The effects of vitamins C and E on layer chickens transported by road for 6 h during the hot dry season were investigated. Two experimental groups consisting of thirty Shika Brown layers were separately administered vitamins C and E orally just before transportation, while another 30 layers, which were only given sterile water, served as control. Blood samples analyzed before and after transportation in the control layers showed a decrease (p<0.05) in total white blood cell, (p<0.01) lymphocyte and monocyte values, and a significant (p<0.05) and (p<0.001) increase in the values of eosinophils and heterophils post-transportation, respectively. In the experimental groups, post-transportation values of total white blood cells, eosinophils and monocytes were not different (p>0.05) from those obtained before transportation. Heterophil/lymphocyte values were highest in the control group. The result showed that transportation was stressful for the control layers. Post-transportation egg production was not significantly (p>0.05) different in the vitamin E treated group, but values recorded for the vitamin C and control groups were significantly (p<0.05) and (p<0.001) reduced compared to pre-transportation. In conclusion, vitamins C and E administration ameliorated the adverse effect of road transportation stress during the hot dry season.

A 30-day experiment involving 720 White Leghorn layer hens was carried out to evaluate the effects of vitamins C and E on leukocyte and heterophil/lymphocytes ratios of the layer hens during the natural summer conditions. The birds were divided into 4 groups, one control with basal diet and three experimental with diet supplemented with vitamin C, vitamin E, or combination of both vitamins. Each group was divided into 4 subgroups. Exposure of layer hens to 31 ± 3 °C and 33 ± 0 °C ambient temperature and 84.6% and 81.5% relative humidity during the experiment caused an increase in the value of temperature humidity index of 15.5 above the threshold value of 70 established for this species. Total white blood cells, lymphocytes, and eosinophil levels were significantly (p < 0.001) higher in all treated groups compared to control. Similarly, heterophil/lymphocyte ratios of 0.51, 0.52, and 0.50 for groups with diet supplemented with vitamin C, vitamin E and vitamins C + E, respectively, were significantly (p < 0.001) lower compared to 0.59 recorded in the control group. However, heterophil, basophil and monocyte values were significantly (p < 0.001) higher in the control group compared to all treated groups. The results of the present study showed that dietary supplementation of vitamins C and E, or their combination, reduces the harmful effect of high ambient temperature and humidity on the leukocyte indicators of exposed layer hens, thereby alleviating the stress imposed on their thermoregulatory mechanism and physiological status. Heat stress, antioxidant vitamins, white blood cells, laying birdsAll over the world, farmers have to solve a problem of heat stress in poultry during the summer period. Global warming as a result of increased industrialization and environmental degradation has led to continuous increase in ambient temperature, thereby making heat stress a major problem of livestock farming, particularly in the poultry sector (Daghir 2009). This is because poultry are particularly sensitive to high ambient temperature (AT), more than to cold. Heat stress interferes with the birds' comfort and suppresses production efficiency. In birds, high ambient temperature leads to increased endogenous heat production, since convective transfer of heat is the major thermoregulatory mechanism of birds and depends on air movement by natural or fan-powered ventilation (Shane 2005). As a response, birds have to make major thermo-regulatory adaptations to prevent death from heat exhaustion. As a result, the genetic potential of layer hens is often compromised (Holik 2009). The responses of poultry to high ambient temperatures have been studied several times, but the effect of relative humidity (RH) on intensifying or modifying these responses has received little attention. Relative humidity is rarely included as an experimental variable or measured for information purposes. Such information is important because in poultry-producing regions high temperature can often be accompanied by a range of RH, which can marked...

Abstract. This study was carried out to investigate the effects of vitamins C and E on some plasma metabolites and production performance of layer chickens reared under hot tropical climate. 720 White Leghorn (L33) layer chickens and 39 weeks old were divided into four groups of 180 birds. One group was fed with basal diet (control) and treatment groups were fed with basal diet supplemented with 150 mg of vitamin C/kg of diet, 150 mg of vitamin E/kg of diet, while the last group was supplemented with 150 mg of vitamin C/kg of diet plus 150 mg of vitamin E/kg of diet. Separately or as a combination, supplemental vitamin C and E decreased plasma concentrations of cholesterol, glucose and creatine phosphokinase (P<0.001) compared to control. There were no significant (P>0.05) effects of supplemental vitamin C and E on plasma metabolites of alanine phosphatase and aspartate transaminase. The single supplementation of vitamin E and its combination with vitamin C considerably increased the plasma metabolite of protein (P<0.01). Egg/bird were significantly (P<0.05) higher in all treatment groups compared to control, but P value was highest in vitamin E treated group. The laying index showed a significant (P<0.05) increase in all treatment groups compared to control. Similarly, feed consumption and conversion were significantly (P<0.05) different in treatment groups compared to control. It is concluded that supplementation of vitamins C and E maintained the stability of some plasma metabolites concentration, thereby, sustained production performance and facilitated adaptation of chicken to stressful hot-humid condition.

