Feed Efficiency by Mike Mehren Ph.D.

Feed Efficiency
BY MIKE MEHREN

Feed efficiency is the term used to describe how feed is converted into meat, and milk. Feed efficiency is normally reported as pounds of feed required to produce 1 lb of gain. As the saying goes ‘rate of gain for show and feed efficiency for dough’. It sounds great to tell your neighbors that your calves gained 3.8 lb per day. That usually brings on some oohs and aahs; however, telling the same group that your calves converted at 6 to 1 may get some vacant stares and a change of subject.

To make a point, let’s use some extreme examples.
1. Feeding 10 lb of straw plus a 2 lb supplement can provide gains of 0.5 lb/day for a calf. This converts to 20 lb. of straw and 4 lb. of supplement to produce one pound of gain. If the straw cost $50/ton and the supplement costs $350/ton, this equates to 20 lb straw @ $.025/lb plus 4 lb supplement at $.175/lb = $1.20/lb of gain (20 x .025 = $.50 + 4 x .175 = $.70 + $.50 = $1.20). All feed conversions should be expressed in dry matter, so $1.20 ÷0.9 = $1.33/lb of gain.

2. Feeding 24 lb of a high energy finishing ration can provide 3.8 lb/day gain. This ration might be made of steam flaked corn, soybean meal, hay, and a supplement. The cost of such a ration this year may be $190/ton. This means that the feed was converted at 6.3 lb of feed for 1 lb of gain. Cost would be 6.3 lb feed @ $.095 = $.60/lb of gain ÷0.9 = $.67/lb of gain.

The figures used in the examples are for feed dry matter. This is very important when calculating feed efficiency. For instance: A growing ration of 7 lb hay and 54 lb of corn silage should produce gain of about 2 lb/day. If we used ‘as fed’ figures, it took 61 lb of feed to produce 2 lb of gain. So feed efficiency would be 30.5 lb of feed for 1 lb of gain. No matter how cheap the feed is, this still won’t work. However if we convert these figures to dry matter, it starts to make sense. Hay is about 90% dry matter and our corn silage is usually 28% dry matter. Take 7 x .90 = 6.3 lb of hay dry matter plus 54 x .28 = 15 lb of silage dry matter we get 21.3 lb of feed dry matter producing 2 lb of gain or 10.7 lb of feed dry matter for each 1 lb of gain. Current cost for hay is about $120/ton and corn silage is $35/ton. These figures need to be converted to cost/ton of dry matter, or $120÷.90 = $133.33/ton of hay dry matter and $35÷.28 = $125/ton of silage dry matter. Finally, we take 6.3 lb of hay @ .067 = $.42 and 15 lb silage @ $.0625 = $.94 to make a daily feed cost of $1.36 for 2 lb gain or $.68 for 1 lb gain.

After doing all these calculations you can easily understand why computers have become so popular. The costs shown are only for feed. To get a total cost of gain, we need to add non-feed costs such as equipment, depreciation, labor, taxes, insurance, death loss, and transportation.

Typically, young cattle are more efficient than older cattle. Also, high energy finishing rations are more efficient than high roughage growing or maintenance rations. Feed efficiencies reported in the scientific literature seem to range from a high of 25:1 to a low of 5.7:1. For comparison, a farrow to finish swine operation converts feed at less than 3:1, including feed for the sows, boars, and gilts. Fish farms are able to convert feed at almost 1:1.

There are many factors that affect feed efficiency. Age was already mentioned. Ration balance is another. This means that the proper nutrients are available to the animal all the time. Not enough protein or energy (TDN) can ruin feed efficiency. Too much energy relative to the amount of protein available also is detrimental. Our friend mud, which will certainly disappear when global warming occurs, is a serious threat to feed efficiency. There have been reports of 30% decrease in feed efficiency just due to mud. This happens when the cattle must wade through mud up to their knees to get to the feed bunk, and then have no dry place to lie down. If the cattle were capable of converting feed at 6:1, a 30% change in feed efficiency would mean that they would convert at 8.6:1. That really hurts when feed prices are high. One study showed that bedding feedlot pens with straw during the time when mud was very severe improved feed efficiency dramatically but did not affect how much the cattle ate. Gain was also improved.

Weather extremes also affect feed efficiency. Cold, wet weather affects feed efficiency because the animals use more energy to stay warm and thus less energy is available to use for gain or milk production. In very hot weather, the animals use more energy attempting to keep themselves cool, and also tend to eat less feed. Steers are more efficient than heifers and bulls are more efficient than the other two.

Some of the feed additives make claims for improved feed efficiency. A partial list of those making this claim is Bovatec, Gain-Pro, and Rumensin. University feed trials over many years has substantiated these claims. Rumensin has a claim for improved feed efficiency for beef cows. This means that you could feed less hay and still see the same performance that you are used to. Imagine feeding 5 to 10% less hay with the same results. That’s really a big deal. These three products also work on grazing cattle, replacement heifers, developing bulls, and in the feedlot. Cattle in programs that don’t allow feeding the products mentioned above will convert feed less efficiently than those being fed these products.

Internal parasites, flies, and ticks would also affect feed efficiency. We know that disease has a dramatic effect on how feed is used. The feed consumed while an animal is sick is not promoting weight gain.

Rate of gain relates to the number of days that an animal will take to reach a certain weight. Feed efficiency measures the amount of feed it will take to reach that weight. Since feed is a high percentage of the total cost of gain or performance, keeping track of feed efficiency is an excellent tool to use in projecting cost of gain.

Michael J. Mehren, Ph.D. is a livestock nutritionist whose tremors are not much help while typing, but are quite beneficial when stirring drinks. He may be contacted by Email at mehrens@eotnet.net.



