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Turkeys may experience stress due to conditions of transport, heat, and in some cases, feed and water restrictions. This may include experiencing conditions present when female turkeys are transported from the brooder house to the grow-out house, typically at 4 to 5 wk of age. This study’s objective was to determine the effect of glucomannan feed additives on performance and corticosterone response in Large White commercial females after an application of simulated conditions which birds might experience during transportation at 4 to 5 wk of age. The transport simulation consisted of reducing the space per bird from 0.198 m2 /bird to 0.028m2 /bird, with no food and water, and exposed to heat lamps, for no more than 18 h. Fourteen hundred and forty Large White female turkeys were randomly assigned to 48 concrete, pine shavings covered floor pens. The experimental design was a completely randomized block design with a one-factor arrangement of 2 sources of glucomannans (medium-chain and long-chain) with two inclusion levels of each (0.02 and 0.20% of the diet). These treatments were compared to two control treatments (no glucomannans), however, one with no simulated transport conditions and one exposed to simulated transport conditions. Bird’s performance, bursa, spleen, and blood corticosterone levels were analyzed in SAS 9.4 in a mixed model. No effects on growth performance of birds fed 0.02% glucomannans were observed. Birds fed glucomannans at 0.20% in the diet had a higher corticosterone level after the transport simulation was applied when compared to other treatments. However, birds fed medium-chain glucomannans at 0.20% had an improved performance after the transport simulation compared to birds fed the other glucomannan treatments. All birds recuperated their performance by d 45. No differences were found in the spleen and bursa weights at 45 d of age. Both glucomannans reduced the stress impact on intestinal bacteria by controlling the overgrowth of Lactobacillus and Fusobacteria while maintaining Bacteroidetes. In conclusion, glucomannans can be used in diets with no change in performance or health at 45 d of age while preserving intestinal microbiota from the negative effects of stress. At 45d, all birds recuperated from the simulated transport conditions applied at 29 d. Thus, the effects of glucomannans on turkey performance and health should be further investigated.

Vitamin A deficiency is one of the major nutritional problems in the world, most common in developing countries. Food fortification is a recognised approach to supply vitamins and minerals to needed populations. Vegetable cooking oils were previously suggested by us as a carrier for vitamin A fortification. Fortification of cooking oil with beta-carotene could also be a strategy to prevent vitamin A deficiency. The objective of this article is to start studies on the use of cooking soya oil as a vehicle for synthetic carotene, to evaluate its stability to heat treatment, and to test its bioavailability and bioconversion to vitamin A in rats. Batches of carotene-fortified soybean oil were prepared, containing 2, 4 and 8 RE/g of diet. Some of them were heated to test its stability. At 100 degrees C there was no loss of carotene, at higher temperature carotene retention was 65%. The bioavailability and bioconversion of beta-carotene added to soybean oil was measured through feeding nursing rats and their pups method. Weight gain was good and plasma vitamin A increased significantly in all groups. Liver vitamin A values of rats fed diets with fortified soybean oil heated at 100 degrees C was similar to the 4 RE non-heated fortified oil group (0.72 +/- 0.06 and 0.64 +/- 0.08 mumol/g, respectively). Heated at 170 degrees C the liver total vitamin A value was reduced (0.45 +/- 0.04 mumol/g), but kept bioavailable vitamin A equivalent to 2 RE (0.47 +/- 0.09 mumol/g). Bioconversion of beta-carotene to vitamin A was validated by the plasma and liver findings. beta-carotene added to soybean oil showed good stability to heat and its bioconversion to vitamin A was shown in rat assays. beta-carotene mixed well with edible soybean oil and the fortified cooking oil showed potential as a carrier to be used for the prevention of vitamin A deficiency.