Should you add an extender to your whole milk feeding program?

With drops in quota and elimination of incentive days, you might be tempted to feed excess whole milk to calves. While this can seem like a good option during these times, there are a few things to consider to successfully use saleable whole milk on your farm.

Feeding a protein: fat ratio of 1.2:1

Over the years demand for butter fat for human consumption has risen drastically, thus creating a need to increase fat in whole milk through genetics and nutrition. While this is good news for human consumers, it does create challenges in feeding to calves.

Several studies have shown the importance of feeding a high protein diet to calves early in life and how it relates to 1st lactation potential. We want to feed our dairy calves for lean growth, which will allow them to have a larger stature and frame required for optimal breeding and milking. It’s more than just feeding high protein. There is a relationship between preweaning milk, fat, and protein production, and a positive relationship between first lactation performance and preweaning average daily gain.

Holstein dairy calf sniffing straw in open pen

Not only do we need to feed higher protein, we also need to ensure there are adequate solids in the diet. Azevedo et al (2016) showed that by increasing total solids in whole milk with the addition of milk replacer powder there was an increase in performance and body frame development of dairy heifers in the pre- and post-weaning periods, with no effect on solid feed intake, fecal score, or days with diarrhea. Increasing total solids is important because we need to ensure calves are getting an adequate amount of calories. Calves would naturally nurse several times a day, but we allow them 2 or 3 feedings a day. Therefore, for optimal growth we need to increase total solids.

Along with feeding a higher protein diet and ensuring adequate starter, we also need a good weaning program in place; especially if we have high fat in our liquid fed diet. When calves show readiness to wean, gradually decrease the quantity of milk and increase the solid feed consumption for the optimal growth scenario and subsequently 1st lactation potential.

Effects on calf growth and development

Feeding a 1.2:1 protein fat ration, a good feeding program with appropriate solids, quality starter, and an excellent weaning program will all allow calves the greatest potential average daily gain (ADG).

Preweaning ADG has a greater long-term influence when growth rates are greater than 0.5 kg/day. This is likely related to the positive effect of preweaning intake on subsequent production, as calves that consume more nutrients will experience faster growth and greater nutrient availability. This may be related to the degree of mammary development (Gelsinger, 2016). Faster growth may also be indicative of metabolic efficiency, implying that metabolically efficient calves continue to be metabolically efficient as adults (Sejrsen, 2000).

Vitamins and Minerals

When considering feeding whole milk, it’s also important to consider the finer ingredients that are not often talked about; vitamins and minerals. According to the NRC requirements for young calves, whole milk is deficient in many vitamins and minerals.

In particular, 6 out of the 8 B-vitamins, Vitamin D and E, and 6 of the 7 trace minerals.

These deficient vitamins and minerals are critical for maximizing growth, and immune response, and development.  Calves can become sub-clinically, if not clinically, deficient within the first few days of life. Calves do have fetal reserves that are influenced by the dry cow nutrition and can quickly be depleted in the first few days of life. Although they can source some of these vitamins and minerals in colostrum and solid feed, the first 3-4 weeks of life a calf is deficient due to the inability to consume enough starter. They are entirely dependent on liquid food source to deliver all essential nutrients.

Many vitamins impact the calf’s health status. Vitamin D has further implications of effecting calcium absorption. Thiamin and Vitamin B12 allow for an improvement to immune responsiveness. Without enough iron calves can become anemic, this is especially important as some calves can be born in an anemic state depending on the dry cow nutrition. As an anemic calf, they have poor feed intakes, slow growth and a depressed immune system causing them to underperform. With copper deficiencies, you’ll also see poor growth and potential scours, anemia, fragile bones, and loss of hair pigmentation.

Some milk replacers can be used as an extender to improve the solids, vitamins and minerals in whole milk.  Determining the amount of milk replacer to add into your saleable whole milk, it will depend on protein, fat, solids present, and the volume fed to calves.

Consistency and cleanliness

When there’s excess saleable whole milk on the farm, it’s often thought of as ‘free feed’. But it could be costing you.  Most farms do not test or manage quality of saleable milk on-farm, thus a big unknown!

In a growth study by Miner Institute, they found a large variation in fat in whole milk fed to calves (1.54% to 7.71%). When fat was analyzed at each milking, they found a morning fat average of 4.55% and an average of 4.92% for the afternoon milking. Of the samples they tested, 24% had fat <3.8%. (Miner Institute, NYADP Study 2019).

Changes in consistency of milk can lead to the unwillingness of calves to drink, digestive upset, nutritional scours, or calorie deficits. All of this can affect ADG and lead to undiscovered 1st lactation potential that ultimately effect dollars on your bottom line. Calves thrive on routine and will become stressed when there are too many changes. Stressed calves are more likely to become sick. More than a 1% difference in solids can be stressful to calves, especially if coupled with other factors such as scours or cold stress.  A milk extender can increase and standardize solids fed to calves. If this is a practice you want to try on your farm it’s important that saleable whole milk solids are tested regularly.

Whole milk must be stored safely to avoid growth of bacteria when feeding calves. Whole milk contains bacteria and if given the opportunity the bacteria will grow exponentially. This could lead to problems in the calf. Ensure that whole milk for calves is cooled quickly, stored in clean equipment and warmed up properly. Pasteurization can reduce the effects of bacteria, but must be done properly. Milk with too high of a bacteria count may not effectively eliminate the bacterial even after pasteurization. High pasteurization temperatures will damage protein in whole milk, and lead to poor digestion, nutritional scours, and the potential for overgrowth of harmful bacteria in the calf’s gut such as clostridia.

For more information on the use of an extender with your whole milk please reach out to one of our Young Animal Specialists.
Grober Nutrition

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