Welcome to my corner of the cattle industry!
Over the years, I’ve collected questions, observations, successes, failures, and plenty of reproductive mysteries. This blog is my attempt to put those lessons into words. Most posts will start with a cow that taught me something. This is one of those cows. Well, a heifer to be exact.
A few years ago, a client came to me with a beautiful heifer that had recently won a major title at a junior show. “I am struggling to get this heifer bred,” he said. “I have AI’ed her twice and she’s been with the bull since the show. I know stress can have an impact on reproduction, but I have seen the bull mount her. Could you take a look and see what you think?”
It wasn’t the first time I’d heard that story, and it certainly wouldn’t be the last. In cattle reproduction, some of the most frustrating cases begin exactly this way: everything should be working, yet somehow, it isn’t.
I grabbed my trusty ultrasound, an OB sleeve, some lube, and gently went to work. Gently is important here because rectal etiquette is extremely important in my line of work! I start every situation like this one the same. First, I palpate the reproductive tract to get a feel for the ‘lay of the land’. I want to know right off the bat if she is reproductively sound-does she have all the parts of her tract and are they sitting in the right place? Then, I use my ultrasound to confirm everything I felt on the ovaries and to ensure there is no fluid or infection in the uterus or a surprise pregnancy.
At first, I expected to find an obvious answer. Maybe she wasn’t cycling consistently. Maybe there was evidence of a uterine infection. Maybe the bull was the problem. What I found was something far more interesting.
I immediately noted that the tract was not sitting neatly in the pelvic rim where I expected it to be, it was farther over the rim, and the ovaries were splayed out away from the uterine horns instead of being tucked next to each horn. Further palpation told me the ovaries were slightly tacked down and did not move as freely as I would expect them to on a normal reproductive tract, same with the cervix. I palpated a distinct corpus luteum which told me she was indeed cycling-that’s good news. Ultrasound confirmed a healthy-looking corpus luteum, several follicles, and no signs of fluid or infection in the uterus. My biggest question mark centered around the position of the reproductive tract. Could that be the reason she’s not getting pregnant?
Everything else seemed to be working. She was cycling. The uterus appeared healthy. The bull had been observed breeding her. Yet something was still preventing her from becoming pregnant. Cases like this are what make reproduction so fascinating. Not every fertility problem announces itself with a cyst, an infection, or a hormone imbalance. Sometimes the challenge lies in anatomy. Sometimes all the individual pieces are functioning correctly, but they are not positioned quite the way nature intended.
Over time, I have noticed that cows and heifers with altered reproductive anatomy, whether from prior trauma, adhesions, or excess conditioning, can be more difficult to breed by either AI or natural service. While every case is different, I’ve often wondered whether the position of the reproductive tract affects the ability of the infundibulum (the structure responsible for capturing the ovulated egg) to do its job effectively. In this heifer’s case, the tract felt as though it was being held down by extra fat in the pelvic area. My suspicion was that ovulation was occurring normally, but the egg was never making it to the site of fertilization. In other words, all the right biological events may have been happening, but they were not coming together at the right place and time. If my suspicion was correct, continuing to breed her conventionally would likely produce the same disappointing result. So, I proposed a different strategy: instead of trying to naturally create an embryo, why not transfer one into her? The client was willing to try. We made a plan to transfer an embryo after her next heat cycle.
A couple of weeks later, the client called to schedule an embryo transfer appointment. The heifer presented with a picture-perfect Day 7 corpus luteum. The embryo was thawed, transferred, and she was headed back home in no time. Thirty days later a small conceptus with a strong heartbeat made its appearance on the ultrasound screen. She was pregnant! There were still many months between her pregnancy diagnosis and a healthy calf on the ground, but for the first time since the client had called, we knew we were headed in the right direction.
This heifer taught me a lesson that has followed me throughout my career: not every cow reads the textbook. We spend a lot of time in cattle reproduction learning what should happen. A follicle should ovulate. The infundibulum should capture the egg. Fertilization should occur in the oviduct. An embryo should develop and eventually establish a pregnancy in the uterine horn. But cows are individuals, and biology does not always follow the script. Sometimes the challenge is hormonal. Sometimes it is anatomical. Sometimes the answer is obvious, and sometimes it requires us to think beyond conventional breeding. This case was also a reminder that assisted reproductive technologies such as embryo transfer are more than genetic tools. While they are often used to multiply elite genetics, they can also help overcome specific reproductive challenges by bypassing a step in the process that is not working as nature intended. Over the years, lessons like this one have shaped how I think about donors, recipients, ovum pick-up, in vitro fertilization, and embryo transfer. This blog is my attempt to share those lessons, one cow (or heifer) at a time.
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