Effect of a screen with flaps and straw on behaviour, stress response, productive performance and meat quality in indoor feedlot lambs

Behaviour and welfare of fattening lambs supplemented with varying sizes and types of straw

The aim was to evaluate the effect of size (long or chopped wheat straw), type (barley or wheat) and presence/absence (1 week) of straw supplementation on behaviour and welfare of fattening lambs. Sixteen lambs (65 days) were individually housed to be used in two simultaneous experiments (8 lambs each) for 5 weeks of fattening. After a habituation period, they were offered straw that differed either in size (Experiment 1) or type (Experiment 2), which was followed by a week without straw and then reallocation of straw. Maintenance behaviours, play and stereotypies were analysed using video recording. Physiological stress responses were measured using blood samples taken at the end of the week without straw and after the reallocation of the straw. A preference test was performed during the last week. Concentrate and roughage consumption, average daily gain and conversion index were estimated. Lambs provided with long straw spent more time eating forage, playing and performed fewer stereotypies (Experiment 1). Lambs given wheat straw increased their play behaviour compared with those given barley straw, without affecting stereotypies (Experiment 2). When the straw was removed, lambs performed more behaviours associated with stress; however, this was not reflected in blood stress indicators. Lambs clearly preferred long straw over chopped straw, but no clear preference was observed between wheat and barley straw. The amount of forage intake was consistent with the time spent eating forage, but the amount of concentrate intake did not vary with eating concentrate behaviour, since the amount of concentrate intake was higher when the straw was removed, especially in Experiment 2. Our results show that size more than type of straw supplement impact the behaviour of lambs. Long straw reduces the stereotypies and increases play. This may improve the welfare and performance of fattening lambs, adding ethical value to a highly appreciated product.

Phytol Promotes the Formation of Slow-Twitch Muscle Fibers through PGC-1α/miRNA but Not Mitochondria Oxidation

Phytol is a side chain of chlorophyll belonging to the side-chain double terpenoid. When animals consume food rich in chlorophyll, phytol can be broken down to phytanic acid after digestion. It was reported that feeding animals with different varieties and levels of forage could significant improve pH and marbling score of steer and lamb carcasses, but the internal mechanism for this is still not reported. The marbling score and pH of muscle was mainly determined by skeletal muscle fiber type, which is due to expression of different myosin heavy-chain (MHC) isoforms. Here, we provide evidence that phytol can indeed affect the diversity of muscle fiber types both in vitro and in vivo and demonstrate that phytol can increase the expression of MHC I (p < 0.05), likely by upgrading the expression of PPARδ, PGC-1α, and related miRNAs. This fiber-type transformation process may not be caused by activated mitochondrial metabolism but by the structural changes in muscle fiber types.