1. Sohail et al., 2010

Poultry Science, 2010

Heat stress (HS), one of the major problems of tropical and subtropical countries, adversely affects the production performance of poultry. Keeping this in view, the present study was designed to investigate some of the biological markers of HS in broilers as modulated by dietary supplementation of mannan-oligosaccharide (MOS) and a Lactobacillus-based probiotic (LBP), either alone or in combination. Two hundred fifty 1-d-old-chicks were randomly divided into 5 groups. From d 22, the birds were either kept at the thermoneutral zone (TN) or exposed to HS to the conclusion of study, d 42. Birds were fed either a corn-based basal diet (TN and HS groups) or the same diet supplemented with 0.5% MOS (HS-MOS group), 0.1% LBP (HS-LBP group), or their combination. Birds were immunized against Newcastle disease virus on d 4 (intraocular; live attenuated) and d 20 (drinking water; live attenuated) and infectious bursal disease virus on d 8 (intraocular; live intermediate strain) and d 24 (drinking water; live attenuated). Birds were killed on d 42 to collect serum for determination of cortisol, thyroid hormones, cholesterol, C-reactive protein, and postvaccinal antibody titers. Results revealed that dietary supplementations decreased (P < 0.05) the serum cortisol and cholesterol concentrations and increased (P < 0.05) thyroxine concentration compared with the HS group without affecting triiodothyronine concentration. The percentage of the C-reactive protein-positive birds was higher (P < 0.05) in the HS group compared with the TN group. Dietary supplementations improved humoral immunity against Newcastle disease virus and infectious bursal disease virus during HS. In conclusion, dietary supplementation of either MOS or LBP alone or in combination can reduce some of the detrimental effects of HS in broilers.

Egyptian Journal of Veterinary Sciences

FFECTS of fed supplements, sodium bicarbonate (NaHCO 3), Ascorbic acid (Vitamin C) and Vitamin E were evaluated on the performance, immune system and biochemical parameters of chronically heat-stressed broiler chicks. Two hundred day old broiler chicks were allotted to one of the five groups (n = 40),(A) normal control [no supplements], (B) heat stressed [no supplements], (C) NaHC0 3 ,2g/kg diet, (D) Vitamin C, 200mg/kg diet and (E) Vitamin E, 300 mg/kg diet. All chicks except group (A) were maintained at 35-40 ºC from day one to 6 weeks (wks) of age (daily 6 hrs heat stress episodes). Samples were taken at 2,4 and 6 weeks of age. The result showed Significantly higher bodyweight gains were recorded in all supplemented groups as compared to control group with better response in birds fed sodium bicarbonate (NaHCO 3) .Bursal index, percentage weights of thymus and spleen in relation to body weight, an indicator of humoral immunity were higher but the heterophil / lymphocyte ratio, an indicator of stress was lower for the all supplemented groups as compared to control group .The dietary supplement significantly increased antibody titer of ND and AI on day12 post vaccination (P<0.05). However, dietary vitamin E had higher effect on antibodies titer compared to other groups. In heat stressed group serum uric acid, urea, glucose, AST, ALT increased significantly (P ≤0.05) while blood Na and K and total proteins, albumin, globulin, decreased significantly (P<0.05) from respective control mean values.There were no significant (P>0.05) effects of supplemental sodium bicarbonate (NaHCO 3), Ascorbic acid (Vitamin C) and Vitamin E on plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Overall, the results indicated significant improvement in the performance and immune response of chronically heat-stressed broiler chicks given the feed supplements, ascorbic acid supplementation enhanced the hematological profile of birds but generally, NaHCO 3 being slightly superior to Vitamin C and Vitamin E.

The present study was carried out to evaluate the effect of exposure to chronic heat stress on broiler chick performance and immune system. Also, the effect of adding probiotics was evaluated. Our results revealed that chicks exposed to chronic heat stress showed significantly decreased final body weight at 6th week of age 1601.67±27.44 grams (gms) as compared to control chicks that weighed 1816.67±8.33 gms, at the same age. While, their feed conversion ratio was 2.14±0.20 and in control group it was 2.08±0.21. Adding probiotics to control or heat stressed chicks improved their performance, as body weights at 6th week were 1918.67±8.33 gms and 1765±17.56 gms in in both groups, respectively. Meanwhile, their feed conversion ratio decreased. There were negative impact of chronic heat stress on immune organs / body weight ratios (bursa, spleen and thymus) as they were significantly reduced. The lowest ratios were 0.15±0.26, 0.21±0.03 and 0.13±0.01, for bursa, spleen and thymus, respect...

