When we evaluate the body condition of a beef cow compared with that of a dairy cow, there are obvious differences. The beef cow is stout and thick, with excess musculature and fat covering the entire body. The dairy cow is lean, with visibility of most of the bony structures of the body and has a much more feminine appearance than that of the beef cow. Nutritional requirements of these types of cattle correlate closely with their body composition and purpose.  We have also genetically improved these animals over many years to focus on the traits we use them for (milk production in dairy cattle and meat consumption in beef cattle). All cattle need nourishment through their diet, which is composed of 6 basic nutrients: water, carbohydrates, fats, protein, vitamins and minerals. Many factors influence the type of nutrition fed, including: digestive system function, feed and ration, environment, age, sex of the animal, size, body condition, weight, breed, genetics, and purpose for which they are being used.

The dairy cow is like an athlete during lactation, or the period during which she is making milk. Cows must calve each year to continue to make milk. Following a lactation period, the cow is dry (non-lactating) for a brief period, which allows her to gain excess body stores and prepare her body for the new calf about to be born. When the dairy cow first calves, she is burning a lot of calories to make milk and stripping herself of many of the body stores she gained in the non-lactating period. A high producing milk cow may eat as much as 100 pounds of feed per day! This feed consists of a total mixed ration, which combines dry hay, silage (ensiled feeds are things such as chopped corn and chopped wet hay), grain, mineral and often other by product feeds, such as soybean meal, cottonseed meal, etc. This ration is often created by a trained dairy nutritionist that optimizes nutrition for the health of the cow and milk production. This ration changes with the stage of lactation the cow is in, as the animal's nutritional needs change based on their milk production and stage of pregnancy.  As you can imagine, their needs shift based on if they're making a lot of milk and not pregnant or early in their pregnancy vs. when they are heavily pregnant and not producing much milk.  Because of their high nutritional demands, dairy nutritionists spend a lot of time balancing the rations for these animals as groups, based on their stage of lactation and gestation.

Beef cattle herds often consist of a group of grown female cattle that are the base of the herd and are the ones which produce calves each year. Some of these calves may stay and be used to grow or maintain the herd, whilst most of the calves are fed for human consumption. Some of the calves may be grown to the size for processing on the farm and some sold at a younger age and fed out at a feedlot.  In comparison to dairy cattle, these calves that are fed for growth are not pregnant and not producing milk. Thus, there nutritional requirements are different, as they are not burning calories for milk production or fetal growth. Beef cattle don't necessarily have a set level of feed intake; however, they require high enough levels of feeds to meet their nutrient requirements based on the factors previously mentioned.

Consumption of forage (grasses, hay, etc.) is limited by quality of forage. The higher the forage quality (protein, energy, digestibility), the greater the intake in most cases. It does not pay to feed poor quality feeds! Beef cattle may be raised solely on rich pasture in the warmer months, when the grass contains enough calories and nutrients and fed supplemental feeds when the grass is poor.  The cows producing calves are like the dairy cow, in that their nutrient requirements change based on the stage of lactation and pregnancy. Those calves fed for consumption may be fed a high energy total mixed ration (like a dairy cow with different levels of nutrients), made for quick growth and optimal muscling of the meat. Beef and dairy cattle need the same quality of minerals, however the quantity needed of the various minerals differs in beef vs dairy cattle.

Efficiency is key with both beef and dairy cattle, and these animals perform much better and have fewer health problems on higher quality feedstuffs and proper ratios of nutrients. If you are unsure of the quality of your feedstuffs, it is recommended that you contact your local extension agent for testing.