A newborn dairy calf has the world at its feet, but every so often it seems to go awry and what results is a sick or dead calf that never reaches its potential.
According to the National Animal Health Monitoring System (NAHMS), the death rate among unweaned heifers in 2006 was 7.8 percent. Scours, diarrhea, or other digestive problems accounted for the highest percentage of unweaned heifer deaths (56.5 percent), followed by respiratory problems (22.5 percent).
Sometimes the calving environment is an overwhelming factor in calf morbidity. The NAHMS Dairy 2007 study reports that the majority of operations (70 percent) used a multiple-animal calving area/pen, and 34.2 percent of the operations indicated that they allowed sick cows in calving areas. It’s no wonder on some operations that newborn dairy calves have the deck stacked against them.
Colostrum remains the key
We’ve known for years how to get dairy calves off to a good start — feed them an adequate volume of good quality colostrum shortly after birth.
“The NAHMS survey would indicate out of those three factors of timing, quality and quantity of colostrum feeding, perhaps quantity is the most important item that needs improvement, “says Lon Whitlow, dairy scientist at North Carolina State University and one of the participants in a roundtable discussion sponsored by Alltech. “A lot of dairy producers are giving only about 2 quarts of milk per calf per day. They’re doing a pretty good job of getting to the calf early, but they’re not giving them a great enough quantity of milk. They need a gallon a day and more in cold weather.”
To back that up, the NAHMS Dairy 2007 study indicated that 45.8 percent of operations hand-fed more than 2 quarts but less than 4 quarts of colostrum during the calves’ first 24 hours of life.
In 2007, 13 percent of operations that hand-fed colostrum either estimated the immunoglobulin levels of colostrum or evaluated its quality before feeding. The most common methods used for evaluating colostrum quality were a colostrometer and visual appearance.
In addition to the passive-transfer issues, there’s a lot of data on the role colostrum plays in growth, says Jim Drackley, dairy scientist at the University of Illinois and another of the roundtable participants.“The initial development of the intestinal tract in the first couple days of life is very much dependent on colostrum intake. We know that the basics include getting enough colostrum into the calf as quickly as possible, and that the colostrum should be of good quality in terms of its antibody concentration. Calves that have failure of passive transfer don’t grow with the same efficiency as calves that have had adequate colostrum. Even at the same feed intake, you might get half the growth. Feed efficiency is very much decreased in those calves. It has to start with adequate colostrum status,” he says.
But even people who feed adequate amounts can still have problems if the colostrum is unsanitary, points out Simon Timmermans, veterinarian from Sibley, Iowa.
“We’ve started a HACCP protocol where we collect a random colostrum sample weekly before it goes into the calf,” Timmermans says. “We can detect if there is a hygiene problem based on the bacterial count. I think that’s the key reason why we see such better performance out of the beef industry. It’s the human element, and it goes to hygiene.”
Timmermans explains that colostrum is a great culture media for iron-loving bacteria like Salmonella. “The producer may do everything perfectly, collecting that one gallon of colostrum, but then he lets it sit out in a bucket for three hours before he gets it fed to the calf” and bacterial levels explode.
Feed gastrointestinal tract
A calf is born as a non-ruminant, so it relies solely on milk. If you look at all the digestive systems in the abomasum and the small intestine, the enzymes are there to digest milk components and they struggle with anything that’s not milk, explains Drackley. “They have very little ability to deal with much starch. Milk is nature’s designed first food. Within a few days of age, we start to get increases in some of the enzyme systems that deal with other non-milk proteins and non-lactose carbohydrates. It’s a transition over the first two or three weeks to have the capacity to deal with non-milk ingredients.”
The whole system is meant to digest milk proteins and milk sugars, adds Sylvia Kehoe, professor of animal and food science at the University of Wisconsin-River Falls. “Milk replacers may have different sources of protein and different sources of carbohydrates, and that’s why some of them work better than others. The faster we can get calves weaned, the better they do. The mortality rate decreases by more than half when they’ve been weaned and the problems move from the intestinal area to the respiratory area. We want to get them digesting very well on a good-quality milk replacer.”
“A healthy gut is very important to the health of the animal,” says Whitlow. “The gut wall is a barrier between the animal and the environment. The speed and development of the gastrointestinal system is important in transitioning those calves from the milk-consumption period to feeding grain and hay.”
