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Effect of a 6-Phytase derived From Buttiauxella spp. expressed in Trichoderma reesei on Apparent Total Tract Digestibility of Ca and P, Bone Ash and Growth Performance in Weaning Piglets
Two studies evaluated the effect of a 6-phytase derived from Buttiauxella spp. expressed in Trichoderma reesei (PHY) on apparent total tract digestibility (ATTD) of Ca and P, bone ash and growth performance in piglets. Five dietary treatments were tested, including a positive control (PC) based on corn-SBM-canola meal adequate in available P and Ca, a negative control (NC) with low available P and Ca and NC supplemented with PHY at 250, 500, and 1000 FTU/kg feed with low available P (-0.2%) and Ca (-0.17%). Experiment 1 used 232 male piglets (Initial BW = 9.62 ± 1.36 kg) with 10 replicates per treatment; 3-4 piglets/replicate. Experiment 2 used 160 piglets (Initial BW = 8.99±0.16 kg) with 8 replicates/treatment; 4 piglets/replicate. Experimental diets were fed in mash form ad libitum in two phases for 6 weeks in Exp 1 and from 9-22kg BW in Exp 2. Faecal samples were collected from one pig/pen at the end of Exp 1 and in the last 4 days of feeding in Exp 2; samples were measured for ATTD using a TiO2 marker. Femurs from both forelegs were collected for bone analysis. Linear and quadratic responses were determined using the Fit Model platform of JMP; trial was used as a random effect. In both experiments, NC reduced all growth and digestibility parameters compared to PC (Table 1). PHY supplementation resulted in linear/quadratic improvement in BWG, G:F, digestible Ca and P as well as bone ash. In conclusion, 1000 FTU/kg 6-phytase derived from Buttiauxella spp., expressed in Trichoderma reesei, can replace 0.2% available P in weaning piglet diets, based on BWG and bone ash data.
Table 1. Effect of phytase supplementation on growth parameters, Ca and P digestibility and bone ash percentage
Phytase dose, FTU |
||||||||
|
PC |
NC |
250 |
500 |
1000 |
S.E.M |
Linear |
Quadratic |
Bodyweight gain (g/day) |
566.8 |
377.1 |
466.2 |
484.3 |
536.3 |
11.84 |
<.0001 |
0.110 |
Feed Intake (g/day) |
942.6 |
774.1 |
896.0 |
910.9 |
954.3 |
18.19 |
<.001 |
0.116 |
Gain:Feed |
0.61 |
0.49 |
0.53 |
0.54 |
0.57 |
0.01 |
0.002 |
0.504 |
Phosphorous ATTD (%) |
28.52 |
6.08 |
23.04 |
43.32 |
47.89 |
1.09 |
0.023 |
0.372 |
Calcium ATTD (%) |
54.51 |
38.00 |
40.99 |
67.04 |
56.21 |
2.23 |
<.0001 |
<.001 |
Bone Ash (%) |
46.45 |
36.82 |
41.06 |
42.45 |
43.67 |
2.15 |
<.0001 |
<.0001 |
Assessment of linear and quadratic responses excluded positive control treatments
Keywords: phytase, swine, performance