The protein percent of the milk you send to the factory not only impacts farm income, but can also provide important indicators for cow health and nutrition.
The most common reason for seeing a low milk protein test in the winter is due to lack of energy in the cow’s diet. If the cow is short of energy, she will break down amino acids (protein building blocks) to get energy. This means less amino acids are available to the mammary gland to make milk protein. It is important to consider both the quantity and quality of the feed on offer to address low milk protein levels.
Maximise dry matter intake (DMI) – by keeping the cow healthy and providing enough feed.
Ensure you have a sound dry cow and transition cow program in place. Aim to dry cows off in the condition you want them to calve in and maintain that condition over the dry period. Aim to calve cows in body condition score (BCS) of 5-5.5 on the 1-8 scale.
Provide grain for at least 21 days prior to calving to adapt the rumen microbial population and the rumen lining to the higher starch diet. This better prepared rumen in the fresh cow will mean greater absorption of volatile fatty acids (breakdown products of carbohydrate fermentation) in the rumen, better fibre digestion, improved DMI and energy status in the fresh cow leading to better production, health and fertility outcomes. The higher energy density feed will also help to maintain BCS as the cow’s intake drops and her energy requirements increase coming into calving. Cows that are losing weight coming into calving are likely to have lower DMI following calving. Similarly, over conditioned cows tend to have lower DMIs following calving and a greater predisposition to mobilise body fat and are at greater risk of metabolic disorders such as ketosis.
Provide enough feed to allow cows to express their dry matter intake potential. Cow’s dry matter intake should steadily increase from around 2.5% of her bodyweight in the week following calving up to 4%+ of her bodyweight at peak. For a 550kg cow that means 13-14kgDM in the week following calving to 22kgDM+ at peak. If your cows are still before peak, are they eating and being offered more feed than they were last week?
If dry matter intakes are on target the second thing to consider is diet balance which we’ll look into in next week’s article.
For further tips on ways to improve you milk components please consult with one of our qualified ruminant nutritionists.