No abstract

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.

The objective of the present study was to evaluate anti-diabetic effects of chromium picolinate (CrPic) and biotin supplementations in type 2 diabetic rats. The type 2 diabetic rat model was induced by high-fat diet (HFD) and low-dose streptozotocin. The rats were divided into five groups as follows: (1) non-diabetic rats fed a regular diet; (2) diabetic rats fed a HFD; (3) diabetic rats fed a HFD and supplemented with CrPic (80 mg/kg body weight (BW) per d); (4) diabetic rats fed a HFD and supplemented with biotin (300 mg/kg BW per d); (5) diabetic rats fed a HFD and supplemented with both CrPic and biotin. Circulating glucose, cortisol, total cholesterol, TAG, NEFA and malondialdehyde concentrations decreased (P, 0·05), but serum insulin concentrations increased (P,0·05) in diabetic rats treated with biotin and CrPic, particularly with a combination of the supplements. Feeding a HFD to diabetic rats decreased PPAR-g expression in adipose tissue and phosphorylated insulin receptor substrate 1 (p-IRS-1) expression of liver, kidney and muscle tissues, while the supplements increased (P, 0·001) PPAR-g and p-IRS-1 expressions in relevant tissues. Expression of NF-kB in the liver and kidney was greater in diabetic rats fed a HFD, as compared with rats fed a regular diet (P, 0·01). The supplements decreased the expression of NF-kB in diabetic rats (P,0·05). Results of the present study revealed that supplementing CrPic and biotin alone or in a combination exerts anti-diabetic activities, probably through modulation of PPAR-g, IRS-1 and NF-kB proteins.

The objective of this study was to determine the forage:concentrate ratio that would provide the greatest duodenal flow of unsaturated fatty acids in ewes supplemented with soybean oil and to determine how diets differing in forage content affect flow of conjugated linoleic acid (CLA) and trans-vaccenic acid (18:1(trans-11)). Five mature ewes (66.5 +/- 12.8 kg) fitted with ruminal and duodenal cannulas were used in a 5 x 5 Latin square experiment. Diets were isonitrogenous and included bromegrass hay, cracked corn, corn gluten meal, urea, and limestone. Dietary fat was adjusted to 6% with soybean oil. Five ratios of forage:concentrate (18.4:81.6, 32.2:67.8, 45.8:54.2, 59.4:40.6, and 72.9:27.1) were fed at 1.3% of BW daily in equal allotments at 0630 and 1830. After 14 d, Cr2O3 (2.5 g) was dosed at each feeding for 7 d and ruminal, duodenal, and fecal collections were taken for the next 3 d. Duodenal flow of 18:0 increased linearly (P < 0.01) with dietary forage. Duodenal flow of 18:1(cis-9) and 18:2(cis-9,12) decreased (P < 0.001) but duodenal flow of 18:3(cis-9,12,15) increased (P < 0.01) with increased dietary forage. Biohydrogenation of dietary unsaturated fatty acids increased (P < 0.001) as dietary forage increased, which was concomitant with increased ruminal pH. Duodenal flow of 18:2(cis-9,trans-11) increased linearly (P < 0.01) with increased dietary forage but increased abruptly when forage was fed at 45.8%. Duodenal flow of the trans-10, cis-12 and cis-10, cis-12 CLA isomers decreased as dietary forage increased, but flow tended to increase on the highest-forage diet, resulting in both linear (P < 0.01) and quadratic (P < 0.01) effects. Duodenal flow of 18:1(trans-11) decreased from 8.28 g/d on the 18.4% forage diet to 5.47 g/d on the 59.4% forage diet then increased to 7.29 g/d on the highest-forage diet (quadratic, P < 0.1). Duodenal flow of 18:1(trans-11) was 27- to 69-fold greater than flow of CLA. We conclude that when ewes were fed a 6% crude fat diet duodenal flows of dietary fatty acids changed incrementally as dietary forage was increased, whereas changes in flows of CLA isomers seemed to be more abrupt. Biohydrogenation changes were gradual with diet, suggesting a gradual shift in ruminal microbial populations with increasing forage. Finally, the highest-concentrate diet supported the greatest duodenal flows of dietary unsaturated fatty acids, as well as the highest flow of 18:1(trans-11).

