Posts by Rob Costello, Dairy Technical/Business Support Manager, Milk Specialties Global

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Friday, August 29, 2014

Animal Plasma In Calf Milk Replacers

Animal plasma provides a unique protein source which is often referred to as functional proteins. These functional proteins contain biologically active albumin and globulin proteins. Immunoglobulins such as IgG are important antibodies that circulate in plasma. Animal plasma is a highly soluble, high quality protein source with an amino acid profile and nutritive value comparable to nonfat dried (skim) milk and casein.

Animal plasma was introduced in commercial calf milk replacers over 20 years ago. Today, about one third of all calf milk replacers made in the United States contain plasma. Large calf ranches where calves are co-mingled and often have not received adequate colostrum are the major users of animal plasma milk replacers, . These operations recognize the advantage of plasma from a health perspective as well as a cost savings. Animal plasma is often fed in conjuction with hydrolyzed wheat protein in calf milk replacers to provide the benefits of plasma at a more significant cost savings.

In the Digestive Tract 
As well as being an excellent source of nutrition for young calves, animal plasma has additional beneficial effects in the digestive tract. During the first two weeks of life, the calf secretes a portion of the immunoglobulins it absorbed from colostrum back into its digestive tract. The more colostrum absorbed, the more immunoglobulins secreted. This recycling of immunoglobulins helps protect the calf against pathogens. Providing animal plasma in milk replacer increases immunoglobulin levels in the digestive tract, and provides an ongoing source after the calf has stopped secreting immunoglobulins from its own bloodstream.

Research with both young calves and baby pigs demonstrates that feeding animal plasma to young animals has a direct effect on the integrity and function of the small intestine. Animal plasma may directly affect antigen growth and attachment in the small intestine, affecting intestinal growth and improving its barrier function.

Calf Performance 
There have been at least 30 trials conducted to evaluate the effects of animal plasma on the growth and performance of baby calves. In these trials, plasma always performed as well as or better than all-milk protein milk replacers. Improvements include:

  • Fewer, shorter scour episodes
  • Reduced medical costs
  • Better gain
  • More starter intake
  • Lower cost than all-milk protein milk replacers

Animal Plasma Characteristics
  • 78% protein, 0.3% fat, 0.5% fiber, 7% moisture, 8.5% ash
  • Light tan color that does not change the color, aroma or solubility of the milk replacer

Spray Dried Animal Plasma
(NutraPro B, APC)
photo courtesy of Dave Wood (Animix)

Monday, May 12, 2014

Milk Replacer Considerations With Automatic Calf Feeders

Milk replacer characteristics can influence how they interact with automatic calf feeders. These interactions can not only affect how the milk replacer behaves in the feeder, but may also affect calf performance. This post explores how the physical structure of milk replacers, solubility, mix temperature and formulation come together with automatic calf feeders.

Physical Form. Most milk replacer manufacturers in the US use protein-encapsulated fats rather than simple fats. By themselves, fats are not soluble in water. The process of making an encapsulated fat involves heating, mixing, homogenizing and spray drying what is basically a mixture of fat, protein and emulsifiers. Very small fat particles are formed which become encapsulated with proteins. With the fat hidden in the center, the protein coating readily interacts with water, allowing the protein-encapsulated fat to go into solution.

Mix Temperature. Since mixing and feeding usually occur simultaneously with automatic feeders, milk replacer should be mixed at the normal feeding temperature, between 100 -105 degrees F. This is lower mix temperature than you will typically find in most milk replacer instructions, usually between 110 - 120 degrees F.

This temperature discrepancy should not generally be of concern. The fats used in most commercial milk replacers melt between 90 and 100 degrees F and the mechanical mixing action of the feeder facilitates solubility. Of course this assumes that the mix temperature of each unit is correct. Low mix temperatures can affect solubility, digestibility and animal performance while high temps can discourage calves from drinking.

A 2012 study by Virginia Tech of 10 dairies in Virginia and North Carolina with automatic feeders showed a range of mix/feeding temperatures from 81 - 118 degrees F. These data point out the need for routine mixing temperature monitoring throughout the year, making any necessary seasonal corrections.
Virginia Tech, 2012

Formulation. Milk replacer formulations vary considerably among farms using automatic feeders. The table on the right shows that six different formulations were being used among the 10 farms in the Virginia Tech study. The best milk replacer formula for any one farm actually depends on the feeding rate and the farm's growth objectives.

Feeding rates with automatic feeders are typically between 1.5 to 2.5+ pounds of milk replacer powder per day. Calves on higher feeding rates usually benefit from higher protein formulations while calves receiving a more traditional amount of milk replacer may benefit more from a more standard formulation such as 20:20 (% protein:% fat) or a 22:20.

The table below demonstrates how the milk replacer formulation works with feeding rate to affect gain. Values were obtained using the 2001 NRC Nutrient Requirements of Dairy Cattle ration program. Consider the 28:20 in the second milk replacer column with a feeding rate of 2.5 lb powder/day. The Energy Allowable Gain of 2.58 reflects the potential gain provided by the energy consumed. The ADP Allowable Gain of 2.49 is the gain supported by the amount of protein consumed. The ADP Balance in this case is -10, indicating that there is not enough protein to convert the available energy to gain. 

2001 NRC, Nutrient Requirements of Dairy Cattle

Maximum gain, therefore is 2.49 lb/day, not 2.58. You would need another 10 grams of protein to match the energy provided by the milk replacer and turn it into gain. The extra energy in this scenario will go toward production of body fat.

