers under the ad libitum and intermittent feeding regimes had superior body weight (BW) and average daily gain (ADG) values and the lowest feed conversion ratio (FCR) at 3 and 6 wk of age. Broilers exposed to flashing light and an intermittent feeding regime had the highest BW and ADG values and the lowest FCR. Birds exposed to intermittent feeding had the highest dressed carcass weight and the lowest heart weight. Broilers reared with flashing light had higher tenderness and juiciness values than the other groups. Broilers subjected to a restricted feeding regime and flashing light had the lowest abdominal fat values of all the groups. Tenderness and juiciness were significantly higher in broilers subjected to the ad libitum feeding regime × flashing light and the intermittent feeding regime × flashing light. Broilers fed an intermittent regime had the lowest spleen %, heterophil, heterophil to lymphocyte (H/L) ratio and body temperature values of all the groups, and broilers reared under the intermittent regime × flashing light had the lowest spleen %, H/L ratio and body temperature values. Non-significant differences in all health aspects (shank length, keel bone length, foot pad burns, breast blisters score, hock discoloration, and mortality) were observed among the experimental groups. In conclusion, intermittent and restricted feeding regimes and a flashing lighting program improved the FCR and did not produce any adverse effects on performance or physiological parameters. The results of this work show that intermittent feeding and flashing lighting programs are more beneficial to broiler management.