Mimeo A. H. 180 September 14, 1956
Two years of research at Purdue (a. Ho Miraeos 133 and 151), concerning the feeding of corn silage to brood sows, has conclusively shown that corn silage can be fed satisfactorily to brood sows during gestation. The feeding of good quality corn silage, 1.5 pounds of a high quality protein supplement and minerals free choice has resulted in (1) a 20 percent reduction in feed costs, (2) an increase of 1.4 to 2.0 more pigs per sow at farrowing and (3) an increase of 0.3 to 1.3 more pigs per litter at weaning.
Purdue University Agricultural Experiment Station Lafayette, Indiana
Since one of the major limiting nutrients in corn silage is protein, an experiment was conducted to determine the amount of protein supplement needed to balance corn silage. Therefore, the objectives of this experiment were as follows:
1.	To compare three levels of protein supplementation.
2.	To compare the reproductive performance of sows fed corn silage with those fed a conventional-type mixed grain and supplement ration.
Experimental Procedure
Forty-four 1- and 2-year-old sows were fed a complete mixed ration during the major part of the breeding season. After a majority of the sows had been bred, they were alloted to four groups on the basis of age, weight and breeding date. Each group of 11 sows was confined to a drylot that was one-half concrete and one-half gravel. Sows were started on the experimental diets November 24* 1955, and continued on their respective diets until they were moved to the farrowing barn. The experimental diets were fed on the average of 103 to 110 days. The experimental gestation rations were as follows;
Lot 1; Complete mixed ration, 6 pounds daily.
Lot 2; Corn silage 12 pounds, plus 1.0 pound of protein supplement, and 1.0 pound of ground corn daily.
Lot 3; Corn silage 12 pounds, plus 1.0 pound of protein supplement, plus 0.5 pound of soybean meal and 0.5 pound of ground corn daily.
Lot 4t Corn silage 12 pounds, plus 1.0 pound of protein supplement and 1.0 pound of soybean meal daily,
The details of the mixtures fed are given in Table 1. From the 1 pound of protein supplement and the additional soybean meal, the sows received the following amounts of crude protein in addition to that in the silage; Lot 2, 0.^8 lb., Lot 3, 0.60 lb.; Lot 4, 0.82 lb.
The complete mixed ration, fed in Lot 1, contained 14/b protein, 69,6 TDN, ^
0*9$ calcium and 0.6$ phosphorus by calculation. The silage supplement, fed in Lots 2 to 4, contained 38$ protein and 1.0 pound of this supplement supplied
icknowlidgement, is made to~Fred Vandergraff, Swine Herdsman, and his associates for feeding and caring for the experimental animals.
W. Mo Beeson and J. H. Conrad
Department of Animal Husbandry
AMOUNT OF PROTEIN SUPPLEMENT SOWS FED ON CORN SILAGE