r -3 FLORIDA AGRICULTURAL EXPERIMENT STATION
Dairy Science Mimeo Report DY65-3
June 14, 1965
WEANING DAIRY CALVES
J. M. Wing
Calves like milk and they will consume enough to support their growth
over relatively long periods. A change to solid feed, however, is
necessary for proper development of the digestive system. At the Florida
Agricultural Experiment Station dairy steers were raised to 11 months
of age on milk which was fortified with minerals and vitamins. They
appeared to be normal but their stomachs were underdeveloped. The sooner
calves can be induced to consume solid feed, particularly roughage, the
sooner the digestive tract will mature, and the sooner the probability
of digestive upsets will be decreased.
Other research at the University of Florida showed that when solid feeds
were available in addition to milk, calves consumed enough for their
stomachs to be functional at 3 weeks of age. Some became functional
earlier but in different studies there has been considerable variation
and thus 3 weeks should be considered the minimum possible age for
Will it work
Early weaning of dairy calves has been investigated frequently with
varying degrees of success. Four weeks is the earliest weaning age that
has been recommended. Even then dairymen are cautioned because some
calves will require longer periods of milk feeding and rather complex,
especially palatable solid feeds are considered to be necessary.
Much stomach development in calves occurs as the result of consuming
leafy feeds. It is necessary to mix the leafy roughage and concentrates
together in order to induce calves to eat enough. This can be as much
as two parts good quality alfalfa hay or equivalent, to one part of
concentrates. At the Florida Agricultural Experiment Station the best
results were obtained with approximately one-third dairy cut alfalfa hay
mixed with two-thirds concentrates. The concentrates were very simple
and since palatability could be a factor and young calves show a particular
liking for dried bakery product, one of the rations investigated recently
included this ingredient as shown in Table 1.
Experimental milks. If milk is fed at levels much higher than 10% of
the calf's body weight in two feedings daily, digestive disturbances
often occur. An obvious way to increase the intake from milk or milk
replacement formulas would be to use high-solids mixtures. This often-
has not been satisfactory, however, because concentrating the mixture
usually upsets the calf's digestion. A mixture containing 13% of solids
appears to be the maximum safe strength.
Table 1. Solid feed mixtures
Ration A Ration B
Corn 300 Corn 500
Dried brewers grain 100 Dried brewers grain 100
Dried bakery product 300 Citrus pulp 100
Hay (dairy cut) 400 Hay (dairy cut) 400
Cottonseed meal 400 Cottonseed meal 400
Salt 15 Salt 15
Defluorinated phosphate 30 Defluorinated phosphate 30
Trace minerals1- 7 Trace mineralsi- 7
1. Common salt, 100 lb; red oxide of iron, 25 lb; pulverized copper
sulfate, 1 Ib; cobalt sulfate, 1 oz.
It is interesting to note, however, that colostrum (the first milk
produced after calving) is as high as 27% in solids. Yet young calves
consume this milk without undue trouble although it is laxative. Research
has shown that colostrum diluted either with milk or water is safe for
calves of any age.
Various experiments at the Florida Agricultural Experiment Station have
shown that high solids remade milk formulas containing approximately
one-half colostrum are satisfactory. They do not cause scours or other
digestive problems no matter how concentrated they are. For most calves,
however, the use of such milks is not satisfactory because twice daily
feeding at the usual rate of 10% of body weight results in consumption
of too little solid feed. Thus the purpose of the dairyman is defeated
unless he is producing veal.
The objective of the experiment reported here was to determine whether
once-daily feeding of high-solids skimmilk and colostrum would keep
calves healthy and promote the tendency to consume solid feeds.
What we did
Six calves in each of three groups were offered one or the other of the
solid feed mixtures from birth. The control calves, Group 1, received
10% of body weight daily in two feedings of one-half colostrum and one-
half remade skimmilk (13% solids) 5 through 21 days, and skimmilk through
60 days of age. The experimental milk used for the early weaned calves
consisted of one-half colostrAm and one-half reconstituted skimmilk
containing 20% of solids.
