I'm always disappointed to see dairy herds that have high days in milk (DIM). A high DIM means two things: There aren't enough fresh cows coming into the herd, and there are too many tailenders still milking.
There's a whole lot of important things that have to happen on a dairy farm to make it profitable, including proper management of financial assets, consistency in milking and feeding, and optimizing efficiencies. But I would argue that all of the things you do on a dairy farm should ultimately be channeled into one main focus - getting cows bred and freshened as often as possible. The concept is simple: the more fresh cows at any given time, the more milk your herd will produce. No dairy can produce milk profitably without fresh cows. No dairy can continue to stay in business for very long without fresh cows.
So, as vitally important as your milking system is, and as vitally important as your farming operation is, and as vitally important as controlling costs and debt are, getting cows bred and freshened into a new lactation will, over the long run, have the greatest impact on cash flow.
Yet many dairy farmers miss this point. For those who utilize DHIA (Dairy Herd Improvement Association) or choose to keep their own records, DIM is a key indicator of how many fresh cows you have. Certainly not every farm is guilty of having high DIM, but many herds are consistently over 200 DIM for much of the year. Whenever your DIM climbs over 200, your herd is getting heavily weighted with cows running longer in lactation relative to fresh cows.
In order to maintain a "fresh" dairy herd, the dairy farmer must focus on two key areas: getting the milking herd pregnant in a timely manner soon after they've reached peak milk production, and having an adequate amount of replacement fresh heifers coming into the herd to offset culling.
Whether you use natural or artificial breeding to get your cows bred, half the battle is won when the bull does his job or the person responsible for AI knows when a cow is in estrus (heat) and sees to it that she's inseminated on time. I'll be the first to admit, from firsthand experience, this is easier said than done. Timing is everything when it comes to getting cows bred.
The other half of the battle focuses on proper nutrition, and that's something that can be managed quite aggressively. The single most important nutritional factor affecting breeding and conception is the energy status of the cow. Managers need to concentrate on high-energy intakes to bring cows out of a decreasing negative energy status just as soon as possible after freshening. Energy status is critical during the weeks prior to freshening, because the follicle supplying the ovum that will be fertilized begins to develop some weeks before freshening. Adequate dietary energy intake has been shown to affect the health of the follicle at its very earliest stages.
Dairy cows require significant dietary energy as well as protein during the last month of pregnancy, when the fetus adds 15 to 20 percent of its total birth weight. Unfortunately, many dairies fall well short of the nutritional needs to support the follicular development along with a growing fetus. The challenge for many dairy farmers during these tough economic times is to not cheat the close-up cows of the nutrition they require to breed back on time after freshening.
Cows may not look like they're losing body condition, but subtle things are going on inside that will affect their ability to conceive at that desired time three to four months after freshening. Forages do not supply the level of energy density required and only a few grains will. I've found that including a fat source in pre-fresh diets is the best means of getting adequate energy into the cow prior to freshening.
There's been a lot of discussion in recent years as to whether increasing energy density in close-up diets is really as effective as first thought or whether it may even be detrimental due to the high-concentrate/low-fiber ration formulations. Pushing energy in all types of dairy diets often means lowering fiber levels, which, if low enough, will have an adverse effect on rumen health. Fats have been used to increase energy density, but it's now recognized that excessive levels of conventional vegetable or animal fats will also disrupt rumen microbes. Commercial rumen-protected fats, also known as bypass fats, do a superior job of keeping negative energy balance to a minimum.
Research has shown that when the right combination of fatty acids is incorporated into these bypass fats, follicular and ovary health are also improved, meaning there is a much improved chance of conception in early lactation. So I think we've moved from the area of thinking that a positive energy balance through adequate energy density is what improves conception to a more advanced idea that it's not so much the use of fat and improvement of energy density per se as it is the types of fatty acid molecules that seem to work best in the reproductive systems of our cows.
Every dairy farm must develop and follow through with a breeding program that works best for its unique situations of management. Timed AI (TIA) programs as well as estrus detection (ED) can work by themselves or in combination. The key is to get every cow and heifer (FCH) bred in that three to four-month time window after freshening. Cows that are still open after 120 DIM quickly become a liability rather than an asset.
The general health and energy status of a cow is something that has to be managed throughout her lactation. Both a cow's propensity and ability to conceive her next pregnancy is already being influenced while she still carries this year's unborn calf. Whether times are financially tough or not, we can never afford to compromise the flow of fresh cows in our dairy herds. Fresh cows are the foundation of cash flow and profitability.
The author is a dairy nutritional consultant and works for Central Connecticut
Cooperative Farmers Association in Manchester, Conn.