Welfare and meat quality of beef cattle housed on two types of floors with the same space allowance

Growth performance, behaviour, cleanliness, carcass traits and meat quality of 48 Simmental young bulls housed on slatted floor or on straw bedding with the same space allowance were compared in the study, which lasted 250 days. The animals (initial body weight = 321.2 +/- 34.1 kg) were assigned to 8 balanced groups, according to their initial body weight. All the groups were reared in separate pens with a space allowance of 3 m(2)/head. Four pens had a concrete floor covered with a straw bedding while the other pens had a fully slatted floor made of concrete slats. All the animals received the same diet provided ad libitum. Type of floor did not affect the bulls' daily gain, feed intake and feed efficiency. Health status of the animals was satisfactory throughout the trial and several blood indicators of chronic stress were not modified by the treatment. Behavioural observations carried out at d 10, 80, 180 and 240 showed differences only on some behaviours due to the type of floor. In particular, the straw bedding increased eating behaviour and it encouraged the simultaneous presence of more bulls at the manger. Regardless of the type of floor, the progress of the trial showed a linear increase of animals' inactivity (P < 0.05) while linear decrease of bulls' lying (P < 0.01), eating (P < 0.001) and ruminating (P < 0.01) was observed. These results can be referred to the growth of the animal body frame, which made the space allowance progressively limiting. In the straw bedded pens, clean straw was added weekly and fully renewed every 3 weeks, but this bedding management did not allow a satisfactory cleanliness of the animals in comparison with the slatted floor. However, the worse cleanliness of the bulls on the straw did not promote their grooming activity. Young bulls were slaughtered at a final weight of 614.6 +/- 14.7 kg and their carcass traits and meat quality were not affected by the treatment. The straw bedded system cannot always be considered the cleanest solution for the housing of beef cattle and its frequent renewal must be carried out, particularly when animals are kept with a minimum space allowance. The minimal differences observed for all the parameters measured in the study between the two types of floors must be related to the adoption of the same space allowance/animal and this factor has shown to be the most critical housing parameter affecting beef cattle welfare during the fattening period.