Effects of Saccharomyces cerevisiae and Bacillus subtilis on in vitro fermentation in the rumen of Hu sheep.

BACKGROUND: The demand for animal products is increasing in developing countries due to population growth. However, livestock production contributes significantly to global warming, accounting for 25%. Probiotics can help improve livestock efficiency by enhancing gut microbes and fat metabolism. They can modify rumen populations, enhance fermentation, reduce methane emissions and improve feed digestion. In this study, the goal was to determine the most effective method of reducing methane emissions in the rumen of sheep in vitro by adding different concentrations of Saccharomyces cerevisiae and Bacillus subtilis. RESULTS: Adding 8 × 106 CFU g-1 S. cerevisiae during fermentation reduced pH levels after 48 h. This also increased the concentrations of NH3-N, microbial protein and total gas production. At the same time, it decreased methane emissions. Furthermore, adding 20 × 106 CFU g-1 B. subtilis to the mixture increased total gas production (TGP) and methane production, with the highest production observed after 48 h. However, it did not affect pH levels after 48 h. CONCLUSION: It can be concluded that S. cerevisiae had significantly increased microbial protein and NH3-N concentrations after fermentation without altering pH. Additionally, the addition of S. cerevisiae enhanced TGP and reduced methane emissions. It is worth noting that TGP increased because B. subtilis was added at a concentration of 20 × 106 CFU g-1, with no significant differences between concentrations. Therefore, we recommend adding S. cerevisiae and B. subtilis to the diet at doses of 8 and 20 × 106 CFU g-1, as it resulted in higher TGP and reduced methane emissions. © 2024 Society of Chemical Industry.

Growth performance, plasma metabolites, meat quality, and meat and lipid health indices of New Zealand White rabbits as affected by dietary dried tomato pomace powder supplementation during the summer season.

One hundred and twenty New Zealand White rabbits (NZW) (5-week-old; 735.27 ± 27.23 g) were kept in an open-sided house during the summer season. The experiment aims to evaluate the impacts of dried tomato pomace powder (DTPP) supplementation on rabbits' performance, blood metabolites, carcass traits, meat quality, and lipid and health indices of NZW rabbits during 5-13 weeks of age. The four treatments were a standard rabbit feed (control) and the control diet supplemented with 0.5, 1.0, and 1.5% DTPP, respectively. Rabbits fed a diet containing 1.5% DTPP showed the highest growth rate through weeks 9-13 of age despite having the lowest feed intake spanning 5-13 weeks. The best feed conversion ratio (FCR) was recorded in rabbits fed with 1.5% DTPP-supplemented diet for 5-13 weeks. Diets supplemented with 0.5 or 1.0% DTPP enhanced markedly dressing %, total edible flesh, saturated (SFAs), monounsaturated (MUFAs), and polyunsaturated fatty acid (PUFAs) contents, as well as the ∑n - 6/∑n - 3 ratio and the total n - 6 of meat. Dietary supplementation with DTPP decreased kidney, abdominal, and back fat. Diets supplemented with DTTP decreased total cholesterol, triglycerides, and very low-density lipoprotein (vLDL) concentrations. The greatest levels of linoleic acid, arachidonic and water-holding capacity in meat were observed in rabbits fed 1.5% DTPP-supplemented diets. Diets containing 1 and 1.5% DTPP improved meats' atherogenic and thrombogenic indices, meat lipid quality desired fatty acids/undesired fatty acids ratio, and meat health index. Conclusively, DTPP up to 1.5% maintained the growth performance of rabbits, boosted meat quality through increasing vitamin E, reduced fat deposition, modified fatty acid composition, and improved atherogenic, thrombogenic, and hypocholesterolemic indices of rabbit meat.

Influence of tomato processing by-product extract as dietary supplementation on growth performance, carcass characteristics and antioxidant status of growing rabbits under high ambient temperature.

This study evaluated the effects of dietary supplementation of tomato processing by-product extract (TPBE) on growth performance, carcass characteristics and antioxidant status of growing rabbits under high ambient temperature. A total of eighty weaned New Zealand White (NZW) male rabbits (6-weeks-old; initial body weight, 730.28 ± 36.05 g) were randomly assigned to 4 groups. The first group was the control without supplementation; while the other groups were fed diets supplemented with 100, 200 and 250 mg TPBE/kg. The results showed that TPBE contained 211.85 mg/100g as total phenols and total flavones of 303.36 mg/100g. Rabbits fed a 250 mg TPBE-supplemented diet showed the heaviest body weight, the lowest feed intake and the best feed conversion ratio. TPBE diets reduced mortality percentage. Dietary supplementation of 250 mg TPBE had the highest dressing percentage. Plasma total protein, globulin, catalase and glutathione peroxidase of rabbits fed diets supplemented with 200 and 250 mg TPBE were high. Plasma total cholesterol, triglycerides, plasma hydrogen peroxide and malondialdehyde concentrations were decreased with dietary levels of TPBE. Rabbits fed 250 mg TPBE had higher T-AOC than the other groups. TPBE supplemented diets improved net revenue and economic efficiency. Conclusively, TPBE is containing appreciable content of polyphenols and flavonoids and the dietary supplementation of TPBE (250 mg/kg diet) had a positive impact on growth performance, reducing mortality and enhancing the antioxidant status of rabbits reared under high ambient temperature.

