MACAÚBA MEAL LEVELS IN THE DIET OF NAKED NECK BROILERS

Abstract A total of 375-day-old naked neck chicks were distributed in a completely randomized design in five diets with 0, 2, 4, 6, and 8% macaúba meal levels to evaluate colonial broiler chickens. The data were submitted to linear or quadratic regression analysis according to the best fit for each studied variable using the statistical program SAS 9.0. Macaúba meal levels increased feed intake without influencing weight gain, resulting in worsening feed conversion and leading to a linear reduction in slaughter weight at 85 days and reduction in carcass yields due to higher abdominal fat deposition. Linear effects were found on the contents of a*, pH, ethereal extract, and ash in the breast and b*, moisture, ethereal extract, and ash in the drumstick + thigh. Thus, macaúba meal inclusion in the diet of naked neck broilers impaired performance by increasing diet intake, impairing feed conversion and reducing carcass yields. However, it favors breast, drumstick, and thigh colors because it is rich in carotenoids.

摘要：本试验共选取375只1日龄裸颈雏鸡，采用完全随机设计，将其分配至5组日粮中，各组日粮分别添加0、2%、4%、6%、8%的马卡乌巴粕（macaúba meal），以评价商品肉用仔鸡的养殖性能。试验数据采用SAS 9.0统计软件，依据各研究变量的最优拟合模型，开展线性或二次回归分析。结果表明，马卡乌巴粕的添加水平提升了肉鸡的采食量，但对增重无显著影响；进而导致饲料转化率恶化，使85日龄时的屠宰体重呈线性降低，同时因腹部脂肪沉积量增加，胴体产率出现下降。此外，胸肌的a*值、pH值、乙醚浸出物含量与灰分含量，以及腿肌与大腿肉的b*值、水分含量、乙醚浸出物含量与灰分含量均呈现线性变化效应。综上，在裸颈肉鸡日粮中添加马卡乌巴粕，会通过增加采食量、降低饲料转化率损害其生产性能，并降低胴体产率；但由于该原料富含类胡萝卜素，可改善胸肌、鸡腿与大腿肉的色泽表现。