Management
It is Time to Begin the Early Evening Feeding
By Glenn Selk, Oklahoma State University
It is generally accepted that adequate
supervision at calving has a significant
impact on reducing calf mortality.
Adequate supervision has been
of increasing importance with the
higher price of live calves at sale
time. On most ranching operations,
supervision of the first calf heifers
will be best accomplished in daylight
hours and the poorest observation
takes place in the middle of the night.
The easiest and most practical method
of inhibiting nighttime calving at
present is by feeding cows at night; the
physiological mechanism is unknown,
but some hormonal effect may be
involved. Rumen motility studies
indicate the frequency of rumen
contractions falls a few hours before
parturition. Intraruminal pressure begins
to fall in the last 2 weeks of gestation,
with a more rapid decline during
calving. It has been suggested that night
feeding causes intraruminal pressures to
rise at night and decline in the daytime.
The concept is called the Konefal
method. A Canadian rancher, Gus
Konefal reported his observations in
the 1970’s. In a follow-up Canadian
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study of 104 Hereford cows, 38.4% of
a group fed at 8:00 am and again at
3:00 pm delivered calves during the
day, whereas 79.6% of a group fed
at 11:00 am and 9:00 pm. In a more
convincing study, 1331 cows on 15
farms in Iowa were fed once daily at
dusk, 85% of the calves were born
between 6:00 am and 6:00 pm.
Kansas State University scientists
recorded data on 5 consecutive years
in a herd of spring calving crossbred
cows at the Kansas State University
Agricultural Research Center at Hays,
Kansas. They recorded the time of
calving (to within the nearest one-
half hour). Births that could not be
estimated within an hour of occurrence
were excluded. Cows were fed forage
sorghum hay daily between 4:00 and
6:00 pm. For statistical purposes, the
day was divided into four-hour periods.
• Between 6:00 and 10:00 am,
34.23% of the calves were born;
• Between 10:00 am and 2:00 pm,
21.23% of the calves were born;
• Between 2:00 and 6:00 pm
29.83% of the calves were born;
• Between 6:00 and 10:00 pm,
8.41% of the calves were born;
• Between 10:00 pm and 2:00 am,
4.4% of the calves were born; and
• Between 2:00 am and 6 am,
1.91% of the calves were born.
It is interesting to note that 85.28% of
the calves were born between 6:00 am.
and 6:00 pm. This is very similar to Iowa
data when cows were fed at dusk.
This data also revealed that for a
majority of animals in the herd, the
time of calving was within 3 hours
of the average time of day that cow
had previously given birth. Feeding
the forage in the early evening
hours undoubtedly influenced the
percentage of cows calving in daylight
hours. (Jaeger and co-workers.
Abstracts 2002 Western Section of
American Society of Animal Science.)
Many cow/calf producers put large
round bales in ring feeders and leave
them out for round-the-clock feeding
for the cows. Records here at Oklahoma
State University indicated that when
cows had constant access to large
round bales but were fed supplements
at about 5:00 pm, 70% of the calves
were delivered between 6:00 am and
6:00 pm. Some producers choose to
put the big round bales and the ring
feeders inside a fenced enclosure. The
gates to the hay feeding enclosure
are opened at dusk and the cows are
allowed access to the hay in the evening
and overnight hours, then they are
moved to another adjacent pasture the
following morning. Anecdotal reports
have indicated that this method has the
desired results with a higher percentage
of calves born in the daylight. I