Wet feed and chilled water as stratigies to ameliorate heat stress impacts in growing turkeys during summer conditions.

The researchers investigated wet feed and chilled water effects on growth performance, carcass characteristics, and physiologic responses of native turkeys during the summer season. We hypothesized that the present treatments during the hot season would show different performances. A total of 180 four-week-old unsexed pullets were divided into six groups in a 3 × 2 factorial arrangement. Pullets were allocated regarding feed conditions to 3 groups (ad libitum dry feed, ad libitum wet feed, and diurnal wet feed). Each group was divided into 2 subgroups according to water temperature (ordinary or chilled water; 15-16 °C). Pullets fed diurnal wet feed and drank chilled water had the highest daily feed intake and the lowest feed conversion ratio during 4-16 weeks of age. Abdominal fat, IgG level and body temperature were low, whereas total antioxidant capacity and the meat quality scores for color, juiciness, and susceptibility were high in turkeys that drank chilled water. The interaction between wet feed and water temperature showed significant changes in glucose, cholesterol levels, and alanine transaminase activity. Pullets fed diurnal wet feed and drank chilled water had the lowest body temperatures. Wet feeding and chilled water may be the appropriate feeding method for native turkeys raised in hot weather.

Efficacy of ascorbic acid and different sources of orange peel on growth performance, gene expression, anti-oxidant status and microbial activity of growing rabbits under hot conditions.

Orange peel and its extract are good sources of phenols and vitamin C that can be used as powerful antioxidants and antibacterial. The effects of dietary ascorbic acid (AA), orange peel powder (OPP) and orange peel extract (OPE) supplementations on growth performance, blood biochemicals, gene expression and antioxidant status of growing rabbits under hot conditions were investigated. A total of 80 weaned Giant Flander male rabbits, five weeks old (606.25 ± 10.08 g), were randomly assigned to four groups. The first group received untreated diet (control group). The other groups received diets supplemented with 0.5 g AA/kg diet, 2% OPP and 500 mg OPE/kg diet. The lowest feed conversion ratio (FCR) was recorded by rabbits consumed diet supplemented with AA. Supplementations of OPP and OPE reduced blood plasma total cholesterol, low density lipoprotein and very-low density lipoprotein concentrations. The tested diets reduced triglycerides, total lipids, hydrogen peroxide, malondialdehyde levels, Staphylococcus aureus and Escherichia coli of the rabbits cecum. Supplementation of OPE improved activities of superoxide dismutase gene (6.1475) and insulin-like growth factor-1 (9.2108). Conclusively, dietary supplementation of OPE improved rabbit performance through improving antioxidant enzyme activities as well as upregulation of insulin-like growth gene. Additionally, OPP and OPE (2% and 500 mg/kg diet, respectively) had antibacterial effects for growing rabbits under hot conditions.

Dietary supplementation of spirulina and canthaxanthin boosts laying performance, lipid profile in blood and egg yolk, hatchability, and semen quality of chickens.

This study examined the impacts of dietary spirulina (SP) and canthaxanthin (CX) supplementation to laying hens on reproductive performance and cock's semen quality evaluation. Three hundred and sixty of indigenous Sinai chickens (300 hens + 60 cocks), 48-weeks-old, were randomly divided into five treatments; a control and four supplemented (0.6 g SP mg/kg, 0.8 g SP mg/kg, 6 mg CX/kg diet, and 8 mg CX/kg diet) with six replications of 10 females and 1 male per treatment for laying trial and 1 male for semen evaluation. The animals were fed with experimental diets for 12 weeks. Supplementing 6 mg CX/kg diet led to an increase in the final body weight and egg production traits, while 8 mg CX/kg diet resulted in an improving feed conversion ratio. Supplementation of 0.6 g SP mg/kg or 6.0 mg CX/kg diet resulted in the highest egg production. The heaviest egg weight and egg mass were induced by 0.8 g SP mg/kg. Eggs laid from hens fed 0.6 g SP/kg diet had a higher concentration of cholesterol than those fed 0.8 g SP/kg and those fed 6.0 and 8.0 mg CX/kg. Cocks fed 6 mg CX/kg and those fed 0.8 g SP/kg diet had the greatest sperm concentration. The supplementation of 0.8 g SP mg/kg diet or both 6 and 8 mg CX/kg diet enhanced hatchability. So, dietary spirulina (0.8 mg/kg) and canthaxanthin (6 mg/kg) supplementation to Sinai laying hens and cocks could be used to improve productive and reproductive and performance.