Italian Journal of Animal Science

The impact of dietary regimens on productive traits, meat quality, physiological adoption, immunological response and digestibility of nutrients was studied using Ross-308 and Cobb-500 strains. Chickens were reared under normal brooding conditions during most of the experimental period, but exposed to heat stress [(HS); 32 C and 55% RH] during 20-22 and 28-30 d of age. During 1-18 d of age, broilers were fed a standard-protein diet [(SPD); 22% crude protein (CP) with 12.97 MJ/kg], a high-protein diet [(HPD); 24% CP with 12.97 MJ/kg], or a high-protein with high-metabolisable energy (ME) diet [(HPMED); 24% CP with 13.60 MJ/kg]. During 19-35 d of age, the SPD group was fed 20% CP with 13.42 MJ/kg, the HPD group was fed 22% CP with 13.42 MJ/kg, and the HPMED group was fed 22% CP with 14.06 MJ/kg. Each group within each strain was replicated six times with five chicken males each. For the whole experimental period, Ross and Cobb chickens fed the HPMED showed higher BWG than chickens on the HPD. Broilers fed the HPMED had improved FCR compared to those on the SPD, independent of broiler strain. Further, independent of broiler strain, the HPMED regimen increased the dry matter, protein, and lipid contents of meat compared to the other regimens, and decreased cloacal temperature, respiration rate and Heterophile/lymphocyte (H/L ratio) compared to the HPD regimen. Growth and feed utilisation, percentage thymus, protein in meat were improved of Ross compared to Cobb, but abdominal fat, meat lipid and pH were decreased. On the other hand, Cobb on HPD had lower cloacal temperature and respiration rate than Ross strain, suggesting that production, physiology and immunological response of broiler chickens depend on feeding regimen that should be specific for each strain.

Annals of Animal Science, 2017

Heat stress is one of the major challenges which the poultry industry faces during summer in tropical and subtropical regions. This study was conducted to evaluate the impact of Vitamin (Vit) E, C and/or probiotics on improving tolerance of broiler chickens to chronic heat stress (CHS). A total of 294, 1-day-old Cobb-500 broiler chicks were allocated into seven treatment groups; Thermoneutral group was raised under a thermoneutral condition during 25–42 d of age. The other six groups were raised for three successive days per week at 36±2ºC and 75–85% relative humidity for 7 h daily: heat stressed group, Vit E (100 mg/kg diet), Vit C (200 mg/kg diet), Vit C+Vit E, probiotics (Saccharomyces cerevisiae and Lactobacillus acidophilus at 2 g/kg diet) and Vit C+Vit E+probiotics. Exposure to CHS decreased body weight gain (BWG), feed intake (FI), and abdominal fat. It had adverse impact on feed conversion ratio (FCR), packed cell volume (PCV), monocyte, basophil, total protein, and phagocyt...

International Journal of Poultry Science, 2009

Effects of water supplements, sodium bicarbonate (NaHCO), potassium chloride (KCl) and acetic 3 acid were evaluated on the performance and immune system of chronically heat-stressed broiler chicks. Two hundred day old broiler chicks were allotted to one of the four groups (n = 50); 1) control [no supplements], 2) NaHC0 0.5%, 3) KCl, 0.15% and 4) acetic acid, 1.5 mL/Liter. All chicks were kept in a controlled 3, environmental chamber maintained at 33±2 C from day one to 6 weeks (wks) of age. Significantly higher o weight gains coincided with decreased feed conversion ratios for all the supplemented groups as compared to control group at 2, 4 and 6 wks of age. Bursal index, percentage weights of thymus and spleen in relation to body weight and natural agglutinin levels, an indicator of humoral immunity were higher but the heterophil:lymphocyte ratio, an indicator of stress was lower for the supplemented groups as compared to control group. Total aerobic spore formers and Enterobactraecae counts in the intestinal swab samples were higher in control group than supplemented groups. Intestinal pH was lower at 2, 4 and 6 weeks of age but water consumption at 5 and 6 wks of age tended to be higher in acetic acid treated group as compared to other groups. Overall, the results indicated significant improvement in the performance and immune response of chronically heat-stressed broiler chicks given the water supplements, acetic acid being slightly superior to NaHCO and KCl.

Journal of Animal Physiology and Animal Nutrition, 2013

This study was planned to investigate the comparative effect of vitamins C (L-ascorbic acid), E (DL-a-tocopherol acetate), probiotics, lower than normal protein level (14%) and combination of these treatments on immune response of male broiler breeders after zinc-induced moulting. One hundred and eighty birds at the age of 65 weeks were induced to moult by mixing zinc oxide (ZnO) in feed at the rate 3000 IU/kg of feed. Upon completion of moulting, birds were divided into six groups (five replicates per group) in a completely randomized design and were fed vitamin C (500 IU/kg), vitamin E (100 IU/kg), lower protein level, probiotics (50 mg/l), and a combination of these components, while one group was kept as control. After completion of moulting phase , the treatment effects were tested as in vitro macrophages engulfment percentage, nitric oxide (NO) production, serum antibody titres against Newcastle disease (ND) and infectious bronchitis (IB). The results showed that in vitro macrophage engulfment percentage in unopsonized conditions was significantly higher in vitamin E-supplemented group. In addition, in opsonized condition, the macrophage engulfment percentage was significantly higher in both vitamin E-and C-supplemented groups. The NO (opsonized and unopsonized) production and antibody titre against ND and IB were significantly higher in vitamin E-supplemented group. It was concluded that vitamin E is a better option for enhanced immune response in broiler breeders after zinc-induced moulting.

