In most parts of the United States, swine diets are predominantly composed of corn, soybean meal and dried distillers grain with solubles due to price and availability. However, pigs are omnivores and have the ability to utilize a wide variety of feedstuffs including barley, oats, wheat, sorghum/milo and rye.
In recent years farmers have changed from a continual corn-soybean rotation to one including cover crops and options including hybrid rye to improve soil health and break weed cycles while at the same time providing an alternate feedstuff for pigs and cattle. Also, by having a crop that's harvested in late-summer, farmers now have an opportunity for earlier manure application as well as decreasing the time needed for corn and soybean harvest.
Since hybrid rye is different from the rye traditionally raised in the Upper Great Plains, more research is needed to evaluate hybrid rye as an acceptable feedstuff for livestock. The objective of this trial was to determine if hybrid rye can be an effective replacement for corn in finishing pig diets.
One hundred mixed-sex pigs with an average body weight of 91 pounds were assigned to one of four dietary treatments. There were five pigs per pen and with four replicates per treatment. Three phases were used: 91 to 140 pounds body weight, 140 to 210 pounds body weight and 210 to 265 pounds body weight.
The four dietary treatments were the percent of corn replaced by hybrid rye. In the first phase, hybrid rye replaced zero, 17, 33 and 50% of the corn in the ration. For the second and third phases, hybrid rye replaced either zero, 33, 67 or 100% of the corn in the rations. Pigs were weighed at each phase change, and feed disappearance calculated for each phase, as well as the overall growth period.
Results and discussion
During the first phase (91 to 140 pounds), pigs fed the highest level of hybrid rye (50% replacement of corn) had the highest gains and were the most efficient of the four treatments. During the second (140 to 210 pounds) and third (210 to 265 pounds) phases, there were no differences in gain or feed intake between pigs fed the zero, 33, 67 or 100% rye-corn replacement rates.
However, there was a tendency (P<0.10) for pigs to be less efficient at the 100% replacement rate. For the overall (91 to 265 pounds) growth period, there were no differences in gain and feed intake between any of the four treatments. However, when hybrid rye replaced 100% of the corn in those diets, the pigs fed the 100% rye replacement diets were less efficient (P<0.05) than pigs fed the other three diets.
Hybrid rye can replace up to 50% of the corn in a grower diet and 100% of the corn in finishing diets without affecting gain and feed intake. While pigs fed the 100% replacement rate were less efficient for the overall growth period, that difference could potentially be made up for if rye is a lower cost ingredient than corn.
In pig farms that also raise their own grains, the inclusion of hybrid rye into their crop rotation has multiple benefits to their overall farming operation, including an option for late-summer manure application, and provides a high-quality feedstuff for grow-finish pigs.
The authors want to thank KWS Cereals USA LLC for their support of our swine research program.