8 research outputs found
Forage selection preferences of experienced cows and naïve heifers grazing native tallgrass range during winter
Beef Cattle Research, 2011 is known as Cattlemen’s Day, 2011Estimating the nutritive value of a grazing animal’s diet is a significant challenge.
Description of the botanical composition of a grazed diet is vital in that regard. Microhistological
analysis of fecal material has been used for estimating the botanical composition
of wild and domestic ungulate diets since first described by Baumgartner and
Martin in 1939.
Little research has been conducted on the diet selection preferences of multiparous beef
cows compared to primiparous beef cows. We hypothesized that foraging strategies
change as cows age. To that end, our objective was to characterize differences in diet
selection between experienced multiparous and naïve primiparous beef cows grazing
dormant, native tallgrass pastures during winter
Spring burning of native tallgrass pastures influences diet composition of lactating and non-lactating beef cows
Diet selection is a dynamic process because of seasonal changes in animal and plant
characteristics. Nutrient requirements of grazing animals are a function of physiological
state; moreover, plant characteristics may be altered with prescribed spring burning of
native rangelands. Prescribed spring burning is used to improve the average quality of
pasture forage by removing old growth and making new plant growth more accessible to
grazing cattle.
Microhistological analysis of fecal material has been a widely used method for quantifying
the botanical composition of a grazing animal’s diet since it was first described by
Baumgartner and Martin in 1939. Little research has been conducted on how diet selection
preferences of lactating beef cows with suckling calves and non-lactating beef cows
are influenced by prescribed burning. We hypothesized that during the summer grazing
season, lactating cows with calves and non-lactating cows would display distinctive
preferences for certain species. Furthermore, we anticipated that these diet selection
preferences might be influenced by prescribed burning. To that end, our objective was
to characterize differences in diet selection between lactating beef cows suckling calves
and non-pregnant, non-lactating beef cows grazing either burned or unburned native
tallgrass prairie during summer
Effects of prepartum and postpartum bolus injections of trace minerals on performance of beef cows and calves grazing native range
Adequate dietary intakes of trace minerals are thought necessary to maximize cow
reproduction, calf health, and calf performance. Diets grazed by beef cattle are generally
deficient to marginal in copper (Cu), manganese (Mn), selenium (Se), and zinc (Zn)
concentrations; therefore, these trace minerals are usually added to the diet in supplement
form.
The most widely used means of trace-mineral supplementation for grazing cattle is selffed,
salt-based, loose mineral supplements. Although cattle do not balance their mineral
needs when consuming a self-fed mineral supplement, usually no other practical way
of supplying mineral needs exists under grazing conditions. The greatest limitation to
using self-fed mineral supplements is variation in animal intake. More direct methods
of mineral supplementation include adding minerals to drinking water or feed, oral
drenching, ruminal boluses, and injection. Variation in mineral intake is reduced relative
to self-fed supplementation, and the additional labor requirement and expense are
relatively small.
Delivery of supplemental trace minerals using an injectable solution may be a more
reliable means of achieving adequate trace-mineral status than using self-fed, salt-based,
loose mineral supplements. Bolus injections of trace minerals have been associated with
improved average daily gain, feed efficiency, feed intake, or health status of beef calves
fed in confinement; however, trace mineral delivery methods of this type have not been
fully evaluated with respect to performance of beef cows and suckling calves. The objective
of our study was to evaluate the effects of pre- and postpartum bolus injections of a
trace mineral solution on beef cow reproductive performance, body weight change, and
body condition score change, as well as performance of suckling calves