To evaluate the effect of broiler growth rate and feed intake on development of the inflammatory response‚ commercial broiler diets were fed to 275 day–old chicks of the modern 2000 strain and 1957 random-bred strain. Half of the chicks had free access to feed while others were restricted. Twelve birds from each strain and group pens were removed‚ weighed, and housed in individual cages by their original feeding programs on 0‚ 7‚ 14, and 28 days. Three feed-restricted and three ad libitum birds from each strain were injected with 1-3 ml of 100 μg/ml solution of Salmonella typhimurium lipopolysaccharide on days 6‚ 13‚ 27‚ and 41, and 3 birds of each group were not injected‚ serving as controls. All birds were weighed and the liver‚ breast muscle‚ thymus gastro intestinal tract and bursa were removed on the day after injection. The thymocytes of the control birds were subjected to an interleukin–1 responsiveness assay. The 1957 strain birds were more severely affected by an inflammato...

Iraqi Journal of Veterinary Sciences, 2019

This study investigated the role of vitamin C and Citrus Sinensis peel (sweet orange peel (Sop)) on growth, carcass characteristics and health status in 160 one day old broiler chickens (Ross308) which were randomly divided into four equal groups consisting 4 pens. Each pen having 10 birds (5 male and 5 female) for 35 days. All chicks were exposed to heat stress (33 0 C) during all the experimental period (35 days). Group one considered as control, groups 2, 3, 4 were given feed containing vitamin C (500ppm/ feed), sweet orange peel (Sop) (1,2 % respectively). Sop 2% significantly increased average body weight gain and feed intake during the grower period (16-28) (P<0.05). The birds fed Sop 2% during the whole experimental period had higher FI and greater feed conversion ratio (P<0.05) compared to the other groups. The mortality rate tended to be the lowest in the birds fed the feed additives (P<0.05). The relative weight of internal organs, blood profiles pictures were not affected by Sop with two tested levels (P<0.05) or vitamin C compared with the control group. Broiler fed vitamin C or Sop levels had greater primary and secondary antibody responses to sheep red blood cells (SRBC) and against phytohemagglutinin (PHA-P) antigen compared with those in the control group (P<0.05). Sop and vitamin C increased antibodies titer against Newcastle disease during the secondary antibody response (P<0.05). Overall, Sop as feed additive improved immune responses in broiler chickens under heat stress. Also the result indicate that the Sop 2 % during the grower period had a positive effect on growth performance of broiler chickens under heat stress.

Egyptian Journal of Nutrition and Feeds, 2018

roduction performance is closely related to feed intake and feed components. Heat stress has a direct effect on feed intake and can impair productivity and immunological responses. The present study was designed to investigate the effect of feed restriction and vitamin C supplementation on broiler performance under heat stress conditions. A total of 180 one-day old Arbor Acres chicks were randomly assigned to four experimental groups with three replicates (15 birds of each). The experimental chicks were fed the basal diet ad libitum (Control), fed the basal diet supplemented with 250 mg/kg vitamin C (Vit. C) ad libitum, deprived of feed for 8h/day (FR), or received the basal diet supplemented with 250 mg/kg vitamin C with feed deprivation for 8h/day (FR+Vit. C). All the experimental groups were exposed to cyclic environmental heat stress of 33.5±1.5˚C for 8h/day starting from 21 to 42 days of age. The feed withdrawal was synchronized with the period of temperature elevation. Feed intake, body weight gain and feed conversion were measured on 0, 21, 35 and 42 days of the experiment. At the end of the experiment, blood samples were collected for determining the H/L ratio and quantifying some relative plasma constituents. Antibody titers of Newcastle (ND), Infectious Bronchitis (IBD) and Avian Influenza (AID) diseases were quantified after three weeks of immunization. Data revealed that feed restriction caused a significant reduction in feed intake and weight gain of broilers during the first three weeks of life. Vitamin C supplementation improved feed intake, body weight gain and feed conversion during the period from 22 to 35 days. Plasma total protein and albumin increased significantly, while transaminases (liver enzymes) activity and the H/L ratio were reduced significantly due to different treatments when compared to the control. Antibody titers for ND and IBD significantly increased due to the different treatments as compared to the control group. The data revealed that feed restriction under thermo-neutral condition reduces the broiler growth performance. But when birds were subjected to elevated environmental temperature, feed rustication with or without vitamin C supplementation improved the broiler performance, with no effect on carcass characteristics, and produced a substantial improvement in immune response of heat stressed broilers. Vitamin C supplementation at 250 mg/kg can be used to alleviate the negative effects of heat stress on broiler productive and immunological responses.