Effect of blue lupin seed or pea seed as a substitute for GM soybean meal in diets of fattening pigs on intestinal health

Abstract This study aimed to determine the composition of the fecal microflora of pigs fed with feed mixtures containing pulses and meals. Two experiments were performed with growing pigs. In their feed mixtures, GM soybean meal was replaced with either peas or blue lupine, and the modified mixtures were further fortified with rapeseed meal. Three-breed piglets were used in the study: ♀ (landrace × yorkshire) × ♂ duroc, (100 pigs in total, sex ratio: barrows : gilts - 1:1). Each experiment was performed with 50 animals divided into 5 groups, each of 10 pigs (control group - C and experimental groups - E1, E2, E3, E4). Population numbers of bacteria from the Enterobacteriaceae and Lactobacillus families, as well as from the genera Clostridium spp. , Shigella spp. , and Salmonella spp. were determined with the deep inoculation method ( Clostridium ) and the surface inoculation method (the other microorganisms tested) in serially-diluted samples of feces collected from the rectum of slaughtered fatteners. The number of bacteria was presented per feces dry matter, and the final result was expressed as colony forming units (cfu) per 1 g of feces. Analyses conducted in the experiment demonstrated an increased count of Lactobacillus spp. bacteria, a decreased count of Enterobacteriaceae bacteria, a stable population number of Clostridium spp. bacteria, and no Salmonella in the fatteners, administered feed mixtures with legume seeds, compared to the control animals. Shigella bacilli were confirmed in fecal samples taken from three experimental groups in Experiment II, while they were absent in the feces of animals from Experiment I. In both experiments, the correct ratio of villi and crypts was found, ensuring adequate intestinal absorption surface. The study results suggest that pulses, including legume grains like blue lupine, can positively affect the enteric microflora, promote the proliferation of bacteria beneficial for the host and promote the proper development of villi and crypts.