		Feed Efficiency BY MIKE MEHREN Feed efficiency is the term used to describe how feed is converted into meat, and milk. Feed efficiency is normally reported as pounds of feed required to produce 1 lb of gain. As the saying goes ‘rate of gain for show and feed efficiency for dough’. It sounds great to tell your neighbors that your calves gained 3.8 lb per day. That usually brings on some oohs and aahs; however, telling the same group that your calves converted at 6 to 1 may get some vacant stares and a change of subject. To make a point, let’s use some extreme examples. 1. Feeding 10 lb of straw plus a 2 lb supplement can provide gains of 0.5 lb/day for a calf. This converts to 20 lb. of straw and 4 lb. of supplement to produce one pound of gain. If the straw cost $50/ton and the supplement costs $350/ton, this equates to 20 lb straw @ $.025/lb plus 4 lb supplement at $.175/lb = $1.20/lb of gain (20 x .025 = $.50 + 4 x .175 = $.70 + $.50 = $1.20). All feed conversions should be expressed in dry matter, so $1.20 ÷0.9 = $1.33/lb of gain. 2. Feeding 24 lb of a high energy finishing ration can provide 3.8 lb/day gain. This ration might be made of steam flaked corn, soybean meal, hay, and a supplement. The cost of such a ration this year may be $190/ton. This means that the feed was converted at 6.3 lb of feed for 1 lb of gain. Cost would be 6.3 lb feed @ $.095 = $.60/lb of gain ÷0.9 = $.67/lb of gain. The figures used in the examples are for feed dry matter. This is very important when calculating feed efficiency. For instance: A growing ration of 7 lb hay and 54 lb of corn silage should produce gain of about 2 lb/day. If we used ‘as fed’ figures, it took 61 lb of feed to produce 2 lb of gain. So feed efficiency would be 30.5 lb of feed for 1 lb of gain. No matter how cheap the feed is, this still won’t work. However if we convert these figures to dry matter, it starts to make sense. Hay is about 90% dry matter and our corn silage is usually 28% dry matter. Take 7 x .90 = 6.3 lb of hay dry matter plus 54 x .28 = 15 lb of silage dry matter we get 21.3 lb of feed dry matter producing 2 lb of gain or 10.7 lb of feed dry matter for each 1 lb of gain. Current cost for hay is about $120/ton and corn silage is $35/ton. These figures need to be converted to cost/ton of dry matter, or $120÷.90 = $133.33/ton of hay dry matter and $35÷.28 = $125/ton of silage dry matter. Finally, we take 6.3 lb of hay @ .067 = $.42 and 15 lb silage @ $.0625 = $.94 to make a daily feed cost of $1.36 for 2 lb gain or $.68 for 1 lb gain. After doing all these calculations you can easily understand why computers have become so popular. The costs shown are only for feed. To get a total cost of gain, we need to add non-feed costs such as equipment, depreciation, labor, taxes, insurance, death loss, and transportation. Typically, young cattle are more efficient than older cattle. Also, high energy finishing rations are more efficient than high roughage growing or maintenance rations. Feed efficiencies reported in the scientific literature seem to range from a high of 25:1 to a low of 5.7:1. For comparison, a farrow to finish swine operation converts feed at less than 3:1, including feed for the sows, boars, and gilts. Fish farms are able to convert feed at almost 1:1. There are many factors that affect feed efficiency. Age was already mentioned. Ration balance is another. This means that the proper nutrients are available to the animal all the time. Not enough protein or energy (TDN) can ruin feed efficiency. Too much energy relative to the amount of protein available also is detrimental. Our friend mud, which will certainly disappear when global warming occurs, is a serious threat to feed efficiency. There have been reports of 30% decrease in feed efficiency just due to mud. This happens when the cattle must wade through mud up to their knees to get to the feed bunk, and then have no dry place to lie down. If the cattle were capable of converting feed at 6:1, a 30% change in feed efficiency would mean that they would convert at 8.6:1. That really hurts when feed prices are high. One study showed that bedding feedlot pens with straw during the time when mud was very severe improved feed efficiency dramatically but did not affect how much the cattle ate. Gain was also improved. Weather extremes also affect feed efficiency. Cold, wet weather affects feed efficiency because the animals use more energy to stay warm and thus less energy is available to use for gain or milk production. In very hot weather, the animals use more energy attempting to keep themselves cool, and also tend to eat less feed. Steers are more efficient than heifers and bulls are more efficient than the other two. Some of the feed additives make claims for improved feed efficiency. A partial list of those making this claim is Bovatec, Gain-Pro, and Rumensin. University feed trials over many years has substantiated these claims. Rumensin has a claim for improved feed efficiency for beef cows. This means that you could feed less hay and still see the same performance that you are used to. Imagine feeding 5 to 10% less hay with the same results. That’s really a big deal. These three products also work on grazing cattle, replacement heifers, developing bulls, and in the feedlot. Cattle in programs that don’t allow feeding the products mentioned above will convert feed less efficiently than those being fed these products. Internal parasites, flies, and ticks would also affect feed efficiency. We know that disease has a dramatic effect on how feed is used. The feed consumed while an animal is sick is not promoting weight gain. Rate of gain relates to the number of days that an animal will take to reach a certain weight. Feed efficiency measures the amount of feed it will take to reach that weight. Since feed is a high percentage of the total cost of gain or performance, keeping track of feed efficiency is an excellent tool to use in projecting cost of gain. Michael J. Mehren, Ph.D. is a livestock nutritionist whose tremors are not much help while typing, but are quite beneficial when stirring drinks. He may be contacted by Email at mehrens@eotnet.net.		About OFGA Services Join OFGA Meetings & Events OFGA Officers OFGA Bylaws Links Contact OFGA Articles Mike Mehren, Ph.D. Feed/Export Wheat Report