Feed Intake Patterns and Growth Performance of Purebred and Crossbred Meishan and Yorkshire Pigs

Two experiments were conducted to compare the feed intake patterns and growth performance of Meishan and Yorkshire growing pigs. Experiment 1 was carried out over a 6-wk period and used 48 barrows with equal numbers of purebred Meishan (M) and Yorkshire (Y). Pigs were allocated to four groups of 12 pigs consisting of equal numbers of M and Y. Initial BW were 36.4 ± 0.32 kg and 42.1 ± 1.41 kg for M and Y, respectively. Experiment 2 was carried out over a 5-week period and used 48 pigs consisting of equal numbers of both barrows and gilts and of crossbred Meishan X Yorkshire (MY) and purebred Yorkshire (Y) animals. Pigs were allotted to 6 pens of 8 pigs, with 4 single- and 2 mixed-genotype groups (initial BW=28.5 ± 0.99 kg). In both experiments, pigs were given ad libitum access to a grower diet (17% crude protein, 0.9% lysine, 3365 kcal/kg ME) via feed intake recording equipment (F.I.R.E.). Pigs carried an ear-tag transponder with an unique identification which allowed the time, duration, and size of individual meals to be recorded. In Exp. 1, Y had higher ADG (721 vs 353 g, p<0.01), daily feed intake (DFI; 2.338 vs 1.363 kg, p<0.01), made more frequent visits to the feeder per day (NFV; 18.5 vs 7.7, p<0.01), had a shorter feeder occupation time per visit (FOV; 7.4 vs 12.9 min, p<0.01), and ate less feed per visit (FIV; 130 vs 177 g, p<0.01) than M pigs. Feed consumption rates (CR) were greater for Y compared to M (19.3 vs 14.8 g/min, p<0.01). Feeder occupation time per day (FOD) was longer for Y than M (114.3 vs 82.8 min/pig, p<0.01). Yorkshire pigs visited the feeder more frequently between 0800 and 1100 h. Meishan pigs showed more frequent feeder visits between 0600 and 0800 h, and between 1600 and 2100 h when feeding competition with Y was reduced. In Exp. 2, there was no effect of genotype or group composition on DFI, ADG or gain:feed ratio. Crossbred pigs (MY) made fewer feeder visits (12.6 vs 17.7, p<0.01), and had greater FIV (124 vs 98 g/visit, p<0.01), and longer FOV (8.11 vs 7.24 min/visit, p<0.01) and FOD (112 vs 100 min, p<0.05) than Y pigs. Results of this study suggest substantial genetic variation in feeding patterns as well as in growth performance.