Abstract #M180

Section: Nonruminant Nutrition
Session: Nonruminant Nutrition: Enzymes & minerals
Format: Poster
Day/Time: Monday 7:30 AM–9:30 AM
Location: Gatlin Ballroom

# M180
Performance of commercial market hogs supplemented with a new generation Buttiauxella phytase.
Janet C. Remus^*1, Yueming Dersjant-Li², Peter Plumstead³, Ajay Awati², ¹Danisco Animal Nutrition/DuPont Industrial Bioscience, St. Louis, MO, ²Danisco Animal Nutrition/DuPont Industrial Bioscience, Marlborough, Wiltshire, UK, ³University of Pretoria, Pretoria, South Africa.

This experiment was conducted to determine if a new generation phytase from Buttiauxella sp. can replace all inorganic phosphate (PO₄) in diets also reduced in Ca and ME and fed to commercial pigs from 12 kg to slaughter while maintaining performance and carcass quality. Four treatments were tested in a randomized block design with 9 replicate pens, each with 31 mixed sex pigs of Newsholm Choice genetics. The corn-soybean meal-wheat middlings-based treatment diets are (1) positive control (PC) that met nutrient requirements; (2) negative control (NC) without inorganic PO₄ and with incremental phase nutrient reductions of 0.131% Ca and 35 kcal ME/kg; (3) NC+500 FTU/kg phytase (NC+500) and (4) NC+1000 FTU/kg phytase (NC+1000). The mash diets were fed ad lib in 5 feed phases. Data were tested using the Fit Model procedure in JMP, mean separation utilized Tukey's test. Significance was P ≤ 0.05 unless noted. Due to poor growth at the end of Finisher 1, the NC was placed on PC feed in Finisher 2 (F2) to see if they could get to target weight. Performance from Nursery 2 (N2) thru F2 shows the PC and NC+1000 have similar ADG and improved results versus NC. The NC+500 had better ADG and FCR than the NC and had similar FCR with PC and NC+1000 in N2 thru F2. From N2 to processing, the PC and both phytase treatments were similar on performance (no NC due to insufficient pens at target weight by F2 end). No differences noted for carcass weight, lean carcass or yield. Carcass data for PC, NC+500, and NC+1000 shows that the NC+500 had higher 10th rib fat but had a tendency (P = 0.07) toward lower yield while NC+1000 had lower muscle depth. Overall, the data indicate that 500 and 1000 FTU phytase/kg can replace all inorganic PO₄ and maintain performance compared with PC in pigs fed a corn-soybean meal-wheat middlings based diet. Table 1. Performance and carcass data

Treatment	N2 to F2 (12-120 kg)				Carcass
ADG, kg	ADFI, kg	FCRmc	Muscle depth, mm	10th rib backfat, mm
PC	0.78^ab	2.17^a	2.80^ab		63.78^a	18.94^b
NC	0.69^c	1.98^b	2.86^a
NC+500	0.75^b	2.09^ab	2.77^b		63.91^a	19.72^a
NC+1000	0.79^a	2.20^a	2.79^ab		62.63^b	18.99^b
P-value	<0.01	<0.01	0.05		0.02	0.05

Key Words: Buttiauxella phytase, pigs, performance