The Cow-Calf Manager:
Nutrition for the Fall-Calving Herd during Lactation and Breeding

Livestock Update, January 1999

John Hall, Extension Animal Scientist, Beef, Animal and Poultry Sciences, Virginia Tech

At last a little rain has fallen, but we are still behind on stockpiled forage. The first snows are threatening Blacksburg. In other areas of the state forage growth is slowing or has stopped. Fall-calving herds are usually blessed with cows in good body condition, and farms that still have some stockpiled fescue at the start of the breeding season. This year things are very different -- hay is in short supply and fair quality, and stockpiled fescue is rare to non-existent. If the nutritional program during breeding is not managed well, producers with fall calving herds could be very disappointed with pregnancy rates this year.

However, feed and by-product prices are relatively low this year. This gives producers a good opportunity to feed cattle properly during the breeding season.

Nutrient needs of the lactating cow

The nutrient needs of a cow are highest, for the entire year, during the period form calving to the end of the breeding season. Cows need high levels of energy for milk production and to rebreed as well as extra protein for milk production. If these needs are not met, reproduction suffers. Figure 1. Shows what happens to pregnancy rates in cows depending on how the are fed before or after calving. The first letter indicates the nutritional levels they were on before calving (High =H; Low=L). The second letter indicates the nutritional level after calving. Cows that were fed well both before and after calving (H-H) have high conception rates. Cows that calve in good condition from good nutrition before calving, but get poor nutrition after calving (H-L) have 15-20% lower pregnancy rates. Cows that don't get enough nutrition before calving, but are fed correctly after calving (L-H) increase pregnancy rates by 20% over underfed cows (L-L) but are still lower than well fed cows. Lactating cows need a diet that at least 60-62% TDN (TDN is a measure of energy) and 11% crude protein.

Diets for lactating fall calving cows

For fall calving herds, most of the nutrition needed by lactating cows usually comes from stockpiled fescue or high quality hay. This year those sources are not available or the quantity is not there. Energy is the nutrient most likely to be lacking in our forages; with a smaller need for supplemental protein. Producers need to find other feeds to stretch hay supplies and ensure cows will be ready for breeding. Some good diets for lactating cows are listed in the table below. Some of the diets will help thin cows gain weight. Others will keep cows in good flesh from losing weight. All diets should be fed with a balanced free choice mineral. Poultry litter diets require a different mineral mix than other diets.

Diet Ingredients	Meets or exceeds needs	Increase or loss of body condition in good weather
17.5 lb hay + 14.5 lbs of soy hulls or barley	X	+1 BCS in 110 d
16.5 lbs hay + 13.5 lbs corn + 2.2 lbs soybean meal	X	+1 BCS in 60 d
5.5 lb hay + 8 lb corn + 21.5 lb Poultry litter	X	+1 BCS in 80 d
16.5 lb fair hay + 14.5 lb dry corn gluten	X	+1 BCS in 180 d
8.8 lb hay + 22 lb dry corn gluten	X	+1 BCS in 60 d, very high energy diet needs to be fed carefully
8.8 lb hay + 95.2 lbs wet brewers grain	X	+1 BCS in 175 d; cows may not be able to eat that much brewers grain
36 lbs hay	NO	-1 BCS in 90 days

By feeding cows well during early lactation and the breeding season, producers can prevent reproductive wrecks. This year's feed situation is a challenge but there are many options for producers in terms of diets and prices of products. The above diets are examples the actual amounts of feed or performance depend on actual nutritional values of the feeds you use. Check with your local extension agent or feed mill for the availability of some of these products in you area.

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