The milk that is fed has to provide for the maintenance of the body, respiration, digestion and many other functions.
“If you’re limit-feeding that calf before it’s getting its energy intake from grain, a pound per day, may not be enough, especially in cold weather,” Kehoe notes. “Then you get poor gain. The gastrointestinal tract is the fastest turning-over organ in the body, which means it needs extra nutrients. It’s trying to fight off the bacteria and it’s trying to absorb nutrients and maintain homeostasis. The more nutrition you provide at that point, the better the calf is going to do and the less the scours is going to affect it, and the better it’s going to recover from the challenge. If you don’t provide that nutrition, the gastrointestinal tract never fully recovers and you have an organ that’s not as efficient as it could be.”
“When calves are young, you feed the gastrointestinal tract,” Kehoe says. “They’ve shown many times that if that young animal gets sick, the gastrointestinal tract never recovers. If we can keep the animal from getting sick, there’s a huge amount of money we can save later on.”
The capabilities of the young intestinal tract are focused on milk, says Drackley. “We ought to be optimizing that ability of the calf. We ought to be feeding more milk or milk replacer than we have traditionally. Calves will grow much more rapidly and efficiently if we allow them to by providing more milk in the first weeks of life. We still can get them transitioned over to ruminants at an early age and go on from there.”
Drackley would prefer to see milk-based ingredients in the milk replacer. “We have to match the protein and energy supplies in the formulation of the milk replacer. If you want to feed for more rapid body development, you have to provide more protein, and those requirements have all been recently worked out in protein-to-energy relationships. At a pound of powder per day, a milk replacer with 20 percent protein and 20 percent fat is adequate, but if you want to go to a pound-and-a-half or 2 pounds per day of gain, then obviously we have to have more protein. So, we have to have appropriate milk-replacer formulation selected with the goals of the producer.”
Water availability is a huge limiting factor on too many farms, and winter is a special problem because of freezing. Water is highly coordinated with starter intake, so if you’re not providing water, that’s going to slow development. Those are factors beyond just feeding the calf.
Whitlow also emphasizes feed sanitation and hygiene, which is extremely important for the young calf.
Part of it has to do with mycotoxins. “The potential for mycotoxin contamination is probably the primary reason we don’t feed silage to calves,” Whitlow explains. “Calves are much more susceptible to the effects of mycotoxins than are cows. Cows are partially protected due to mycotoxin degradation in the rumen. Mycotoxins can reduce immunity and result in gut irritation and digestive upsets.”
Therefore, Whitlow says, it is important to ensure that clean grains are fed fresh daily to calves, that feed is not allowed to get wet, and that feeders are routinely cleaned. Hay or other forage should not be moldy. “If we don’t follow those hygiene and sanitation practices, we’re going to have problems and it doesn’t matter if these problems are classified as nutritional or health-related — we have the same poor results.”
Impacts the bottom-line
Optimizing young calf gut health impacts the farm’s bottom-line financial performance.
“How do you get producers to understand?” Kehoe asks. “To them, calf health is just an expense. They don’t see the future earnings, or if they do, they try to make this part as least expensive as possible. We’ve talked about the 50:50 costs of labor and feed, but if a calf gets sick, it’s not 50:50 anymore. You look at these farms that have problems and they’re spending 75 percent of their time in the calf area trying to maintain these calves so they just survive. They get them to survive and then they have these animals that are cripples as far as growth and production.”
Byron Housewright, of Nutrition Service Co. in Pulaski, Wis., and a consulting nutritionist in Texas, says producers need to look at the long-term success of the heifer calf.
“We need them to prioritize and make these calves as critical as the lactating herd. If we take care of these calves, they mean something to us two years from now when we’re trying to get an extra thousand pounds out of them. It means more than just saving $2.25 for that day. It could mean thousands of dollars from increasing our rolling herd average.”
Drackley agrees. “Today, it takes about $2,000 to raise a heifer, and we get hung up over spending $50 during the first six weeks of life. It makes no sense.”
The two areas that should make money and sustain the dairy are the dry cows and the calves, Housewright adds. “You have to take care of those two groups. Feed the calves, feed the dry cows. That’s where you find out whether that dairy’s going to make it.”
Geni Wren is editor of Bovine Veterinarian, a sister publication of Dairy Herd Management. This information was based off of a young calf nutrition roundtable sponsored by Alltech.