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Influence of Supplementing Cobalt in the Receiving Ration on
Performance of Heifers New to the Feedlot Environment
T. J. Wistuba, E. B. Kegley, D. L. Galloway, J. A. Hornsby, and S. M. Williamson 1
Story in Brief
The influence of dietary cobalt concentration on performance of growing heifers was studied using 86 crossbred
heifers (465.2 ± 36.4 lb) in a 42-d receiving trial. Treatments consisted of a control diet that had a calculated cobalt concentration
of 0.1 ppm or the control diet with an additional 0.1 ppm supplemental cobalt/kg of DM from cobalt carbonate.
Heifers were weighed on d 0, 7, 14, 28, and 42 and were observed daily for signs of clinical disease. For the
entire 42-d study ADG (2.36 vs. 2.25, lb/d), ADFI (13.7 vs. 13.6 lb as fed), and feed/gain (5.80 vs. 6.04) did not differ
(P > 0.10) for the control heifers vs. the heifers supplemented with cobalt, respectively. Supplemental cobalt tended to
increase ADG (P = 0.07) and decrease feed/gain (P = 0.06) from d 8 to 14. However, from d 15 to 28 control calves
tended to have increased ADG (P = 0.09) and decreased feed/gain (P = 0.07). Percentage morbidity was not affected (P
> 0.10) by supplemental cobalt (65%) vs. control (76%), and neither were medication costs, $12.37 for cobalt supplemented
calves vs. $12.57 for controls. Supplementing cobalt did not improve growth performance or lower medication
costs for stressed heifers in the present study.
Introduction
The cobalt requirement for cattle is very low (0.1 ppm),
but it is a crucial element for the formation of vitamin B12 by
microorganisms in the rumen. Vitamin B12 requiring
enzymes synthesize one-carbon units, making it very important
in the metabolism of nucleic acids, proteins, carbohydrates
and lipids. Furthermore, recent research has indicated
that the immune response is depressed in cobalt deficient cattle
suggesting that cobalt deficient animals have an increased
vulnerability to disease and parasites. The objective of this
study was to determine the effect of cobalt supplementation,
an essential trace mineral, on feed intake, growth, feed conversion,
morbidity, and medication costs of receiving cattle.
Materials and Methods
Eighty-six crossbred heifers weighing 465.2 ± 36.4 lb
were purchased at sale barns and delivered to the Beef Cattle
Research Facility in Savoy. Upon arrival, calves were branded
with an electric iron, any horns were tipped, and calves
were dewormed (Ivomec, Merial Limited, Iselin, NJ) and ear
tagged. Calves were vaccinated against bovine respiratory
syncytial virus, infectious bovine rhinotracheitus virus,
bovine viral diahrrea, and parainfluenza –3 (BRSV – Vac 4,
Bayer Corp., Shawnee Mission, KS). All calves were given a
vaccine containing Pasteurella haemolytica, Pasteurella multocida,
Haemophilus somnus, and Salmonella typhimurium
(Poly-Bac-HS, Texas Veterinary Labs, San Angelo, TX) and
a clostridial toxoid injection (Vision 7, Bayer Corp.). Calves
were weighed upon arrival, blocked by weight (eight blocks),
stratified by horn tipping and randomly assigned to pens (two
pens per block, six heifers per pen in six pens and five heifers
per pen in ten pens). Pens within a block were randomly
assigned to a treatment. Heifers were kept in 12 ft X 98 ft dry
lots and had ad libitum access to feed and water.
The dietary treatments included either a control diet or
the control diet supplemented with 0.1 ppm of cobalt (Table
1). The diets were formulated to meet or exceed NRC (1996)
recommendations. Calves were offered a small amount of
long hay in addition to the dietary treatments for the first 5 d
of the study. Throughout the experiment, each feedbunk was
examined visually at 0800 h daily. The quantity of feed
remaining in each bunk was determined and a decision was
made on the amount of feed to be offered. The objective was
to allow for a minimal accumulation of unconsumed feed (<
15 lb). Feed was offered once daily at approximately 0800 h.
Daily feed offered and any refusals were recorded.
Heifers were fed their respective diets for 42 d. Heifers
were weighed on d 0, 7, 14, 28, and 42 and were observed
daily for signs of clinical disease. Any calves that were
observed to be depressed were pulled and rectal temperature
was measured. Consecutive weights were taken on d 0 and 42
to start and finish the trial. Calves with a rectal temperature
greater than 104°F were treated with antibiotics according to
a preplanned treatment protocol. On d 42 of the study all
calves were sampled via jugular venipuncture to determine
plasma vitamin B 12 concentrations.
Weights, ADG, ADFI, feed/gain, medication costs,
1 All authors are associated with the Department of Animal Science, Fayetteville.
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