This study was conducted to determine the effects of dietary vitamin C (L-ascorbic acid) and vitamin E (alpha-tocopherol acetate) on lipid peroxidation status measured as MDA and serum triiodothyronine (T3), thyroxine (T4), thyroid-stimulating hormone (TSH), adrenocorticotropic hormone (ACTH), as well as some other serum metabolite and mineral concentrations of Japanese quails reared under heat stress (34 degrees C). One hundred-eighty 10-day-old Japanese quails were randomly assigned to six treatment groups, three replicates of 10 birds each. Using a 2 x 3 factorial design, the birds received two levels of vitamin C (100 and 200 mg/kg of diet) or three levels of vitamin E (125, 250, or 500 mg/kg of diet). Greater dietary vitamin E and vitamin C resulted in a greater serum T3, T4, and TSH (p = 0.001), but lower ACTH (p = 0.001) concentrations. Serum concentrations of T4 and TSH increased to a greater extent by increasing dietary vitamin C when greater vitamin E levels were fed (interaction, p = 0.001). Serum glucose, urea, triglycerides, and cholesterol concentrations decreased (p = 0.001), while protein and albumin concentrations increased (p = 0.001) when both dietary vitamin C and vitamin E were increased. Serum activities of SGOT and SGPT were not influenced by dietary vitamin C and vitamin E (p > 0.43). However, serum activity of AP increased (p = 0.001) by increasing both dietary vitamin C and vitamin E. Increasing both dietary vitamin C and vitamin E caused an increase in serum concentrations of Ca, P, K (p = 0.001), Fe, and Zn (p = 0.01) but a decrease in serum concentrations of Na (p = 0.001) and Cu (p = 0.01). Interactions between vitamin C and vitamin E were detected for Ca, P, Na, and K (p = 0.001). Greater dietary vitamin C and vitamin E resulted in a greater serum and liver vitamin E, C, and A (p < or = 0.05), but lower MDA (p = 0.001) concentrations. Results of the present study conclude that supplementing a combination of dietary vitamin C (200 mg) and vitamin E (250-500 mg) offers a good management practice to reduce heat stress-related decreases in performance of Japanese quails.

This study was conducted to determine the effects of vitamin C (L-ascorbic acid) and vitamin E (DL-alpha-Tocopheryl acetate) on performance, digestion of nutrients and carcass characteristics of Japanese quails reared under chronic heat stress (34 degrees C). A total of 180 10-day-old Japanese quails were randomly assigned to six treatment groups, three replicates of 10 birds each. The birds with a 2 x 3 factorial design received either two levels of vitamin C (100 and 200 mg/kg of diet) or three levels of vitamin E (125, 250, or 500 mg/kg of diet). Then, 200-mg vitamin C/kg of diet, compared with that of 100 mg/kg of diet, and higher dietary vitamin E inclusions resulted in a higher performance. The interaction between vitamin C and vitamin E for final body weight change (p=0.01) and feed efficiency (p=0.02) was detected. Final body weight change and feed efficiency increased to a higher extent by increasing dietary vitamin C when higher vitamin E levels were fed. Carcass characteristics improved with an increase of both dietary vitamin C and vitamin E (p=0.004). The interactions on carcass characteristics were all significant (p=0.02) and manifested themselves in a way that they were improved to a higher extent by an increase of dietary vitamin C when higher vitamin E levels were fed. Digestibility of nutrients (DM, OM, CP and EE) was greater with higher dietary vitamin C (p < 0.02) and also with higher vitamin E (p=0.07). There were no interactions detected for digestibility of nutrients (p=0.32). Taken together, the results of the present study conclude that a combination of 200 mg of vitamin C and 250 mg of vitamin E provides the greatest performance in Japanese quails reared under heat stress and can be considered as a protective management practice in poultry diet, alleviating the negative effects of heat stress.

