Heat stress had a negative effect on laying hens’ performance, thus this research was to study the influences of betaine (Bet, 1000 mg/kg betaine), vitamin C (VC, 200 mg/kg ascorbic acid), and vitamin E (VE, 150 mg/kg α-Tocopherol acetate) and their possible combinations on egg production, digestibility of nutrients, plasma hormones and reproductive organs of dual-purpose hens exposed to chronic heat stress. Two hundred and eighty eight hens and thirty-six cocks from 32 to 48 weeks of age were divided into nine treatment groups of four replicates, each containing eight hens and one cock. One group was kept under thermo-natural condition and the eight others were kept under chronic heat stress (CHS). One of these eight was used as a negative control, while the others were supplemented with VC, VE and/or betaine and their possible combinations. Body weights, laying rate, feed intake, and feed conversion ratio in hens reared under CHS rooster without any supplementation during 32 to 48 weeks of impairment (P = 0.0052) were recorded. Hens reared under heat stress and fed a diet supplemented with either Bet, VC, VE or combination of the supplements increased production traits. However, hens supplemented with VC showed the greatest production traits. Plasma glucose, estradiol-17 (E2), progesterone (P4), tri-iodothyronine (T3) and thyroxine (T4) decreased in hens reared under CHS and fed a diet with no supplementation compared to the other treatments (P = 0.001). Liver weights, spleen weights, thyroid gland weights, ovary weights, oviduct weights and oviduct lengths were lowest in hens reared under CHS and fed a diet with no supplementation (P = 0.0480). In conclusion, dual purpose hens reared under CHS and supplemented with VC at 200 mg/kg diet and Bet at 1000 mg/kg enhanced the laying performance and combated CHS.

Four hundred and twenty, 21-day-old slow-growing chicks were divided randomly into seven treatments, each containing five replicates. Each replicate was kept in a 1 × 1-m floor pen. One treatment was kept under thermo-neutral conditions in a semi-open house and fed a corn-soybean meal diet (positive control). The other six groups were kept under chronic heat stress (CHS) at 38 °C and 60% RH for 4 h from 12:00 to 16:00 pm for three successive days per week. Chicks in CHS treatments were fed a corn-soybean meal diet without (negative control) or with increasing metabolizable energy (ME) level by oil supplementation alone, or also with increasing some essential amino acids (EAA) such as methionine (Met), methionine and lysine (Met+Lys) or methionine, lysine and arginine (Met+Lys+Arg) or supplemented with 250 mg of ascorbic acid (AA)/kg. CHS impaired (p < 0.05) growth performance, increased plasma triglycerides and total serum Ca while decreasing (p < 0.05) plasma glucose and total serum protein. Meanwhile 250 mg AA/kg diet or an increasing ME without or with some EAA partially alleviated (p < 0.0001) the negative effect of CHS on growth while increasing (p < 0.05) feed intake and improving (p < 0.05) feed:gain ratio (F:G) and crude protein (CP) digestibility (p < 0.05). AA or increasing ME with or without EAA increased (p < 0.05) percentage dressing, liver and giblets to those of the positive control. AA or increasing ME with or without EAA partially alleviated the negative effect of CHS on blood pH, packed cell volume (PCV), haemoglobin (Hgb), total serum protein and total Ca, plasma glucose and triglyceride, rectal temperature and respiration rate. Increasing ME level improved chickens' tolerance to CHS without a significant difference from those supplemented with AA. However, increasing Met, Lys and Arg concentration did not improve performance over that recorded with increasing ME level alone. Under CHS, 250 mg AA/kg diet or increasing ME level by addition of 3% vegetable oil could be an useful approach to improve productive and physiological traits of slow-growing chicks, which may be applicable also to fast-growing one.