. 2010. Effects of vitamins C and E on erythrocytes and blood chemistry profile of shika brown layer hens transported by road. Acta Zool. Mex. (n. s.), 26(3): 527-537. ABSTRACT. This study was conducted to determine the effects of dietary supplementation of vitamin C (l-ascorbic acid) and vitamin E (dl-·-tocopherol acetate) on some erythrocytes and blood chemistry parameters of laying hens transported during hot-dry season. Ninety, 22 weeks old indigenous hybrid Shika Brown layer (SBL) hens were randomly divided into three groups of 30 each, and three replicates of 10 birds within each group. The first group was administered vitamin C at a dosage 200 mg/kg of bodyweight dissolved in 5 ml of sterile water w/v, the second group was administered vitamin E at a dosage 200 mg/kg of bodyweight dissolved in 5 ml edible vegetable oil w/v, while the third group was administered 5ml sterile water (control) v/v only. All administration was through the oral route. All groups were fed basal diet pre-and post experiment. Just before transportation, food and water were withdrawn. Post-transportation, hemoglobin (H b ), packed cell volume (PCV) and blood platelets concentrations were significantly (P < 0.01) and (P < 0.001) reduced in vitamin C treated group; vitamin E and control groups compared with pre-transportation values respectively. However, posttransportation value of red blood cell (RBC) was only significantly (P < 0.05) reduced in control group compared with pre-transportation value. Post-transportation blood chemistry concentrations of total protein (TP) and alkaline phosphatase (ALP) were significantly (P < 0.05) and (P < 0.01) reduced in all experimental groups compared with pre-transportation values respectively. However, posttransportation values of creatine phosphokinase (CPK) and aspartate aminotransferase (AST) were significantly (P < 0.01) and (P < 0.05) reduced in vitamins C and E groups compared with pretransportation values respectively. It is concluded that the administration of antioxidant vitamins C and E alleviated the negative effects of stress in birds transported during the hot-dry season. Keywords : Layer hens, transport stress, vitamins C and E, blood parameters. ISSN 0065-1737Acta Zoológica Mexicana (n.s.) 26(3): 527-537 (2010) RESUMEN.Se realizó el trabajo con el objetivo de determinar los efectos de la suplementación alimentaria de las vitaminas C (L-ácido ascórbico) y vitamina E (dl-·-tocoferol) sobre algunos parámetros de eritrocitos y químicos de las aves ponedoras transportado durante la temporada cálida y seca. Se seleccionaron noventa gallinas ponedoras Shika Brown, hibrido indígena de 22 semanas de edad y fueron divididas aleatoriamente en tres grupos de 30 gallinas, y tres réplicas de 10 gallinas dentro de cada grupo. Para el primer grupo, se suministró 200 mg/kg/peso vivo (pv) de la vitamina C disuelto en 5 ml de agua estéril p/v (peso por volumen), en el segundo grupo se suministró 200 mg/kg/pv de la vitamina E disuelto en 5ml de aceite comestible p/v. Al último grupo (control) ...

A 6 hours experiment involving 90 apparently healthy Shika Brown layer hens of twenty-two weeks age and an average live weight of 1.1 ± 0.2 kg was carried out in a completely randomized design to evaluate the effects of vitamins C and E on rectal temperature (RT) and behaviour of the birds transported by road during the hot-dry season. Two experimental groups consisting of thirty layers each were separately administered orally with vitamins C and E just before transportation, while another 30 layers given sterile water only served as control. At journey time the RT was higher (p<0.05) in control compared with treatment groups. After the journey, the maximum RT values of 42.3 ± 0.2°C and 41.9 ± 0.1°C obtained in control and vitamin C groups were significantly (p<0.001) and (p<0.05) higher than their pre-journey values. There was a non-significant (p>0.05) difference in the vitamin E group. When pre-and post-transportation values were compared, the behavioural activities of tonic immobility (TI), regrouping and awareness tests were non-significant (p>0.05) in treatment groups, but control showed significant (p<0.01) difference for TI, and (p<0.05) for regrouping and awareness tests, respectively. In conclusion, vitamins C and E ameliorated the negative psycho-physiological effect of heat stress in transported birds.