3. UNDER- OR OVER-FEEDING FAT – Colburn says too little fat in the diet (often accompanied by too little protein) can impede reproductive organ development and delay the onset of puberty, again causing late entry to the lactating herd. “The grower phase also is a critical time for mammary tissue development, which can be impaired by dietary energy deficiency,” he notes.
Too much fat produces its own set of issues, including heifers that experience higher rates of dystocia, fresh-cow metabolic diseases, and going off feed in early lactation. And, North Carolina State University Dairy Nutrition Extension Specialists Brinton Hopkins and Lon Whitlow point out that feeding too much fat to heifers before puberty also interferes with mammary tissue development. It can cause fat infiltration of the mammary gland, which impairs future milk production capacity.
4. SKIMPING ON TRACE MINERALS, VITAMINS AND IONOPHORES – Nutritionists have, by necessity, become very creative using a variety of by-products to formulate heifer TMRs. But don’t forget to evaluate new rations for their levels of trace minerals and vitamins essential for heifer development, and supplement accordingly. Hopkins and Whitlow also point out that the minimal investment in ionophores for heifer rations is definitely worthwhile. These additives increase feed efficiency by reducing methane losses, increasing propionate in the rumen, and helping control coccidiosis.
5. OVERCROWDING – Improved breeding efficiency, excellent calf-rearing practices and sexed semen have contributed to a happy problem on many dairies — too many heifers. Trying to raise every animal in overcrowded facilities will impact nutrient intake and growth performance for all of them. Kells advises producers to look more selectively at the heifers they retain, culling animals early if they have poor growth and/or a history of respiratory disease.
In the breeding phase, Colburn suggests setting a three- or four-service limit and culling heifers that are still open. “If you look closely at the records, you’ll find that a lot of ‘problem breeders’ were also ‘problem growers,’” he points out.
“Given fairly healthy beef prices today, those animals are likely worth more out of the breeding pen and on the rail.”
6. LIMIT-FEEDING WITHOUT PROPER NUTRIENT CONCENTRATION – Limit-feeding heifers is becoming a widely adopted practice. “It can be done very successfully with one very important caveat,” says Colburn. “The ration must be highly concentrated to deliver the appropriate level of nutrients. If it’s not, heifers will be undernourished.”