Effect of Yeast Rare Earth on Growth Performance, Nutrient Digestibility, Blood Profiles, Meat Quality, and Fecal Microbiota in Finishing Pigs

Abstract Text: Yeast rare earth (YRE) is a new alternative to antibiotics, which can improve growth performance and fecal microbiota in livestock. It contained 2.82% lanthanum and 4.71% cerium in this study. A total of 100 finishing pigs [(Landrace × Yorkshire) × Duroc, BW = 51.1 ± 2.12 kg] were used in a 70-d study to evaluate effects of YRE on growth performance, nutrient digestibility, blood profiles, meat quality, and fecal shedding. Pigs were randomly assigned to 1 of 5 treatments with 5 pens per treatment and 4 pigs per pen by BW and sex. Treatments were corn soybean meal based diets supplemented with 0, 0.05, 0.10, or 0.15% YRE and 0.05% tiamulin. Experiment was separated into 2 phases, from d 0 to 35 and from d 36 to 70. All diets were formulated to meet or exceed the nutrient requirements recommended by the NRC (2012). During d 36 to 70 and d 0 to 70, dietary YRE improved average daily gain (linear, P=0.007, 0.007, respectively) and gain/feed (G/F; linear, P=0.018, 0.030, respectively) as dietary YRE increased in the diet. From d 0 to 35, pigs fed 0.1 and 0.15% YRE had the higher G/F (P=0.036) than pigs fed 0.05% tiamulin. At the end of the experiment, pigs fed 0.1% YRE had the higher digestibility of dry matter (P=0.012) than pigs fed control diet. The digestibility of energy (P=0.011) increased with increasing YRE levels in the diet and the greatest value was observed in pigs fed 0.1% of YRE. At the end of 10^th week, red blood cells (linear, P=0.035) and longissimus muscle color (linear, P=0.044) increased with increasing amount of YRE in the diet. The values of fecal E. coli (P=0.047) and Lactobacillus (P=0.002) in pigs fed 0.15% YRE were significantly lower than pigs fed other diets. E. coli (linear, P=0.004) and Lactobacillus (linear, P=0.048; quadratic, P=0.023) were also decreased with the increasing YRE levels in the diet. In conclusion, results indicate that YRE supplementation can improve growth performance, digestibility and gut health, and can be considered as a good alternative to antibiotics in finishing pigs.

Keywords: growth performance, finishing pig, yeast rare earth