Resumo
Emulsifiers and exogenous lipases are feed additives used to increase lipid utilization in broiler diets. A meta-analysis was carried out to quantify the effects of the supplementation of emulsifiers and exogenous lipases on broiler weight gain (BWG, g/broiler/d) and feed conversion ratio (FCR, g/g) during the whole production cycle. Studies were obtained from the PubMed, Scielo, Science Direct, Scopus, and Web of Science databases. A total of 2669 studies were identified, 25 of which composed the database for the meta-analysis, representing data from a total of 14,643 broilers. These results demonstrate that there is evidence in the literature supporting that supplementation with emulsifiers or lipases improves broiler weight gain and feed conversion during the whole production cycle. However, the effect of the additives is influenced by bird sex, lipid source and concentration, type of additive and concentration, energy level of the feed, and bird strains. The isolated use of emulsifiers increases weight gain by 1.62g/day and reduces feed conversion by 0.04. However, there is no evidence that exogenous lipase use alone improves weight gain or feed conversion in broilers during the whole production cycle. The latter result may be due to the small number of studies with the additive in question, rather than its possible effects on weight gain and feed conversion. Therefore, further investigation should be conducted on this topic, especially studies on females fed diets supplemented with lipases.(AU)
Assuntos
Animais , Galinhas/fisiologia , Emulsificantes/efeitos adversos , Aditivos Alimentares/análise , Lipase/efeitos adversosResumo
Two hundred and forty Japanese quail aged 125 days were randomly allocated to five treatment groups based on laying (%) and quail's weight (90.71 ± 1.8% egg/day × 100 and 178.05 ± 9.38 g, respectively), each of which included six replicates of eight quails. The diets were formulated based on corn, soybean meal, and industrial amino acids. An optimal diet achieves 100% of amino acids required by the quail requirements, except for threonine. Five treatments were made: 20% less amino acid; 10% less amino acid; optimal diet; 10% more amino acid; and 20% more amino acids than those in the optimal diet. The increase in amino acid levels in a fixed Lys: amino acid ratio led to histological alterations in the liver and uterine epithelium, reduction in blood lipid peroxidation, lower hepatic HSP70 gene expression, and the performance of laying Japanese quail. The optimal diet based on the NRC with an adjusted Thr: Lys 78 ratio (Lys 1.0%) improved the performance and efficiency of Japanese quail from 125 to 230 days of age.(AU)