TINNAGON TARTRAKOON1, WANDEE TARTRAKOON2, JOHN DAVID KABASA3
1Georg-August-Universität Göttngen, Institute for Animal Physiology and Animal Nutrition, Germany
2Chiang Mai University, Department of Animal Science, Thailand
3Georg-August-Universität Göttingen, Institute of Animal Physiology and Animal Nutrition, Germany
An experiment was conducted at Rajamangala Institute of Technology, Phitsanulok Campus, Thailand to investigate the effect feeding diets with normal and low phosphorus (P) contents supplemented with phytase on P excretion in growing pigs. Twenty cross-bred (DxLWxLR) castrated pigs were randomly divided into four groups under a Randomised Complete Block Design. Within each class the pigs had an initial average body weight (BW) of 30kg and were kept in individual steel metabolism cages equipped with a nipple waterer, a stainless steel feeder and urine and faeces collectors. Each group was allocated to one of the dietary treatments: Diet 1 (control, normal P level without phytase), Diet 2 (normal P level with phytase 1,000 U kg-1), Diet 3 (low P level without phytase) and Diet 4 (low P level with phytase 1,000 U kg-1). The utilisation of P was determined.
The mean faecal P and P excretion in slurry (g/day) were 3.75, 3.16, 4.45 and 3.20 and 4.69, 4.00, 5.20 and 4.01, respectively. Faecal P and P excretion in slurry as percent of P intake were 32.02, 25.12, 41.55 and 30.85 and 40.04, 31.80, 48.55 and 38.66%, respectively and differed significantly (p < 0.05). P retention was 7.02, 8.58, 5.51 and [6.36]gday and 59.96, 68.20, 51.45 and 61.34%, respectively. Apparent P digestibility were 67.98, 74.88, 58.45 and 69.15%, respectively and differed significantly (p < 0.05). Pigs fed on diet 2 (normal P level with phytase 1,000 U kg-1 ) had the most P utilisation. Pigs fed diet 4 (low P level with phytase 1,000 U kg-1) showed no significant difference in P utilisation when compared with the control group (fed normal P level without phytase). The results indicate that supplemental phytase is effective in improving P utilisation in pigs and decreases P excretion in growing pigs.
Keywords: Growing pigs, apparent digestibility, excretion, phosphorus utilisation, phytase, retention