*Dr. R.M. Thornsberry is a veterinarian with Mid America Veterinary Consulting in Richland, Mo. Dave Wood is director of sales and technical support for Animix.
BABY calf raisers should weigh the potential benefits and disadvantages of feeding milk via a bottle and nipple (or nipple bucket) or an open-top bucket or pail.
Calves are inclined by nature to suckle a nipple, and suckling is mentally satisfying to calves of all ages. Many calves will actively seek something to suckle after consuming their milk or milk replacer meal from a bucket or open pail in order to satisfy this desire to suckle. Unfortunately, for calves housed together, this suckling desire will be exercised on a penmate's udder, ear or navel, with clinically recognized negative consequences.
Calves can continue to suckle a nipple on an empty nipple bucket or nipple bottle, which seems to satisfy their suckling desire. This cross-suckling issue is why many veterinarians advise their clients to house milk or milk replacer-fed calves separately.
Bottles and nipples are typically better sanitized than buckets, and calves usually must be trained to drink out of a bucket but will readily nurse from a nipple.
Calves have incisors only on the lower jaw, but these teeth are very sharp. Part of the suckling mechanism involves the calf extending its tongue forward over these sharp teeth and forming a semicircle with the surface of the tongue, forcing the nipple between the tongue and the hard palette. This allows for a suckling action that forces milk or milk replacer out of the nipple through a combination of squeezing the nipple between the tongue and hard palette and sucking the milk or milk replacer out of the nipple onto the distal surface of the tongue, where the liquid is swallowed into the esophagus.
The esophagus, through muscular action, moves the liquid bolus down in stages of muscle contractions into the rumen or the esophageal groove.
Drinking from a bucket accomplishes the same general action, but suckling is not part of the muscular and physiological process. The calf must learn to force milk or milk replacer through the mouth into the oral cavity and then into the esophagus. In essence, the calf learns to use the oral cavity like a big straw.
This is a learned process that some calves will not master until they're several days old. For this reason, some calf raisers feed calves on a bottle and nipple for several days after birth and then spend time training calves to drink out of a bucket. Training some calves to drink milk or milk replacer out of an open bucket can be challenging, and some will refuse the training.
Growers rearing special milk-fed veal calves prefer starting calves directly on buckets. Individual feedings reach 11 lb. or more (5.25 quarts per feeding) of fluid milk replacer by 42 days and can exceed 18 lb. (8.6 quarts per feeding) by 20-22 weeks, when the calves are marketed.
Obviously, bottles and nipples are impractical in this setting, and experienced veal growers report that once a calf is started on a nipple, it can be challenging to convert it to a bucket.
Dairy replacement heifer and beef calf growers should acknowledge these veal grower findings: If bucket feeding, it is advisable to acclimate calves to the bucket early in the milk or milk replacer feeding period.
There is much debate about which method of feeding is best for the calf. This debate is not new. In the 1950s, data from two scientific studies were published: one that said feeding calves with a bottle and nipple demonstrated superior performance (Alexander, 1954), and another that said feeding calves out of a bucket was superior to using bottles and nipples (Kesler et al., 1956).
In 1968, a scientific paper published in one of the same journals presented data that nipple-fed calves performed better than bucket-fed calves (Wise and Lamaster, 1968).
Research facilities and university dairy science departments have published many papers on this topic -- some supportive of bucket feeding, and others clearly advocating that bottle- and nipple-fed calves exhibited superior performance. These studies are too numerous to reference as the data go all the way back to the early 1900s.
One consideration for choosing one method of feeding calves over another is the effect of the feeding method on the closure of the esophageal groove. The esophageal groove is a muscular tube connecting the opening of the esophagus to the opening of the omasum, allowing swallowed fluids to bypass the reticulum and rumen. The reticulo-rumen cavity in the newborn calf is small, about 500 mL (approximately one pint) in volume, but this is the stomach compartment where fermentation takes place (Lateur-Rowet and Breukink, 1983).
Milk or milk replacer that enters the rumen undergoes fermentation, producing gas and potentially causing bloat. Since the esophageal groove does not close properly when an esophageal tube feeder is utilized, veterinarians do not recommend force-feeding milk or milk replacer utilizing an esophageal tube feeder (Lateur-Rowet and Breukink, 1983).
Research conducted in 1939 determined that calves suckling from a nipple have almost complete closure of the esophageal groove, preventing milk or milk replacer from entering the reticulo-rumen compartments. Forty percent of calves drinking milk or milk replacer from an open pail did not have good closure of the esophageal groove, with spillage of up to 50% of the milk or milk replacer into the reticulo-rumen compartments (Wise and Anderson, 1939).
It has been determined that the position of the neck while suckling does not negatively affect the closure of the esophageal groove (Wise et al., 1942); however, the position of the head and neck while suckling does affect the potential for milk or milk replacer to accidentally enter the trachea. When the nose is elevated above the eyes, the epiglottis moves forward by reflex action and opens the trachea to potential contamination by milk or milk replacer that is swallowed in too large of volumes or, in the excitement of feeding, too quickly.
