Cow Tales: Winter feeding & supplementation

Fall pregnancy diagnosis is the first time producers have to thoroughly evaluate the condition of their cowherd. Calves are either recently weaned or will be within weeks. Energy and protein requirements decrease with weaning but will soon increase with winter maintenance needs and to support a third-trimester fetus. This is the opportunity to economically change the body condition score (BCS) of a cow.

Feeding strategies are variable and flex to accommodate many management styles and goals. Styles range from “survival of the fittest” to “next of kin.” Maximum production in the subsequent year will require producers to feed something similar to a complete ration. Optimal production will generally mean less harvested feeds being fed with more emphasis on targeted supplementation. However, there are many other factors influencing winter feeds such as the presence of pine trees, snow cover, ice, breeding season, stage of production, and many others. Just when we think we have it all figured out, Mother Nature gladly escorts us behind the barn for a long conversation.

Replacement heifers, two-year old cows, and aged cows are the age groups within the herd that have the greatest nutritional demands. These animals benefit from a more targeted approach by feeding to meet management goals after sorting from the main herd. The ration may have elevated protein and energy concentrations and separation from the main herd decreases competition for feedstuffs. Energy requirements wane as lactation drops off and weaning ensues. So long as Old Man Winter is running late we can use this period to utilize winter pasture/stockpiled forage and crop residue. Additionally, fall and early winter are an opportunity to economically alter BCS before the coming colder months. We tend to recommend cows enter winter with a BCS of a 5 or 6. Cows can maintain or lose a BCS and still calve in adequate condition. In a BCS 5 the last two ribs are barely noticeable, the backbone can be felt but is not too obvious, and the sides of the tail head are filled but not mounded.

Dormant feeds can have drastically different energy and protein values across species and across years. However, they are almost uniformly deficient in protein. Supplemental protein not only provides more protein for the cow but also the bacteria in the rumen. Just like the cow or a person, bacteria also have nutrient requirements. When bacteria has adequate protein they are more efficient at liberating the nutritive value of feedstuffs. In fact, cows on winter range or cornstalk residue will consume more roughage and digest it better if supplemented with protein. The enhanced digestibility allows the cow to consume enough forage to meet her own needs.

Protein supplements for dormant feeds vary considerably. Not all protein sources are created equal. Some proteins blend better with forage and others are more suited for grain-based diets due to their increased rate of digestion. Crude protein concentration can range from 15-40 percent. It comes in traditional formats such as lick tubs, pellets and cake. Some people may use a less common approach and feed a portion of a total mixed ration in feed bunks or periodically roll out high protein hay.

A useful calculation when comparing protein supplements is the cost per pound of protein. This number can vary from less than $0.20 to well over $3. Processed and liquid feeds tend to bracket out the higher end of the expense but also provide a way to supply vitamins, minerals, feed additives and feed-grade medications. Some producers enjoy the convenience of pelleted and liquid feeds.

Producers have a lot to consider when planning for the nutritional requirements and winter feed needs to reach their production goals. Veterinarians can play a valuable role when evaluating feeding strategies. In our practice we often formulate rations for heifers, protein supplements, and rations for developing bull calves. In the end, cows need to enter winter in good condition. They have to be in decent condition and in a positive energy balance at breeding. Therefore, our job is to make sure they don’t lose too much condition before calving.

Fall pregnancy diagnosis is the first time producers have to thoroughly evaluate the condition of their cowherd. Calves are either recently weaned or will be within weeks. Energy and protein requirements decrease with weaning but will soon increase with winter maintenance needs and to support a third-trimester fetus. This is the opportunity to economically change the body condition score (BCS) of a cow.

Feeding strategies are variable and flex to accommodate many management styles and goals. Styles range from “survival of the fittest” to “next of kin.” Maximum production in the subsequent year will require producers to feed something similar to a complete ration. Optimal production will generally mean less harvested feeds being fed with more emphasis on targeted supplementation. However, there are many other factors influencing winter feeds such as the presence of pine trees, snow cover, ice, breeding season, stage of production, and many others. Just when we think we have it all figured out, Mother Nature gladly escorts us behind the barn for a long conversation.

Replacement heifers, two-year old cows, and aged cows are the age groups within the herd that have the greatest nutritional demands. These animals benefit from a more targeted approach by feeding to meet management goals after sorting from the main herd. The ration may have elevated protein and energy concentrations and separation from the main herd decreases competition for feedstuffs. Energy requirements wane as lactation drops off and weaning ensues. So long as Old Man Winter is running late we can use this period to utilize winter pasture/stockpiled forage and crop residue. Additionally, fall and early winter are an opportunity to economically alter BCS before the coming colder months. We tend to recommend cows enter winter with a BCS of a 5 or 6. Cows can maintain or lose a BCS and still calve in adequate condition. In a BCS 5 the last two ribs are barely noticeable, the backbone can be felt but is not too obvious, and the sides of the tail head are filled but not mounded.

Dormant feeds can have drastically different energy and protein values across species and across years. However, they are almost uniformly deficient in protein. Supplemental protein not only provides more protein for the cow but also the bacteria in the rumen. Just like the cow or a person, bacteria also have nutrient requirements. When bacteria has adequate protein they are more efficient at liberating the nutritive value of feedstuffs. In fact, cows on winter range or cornstalk residue will consume more roughage and digest it better if supplemented with protein. The enhanced digestibility allows the cow to consume enough forage to meet her own needs.

Protein supplements for dormant feeds vary considerably. Not all protein sources are created equal. Some proteins blend better with forage and others are more suited for grain-based diets due to their increased rate of digestion. Crude protein concentration can range from 15-40 percent. It comes in traditional formats such as lick tubs, pellets and cake. Some people may use a less common approach and feed a portion of a total mixed ration in feed bunks or periodically roll out high protein hay.

A useful calculation when comparing protein supplements is the cost per pound of protein. This number can vary from less than $0.20 to well over $3. Processed and liquid feeds tend to bracket out the higher end of the expense but also provide a way to supply vitamins, minerals, feed additives and feed-grade medications. Some producers enjoy the convenience of pelleted and liquid feeds.

Producers have a lot to consider when planning for the nutritional requirements and winter feed needs to reach their production goals. Veterinarians can play a valuable role when evaluating feeding strategies. In our practice we often formulate rations for heifers, protein supplements, and rations for developing bull calves. In the end, cows need to enter winter in good condition. They have to be in decent condition and in a positive energy balance at breeding. Therefore, our job is to make sure they don’t lose too much condition before calving.

kenny barrett jr. is a veterinarian at the belle fourche veterinary clinic in belle fourche, sd and pens “cow tales” monthly. learn more about the clinic on the web at http://www.bfvetclinic.com, or drop them an e-mail at: office@bfvetclinic.com to suggest a topic for the next installment of “cow tales.”