The Effect of Superdose Levels of Phytase, Plasma Source and Plasma Level on Nursery Pig Performance

The use of vegetable based proteins continues to increase in nursery feeds as a replacement for more expensive animal proteins such as plasma protein. Increasing the vegetable protein content of the diet increases the level of dietary phytate. Dietary phytate is an anti-nutrient and the use of phytase at high levels can hydrolyse phytate improving nutrient utilization and thereby potentially improving pig performance. Hence, the objective of this trial was to investigate the effect of bovine plasma level and source with and without the addition of superdosing phytase (Quantum Blue, AB Vista) on nursery pig performance. A total of 720 weaned pigs (6 kg BW at 21d) were randomly assigned to one of 8 dietary treatments (2 x 4 factorial) with main effects of plasma (0%, 0.33%, 6% plasma and 0.33% specialized concentrated plasma (SCP)) and phytase level (0 and 2000 FTU/kg). Each treatment consisted of 9 pen replicates with 10 pigs per pen (mixed sex) and were fed a 2 phase feeding program; P1 (Wean-d21) and P2 (d210-d42). In P1 all diets were iso-nutrient and formulated to meet the pig’s nutrient requirements (NRC. 2012), including adequate phosphorus and calcium. In P2, plasma was removed from the diets but phytase levels were maintained. With phytase addition in P2, the diets were formulated at 0.15% and 0.16% below requirement for available P and calcium, respectively. At 21 d or 42 d there was no effect of plasma on ADG, ADFI or FCR. In contrast, the addition of phytase improved 21 d ADG (246 v 265; P < 0.001) and ADFI (282 v 298; P < 0.001), with no response in FCR. Phytase improved 42 d ADG (427 v 440; P < 0.001) and tended to improve FCR (1.33 v 1.31; P < 0.07). The results showed that at 42 d there was no significant main effect of plasma (P = 0.58) on live weight; 0% plasma, 24.3 kg; 0.33% plasma, 24.4 kg; 6% plasma, 24.1 kg; 0.33% SCP, 24.0 kg. In contrast there was a main effect (P < 0.02) of superdosing phytase; 0 FTU/kg, 23.9 kg; 2000 FTU/kg, 24.5 kg. In conclusion, the use of phytase at 2000 FTU/kg can positively impact piglet growth performance in the nursery.