The Effect of the Plane of Nutrition on the Composition of Sow's Colostrum and Milk

The total solids, solids-not-fat, protein, lactose, and ash content of sow's milk are reported for two groups of sows, one group on pasture, and one group in dry lot. The sows were milked manually after the injection of 1 ml. of Pitocin, on the first day of lactation, the third day, at the end of the first week, and each subsequent week throughout lactation. The mean values of milk constituents for pasture sows were, for first day colostrum: total solids 22.81 percent, solids-not-fat 15.92 percent, protein 11.25 percent, lactose 2.89 percent, and ash 0.72 percent; for later milk: total solids 19.47 percent, solids-not-fat 13.16 percent, protein 7.09 percent, lactose 5.18 percent, and ash 0.99 percent. The mean values of milk constituents for dry-lot sows were, for first-day colostrum: total solids 22.81 percent, solids-not-fat 17.21 percent, protein 14.29 percent, lactose 3.42 percent, and ash 0.73 percent; for later milk: total solids 20.69 percent, solids-not-fat 13.38 percent, protein 7.42 percent, lactose 5.08 percent, and ash 0.98 percent.