Effects of two sources of Mexican oregano oil on performance, blood profile, carcass variables, and meat of broilers

ABSTRACT The current study was conducted to investigate the effects of Mexican oregano essential oil (MOO) extracts from Lippia berlandieri Schauer (LBS) and Poliomintha longiflora Gray (PLG) on performance, blood profiles, carcass variables, and meat composition of broilers at slaugther. A total of 360 one-day-old Ross broilers were randomly distributed into four dietary treatments with six replicate pens per treatment and 15 birds per pen. The dietary treatments were: a basal diet (control), control + 0.40 g of LBS/kg of feed, control + 0.40 g of PLG/kg, and control + 0.40 g of LBS/kg + 0.40 g of PLG/kg. Results showed that linear, quadratic, and cubic effects of days were significant in the performance variables of broilers. The treatments with LBS and PLG maintained the broiler body weight without increasing feed intake and water intake when compared with the control group. Broilers given LBS+PLG and PLG had increased blood leukocytes, lymphocytes, low-density lipoprotein, and hot carcass yields. In meat composition, treatments with PLG and LBS+PLG presented similar breast protein content compared with the control treatment. Supplementation with these two MOO exhibits positive effects on broiler performance, blood profiles, carcass traits, and meat composition. These two MOO may be promising feed supplements as growth promoters and enhancers of meat quality in broiler production.

摘要
本研究旨在探究源自贝兰氏牛至（Lippia berlandieri Schauer, LBS）与长花波利明塔草（Poliomintha longiflora Gray, PLG）的墨西哥牛至精油（Mexican oregano essential oil, MOO）提取物，对屠宰期肉用仔鸡生产性能、血液生化指标、屠宰性状及肉品组成的影响。本试验共选取360只1日龄罗斯（Ross）肉用仔鸡，随机分为4组日粮处理，每组设置6个重复栏，每栏饲养15只鸡。日粮处理组分别为：基础日粮对照组、基础日粮+0.40g LBS/kg饲料组、基础日粮+0.40g PLG/kg饲料组，以及基础日粮+0.40g LBS/kg + 0.40g PLG/kg复合组。
试验结果表明，饲养天数对肉用仔鸡的生产性能指标存在显著的线性、二次及三次效应。与对照组相比，单独添加LBS或PLG的试验组可维持肉用仔鸡体重，且未提高采食量与饮水量。饲喂LBS+PLG复合组与PLG组的肉用仔鸡，其血液白细胞、淋巴细胞、低密度脂蛋白（low-density lipoprotein, LDL）及热胴体率均显著升高。在肉品组成方面，PLG组与LBS+PLG复合组的胸肌蛋白质含量与对照组无显著差异。
在日粮中添加这两种墨西哥牛至精油提取物，可对肉用仔鸡的生产性能、血液生化指标、屠宰性状及肉品组成产生积极影响。上述两种提取物有望作为肉用仔鸡生产中的生长促进剂与肉品质改良剂，成为极具应用潜力的饲料添加剂。