Protein requirement of baby pigs on low-fat diets

For some time studies have been made in this laboratory on the use of the baby pig as an experimental animal, and during this work diets low in fat have been found to support satisfactory performance (Tribe, 1954;McCrea & Tribe, 1956).This finding is somewhat surprising in view of the fact that sow's milk is very rich in fat.For routine rearing of piglets a low-fat diet is preferable to one rich in fat because it is easy to prepare and can be stored with less risk of deterioration.In the three experiments described the protein content of the diet was varied within wide limits in order to determine the optimum protein content in low-fat diets. EXPERIMENTAL Experimental design and analysisA randomized block layout was used.Groups of litter-mates of uniform weight were chosen for the experimental blocks, and the members of these groups were allocated at random to the different treatments.Four treatments were replicated five times in Expt I.In each of Expts 2 and 3, four treatments were replicated eight times.The significance of differences between treatments was tested by analysis of variance. AnimalsLarge White x Wessex piglets were used for Expts I and 3 and for half of Expt 2 .The remaining four replicates in Expt 2 were with pure-bred Wessex. DietsDetails about the diets used in the three experiments are given in Tables I and 2 .The diets used in Expts I and 2 were very similar and included several carbohydrates and protein from several sources.In Expt 3 glucose was chosen as the sole carbohydrate as other workers had shown it to be well utilized by the very young pig, whereas there was some doubt about the utilization of maize starch and sucrose (Becker, Ullrey & Terrill, 1954).Casein had been the major source of protein in Expts I and 2 and was the sole source of protein in Expt 3. ManagementThe piglets were taken from their dams at 2-3 days of age and were kept on the experimental diets until 28 days old.They were reared singly in modified rabbit cages.The cages were 19 in.wide x 24 in.deep and 16 in.high and had a door at the