If calves are fed by bottle and nipple or nipple bucket, it is imperative that the nipple be placed low enough in the pen for the calf to suckle with its head in a normal-level position. This helps prevent fluid milk or milk replacer from inadvertently entering the lungs.
The speed and volume at which milk or milk replacer is suckled and swallowed has been studied. It has been determined that calves suckling from a cow's nipple will consume milk at about one pint per minute, taking four minutes to consume two quarts, while calves drinking milk or milk replacer from an open pail drink four to five times faster, consuming two quarts in fewer than 40 seconds to one minute (Abe et al., 1978). This factor alone may explain why large commercial calf raisers prefer to feed calves with a bottle and nipple. They often report an increased incidence of respiratory disease in open pail-fed calves.
Calves excited about their milk or milk replacer feeding may consume their meal too quickly, allowing some fluids to slip into the trachea, where the milk acts as a foreign body in the respiratory system. This same observation -- calves hacking and coughing following feeding -- occurs when bottle and nipples are set too high, allowing the epiglottis to come forward and opening up the trachea to milk or milk replacer contamination.
Nipple size, nipple resilience and the opening in the end of the nipple are all considerations for the proper feeding of calves with a bottle and nipple or nipple bucket. If the opening is too large, the fluid will flow too fast, potentially setting up the calf for tracheal contamination. If the orifice in the nipple is too small, the young calf may exhaust itself before the proper amount of nutrition is suckled. If the nipple has lost its resilience and collapses upon itself while the calf is suckling, the same scenario may result.
Consult with the nipple and bottle manufacturer for proper nipple and orifice size, paying particular attention to the nipples utilized for calves younger than two weeks of age.
Research has also been performed to determine if any differences exist in digestive physiology between open pail-fed and nipple-fed calves.
Two studies found that calves fed out of open pails passed fluids through the abomasum and on into the intestinal tract at a faster rate, resulting in increased amounts of pancreatic enzyme production (Abe et al., 1978; Ternouth and Roy, 1978).
Another study discovered that nipple-fed calves had a three-fold increase in saliva production, resulting in more salivary lipase (a fat-digesting enzyme) being swallowed with the milk or milk replacer meal (Wise et al., 1975).
Wise and LeMaster (1967) reported that nipple-fed calves exhibited greater enzymatic activity in abomasal fluids with greater protease (a protein-digesting enzyme) production, while Ternouth and Roy (1978) demonstrated that nipple-fed calves had a lower abomasal pH and more abomasal acid secretion.
While two studies found that calves fed from an open pail had a greater incidence of diarrhea (Wise and Lamaster, 1968; Roy, 1990), another study found no difference in the number of calves with diarrhea but did determine that calves fed out of an open pail had a three-fold increase in the duration of diarrhea (Rajala and Castren, 1995).
For these many reasons, it appears that feeding calves from an open pail is a matter of convenience.
Bottles and nipples usually get a proper cleaning, and only the nipple makes contact with the calf. Pails are often simply rinsed out and utilized as water containers after the milk or milk replacer is fed.
Calves scrape their sharp lower incisor teeth over the bottom and sides of a plastic pail, making scratches and grooves in the surface of the pail and creating an ideal location for bacteria and fungi to conceal themselves from cursory cleaning.
Conversely, bottles are usually cleaned out by the use of a large, bristled brush. This brush should be made entirely of plastic material and should not have a metal or sharp spring upon which the bristles are wound. A sharp metal center spring will scratch and groove the inside of the bottle, producing the same issues as with scratched and grooved pails.
Many experienced, practicing food animal veterinarians will recommend bottles and nipples to their clients raising baby calves. Use of bottles will result in feeding consistent volumes of milk or milk replacer. Often, pails are simply filled to varying heights at each feeding, resulting in inconsistent volumes being fed.
Most veal growers take special care to ensure that fluid milk replacer is presented in buckets in near-precise quantities, thus minimizing variation between meals. They also increase milk feeding only as an individual calf can take the extra nutrition without too much excessive or increased stress.
When heifer calf growers attempt to mimic the veal grower strategy of bucket feeding and increasing milk feeding volumes over time during utilization of an accelerated heifer development program, they may miss these important points.
Veal growers often attach a stick with graduated scales to the end of their feed hose to make sure the bucket is filled to the desired level. Equally important, knowledgeable calf growers respond when an individual calf leaves any portion of its meal or shows discomfort in consuming increased quantities of milk.
This point is particularly important when implementing accelerated nutrition programs in rearing replacement heifer calves.
Anyone can fill a bucket with milk and present it to a calf, but what differentiates a knowledgeable calf grower is the ability to appropriately perform this task with each individual calf at every feeding. Feeding with bottles and nipples is much more "forgiving" as a management strategy compared to utilizing buckets to feed calves, and this fact is a "bottom line" consideration in weighing both options.