ne hundred and eight 8 wk-old Japanese quail were distributed randomly into six different dietary treatments in a 2 x 3 factorial with three replicates, each containing 6 birds (2 males and 4 females), assigning experimental unit to investigate the effect of vinegar (acetic acid) and date residues (date's by-product) on egg production, fertility and hatchability percentages, some physiological characteristics, blood parameters, hormones, antioxidant indices and immunity parameter. Average temperature ranged between 40°C and 43°C with 50 % relative humidity from 8 to 14 weeks of age. Dietary treatments were date residues levels (0 and 10%) supplemented into diets with three levels of acetic acid (0.0, 0.5 and 1ml /liter water) in drinking water. Results showed that dates residues and vinegar (acetic acid) and interactions between them had significant effect on all the productive performance (egg weight, egg production, egg mass/hen/day, feed conversion as (g feed/g egg)) and improved significantly (P<0.05) fertility and hatchability percentages while decreased significantly (P<0.05) non pipping embryos (%) and embryonic mortality (%). All treatments and interactions between them increased significantly some blood hematological, blood biochemical parameters, antioxidant indices and immunity parameter and hormones of quail, i.e., total protein, albumin, total lipids, HDL, GPX ,GSH, SOD, IgG, progesterone and T3, T4 hormones, but WBCs count in all treatments were slightly increased in number, while serum cholesterol, glucose concentrations, AST and ALT were decreased significantly (P<0.05) birds' in compared with control group. The nutrients digestibility were improved by treatment groups and interactions between them. The counts of total aerobic and anaerobic bacteria and total coliform of chick intestinal were decreased due to add different treatments compared with the control. In conclusion, It may be the application of date residues 10% (in feed) with vinegar (acetic acid) in drinking water (0.5 or 1ml/liter) improved the productive performance such as egg production, fertility, hatchability percentages, some physiological parameters and nutrients digestibility of laying Japanese quail during summer season.

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ABSTRACT:This study was conducted to investigate the effect of milk thistle plant (Silybum marianum) as a phytoantioxidant for improving the performance of Gimmizah cockerels during summer season (18 June -26 August, 2017). One hundred and twenty five Gimmizah cockerels aged 21-day were individually weighed and randomly divided into five treatment groups. Each treatment was represented by five replicates, of 5 cockerels each and housed in 25 rearing cages (open system) until the end of the experiment (91 day of age). The first group was used as a control and fed the unsupplied basal diet (without any agent). The second group was fed the basal diet supplemented with vitamin E (150 mg VE /kg diet) as an immunomodulator nutrient. The third group was fed the basal diet supplemented with 0.5g commercial silymarin (SLM) /kg diet. The fourth and the fifth groups were fed the basal diet supplemented with 12.5 and 25g of fine grind aerial parts of milk thistle plant (MTh) /kg diet as a natural source of SLM (represented 0.5 and 1g SLM /kg diet, respectively). Diets were kept isocaloric and cover nutrient requirements of the experimental birds. All birds received feed and water ad-libitum throughout the experimental period. The chemical analysis indicated that MTh contain 188.5 mg of total polyphenols and 320 mg of antioxidant activity /100g sample. Body weight of cockerels fed diet supplied with different agents was significantly increased compared to the control group through all experimental periods. In addition, the group supplied with 25 g MTh /kg diet induced the highest BW and BWG followed by those supplied with VE. Supplementation of cockerels diet with different agents significantly improved feed intake and feed conversion ratio during the whole experimental period compared to the control group. The results indicated that the relative weights of dressing, liver, spleen, bursa of Fabricius and testes significantly increased for the groups supplied with different agents compared to the control group. Moreover, the group supplied with 25g MTh /kg diet significantly increased relative weight of liver and bursa of Fabricius compared with the other experimental groups. Supplying cockerels diets with different agents significantly improved all blood biochemical constituents compared to the control group. However, diet supplied with both levels of MTh significantly improved the liver function (AST, ALT and ALP) and significantly decreased lipid profile (total lipids, triglycerides and cholesterol) compared with the group fed diet supplied with VE and the control groups. Diets supplied with different agents significantly improved TAC, GSH, MDA, lymphocyte, the heterophil to lymphocyte ratio (H/L ratio), phagocytic activity and phagocytic index compared to the control.