Raising healthy replacement heifers takes time, commitment, skill and knowledge. Today’s dairy economy has put a great deal of pressure on the cost of raising heifers. Since replacement heifers produce no daily income until they hit the milking string, viewing heifers purely as cost instead of an investment can set up your dairy for disappointment. The future of your dairy’s profitability lies in the care of whoever has fed, doctored and worked with these females.
Whether heifers are raised on-farm or outsourced to custom-raisers, items of consideration for change usually fall within economics and management. Raising dairy females most economically – with the best nutrition – means nothing if their environment impedes growth, health and production. While nutrition costs make up a large portion of raising a replacement heifer, her health, labor and management make up the rest. The key is to focus on the areas that are most influential and make the most impact, and then evaluate if changes are needed.
Let’s look at the bottom line. If you minimize variation and risk associated with environment and management, you should see healthy heifers that are young enough, yet mature enough, to enter the milking herd and retain some costs of production if you also make sure to value and evaluate sound nutrition and health. If we evaluate rearing healthy females, three key items impact the longevity and future milking ability of your replacement herd – those being growth, nutrition and health.
Puberty of females should begin at 50 to 55 percent of their mature bodyweight. This will usually put them on track to calve after reaching 85 percent of their mature bodyweight. Replacement heifers should calve, and subsequently enter the milking herd at 22 to 24 months of age for large breeds and 22 to 23 months of age for smaller breeds.
Holstein heifers must gain more than 1.7 pounds per head per day if they are expected to calve at 23 to 24 months of age, weigh more than 1,250 pounds after calving and achieve lactation yields above herd average. While not the sole way to define future milking ability, live bodyweight does have some application as long as one is accustomed to variation within and among breeds. In addition to bodyweight, wither height is also a good tool to be accustomed to measuring and can easily be done by trained personnel. Monitoring height is important to ensure proper frame development without excess body condition, which is the danger in monitoring bodyweight alone. There are also multiple studies that outline by breed the growth curve of these replacement females. Tools such as these should be visible in replacement operations.
Common sense, combined with research, would dictate that having adequately balanced diets for growth goals, without producing excessive body condition, produces healthy heifers that can achieve superior levels of milk production. Therefore, ensuring adequate (not excessive), balanced nutrition to achieve growth goals should be evaluated at each stage of the heifer’s life. Continually benchmarking heifer bodyweight, body condition score and height at weaning, pre-breeding and pre-calving, will ensure long-term success and/or head off long-term problems in replacement development.
The link between sound nutrition and genetic expression is the subject of much current research. Digging deeper into the genetic code and learning how genes for growth – and ultimately milk production – are expressed, may be heavily dependent on nutrition “triggers” at certain stages in life. These nutrition triggers influence mammary development at an early age, meaning early life-stage nutrition choices have long-term ramifications on lifetime milk production.
Focusing on nutrition is a very large factor in successful and healthy replacement females. While taking into consideration the most economical way to raise heifers, one system is not right for every producer. Evaluate your farm’s feeds from the mineral you purchase to the feedstuffs you procure. Be cautious of cutting cost on minerals or protein, as these savings may be more than nullified if conception rates decline due to inadequate mineral absorption, or if calf health is compromised due to inadequate consumption.
It has already been noted that taking shortcuts in the calf barn can impact future milking ability, so be thrifty, but utilize sound science behind your decisions. Ask your nutritionists about differing replacement programs they implement at other farms and how they benefit other producers. Obtain a broad understanding of what works not only for you, but for other thriving operations. We have a vast amount of products and research at our disposal that are being used at farms throughout the country. From the presence of starters that contain probiotics and/or mannanoligosaccharides (MOS) to the appropriate amount of organic trace elements in a mineral blend; if you are open to looking at opportunities that can reduce labor or treatment costs, you can implement a change that still promotes healthy growth, but also takes stress off farm labor.
While replacement diets aren’t as complicated as lactation diets, they should not be disregarded or cheapened to make up for the lactation herd’s diet. Consistency in feeding, and understanding the challenges you may run into with the type of system you have to raise your females, will help you cut costs. Adjusting diets to environmental conditions, using quality feeds and an ionophore will help improve your performance and health. As we move further into summer conditions, realize the effects that heat has on intakes and performance. While you see the impact heat has on milk production, do not forget to also manage heifers through this period. Reduced DMI affects gain and health. These challenges will be noted later in life during stressful events or return as digestive disturbances if not managed during the present. Products that help keep animals on feed during the heat and obtain internal cooling should be evaluated for use.
Simply focusing on cost in heifer feeding strategies, without achieving growth and age goals has a greater cost – loss of revenue. For every day beyond 24 months that heifers are fed without yet calving, costs average an extra $2 per head per day on feed cost alone. Combine this with lost revenue from milk not yet realized, and there may be as much as a $6 to $8 per head per day swing in lost opportunity that will never be recovered in the lifetime of the cow. Saving a few cents per head to sacrifice sound nutrition and growth goals cannot replace the dollars lost. That is leaving real money on the table.
As much as sound nutrition can affect milking ability, health of calves has an equal impact and importance on future milking ability. Rossini researched the effects of respiratory and digestive disorders on calf mortality and of great interest, first lactation and survival. First-lactation heifers that experienced one health episode as a calf were more likely to experience digestive infections (49.1 percent), along with respiratory infections (30.2 percent). If heifers experienced two health challenges, the instance of two respiratory infections was 17.5 percent and two digestive disorders 21 percent.
These health challenges directly related to calving age. Heifers that experienced one health challenge had an increased calving age by 0.21 months. This value increased to 0.53 months if the heifer experienced two or more health challenges as a calf. Heifers that experienced zero calfhood diseases had a 5 percent greater chance of experiencing a second lactation and an 8 percent greater chance of remaining in the herd beyond the second lactation. Based on these values, it becomes clear that calf health impacts future lactation, with milk losses between 2.3 to 10 pounds per day.
The easiest way to impact these values seems to be to evaluate passive immunity and colostrum intake. Stated simply, calves that have evidence of good passive immunity (IgG levels > 1000 mg/dl) have lower mortality, cost less to raise and stay in the herd longer. Discussing proper growth protocols with your veterinarian and nutritionists to establish checkpoints for health are a sound financial and proper husbandry decision.
There are many items and programs one could discuss about rearing replacement heifers. The magnitude of raising heifers lies in a producer’s ability to manage multiple items without overspending. Approaching the dairy replacement enterprise as an investment in the dairy’s future helps keep those costs and the resulting product – a high-quality milking female – in perspective. Utilizing the expertise of a nutritionist and managing through environmental stressors is only part of a good replacement program. Working with a veterinarian to check antibody status of calves and conduct herd health checks is a necessity.
If you have all of these factors under control and still have substandard raising conditions or facilities, you will not be as successful as producers who implement clean environments and work towards strong managerial practices every day. Be accountable for your program, whether you raise your own replacements or contract this work out. Future milking ability and longevity of your herd depends on the teamwork between yourself, your nutritionist and your veterinarian. PD
Heidi Doering-Resch, M.S. in nutrition, is on staff at the Form-A-Feed and TechMix companies, headquartered in Stewart, Minnesota.