Evaluation of a diet free of animal protein in germfree swine

Background: Two experiments were conducted in which germfree pigs or pigs monoassociated with Lactobacillus paracasei subspecies paracasei were fed either a traditional milk-based diet (Esbilac) or an experimental diet free of animal protein (DFAP). Methods: Throughout the 16-day study, animals' clinical condition, total weight gain, feed conversion, and bacterial contamination were monitored. At the conclusion of the study the animals were killed, necropsied and tissues sampled for L. paracasei isolation. Results: General pig disposition remained consistent between treatment groups and trials, except for two animals that developed mild diarrhoea during trial 1. All pigs remained viable during the study irrespective the diet fed or probiotic inoculation. Germfree pigs fed the Esbilac diet gained on average a total of 1034 ± 63.0 g, and had a feed conversion ratio of 0.17 ± 0.01 g of gain per 1 ml of diet. Germfree pigs fed the experimental diet gained on average a total of 599 ± 151 g, and had a feed conversion ratio of 0.10 ± 0.02 g of gain per 1 ml of diet. Monoassociated pigs fed the Esbilac diet gained on average a total of 862 ± 70.3 g, and had a feed conversion ratio 0.14 ± 0.01 g of gain per 1 ml of diet. Monoassociated pigs fed the experimental diet gained on average a total of 563 ± 96.8 g, and had a feed conversion ratio of 0.09 ± 0.02 g of gain per 1 ml of diet. Lactobacillus paracasei established extensively in pigs fed either the Esbilac or experimental diets. Lactobacillus paracasei had no effect (P > 0.05) on piglet growth and did not display any interactions based on the diet fed. Measured growth parameters were statistically different (P < 0.05) based on the diet fed and variance seen between trials. Conclusion: In conclusion, a DFAP has been developed and has been shown to be capable of sustaining life in piglets up to 16 days of age.