Seasonal Effects on Milk Components

Lizzy SchultzAg Group, Animal Health, Cattle, Dairy, dairy farming, Milk, Nutrition

hubbard-milkfat As summer swings into full force, you may be seeing a decline in milk fat and protein concentrations. These components tend to peak in the winter months and fall to their lowest point around July and August. Jon Pretz, Dairy Nutritionist, and Dr. Sarah Schuling, Dairy R & D Nutritionist with Hubbard Feeds, have offered some insight into the decline, as well as ways to keep it to a minimum this summer.

Heat stress is a major cause in the decline, as heat stress may cause animals to have lower levels of blood protein and energy, both of which can influence milk and milk fat yields. Cows also tend to slug feed during cooler periods of the day, so as not to increase the heat of digestion, and this can result in periods of luminal acidosis and resulting decrease in milk fat content.

A recent trial conducted in Australia determined that heat stressed animals also have lower milk protein content than animals in a thermal neutral climate. This is due to cows using more amino acids, which are typically used for protein production, for energy production in times of extreme heat compared to normal conditions. the cow prefers to use AA for protein production, and fewer AA may be available for milk protein production.

Some nutritional strategies that can held improve milk components in the summer include increasing sodium bicarbonate levels by around 8 ounces. This improves rumen buffering capacity. Also, try to feed more digestible forages to high producing cows, which reduces the heat of digestion. Increase the fat content of rations with rumen inert fat, which will improve the energy supply, and feed higher metabolizable protein diets.

Higher protein diets can better match the increased amino acid supply with demand. Balancing rations for lysine and methionine can also be helpful by Improving the efficiency of use of total dietary protein.

The final tip: don’t feed excess, and it causes energy to be wasted in order to metabolize the excess RDP.

The entire article can be found here.