Effects of in ovo feeding with glycerol for broilers.

The objective was to evaluate the effect of in ovo feeding with glycerol on post-hatch development in broiler chicks. A total of 408 fertile eggs were divided into six experimental groups consisting of five 0.9% saline solutions containing various concentrations of glycerol (12.5, 25.0, 37.5 and 50.0 nmol/ml), and a placebo group (inoculation with saline only) and a control group (without inoculation). Inoculations were performed at 17 days of incubation for the evaluation of hatchability, embryo mortality, body and viscera weights, intestinal epithelium morphometry, blood glucose and liver glycerol kinase activity of chicks at hatching. Inoculation of solutions containing glycerol did not influence body weight at hatching and relative weights of liver, pancreas, intestine and breast. There was a quadratic effect of glycerol levels on the weights of yolk residue and gizzard and on blood glucose, and an increasing linear effect on spleen and heart weights. Higher duodenum and ileum villous height and deeper jejunum and ileum crypts were obtained with 50.0 nmol/ml of glycerol. A linear increasing effect was also observed in liver glycerol kinase activity; however, lower blood glucose was observed with 37.5 and 50 nmol/ml of glycerol. It is therefore concluded that glycerol may be used at doses of 25 nmol/ml as a substrate in in ovo feeding of broiler chickens. However, further studies must be conducted not only to establish an optimal dose but also to evaluate the combination of this substrate with other nutrients used in the in ovo feeding.

Validation of Prediction Equations of Energy Values of a Single Ingredient or Their Combinations in Male Broilers.

A set of prediction equations to estimate the nitrogen-corrected apparent metabolizable energy (AMEn) of individual ingredients and diets used in the poultry feed industry was evaluated. The AMEn values of three energy ingredients (maize, sorghum and defatted maize germ meal), four protein ingredients (soybean meal, maize gluten meal 60% crude protein, integral micronized soy and roasted whole soybean) and four diets (three containing four feedstuffs, complex diets, and one containing only corn-soybean meal, basal diet) were determined using a metabolism assay with male broilers from 1 to 7, 8 to 21, 22 to 35, and 36 to 42 days old. These values were compared to the AMEn values presented in the tables of energy composition or estimated by equation predictions based on chemical composition data of feedstuffs. In general, the equation predictions more precisely estimated the AMEn of feedstuffs when compared to the tables of energy composition. The equation AMEn (dry matter [DM] basis) = 4,164.187+51.006 ether extract (% in DM basis)-197.663 ash-35.689 crude fiber (% in DM basis)-20.593 neutral detergent fiber (% in DM basis) (R(2) = 0.75) was the most applicable for the prediction of the energy values of feedstuffs and diets used in the poultry feed industry.