Reproductive failure or infertility in dairy cattle is a common problem that many farmers have to deal with.
Some have quit the venture because their cows cannot come on heat; if they do, they do not conceive; if they conceive they do not carry the pregnancy to term and if they calve the offspring do not survive.
This is frustrating because if a cow does not calve, she will not produce milk, and as such, the farmer will not make money. Without calves there is no replacement stock and the herd has no future.
So, what is the cause? There are infectious and non-infectious causes of infertility. The problem might be the farmer, the inseminator or the cow. Unfortunately, more often than not, the cow is wrongly blamed.
Analysis of herd records reveal that low reproductive efficiency is mostly due to poor nutrition, poor estrus (heat) detection, poor insemination techniques and conception failure. These factors cause inefficiency either individually or in concert. The challenge is to identify them and institute management changes for improvement. Evaluation of the key stakeholders is an effective approach in identifying the causes
Poor animal management, especially in terms of nutrition and housing, impacts a lot on reproductive efficiency. Animals that have inadequate food and those fed on unbalanced, deficient feeds will either not cycle or, if they do, they will have silent heats (heat that shows no signs).
Equally, over-conditioned animals have similar challenges. Animals housed individually and on uneven, slippery floors do not manifest some classical signs of heat.
A farmer must be able to detect heat appropriately. This requires close monitoring of the animals. A cow on heat shows primary and secondary signs. Standing-to-be-mounted is the classical and primary sign that is the most reliable.
Animals should be socialized and observed at intervals of 20 to 30 minutes. Secondary signs such as restlessness, vaginal discharge, mounting other cows, dirty flanks, decreased feed intake and milk yield are unspecific and should be used as clue to watch the cow more closely to observe the standing-to be- mounted behavior.
Always call your inseminator immediately you see the first standing-to-be-mounted sign.
The animal should be inseminated 10 to 14 hours after this. A cow that comes on heat early in the morning should be inseminated late in the evening, while those that come on heat in the evening should be inseminated in the morning (AM/PM rule).
Some animals are, at times, re productively problematic. A cow in good body condition may not conceive because of
some anatomic disorder, for example, blocked oviducts. Some breeds are also difficult to reproduce than others. Infections
are a major cause here. Diseases such as Leptospirosis, Brucellosis, Bovine
Viral diarrhea, campylobacteriosis and many febrile diseases will not only affect conception, but will also cause abortions. Poor mothering ability of a cow will impart survival of the calf, especially if she calves in isolation.
With the privatization of veterinary services in Kenya in the 1990s the number of inseminators mushroomed, sometimes to the farmers’ detriment. Individuals with little knowledge on animal health soon became inseminators.
This problem persists. It is important to seek the services of a qualified inseminator. Quacks will walk into your farm carrying dead semen because of poor storage. They will not thaw the straws of semen properly and the semen will remain inactive even on deposition. They may also deposit the semen on the wrong place within the reproductive system.
If a cow returns to service after three inseminations, a farmer should try a second inseminator assuming that everything else is perfect. All animal health service providers, including inseminators, are registered and regulated by the Kenya Veterinary Board. Farmers should always ask for their registration card.
Infertility can be caused by all these factors, among others. Farmers should consult a qualified veterinarian to unravel this web.
By Dr Nyaga Nderitu S
The writer is Veterinary Surgeon and a Tutorial
fellow at the Faculty of Veterinary Medicine
and Surgery at Egerton University