Cruz R F A, Vieira S L, Kindlein L, Kipper M, Cemin H S, Rauber S M
Departamento de Zootecnia, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 7712, Porto Alegre, RS, 91540-000, Brazil.
Departamento de Zootecnia, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 7712, Porto Alegre, RS, 91540-000, Brazil
Poult Sci. 2017 Feb 1;96(2):501-510. doi: 10.3382/ps/pew310. Epub 2016 Sep 21.
Two experiments were conducted to evaluate the prevalence and severity of white striping (WS) and wooden breast (WB) in breast fillets from broilers fed diets with increasing digestible Lysine (dLys) from 12 to 28 d (Exp. 1) and from 28 to 42 d (Exp. 2). Trials were sequentially conducted using one-d-old male, slow-feathering Cobb 500 × Cobb broilers, both with 6 treatments and 8 replicates. Increasing dLys levels were equally spaced from 0.77 to 1.17% in Exp. 1 and from 0.68 to 1.07% in Exp. 2. The lowest dLys diet was not supplemented with L-Lysine (L-Lys) in either one of the studies and all other essential amino acid (AA) met or exceeded current commercial recommendations such that their dietary concentrations did not limit broiler growth. Four birds per pen were randomly selected from each replication and processed at 35 and 42 d in Exp. 1 and Exp. 2, respectively. Deboned breast fillets (Pectoralis major) were submitted to a 3 subject panel evaluation to detect the presence of WS and WB, as well as to provide scores of WS (0-normal, 1-moderate, 2-severe) and WB (0-normal, 1-moderate light, 2-moderate, 3-severe). Increasing the level of dLys had a positive effect on BW, carcass, and breast weight, as well as breast yield. White striping and WB prevalences were 32.3 and 85.9% in Exp. 1 and 87.1 and 89.2% in Exp. 2. Birds fed diets not supplemented with L-Lys had the lowest average WS and WB scores (0.22 and 0.78 in Exp. 1 and 0.61 and 0.68 in Exp. 2). White striping and WB presented linear responses to performance variables in Exp. 1, whereas quadratic responses were observed for all variables in Exp. 2. In conclusion, increasing the level of dLys improved growth performance and carcass traits as well as induced the occurrence and severity of WS and WB lesions.
进行了两项试验，以评估12至28日龄（试验1）和28至42日龄（试验2）饲喂可消化赖氨酸（dLys）水平递增日粮的肉鸡胸肉中白条（WS）和木胸（WB）的发生率及严重程度。试验依次使用1日龄雄性、慢羽型科宝500×科宝肉鸡进行，均设6个处理，8个重复。在试验1中，dLys水平从0.77%至1.17%等间距增加，试验2中从0.68%至1.07%等间距增加。在两项研究中，最低dLys日粮均未添加L-赖氨酸（L-Lys），所有其他必需氨基酸（AA）均达到或超过当前商业推荐水平，因此其日粮浓度未限制肉鸡生长。试验1和试验2中，分别从每个重复栏中随机选取4只鸡，在35日龄和42日龄时进行屠宰。去骨胸肉（胸大肌）由3名评估人员进行评估，以检测WS和WB的存在情况，并给出WS（0-正常，1-中度，2-重度）和WB（0-正常，1-轻度中度，2-中度，3-重度）的评分。提高dLys水平对体重、胴体和胸肉重量以及胸肉产量有积极影响。试验1中WS和WB的发生率分别为32.3%和85.9%，试验2中分别为87.1%和89.2%。饲喂未添加L-Lys日粮的鸡，其WS和WB平均评分最低（试验1中为0.22和0.78，试验2中为0.61和0.68）。试验1中，WS和WB对生产性能变量呈线性反应，而试验2中所有变量均观察到二次反应。总之，提高dLys水平改善了生长性能和胴体性状，同时诱发了WS和WB病变的发生及严重程度。