It is also important to emphasize nipple sanitization between each feeding. An emulsifier, such as dishwashing liquid, should be utilized to cut and destroy any biofilm accumulated on the surface of bottles, nipples, buckets and pails. Fat in milk and milk replacer is responsible for the formation of these biofilms. Cleaning should be sufficient to remove any trace of biofilm or fatty residue.
Once cleaned, sanitize the bottle, nipple, bucket or pail with a strong disinfectant, such as a mix of liquid bleach and hot water blended in a ratio of 0.5 fluid ounce of bleach to 23 fluid ounces of hot water. Turn the equipment upside-down, and allow it to air dry between feedings.
Calves can be successfully fed and raised utilizing a nipple and bottle, nipple buckets and open pails. Sanitation, ease of cleaning and an established cleaning routine are necessary protocols for any calf raiser.
A final consideration: Feeding calves from a nipple approximates normal feeding behavior for the baby calf.
French veal calf research comparing calves fed milk from an open bucket versus through a nipple attached to a bucket found that bucket-fed calves had significantly higher heart rates during the meal and exhibited more non-nutritive oral activities such as bar sucking, licking their neighbor and cross-sucking in group settings compared to calves fed using a nipple and bottle (Veissier et al., 2002).
Interestingly, although these researchers found that bucket-fed calves fed in groups spent more time nibbling at one month of age, they also spent significantly less time nibbling or cross-sucking at three months of age than calves fed via a nipple. No differences in stress parameters were identified -- the weight of the thymus and the adrenals did not differ between bucket-fed and nipple-fed calves -- and no improvement in growth was observed with either feeding method.
In summary, when utilizing a bottle and nipple, a nipple bucket or an open-top pail or bucket, make sure the calf feeding staff is trained to consistently feed targeted quantities of milk or milk replacer. Make feeding changes gradually, and closely observe how individual calves respond to the changes. Make sure the feeding system utilized allows for proper equipment cleaning and sanitation between feedings.
Make sure the nipple is presented to the calf below the level of its eyes to avoid inadvertent spillage of liquid into the trachea, thus potentially increasing the risk for calves developing aspiration pneumonia.
Abe, M., T. Iriki, K. Kondoh and H. Shibui. 1978. Effects of nipple or bucket feeding of milk substitute on rumen by-pass and on rate of passage in calves. Br. J. Nutr. 41:173.
Alexander, G.I. 1954. Rearing dairy calves. Australian Veterinary Journal 30:68.
Kesler, E.M., R.D. McCarthy and C.B. Knodt. 1956. Nipple vs. pail feeding of milk to Holstein calves. J. Dairy Sci. 39:542.
Lateur-Rowet, H.J.M., and H.J. Breukink. 1983. The failure of the esophageal groove reflex when fluids are given with an esophageal feeder to newborn calves. Veterinary Quarterly 5:68-74.
Rajala, P., and H. Castren. 1995. Serum immunoglobulin concentrations and health of dairy calves in two management systems from birth to 12 weeks of age. J. Dairy Sci. 78:2737.
Roy, J.H.B. 1990. Predisposing factors in calf diarrhea. Chapter 3 in The Calf, 5th edition. Buttersworths, Boston, Mass.
Ternouth, J.H., and J.H.B. Roy. 1978. Concurrent studies of the flow of digesta in the duodenum and of exocrine pancreatic secretion in calves. 6. The effect of feeding warm or cold milk by bucket or teat. Br. J. Nutr. 40:553.
Wise, G.H., and G.W. Anderson. 1939. Factors affecting the passage of liquids into the rumen of the dairy calf. I. Method of administering liquids: Drinking from open pail versus sucking through a rubber nipple. J. Dairy Sci. 22:697.
Wise, G.H., and J.P. Lamaster. 1968. Responses of calves to open pail and nipple pail systems of milk feeding. J. Dairy Sci. 51:452.
Wise, G.H., and J.P. LeMaster. 1967. Responses of calves to open-pail and nipple-pail systems of milk feeding. J. Dairy Sci. 51:452.
Wise, G.H., G.W. Anderson and P.G. Miller. 1942. Factors affecting the passage of liquids into the rumen of the dairy calf. II. Elevation of the head as milk is consumed. J. Dairy Sci. 25:529.
Wise, G.H., P.G. Miller and G.W. Anderson. 1975. Changes in milk products sham fed to calves. IV. Suckling from a nurse cow versus consuming from either a nipple feeder or an open pail. J. Dairy Sci. 59:97-103.
Veissier, I., A.M. de Passille, G. Despres, G. Rushen, I. Charpentier, A.R. Ramirez de la Fe and P. Pradel. 2002. Does nutritive and non-nutritive sucking reduce other oral behaviors and stimulate rest in calves. J. Anim. Sci. 80:2574-2587.