Del Campo Gigena Marcia, Soares de Lima Juan Manuel, Brito Gustavo, Manteca Xavier, Hernández Pilar, Montossi Fabio
INIA Tacuarembó, Ruta 5 km 386, C.P.45000 Tacuarembó, Uruguay.
Universidad Autónoma de Barcelona, 08193 Bellaterra, Spain.
Animals (Basel). 2021 May 7;11(5):1329. doi: 10.3390/ani11051329.
The objective of this experiment was to evaluate the effect of two different pasture-based finishing strategies and lairage time on steers welfare in Uruguayan conditions. Sixty Hereford (H) and Braford (B) steers were assigned to two different diets for finishing purposes: (D1) native pasture plus corn grain (1% of live weight) (H = 15, B = 15) and (D2) high-quality pasture (H = 15, B = 15). The average daily gain was registered every 14 days, and temperaments were individually assessed one week before slaughter by three individual tests: crush score, flight time and exit speed, building a multicriterial temperament index (TIndex). Animals were slaughtered the same day in two groups (50% from D1 and 50% from D2 in each group) after traveling for 3.5 h and staying 15 (long lairage) and 3 h (short lairage) in the lairage pens, respectively. The behaviors were observed during lairage, and physiological indicators were used to assess stress at the farm after transport, after lairage and at slaughter. Bruises incidence and final pH were registered at the abattoir as a means of assessing the overall animal welfare. Calmer animals had higher average daily gains with no differences either between diets or between breeds. Calmer animals also had a lower stress response during all preslaughter stages, regardless of the time in lairage. Transport did not imply psychological stress (cortisol) for any slaughter group, but physical stress was evident after transport in both groups through NEFA and CPK increases. Bruise incidences did not differ between lairage groups. The short lairage group did not have enough time to cope with the environment before slaughter, with the consequent deleterious effects on the carcass pH. Animals from the long lairage group had a higher metabolic response shown through NEFA values, but they had enough time to rest and recover overnight, reaching final pH values lower than 5.8, considered the upper limit of the normal range. According to this experiment, with pasture-based animals without fasting on the farm and after 3.5 h of transportation, a resting period of 15 h in lairage should be better than a 3-h one.
本实验的目的是评估两种不同的基于牧场的育肥策略以及待宰时间对乌拉圭条件下公牛福利的影响。六十头赫里福德（H）和布拉福德（B）公牛被分配到两种不同的育肥日粮：（D1）天然牧场加玉米谷物（占活重的1%）（H = 15头，B = 15头）和（D2）优质牧场（H = 15头，B = 15头）。每14天记录平均日增重，并在屠宰前一周通过三项个体测试对性情进行单独评估：挤压评分、逃跑时间和出栏速度，构建一个多标准性情指数（TIndex）。动物在运输3.5小时后，分别在待宰栏中停留15小时（长待宰期）和3小时（短待宰期），于同一天分两组屠宰（每组中50%来自D1，50%来自D2）。在待宰期间观察行为，并使用生理指标评估运输后、待宰后和屠宰时农场的应激情况。在屠宰场记录瘀伤发生率和最终pH值，作为评估动物整体福利的手段。性情较温顺的动物平均日增重较高，日粮之间或品种之间均无差异。性情较温顺的动物在所有屠宰前阶段的应激反应也较低，无论待宰时间长短。运输对任何屠宰组都不意味着心理应激（皮质醇），但两组在运输后通过非酯化脂肪酸（NEFA）和肌酸磷酸激酶（CPK）升高均出现明显的身体应激。待宰组之间的瘀伤发生率没有差异。短待宰期组在屠宰前没有足够的时间应对环境，从而对胴体pH值产生有害影响。长待宰期组的动物通过NEFA值显示出较高的代谢反应，但它们有足够的时间过夜休息和恢复，最终pH值低于5.8，这被认为是正常范围的上限。根据本实验，对于农场不禁食且运输3.5小时后的以牧场为基础的动物，待宰期15小时应优于3小时。
