Effect of Substituting Field Beans (Vicia faba) for Soybean Meal in Diets for Grow-Finisher Pigs

Field beans (FB) availability has increased greatly in Ireland in recent years. This study examined the substitution of field beans for soybean meal in diets for grow-finisher pigs. A total of 80 pigs (38.9±0.60 kg) housed in same sex pen pairs were blocked by sex and weight, and allocated to 1 of 4 dietary treatments (n=10 replicates) in a 2x2 factorial arrangement. The factors were: 1) Diet density (high: 10.0 MJ NE/kg and 9.9 g SID Lys/kg vs. low: 9.3 MJ NE/kg and 8.9 g SID Lys/kg) and 2) FB inclusion level (0 vs. 40%). The experiment lasted 50 d. Data were analyzed using PROC MIXED in SAS (SAS Inst. Inc., Cary, NC). There was no interaction between diet density and FB inclusion. Pigs fed the low density diets had a poorer FCR (P<0.001) than pigs fed the high density diets. Pigs fed the FB based diets had higher final weight (P<0.01), higher ADG (P<0.01), higher ADFI (P<0.001) and a similar FCR to pigs fed diets without FB. At slaughter, diet density had no effect on carcass weight (85.8 vs. 86.7±0.77 kg, P>0.10), kill out % (77.4 vs. 77.7±0.23%, P>0.10), fat depth (11.9 vs. 11.6±0.39 mm, P>0.10), muscle depth (59.7 vs. 59.8±2.69 mm, P>0.10) and lean meat % (59.2 vs. 59.1±0.63%, P>0.10). Pigs fed the FB based diets, had higher carcass weight (87.9 vs. 84.7±0.77 kg, P<0.01), similar kill out % (77.5 vs. 75.6±0.23%, P>0.10), higher fat depth (12.4 vs. 11.1±0.39 mm, P<0.05), similar muscle depth (59.6 vs. 59.9±2.69 mm, P>0.10), and similar lean meat % (59.5 vs. 58.8±0.63%, P>0.10). Higher growth, feed intake and fat depth of pigs fed FB based diets may indicate that the energy value used for FB in our diet formulation may have been underestimated. Field beans are a good protein source and can be included at a level of 40% in grow-finisher diets without causing deterioration in feed efficiency.

Effect of diet density and field bean inclusion (%) on growth performance of grow-finisher pigs

	Diet density					Field beans inclusion
Item	High	Low	SEM	P-value		0%	40%	SEM	P-value
d 0-50
Weight d 0, kg	38.8	38.8	0.57	0.950		39.0	39.0	0.60	0.971
Weight d 50, kg	111.5	110.8	1.00	0.632		109.2	113.1	1.00	<0.01
ADG, g/d	1039	1027	16.0	0.576		1002	1064	16.0	<0.01
ADFI, g/d	2271	2364	36.5	0.079		2242	2394	36.6	<0.001
FCR, g/g	2.19	2.31	0.023	<0.001		2.24	2.26	0.020	0.712