This was ordinary, animal grade skimmilk powder without antibiotics or
other additives. It was chosen because of its plain nature, since more
complex commercial calf starters which are fortified with various
medicaments should be safe when used in a system which is satisfactory
with ordinary skimmilk.
The experimental schedule for milk feeding was as,follows: Group 2 was
fed the mixture of colostrum and high solids skimmilk twice daily for
one week at the rate of 10% of body weight, then once daily through 21
days of age at the rate of 5% of body weight. At this time all the calves
were weaned abruptly. Group 3 was fed the mixture of colostrum and high
solids skimmilk twice daily at the rate of 10% body weight for two weeks
and then once daily (5% of body weight) through 21 days of age. At this
time calves in this group also were weaned abruptly. Criteria included
the number of days required to consume four pounds of solid feed daily,
efficiency of feed utilization, changes in body weight, and general health.
What we found
The control group required an average of 60.8 days to consume the four
pounds of solid feed daily. This figure was the same whether dried
bakery product was included or not. The calves in group 2 which received
twice daily milk feedings through only 7 days consumed four pounds of
solid feed daily at an average age of 35 days. Those that were fed twice
daily through 14 days (group 3) required 50.3 days. A statistical
analysis showed the early weaned groups to be significantly different
from the control at a level of 1%.
Table 2. Mean calf performance
Rate of daily gain Feed efficiency. Daysb.
1 1.089 1.793 60.8
2 0.735 2.593 35.0
3 0.622 3.157 50.3
A 0.886 2.254 48.7
B 0.744 2.774 48.8
H 0.970 2.057 48.7
G 0.886 2.320 43.3
J 0.589 3.167 54.2
a. Pounds gained/megacalories ENE
Days required to reach 4 lbs daily solid feed consumption
The daily gains were calculated as linear regression coefficients in
order to eliminate errors due to nature of early growth. Calculated in
this way, the daily gains were: Group 1 (control), 1.089 pounds; Group 2
(fed twice daily for only one week), 0.735 pounds; and Group 3, which
was fed twice daily through 2 weeks of age, 0.622 pounds. Groups 2 and 3
differed significantly from the control group but not from each other.
This should have been expected.
The efficiencies of feed utilization were calculated as the mean gains
divided by the megacalories of estimated net energy consumed. These
ratios by groups were: 1 1.793; 2 2.593; 3 3.157. Here again
Groups 2 and 3 were not significantly different from each other but were
different from Group 1 at the level of 1%.
Table 3. Analysis of variance of calf performance
Source d.f. Mean squares
Rate of gain Feed efficiency Daysa.
1 vs 2, 3 1 0.674** 4.680* 1320**
2 vs 3 1 0.038 0.952 705**
Ration 1 0.091 1.220 0
Breed 2 0.241* 2.018 176
Pooled interactions 11 0.044 0.555 53
a. Days required to reach 4 lbs daily solid feed consumption
** P < 0.01
* P < 0.05
More information. One very good rule for weaning calves is to reduce the
milk allowance gradually and to stop feeding milk entirely when the calf
is eating as much as a pound of solid feed per day. The best way to do
this appears to be to increase the solids content of the milk or milk
replacement formula and to limit the number of times it is fed. Early
weaning is advantageous because less expensive barn space is required,
less labor is needed, digestive upsets are not as likely to occur with
calves on solid feed, all the whole milk produced can be sold, and
automated systems for handling calves in groups is closer to reality.
Calves probably always will need some type of milk formula. It gives
them an easily digestible feed which does not irritate the digestive
system if it's fed carefully and it furnishes a nearly complete diet for
the young animal. It provides most of the required vitamins, high quality
protein and necessary minerals. Very young calves must have milk in
order to keep their nutrient intake normal. Thus either whole milk, a
mixture of colostrum and other milks, or well fortified milk replacement
formulas are necessary for a short period.
Because of individual variation no definite weaning age can be recommended
although under conditions of this experiment three weeks was satisfactory.
This experiment shows that it is practical to use high solids milk and
colostrum and to reduce the milk feeding to once daily at an early age.
This definitely will cause greater consumption of solid feeds which
suggests that early weaning is feasible.