The effect of 25‐hydroxyvitamin D3 and phytase inclusion on pig performance, bone parameters and pork quality in finisher pigs

The objective of this study was to investigate the effects of supplementing both phytase and 25-hydroxyvitamin D3 (25-OH-D₃) on pig performance, nutrient digestibility, carcass characteristics, bone parameters and pork quality in finisher pigs. The experimental design was a 2 × 2 factorial comprising of four dietary treatments. One hundred and twenty pigs (60 male, 60 female) were blocked according to live weight and sex and allocated to the following dietary treatments: low P (4.81 g/kg) diet (basal) (T1); low P diet + phytase (T2); low P diet + 25-OH-D₃ (T3) and low P diet + phytase + 25-OH-D₃ (T4). Pigs supplemented with phytase had a lower average daily feed intake (ADFI) (2.45 kg vs. 2.59 kg; p < 0.05) and lower feed conversion ratio (FCR) (2.74 kg/kg vs. 2.85 kg/kg; p < 0.05) compared to pigs offered the nonphytase diets. Pigs offered phytase diets had a higher (p < 0.05) coefficient of apparent total tract digestibility (CATTD) of ash, phosphorous (P) and calcium (Ca) compared with pigs offered the nonphytase supplemented diets. Pigs offered the 25-OH-D3 diets had a higher CATTD of N and ash. Pigs offered the phytase diets had increased (p < 0.05) bone DM, ash, Ca, P and density compared to the nonphytase diets. There was a significant interaction (p < 0.05) between phytase and 25-OH-D3 on cook loss. Pigs offered 25-OH-D3 had increased cook loss over the basal diet; however, there was no effect on cook loss when phytase and 25-OH-D3 were offered in combination compared to the phytase only diet. Pigs offered 25-OH-D3 exhibited higher (p < 0.05) Warner Bratzler shear force values and lower (p < 0.05) pork lightness (L*) surface colorimeter values. In conclusion, there was no benefit to offering a combination of phytase and 25-OH-D3 on pig performance, bone parameters or pork quality.