269 Influence of herbal active D on nursery pig growth performance, bone characteristics and blood measures

Abstract

Abstract Pigs [n = 2.268; L337×1050 PIC; initial body weight (BW) = 5.5 ± 0.17 kg] were used in a 42-d growth study to evaluate the effects of herbal active D (a source of calcitriol) on growth performance, bone characteristics, and serum criteria of nursery pigs. Pigs were weaned at approximately 21-d of age and randomly allotted to 1 of 3 dietary treatments in a randomized complete block design. There were 27 pigs/pen and 28 replications/treatment across 2 rooms with pens blocked by BW and weaning date. Treatment diets were corn-soybean meal-based and consisted of a control diet (1,650 IU/kg of vitamin D3), or the control diet with 120 or 200 mg/kg of herbal active D (Phytobiotics, St. Louis, MO). Blood samples were collected from 25 gilts/treatment on d 21 and 42 to assess 25(OH)D3 and cytokine concentrations. At the end of the study, 10 pigs/treatment were euthanized and the right fibula, metacarpal, 2nd rib, and 10th rib were collected to determine bone density, bone breaking strength, and percentage bone ash by utilizing the de-fatted processing method. Overall (d 0 to 42), there was a marginally significant (P = 0.067) reduction in gain to feed ratio (G:F) as herbal active D increased, but no effect on final BW, average daily gain (ADG) and average daily feed intake (ADFI), or mortality (P > 0.10; Table). For bone breaking strength and bone ash, there was no evidence of a treatment × bone interaction (P > 0.10). Percentage of bone ash increased linearly across all bones as herbal active D increased (P = 0.026). Treatment did not affect bone ash weight and breaking strength (P > 0.10). However, metacarpals and 10th ribs had the greatest bone ash weight followed by the fibula with 2nd rib having the least (P < 0.05). Metacarpals had greater breaking strength compared with all other bones, followed by the fibula and 10th rib, with the 2nd rib having the least (P < 0.001). There was a bone × treatment interaction for bone density, where increasing herbal active D increased bone density for the 2nd rib (P = 0.012), but there were no treatment differences for other bones (P > 0.10). Additionally, there was no difference (P > 0.10) between treatments for porcine circovirus type 2 S/P ratio, porcine reproductive and respiratory syndrome, Mycoplasma hyopneumoniae, 25(OH)D3 status or circulating cytokine concentrations except for IL-8 concentrations which increased linearly (P = 0.027) as herbal active D increased. Antibodies and cytokine concentrations were greater on d 21 compared with d 42 (P < 0.001), except for IL-1ra and IL-8 having no significant (P > 0.10) day effect. In summary, herbal active D had minimal impact on growth or serum parameters; however, increasing herbal active D increased percentage bone ash.