Dr. Dwight Roseler, Adjunct Professor, Department of Animal Sciences, The Ohio State University and Dairy Nutrition Specialist, Purina Animal Nutrition, Great Lakes Dairy
Cows love cooler weather and good forage. Just like an effective football coach, you must prepare and coach your herd to perform properly in the fall and prepare the cow herd to win each game. Corn silage harvest is in the rearview mirror for most Midwest dairy farms, and the best coaches prepare their cow herd, facilities (weight room), and staff to prepare for top performance. The fall season can be difficult on your cow herd and negatively affect milk production if the herd is not prepared. Shorter day length, lingering summer heat, cow fertility, hoof quality, bird infestations, and new corn silage are among factors to prepare.
Day Length
The most consistent research response many university and farm data in the northern U.S. has been the response in milk production to long day lighting. An added 4 to 6 lb/day of milk per cow occurs when 18 hours are provided. Lighting intensity must be a minimum of 20 footcandles across the entire barn along with 6 hours of darkness or red light. Lights need to be cleaned yearly or upgraded to gain the benefit for the cows.
Feed Changes
2022 corn silage across Ohio has higher starch, lower neutral detergent fiber (NDF) corrected to an organic matter basis (NDFom) and similar NDF 30 hr digestion compared to 2021 corn silage. Initial rumen starch Kd will be lower but increase with fermentation time. These trends will vary by county. Feeding corn silage that is 60 days fermented or longer is ideal to allow rumen starch and fiber Kd to increase and fermentation to stabilize. Nutrition clients successful in feeding new corn silage without production decline take great care in proper corn hybrid selection (floury), in season plant care (fungicide, plant health), effective kernel chop processing score (>77), rumen starch Kd (20%), and ration formulation [NDF digestibility (NDFd) >60, effective undigested NDF (eUNDF), buffer, etc.] Diet additives need to be altered from summer to properly prepare for fall [Diflourobenzonon (DBZ), dietary cation-anion difference (DCAD), buffer, minerals, passage rate, enzyme, etc.).
Lingering effect of summer heat
Summer heat and humidity in the Midwest will have a lingering effect on the cows. Cows that peaked in the summer can have lower body condition repletion due to intake and priority of nutrient demand to milk production. As day length shortens, the cow body condition repletion will shift more energy to body condition and less towards milk production. Lower fertility from summer heat results in lower quality embryos and lower fertility of summer bred cows. In addition, longer days open can increase herd days in milk and reduce overall herd production. Cows that stand excessive hours due to heat stress will have poor quality hoof tissue and more potential lameness. Update diets and intensify reproductive focus and hoof trimming to maintain proper herd performance.
Fall health challenges
As birds mount their annual flocking, they are drawn to indoor feeding and nesting areas in dairy barns. Birds can transmit disease, dysentery, consume grain from TMR, and reduce performance. In some herds, fall can result in more confined and unclean calving pens and poor air quality. This can result in more metritis, mastitis, and respiratory health challenges. These health challenges can illicit an immune response that can reduce milk production, possibly with severe challenges by 8 lb/day of milk per cow. Feed treatment options are available, some experimental, to reduce health and performance challenges in your herd. Discuss options with your nutritionist.
Do not overlook the obvious
There are many factors unrelated to the fall season that affect milk production. The ABC of air, bunk, and comfort always need to be part of a winning team. Coach up your cow team this fall for a winning season and Go Bucks.