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.

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.

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).

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.

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.

Environmental heat stress in rabbits: implications and ameliorations.

Profitable production of rabbit meat requires comfortable environment for expression of good quality traits embedded in the genetic components of rabbits. One of the major problems facing rabbit production is heat stress, especially in hot regions of the world. This is further aggravated by global warming being experienced as a result of climate change. Rabbits have no or few sweat glands, complicating the problem of heat dissipation, thereby predisposing the animals to heat stress (HS). Heat stress adversely affect welfare and adaptation, feed consumption and utilization, immunity and health status, growth, reproduction, and milk production in rabbits. Rabbits are homoeothermic animals. They should be capable of body temperature regulation within a narrow range. Thermoregulation is extremely poor in rabbits because of lack of sweat glands. Rabbits are highly sensitive to high ambient temperature. The presence of thick insulator fur on the skin further impedes heat loss in rabbits. This review summarizes data available literatures in the last two decades (2000-2020). Short compilation on management techniques adopted in rearing rabbits under hot conditions is included.

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.

Dietary Echinacea purpurea administration enhanced egg laying performance, serum lipid profile, antioxidant status and semen quality in duck breeders during summer season.

This work investigated the outcomes of dietary administration of Echinacea purpurea (EP) powder to breeder ducks on productive and reproductive performance during summer season. Sudani ducks (320 birds) of 32-weeks-old (240 females and 80 males) were randomly allocated into four collections (body weight; 1850 ± 15.2 g for females and 2960.0 ± 40.5 g for males). The primary collection consumed the basal diet without supplementation and was deliberated as control. The other three collections were fed the basal diet supplemented with 2.5, 5.00 and 7.5 g EP/kg diet, correspondingly. Egg number and mass, laying rate, feed consumption and feed conversion ratio (FCR) were significantly changed by dietary EP levels. Drakes fed EP-supplemented diets had higher ejaculate volume, sperms concentration and live sperms (%) as well as lower dead sperms (%) than the control group. Eggs laid by ducks fed diet supplemented with 2.5 g/kg had the greatest fertility and hatchability percentages, followed by those fed 5.0 g EP/kg. Ducks fed different EP diets had higher values of haemoglobin, RBCs, WBCs and lymphocytes, lower values of heterophils percentage and lower H/L ratio than the control. All serum constituents were significantly changed by dietary EP supplementation, except of total protein and Alanine Aminotransferase (ALT) enzyme. Conclusively, dietary EP supplementation at 2.5 g/kg had beneficial effects on productive and reproductive performance as well as lipid profile and antioxidant status and economically valued in breeder ducks under summer conditions.

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.

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.

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.

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.

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.

Pathobiology of Avian avulavirus 1: special focus on waterfowl.

Avian avulaviruses serotype 1 (abbreviated as APMV-1 for the historical name avian paramyxovirus 1) are capable of infecting a wide spectrum of avian species with variable clinical symptoms and outcomes. Ease of transmission has allowed the virus to spread worldwide with varying degrees of virulence depending upon the virus strain and host species. The emergence of new virulent genotypes from global epizootics, and the year-to-year genomic changes in low and high virulence APMV-1 imply that distinct genotypes of APMV-1 are simultaneously evolving at different geographic locations across the globe. This vast genomic diversity may be favoured by large variety of avian species susceptibility to APMV-1 infection, and by the availability of highly mobile wild birds. It has long been considered that waterfowls are not sensitive to APMV-1 and are unable to show any clinical signs, however, outbreaks from the 90's contradict these concepts. The APMV-1 isolates are increasingly reported from the waterfowl. Waterfowl have strong innate immune responses, which minimize the impact of virus infection, however, are unable to prevent the viral shedding. Numerous APMV-1 are carried by domestic waterfowl intermingling with terrestrial poultry. Therefore, commercial ducks and geese should be vaccinated against APMV-1 to minimize the virus shedding and for the prevention the transmission. Genetic diversity within APMV-1 demonstrates the need for continual monitoring of viral evolution and periodic updates of vaccine seed-strains to achieve efficient control and eradication of APMV-1 in waterfowls.