Our objective was to measure ruminal fermentation characteristics and site and extent of nutrient digestion in sheep limit-fed an 81.6% (DM basis) concentrate diet supplemented with increasing levels of soybean oil. Eight white-faced wether lambs (39.9+/-3.0 kg BW) fitted with ruminal, duodenal, and ileal cannulas were used in a replicated 4 x 4 Latin square experiment. Diets were formulated to contain 15.0% CP (DM basis) and included bromegrass hay (18.4%), cracked corn, soybean oil, corn gluten meal, urea, and limestone. Soybean oil was added to diets at 0, 3.2, 6.3, and 9.4% of dietary DM. The diet was limit-fed at 1.4% of BW. After 14 d of dietary adaptation, Cr2O3 (2.5 g) was dosed at each feeding for 7 d followed by ruminal, duodenal, ileal, and fecal sample collections for 3 d. Digestibilities of OM, starch, NDF, and N were not affected (P = 0.13 to 0.95) by increasing dietary soybean oil level. Means for true ruminal (percentage of intake), lower-tract (percentage entering the duodenum), and total-tract (percentage of intake) digestibility for each nutrient were (mean+/-SEM): OM = 50.7+/-4.66%, 71.6+/-2.58%, and 82.7+/-0.93%; starch = 92.0+/-1.94%, 96.1+/-0.70%, and 99.8+/-0.05%; NDF = 36.7+/-6.75%, 50.9+/-7.58%, and 71.7+/-1.93%; and N = 31.6+/-9.93%, 84.1+/-1.50%, and 81.0+/-1.10%, respectively. Total VFA concentration was greatest in sheep fed 6.3% soybean oil and least in sheep fed 9.4% soybean oil (cubic, P = 0.01). Duodenal flow of fatty acids from the diet and those metabolized within the rumen increased (linear, P < 0.001) with increasing dietary soybean oil level. Ileal flow of 16:0, 17:0, 18:0, 18:1trans, and 18:1cis-9 fatty acids increased (P < or = 0.04) with increasing dietary soybean oil level. Apparent small intestinal disappearance of 18:0 decreased (linear, P = 0.004) as dietary soybean oil increased, and with 9.4% dietary soybean oil, nearly half the duodenal 18:0 was observed at the ileum; thus, the true energy value of the soybean oil decreased with increasing oil supplementation. We conclude that supplementation of a high-concentrate diet with increasing amounts of soybean oil in limit-fed sheep resulted in a trade off between loss of potential dietary energy from the fat and gain of important PUFA and biohydrogenation intermediates, but without a marked influence on digestibility of other important macronutrients.

This experiment was conducted to evaluate the effects of zinc (ZnSO4.H2O) and vitamin A (retinol) supplementation on performance, carcass characteristics, and serum concentrations of glucose, cholesterol, total protein, and malondialdehyde (MDA) as an indicator of lipid peroxidation in broiler chickens (Ross) reared at a high temperature (34 degrees C). One hundred twenty 10-d-old male broilers were randomly assigned to 4 treatment groups, 3 replicates of 10 birds each. The birds were fed either a basal diet or the basal diet supplemented with either 30 mg Zn/kg diet, 4.5 mg (15,000 IU) retinol/kg diet, or 30 mg Zn + 4.5 mg retinol/kg diet. Supplemental zinc and vitamin A significantly increased live weight gain and improved feed efficiency (p<0.05). However, a combination of zinc and vitamin A, rather than each separately, provided a greater performance. Hot and chilled carcass weights and yields and the weights of internal organs with the exception of abdominal fat were greater for each supplement (p<0.05) compared to the control group. Abdominal fat decreased (p<0.05) upon dietary zinc and vitamin A supplementation. Supplemental treatments resulted in an increased total serum protein but decreased glucose, cholesterol, and MDA concentrations. The results of the study show that, separately or as a combination, zinc and vitamin A supplementation resulted in an improved live weight gain, feed efficiency, and carcass traits, as well as a decrease in serum MDA concentrations. The results of the present study also suggest that zinc and vitamin A have similar effects and that a combination of zinc and vitamin A may offer a potential protective management practice in preventing heat-stress-related depression in performance of broiler chickens.