Using Calcium Oxide to Improve the Quality of Indigestible Feeds

Background

Canada produces approximately 82.4 million tonnes of crop residues each year, representing a significant source of unused feed for livestock. Given continually increasing feed prices, utilization of more cost-effective by-products or crop residues would represent a significant source of savings. However, these feed types have low rumen degradability and therefore lower feed value. If the rumen degradability of these feeds could be improved through incorporation with alkaline treatments, utilization of these feed types could be enhanced. Recent studies have shown that calcium oxide could offer as a low-cost solution for improving the fibre digestibility of crop residues when barley straw is hydrated and treated with calcium oxide.

Objectives

• Assess the impact of including calcium oxide in backgrounding and finishing feedlot diets on weight gain, feed efficiency and feed digestibility
• Evaluate the effect of calcium oxide on beef cattle indicators of health and stress
• Evaluate the economic benefit of replacing barley silage with barley straw and calcium oxide

What they Did

This team tested replacing limestone with calcium oxide and evaluated the effects on animal health and performance. Researchers have individually feed 60 steers one of 4 different rations. They fed either a corn silage ration, dry calcium oxide added to corn silage ration, corn silage and barley straw ration, and dry calcium oxide added to corn silage and barley straw ration. They looked at animal performance, stress, and economics of beef steers fed throughout a backgrounding and then finishing diet. They recorded animal welfare indicators, carcass characteristics, and cost benefit analysis of substituting corn silage with straw mixed with calcium oxide.

What You Learned

Dry matter intake was similar across treatments during the backgrounding diets; however, feeding of calcium oxide decreased weight gain, average daily gain, and gain:feed in both diets with and without barley straw replacing corn silage. Similarly, replacing corn silage with barley straw decreased gain:feed by 9.19%. In the finishing phase of the trial, dry matter intake was lower for cattle fed the calcium oxide, but weight gain, average daily gain and gain:feed were similar. Replacing corn silage with barley straw decreased gain:feed by 7.23%. Calcium oxide supplementation had no effect on blood parameters like haptoglobin, or serum amyloid A that would indicate it has any negative impact on health on cattle consuming it.

What This Means

This study suggests that feeding calcium oxide in replacement of limestone did not have any benefit to feedlot cattle performance, and decreased performance in high forage diets. However, results suggests that barley straw could replace corn silage in high grain diet, but a cost-benefit analysis should be conducted.