Compare this to the values in the adjacent 28:20 column where the feeding rate is 1.5 lb/day. In this case, insufficient energy is consumed, limiting maximum gain to 1.26 lb/day. Finally, take a look at what happens when you feed a 20:20 at 1.5 lbs/day. Potential gain is limited to 0.92 lb/day with all that extra energy going toward body fat. When choosing a milk replacer, it's important to pick a formulation that matches your feeding rate and growth objectives.

Ingredients and Other Factors.  Most milk replacers used in automatic feeders are manufactured with all-milk proteins. This is typical of milk replacers designed for high feeding rates. Nonetheless, milk replacers containing non-milk proteins such as animal plasma and a wheat & plasma combination are being fed successfully through automatic feeders. At high feeding rates you may want to check with the manufacturer to assure that non-milk protein inclusion levels don't pose a concern when high volumes of milk replacer are fed.

Automatic calf feeders can all do a good job of mixing milk replacer, but there are differences in mixing equipment, with some being less forceful than others. These feeders may tend to be a bit more sensitive to differences among milk replacers which can result in some undissolved powder after mixing.

In addition, milk replacer powder attracts moisture which changes its storage and mixing characteristics. Practices such as transferring milk replacer powder from the original bags to a storage container can greatly increase exposure of the powder to air and moisture. Filling a 150 pound hopper with milk replacer powder to feed for several days not only exposes the powder to moisture, but the weight of the powder can cause it to compact, leading to bridging and flow issues. With a bit of care and attention to details, undesirable interactions between milk replacer and the feeder can be minimized.

Sunday, January 12, 2014

Calf Feeding - Cold Weather Feeding, Energy Intake & Solids Levels

As environmental temperatures decrease, a calf's need for energy increases. Calves need between 1.0 and 1.3% more energy for each degree the environmental temperature drops below 50° F. Below this temperature, calves must increase heat production to stay warm.

Calves that are younger than three weeks of age have a larger surface area relative to their body weight and may not be able to withstand changes in environmental temperature as well as older calves. These younger calves may need additional energy beginning at environmental temperatures as high as 59° F. Keep in mind that each calf is different and no one temperature describes all calves or all situations. Exposure to wind, sun and moisture as well as bedding and housing all influence how environmental temperature affects calves.

Feeding options used to increase energy intake through milk and milk replacer include:

  • increasing the volume of fed 
  • utilizing a higher fat milk replacer 
  • adding more milk replacer powder
  • adding a high energy supplement. 

This post will explore these changes in energy and effects on solids (concentration) of milk or milk replacer.

Energy Intake

When the environmental temperature falls to 30° F, the calf needs about 25% more energy than at 50° F. As the temperature drops to 10° F it needs 50% more energy. The table below shows the energy provided by one ounce of milk replacer that's formulated to 20 percent protein and three different fat levels. The energy provided by a 7-60 high fat energy supplement is also shown. Values are on a dry matter basis.

Energy Comparison
Milk Replacer and 7-60 Energy Supplement

Table 1

The total energy in a feed is a combination of the energy from the protein, fat and carbohydrates contained in the feed. As seen in the table, using a milk replacer with a higher fat percentage does not increase the overall energy by very much. Simply switching to a higher fat milk replacer during cold weather and feeding at the regular rate, will probably fall short of the calf's increasing energy need during cold stress -- maybe by a lot.

The 7-60 in the table is a high fat energy supplement, providing 7% protein and 60% fat. This energy supplement provides about 30% more energy than milk replacer.


The higher energy density of the 7-60 energy supplement makes it possible to increase energy consumption without increasing solids as much as what occurs when increasing the concentration of milk replacer powder in water. Table 2 shows what happens to solids when you add more milk replacer powder or use an energy supplement to meet the calf's increasing need for energy.

Table 2

The left column lists three levels of powder commonly used when mixing milk replacer. The solids levels of the mixtures are provided in the next column. For example, when you feed 8 oz of powder and increase the energy by 25%, you would  use 10 oz of powder, which results in solids at 14.5%.

A 50% increase in energy requires 12 oz of powder at a solids level of 17%. Meeting these energy needs with the 7-60 energy supplement lowers the final solids to 13.5 and 15.5%, respectively. You can also see what happens when your  normally feeding rate is 10 oz and 12 oz of powder and you increase the concentration of powder.

Solids levels of 17-18% are often used with intensive milk replacer feeding programs. Calves should be able to adjust to this feeding level. But when you get into the 20-24% solids range, the likelihood of causing digestive issues increases. Highly concentrated milk replacer, especially when fed  in large volumes, pulls water from the calf into the digestive tract and may ultimately lead to scours and dehydration. If you choose to feed at higher solids, access to clean water is a must.


As the tables demonstrate, a high fat energy supplement may offer an advantage when solids are being altered to meet the calf's energy needs. The table also shows that there are situations where it is better to simply feed more of the regularly concentrated milk replacer rather than concentrating it. You can either feed more at each feeding or add another feeding during the day.

Calves that are older than three weeks of age should be eating a significant amount of starter and can offset much of their need for energy during cold stress through increased starter intake. Access to water is a necessity for increasing starter intake.

Calves that are younger than 3 weeks of age are more dependent on milk or milk replacer for meeting their energy and protein needs. Very young calves may have difficulty consuming all of the energy they need during cold stress through increasing consumption of milk and milk replacer. Some calf raisers extend colostrum feeding to help improve the level of nutrient intake of these calves. Compared to the values in Table 1, the average energy value of one ounce of colostrum is about 185 kcal.  In any case, you may need to go beyond a strictly nutritional solution and actually reduce the effect of lower environmental temperatures on these young calves by using tools such as calf coats which can greatly increase the calf's insulation against cold temperatures.