4 Epidermal growth factor-expressing Lactococcus lactis enhances growth performance of early-weaned pigs fed diets devoid of blood plasma A. Bedford,* Z. Li,† M. Li,† S. Ji,† W. Liu,‡ Y. Huai,‡ C. F. M. de Lange,* and J. Li* 1 *Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario N1G 2W1; †Premix INVE Nutrition, Shenzhen, Guangdong, China, 518103; and ‡College of Life Science, Foshan University, Foshan, Guangdong, China, 528000 1 Corresponding author: jli@uoguelph.ca ABSTRACT: The effect of supplementing Lactococcus lactis (L. lactis) that was engineered to express epidermal growth factor (EGF-LL) to early-weaned pigs fed diets with typical levels of blood plasma (5%) or diets without blood plasma [blood plasma was substituted with soybean (Glycine max) meal and fish meal, based on amino acid supply] was examined. A total of 108 weaned piglets (19–26 d of age; mean initial BW 6.58 kg; 9 pigs per pen) were fed ad libitum according to a 2-phase feeding program without growth promoters. Three pens were assigned to each of 4 treatments: i) blood plasma-containing diet with blank bacterial growth medium (BP-Con), ii) blood plasma-containing diet with fermented EGF-LL (BP- EGF), iii) blood plasma-free diet with blank bacterial growth medium (BPF-Con), and iv) blood plasma-free diet with fermented EGF-LL (BPF-EGF). The amount of epidermal growth factor (EGF) was determined in the fermentation product and pigs were allotted 60 μg EGF/kg BW/d for 3 wk postweaning. There were no differences in overall growth performance between BP- Con and BP-EGF pigs and no differences in overall growth performance between LoCon and BPF-EGF pigs. Pigs fed BPF-EGF showed increased daily BW gain (410 vs. 260 g/d; P < 0.01) and gain:feed (0.67 vs. 0.58; P < 0.05) compared to BPF-Con pigs in wk 3 postweaning; this was comparable to values for the BP- Con group (400 g/d and 0.64). These results indicate that supplementation with EGF-LL can be effective in enhancing the performance of early-weaned piglets fed a low complexity diet and reduces the need for feeding high-quality animal proteins and antibiotics. Key words: epidermal growth factor, growth performance, pigs, probiotics © 2012 American Society of Animal Science. All rights reserved. J. Anim. Sci. 2012.90:4–6 doi:10.2527/jas53973 INTRODUCTION Early weaning of pigs can lead to postweaning diarrhea, reduced feed intake, reduced nutrient digestion and absorption, and a lag in growth performance (Gu et al., 2002). One strategy to improve feed intake and gut health after weaning is the addition of animal proteins (AP), such as blood plasma, to the feed, which are generally more digestible than plant proteins and can provide functional proteins that stimulate gut health and development. However, AP are generally more expensive and contribute to food safety concerns (Sapkota et al., 2007). Spray-dried porcine blood plasma contains immunoglobulins and growth factors, including epidermal growth factor (EGF) that may add to their beneficial effects (van Dijk, 2001), which stimulate cell proliferation and differentiation. Lactococcus lactis is a food grade, gram-positive lactic acid bacteria that is metabolically active throughout the intestinal tract (Drouault et al., 1999). We previously generated porcine EGF-secreting recombinant L. lactis (EGF-LL) and showed its ability to enhance body weight gain of early-weaned mice (Mus musculus) (Cheung et al., 2009) and increased villus height as well as intestine cell proliferation in early- weaned pigs (Kang et al., 2010). The objective of the current investigation was to study if supplementing a blood plasma-free diet with EGF-secreting L. lactiscan improve early weaned piglet intestine development and performance compared to a nonsupplemented diet containing blood plasma. MATERIALS AND METHODS The EGF-LL was generated as previously described (Cheung et al., 2009) and fermented in M17 broth Published January 23, 2015