Effect of Yeast Cell Wall (YCW) Inclusion Rate on Growth Performance in Nursery Pigs

To evaluate the effect of YCW on performance of nursery pigs, a total of 144 weaned piglets (BW: 5.76 ± 0.02 kg; PIC C-29 x 380) were randomly allotted to 1 of 3 dietary treatments (24 pens with 6 pigs/pen). Treatments were: 1) a nutrient adequate control (CON) with 0 mg/kg yeast cell wall, 2) CON + 250 mg/kg YCW (YCW250), and 3) CON + 1000 mg/kg YCW (YCW1000) for phase 1 (7 d), 2 (14 d) and 3 (7 d). At the end of phase 3, all pigs were fed a common diet (3.4 Mcal/kg of ME; 1.46 % standardised ileal digestible Lys) for 14 d (phase 4). Pig weight and pen feed disappearance were measured at end of each phase to calculate performance. Blood was sampled from 1 pig of average BW per pen at the end of phase 3 and 4 to assess haematology characteristics. Data were analysed as RCBD using mixed procedure of SAS with treatment as the fixed effect. PROC IML was used to generate contrast statements. Pigs fed YCW250 tended to have the improved ADG (quadratic, P < 0.06) and ADFI (quadratic, P = 0.02) in phase 2 and phase 1 and 2. However, G:F tended to decrease linearly with increasing level of YCW in phase 1 (P = 0.07). There were no other significant differences in ADFI, ADG or G:F; however, at study conclusion, pigs fed YCW250 were 0.93 kg heavier than pigs fed the CON. At d28 and d42, pigs fed YCW250 had increased (quadratic, P < 0.05) eosinophils, red blood cells, haemoglobin, and haematocrit, and a lower platelet count compared with pigs fed the CON or YCW1000. There was no significant day by treatment interactions for blood profiles. Results indicate that supplementation of YCW at 250 mg/kg during early post-weaning improved feed intake and gain, and modulated blood cell count. However, feeding YCW above 250 mg/kg resulted in a reduction in growth performance to levels similar to that observed in pigs fed CON diets

Table 1. Effect of YCW on the complete blood cell count at day 28 and day 42

	CON	YCW250	YCW1000	SEM	Quadratic
Eosinophil, 103/µL	0.45	0.71	0.42	0.08	0.02
Red blood cells, 103/µL	6.88	7.60	7.08	0.15	<0.01
Haemoglobin, 103/µL	9.36	10.18	9.23	0.25	<0.01
Haematocrit , %	32.04	36.14	32.17	0.78	<0.01
PLT, 103/µL	624.0	438.0	643.9	40.6	<0.01

Keywords: yeast cell wall, ADG, weaning, eosinophil