A crossbred cow with four failed inseminations
Sunita Devi of Karnal owns a 5-year-old Holstein Friesian × Sahiwal cow that calved 10 months ago and is still giving 14 L of milk a day. She has been inseminated four times since April, the last three times 12–14 hours after the first sign of standing heat. Twice the animal was inseminated again 24 hours later 'for safety'. Her heat signs are now short and weak, mainly mucus and bellowing at night. There is no vaginal discharge, the cervix feels normal on examination and the body condition score is 3.75 on a 5-point scale. She feeds 5 kg of home-mixed concentrate (maize, mustard cake, wheat bran), about 15 kg wheat straw and whatever green fodder is available, with no mineral mixture. The cow is milked three times daily and is let out only for milking and watering. The last calving was followed by a retained placenta.
1. List the most likely reasons for repeated failure to conceive in this cow and state how you would confirm or eliminate each one.
Read the worked answer
- Insemination timing. Heats are short; 12–14 hours after detection may be too early if she ovulates early, and the 24-hour repeat may be too late. Confirm by observing the actual onset with a teaser bull or tail paint and by applying the AM–PM rule.
- Weak heat detection. With short heats she may be inseminated after ovulation. Confirm by twice-daily 20–30 minute observation, a teaser or a heat-mount patch.
- Subclinical uterine infection after retained placenta. Confirm by vaginal examination, the white-side test on cervical mucus and, where available, endometrial cytology.
- Nutritional imbalance. BCS 3.75 suggests overconditioning; 5 kg concentrate with no mineral mixture risks energy–protein imbalance and deficiency of copper, zinc, selenium, manganese and phosphorus. Confirm by ration calculation and, if possible, blood mineral levels.
- Cystic ovaries or anovulation. Confirm by rectal palpation or ultrasound on days 8–12 and 20–22 of the cycle, or by progesterone assay.
- Semen or technician problem. Check the records of other cows served from the same batch by the same technician.
- Infectious causes such as brucellosis, IBR or campylobacteriosis. Confirm by herd serology and, where relevant, mucus culture. Age and chronic heat stress should also be considered.
2. She asks whether she should inseminate at 12 hours or wait longer. Explain the timing logic and practical heat-detection steps for this cow.
Read the worked answer
The aim is to place fertile sperm in the tract a few hours before ovulation, because the ovum remains fertile for only about 8–12 hours while sperm survive 24–48 hours. The standard AM–PM rule works well for clear heats: an animal first seen standing in the morning is inseminated that evening, and one first seen standing in the evening is inseminated the next morning, roughly 10–14 hours later. For a cow with short, weak heats, 12 hours after the first sign is reasonable only if standing heat was actually seen; if heat detection is unreliable, a single fixed 12-hour rule cannot work.
Practical steps: observe twice daily for 20–30 minutes, especially in the cool parts of the day; use a teaser bull or a chin-ball marker; apply tail paint and check it morning and evening; record the time standing heat is first seen. A second insemination 24 hours later is justified only if she is still standing. If heat detection remains poor, discuss oestrus synchronisation with a veterinarian and use fixed-time insemination.
3. What records would you ask her to keep, and on what evidence would you advise keeping the cow rather than culling her?
Read the worked answer
Ask her to record calving date, first observed heat, each insemination date and time, the technician and semen batch, the result of pregnancy diagnosis at 45–60 days, milk yield, feed offered, and every treatment with cost.
Decision logic: a cow that has had four services with no conception needs a diagnosis first, not immediate culling. If examination finds a treatable cause (subclinical endometritis, cystic ovary, mineral deficiency), treat and allow two more services; if she conceives within that period, keeping her is usually cheaper than buying a replacement. If no cause is found and she fails after five to six services, or if the calving-to-conception interval crosses about 150 days with milk yield falling and dry period lengthening, culling becomes economically sound. Compare the cost of the extra treatments and extended dry period with the price of a pregnant replacement heifer and her expected lifetime yield; the decision should be based on that comparison, not on the number of services alone.