How long does a cow's pregnancy last?
Gestation length does vary by breed and by sex of the calf. Gestation length ranges from 279 to 287 days. For most breeds, 283 days would be common. Cows carrying bull calves tend to have a slightly longer gestation compared to cows carrying heifer calves.
How long after a cow gives birth can she get pregnant again?
It depends on a number of things:
- body condition at calving,
- age of dam,
- if there was any calving difficulty during the calving process, and
- if diet is adequate after calving during lactation so that weight and body condition losses do not occur or are minimal.
Cows that calve in a body condition of less than 4 (scale 1 to 9) have a longer post-partum interval.
First-calf cows have a longer post-partum interval than do mature cows.
Cows that have calving difficulty have longer post-partum intervals.
And, cows that lose weight and body condition after calving have longer post-partum intervals.
I have some forage that is a summer annual and I tested it for nitrates. It tested on the high side of acceptable level of nitrates to be fed to pregnant beef cows. Do you have any suggestions for feeding this forage?
NOTE: Please see the October 6, 2015 update for more details and links to additional resources.
There needs to be some caution when feeding this forage to pregnant beef cows. If the forage is high in nitrites, then it needs to be mixed with a forage that is much lower in nitrates or a forage that does not contain any nitrates. Using other forages, the nitrates can be dilute to safe levels and fed.
The easiest way to dilute the forage that has the nitrates is to grind and mix with the other forages. Keys to feeding a forage that contains nitrates: Dilute the forage that has nitrates to a safe level. Adapt cattle slowly to a forage that contains the high nitrates. Never allow cattle that are hungry access to forages that contain high nitrates.
What info is available on pine needles abortions in bred cows?
Pine needles consumed by cows during late pregnancy can cause abortion, or premature calving. Producers need to be aware that few options exist to decrease the risk of pine-needle-induced abortion other the physically isolating cows from exposure during late pregnancy. Exposure to any source of pine needles, whether they are fresh, dry, weathered, on the ground, on standing trees, or on fallen trees during late pregnancy should be avoided.
The culprit is isocupressic acid, a yellow, oily substance in pine needles. Identification of the culprit is the first step in developing an antidote. As far as I am aware, the antidote is not yet available. (Answer from 2008)
Can pregnant cows be vaccinated for BVD or can the vaccine be given only prior to breeding?
Pregnant cows can be vaccinated against bovine viral diarrhea virus (BVDV) using killed-virus (KV) vaccines. Modified-live virus (MLV) vaccines should be given when the cow is not pregnant — ideally 30-60 days prior to breeding. Some BVDV MLV products state on the label that they can be safely administered to pregnant cattle if the cattle had also received the vaccine prior to breeding.
Although some cattle producers prefer to vaccinate during fall work for convenience; it makes the most sense from a BVDV control standpoint to vaccinate prior to breeding so that cattle have the best protection during early pregnancy.
Looking for information on the first cycle after a cow has calf. Want to move the calving earlier in the year. Best ways to accomplish?
Not an easy task to accomplish. Usually the length of the post-partum interval (PPI, time from calving to the first estrous cycle) is 45 to 55 days in beef cows. If cows are in good body condition at calving, then the PPI would be in the 45 to 50 day range and if in poor condition, the PPI would be longer. First-calf heifers have a longer PPI compared to mature cows, about 10 days longer if she has no calving difficulty and is in good body condition. If cows are exposed to bulls (bull exposure) after calving, then the PPI is usually shorter by may be as much as 10 days shorter.
It has been documented in beef cows that uterine involution is not completed by 20 days post-calving, but the uterus is back to its non-pregnant size by 30 days post-calving. Another 10 or so days is needed to complete uterine involution and be prepared for another pregnancy. I don't think many cows will come into heat (estrus) before 35 day post calving.
You can "jump start" estrous cycles with progestins and gonadotropins (GnRH), but this will only happen in females that are close to begin cycling. There are synchronization programs for cows that use CIDR (progesterone) and GnRH (Cystorelin, Factrel, Fertagyl, OvaCyst). Use of these programs has the potential to induce estrous cycles in cows that are close to cycling.
So, nutrition is very important, have cows in at least body condition score 5 at calving and don't skimp on the groceries after calving. Ionophores such as Rumensin or Bovetec have a positive impact on the reproductive axis, at least there are experiments using the heifer that demonstrate this, so consider using an ionophore in the ration after calving. Expose cows to sterile bulls as soon after calving as possible. Jump-start the reproductive axis using a progestin and/or GnRH. These considerations are all for not if the cows have not been managed properly from a nutritional perspective.
ARTICLES SOURCES : https://beef.unl.edu/faq/pregnant-cows