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An adequate supply of all nutrients, including proteins, fats, carbohydrates, vitamins, minerals and water, has to be provided to support maximum productivity of laying hens. Among these nutrients, vitamins are particularly important, since they are essential for optimum health as well as normal physiological functions of the hens. As most vitamins cannot be synthesized by poultry in sufficient amounts to meet physiological demand, they must be obtained from the diet. The absence from feed or impaired absorption or utilization of vitamins can lead to specific deficiency disorders. This review reports on the occurrence and the physiological functions of all vitamins and summarizes research related to the requirements for and the beneficial effects of supplemental vitamins for laying hens. The recommendations for dietary supplementation of vitamins from various organizations are compared and put into perspective of modern poultry genotypes and current husbandry conditions. As there is good evidence that the minimum dietary vitamin levels, required to prevent clinical deficiencies may not support optimum health, performance and welfare of poultry under today's conditions it is recommended to include a safety margin to the vitamin requirements of laying hens

Two experiments were conducted to investigate the use of sorghum, cottonseed meal and millet in broiler diets and their interaction when they are used simultaneously. In Experiment 1, a corn-soybean meal control diet was compared with eight experimental treatments based on low tannin sorghum (S30, S45 and S60), cottonseed meal (CM15, CM40) or both ingredients included in the same diet (S30/CM40, S45/CM25 and S60CM15). Results showed that BW gain was not affected by the inclusion of sorghum or cottonseed meal. However, feed intake tended to be affected by the cereal type with the highest values with sorghum-based diets. Feed conversion ratio increased (P<0.001) with sorghum-based diets compared with the control diet, whereas a combination of cottonseed meal and sorghum in the same diet did not affect the feed conversion ratio. Significant differences (P<0.001) were observed in apparent ileal digestibility (%) of protein and energy with the cottonseed meal and sorghum/cottonseed meal-based diets having lower protein and energy digestibility compared with corn-based diets. In Experiment 2, a control diet was compared with six diets in which corn was substituted at 60%, 80% or 100% by either sorghum or millet and other three diets with simultaneous inclusion of these two ingredients (S30/M30, S40/M40, S50/M50). Single or combined inclusion of sorghum and millet resulted in similar feed intake and growth performance as the control diet. Apparent ileal digestibility of protein and energy was higher with millet-based diets (P<0.001). Total tract digestibility of protein in sorghum and millet-based diets tended to decrease linearly with the increasing level of substitution. Sorghum-based diets resulted in lower total tract digestibility of fat compared with millet and sorghum/millet-based diets (P<0.001). Higher total tract digestibility of starch were obtained with the control diet and millet-based diets compared with the sorghum-based treatments. Results of the two experi

A meta-analysis was conducted (i) to evaluate broiler response to partial or total substitution of corn by sorghum and millet and (ii) to determine the effect of soybean meal replacement by cottonseed meal in broiler diet. The database included 190 treatments from 29 experiments published from 1990 to 2013. Bird responses to an experimental diet were calculated relative to the control (Experimental−Control), and were submitted to mixed-effect models. Results showed that diets containing millet led to similar performance as the corn-based ones for all parameters, whereas sorghum-based diets decreased growth performance. No major effect of the level of substitution was observed with millet or cottonseed meal. No effect of the level of substitution of sorghum on feed intake was found; however, growth performance decreased when the level of substitution of corn by sorghum increased. Cottonseed meal was substituted to soybean meal up to 40% and found to increase feed intake while reducing growth performance. Young birds were not more sensitive to these ingredients than older birds since there was no negative effect of these ingredients on performance in the starter phase. Results obtained for sorghum pointed out the necessity to find technological improvements that will increase the utilization of these feedstuffs in broiler diet. An additional work is scheduled to validate these statistical results in vivo and to evaluate the interactions induced with the simultaneous inclusions of sorghum, millet and cottonseed meal in broiler feeding.

An adequate supply of all nutrients, including proteins, fats, carbohydrates, vitamins, minerals and water, has to be provided to support maximum productivity of laying hens. Among these nutrients, vitamins are particularly important, since they are essential for optimum health as well as normal physiological functions of the hens. As most vitamins cannot be synthesized by poultry in sufficient amounts to meet physiological demand, they must be obtained from the diet. The absence from feed or impaired absorption or utilization of vitamins can lead to specific deficiency disorders. This review reports on the occurrence and the physiological functions of all vitamins and summarizes research related to the requirements for and the beneficial effects of supplemental vitamins for laying hens. The recommendations for dietary supplementation of vitamins from various organizations are compared and put into perspective of modern poultry genotypes and current husbandry conditions. As there is good evidence that the minimum dietary vitamin levels, required to prevent clinical deficiencies may not support optimum health, performance and welfare of poultry under today's conditions it is recommended to include a safety margin to the vitamin requirements of laying hens