By Francis Ndungu

Hannah Mwangi, a dairy farmer in Nyeri County, was close to giving up on her two cows after repeated failed attempts to get them pregnant. Both animals had shown signs of being on heat, but three rounds of artificial insemination (A.I.) had failed, leaving her without calves and without milk to sell.

“I called the vet thrice to give an A.I. but all was in vain. I felt a lot of pain because the three times I spent a lot of money which was never refunded and I considered it as a loss,” said Hannah.

Her case was typical of what veterinary officer Alex—who works in her area—describes as a growing problem in dairy farming: poor heat detection and hormone imbalances caused by inadequate feeding. He explained that cows are biologically meant to give birth once a year, but many now struggle to come on heat or conceive due to poor diets and management.

“Well-fed cows are supposed to calve every year when taken good care of. The care includes proper feeding and meeting the freedoms cattle need,” said Alex.

He advised Hannah to adopt a fixed-time insemination protocol, a method designed to bypass natural heat detection by preparing the cow hormonally for insemination on a scheduled day. He also reviewed her feeding regimen, helping her formulate home-made feed mixes that restored her animals’ health and fertility.

Hannah had been buying commercial feeds, but with high costs and little improvement in yields, she switched to feed formulations based on Alex’s training. The result was immediate. Her cows’ milk production rose from 20 litres to 37 litres per day.

“During dry-off periods I feed my cows with feeds and salts rich in selenium and phosphorus to enhance heat. During lactation, I use feeds rich in calcium and protein to prevent diseases like milk fever and ketosis,” said Hannah.

One of her cows was a heifer that had failed to go on heat for two consecutive years. According to Alex, mating too early—at around 12 months—can lead to reproductive issues. He recommends breeding heifers at 15 to 18 months or once they reach 150kg to ensure their reproductive systems are mature enough.

“I have experienced that heifers mated at 12 months tend to develop complications when calving. They are often unable to calve down properly and sometimes even give birth to paralyzed calves,” he said.

Delayed or failed heat can also stem from mineral deficiencies, particularly of selenium, magnesium, and iron, which disrupt hormone function. In some cases, cows may experience ‘silent heat’, showing no behavioural signs of ovulation.

“Most farmers get confused when their cows experience silent heat and declare failed heat. These animals don’t mount others but may show creamy mucus from the vulva, swelling, or reddening,” said Alex. “This is why it’s important for farmers to develop close relationships with their cows to notice subtle changes.”

Once the diet was corrected, Alex enrolled Hannah’s cows on the fixed-time insemination programme. The process involved a 10-day hormone protocol.

“I selected the first day. The vet injected hormones to prepare the cow for ovulation. On the seventh day, he gave another hormone (GnRH) to enhance ovulation, and on the ninth day, he injected PGF2α to complete the process. Then, between 16 to 24 hours after the last injection, he inseminated the cow,” said Hannah.

During the gestation period, she ensured her cows received a balanced diet to support foetal growth and safe delivery. Nine months later, both cows delivered successfully.