The Feeding Behaviour Habits of Growing-Finishing Pigs and Its Effects on Growth Performance and Carcass Quality: A Review

SIMPLE SUMMARY: The study of feeding behaviour habits (FBHs) of growing-finishing pigs is of interest due to its influence on growth performance and carcass quality. The present review collates the available scientific data regarding the internal and external factors affecting the FBHs and its influence on growth performance and carcass quality. Factors explored were age, sex, breed, space allowance, feeder design, feed form, diet composition, and environmental conditions. The reviewed data indicate that the factors explored affect the FBHs of growing-finishing pigs. Moreover, meal size and feeding rate were the two FBHs most related with performance, being positively correlated with average daily feed intake, growth rate, and final body weight, but with no clear effect on feed efficiency, whereas the few studies regarding the influence of FBHs on carcass traits indicate a positive correlation between meal size and feeding rate with backfat thickness. Therefore, the available data provide evidence that modifying FBHs may improve the performance of grow-ing-finishing pigs, but not necessarily feed efficiency. ABSTRACT: Based on the available data of feeding behaviour habits (FBHs), this work aimed to discuss which type of pig, according to its FBHs, performs better and is more efficient. As pigs grow, average daily feed intake, meal size, and feeding rate increase, whereas small variations or even decreases in time spent eating and daily feeder visits have been reported. Moreover, the sex, breed, space allowance, feeder design, feed form, diet composition, and environmental conditions modify FBHs. On the other hand, the literature indicates the existence of four types of pigs: pigs that eat their daily feed intake in many short meals (nibblers) or in few large meals (meal eaters) combined with eating fast (faster eaters) or slow (slow eaters). The available scientific literature about ad libitum fed pigs suggests that pigs eating faster with bigger meals eat more, gain more weight, and are fatter than pigs eating less, slower, and with smaller meals. However, the feeding rate and the meal size do not influence feed efficiency. In conclusion, studies comparing growing-finishing pigs with similar feed intake, but different feeding rate and meal size are needed to better understand the influence of FBHs on feed efficiency.