When buying young immature cattle, it can be extremely difficult to know exactly what you’ll get. You might think that the adult height of the prospect cow or bull will be an average between the parents heights but that isn’t necessarily the case. Or you might think a current height is all the info you need, well… that too depends on the several factors.
This post will try to help you remove some of the mystery from your selection process to hopefully reduce, if not eliminate a few surprises all the way.
First, let’s talk about age. All calves are small, this does not mean that they will stay small. Highlands in particular are known to be slow developers that will continue growing until around 5 yrs old. When you hear about a cow or bulls measurement, however, those heights are what is captured at three years of age. Three years is the industry accepted height recording age. So if you buy a calf and mom is 7 yrs old and 45” it’s entirely possible that she was 42” and therefore “miniature” on her third birthday. Cows in that 3-5 yr range will grow on an average of an additional 1 - 1.5 inches per yr until they are 5 yrs old.
Over the years, WHERE the cows are measured has changed. It used to be that mini cows were measured at the hook, but in the past two years, I see more people measure from the ridgeline directly above the hook. Still, others measure at the shoulder. I’ve found that the ridgeline and shoulder measurements are pretty consistent but the hook measurement is roughly 2-3” shorter. When inches count, be sure to ask sellers where they are measuring from.
Sometimes cows birthdates are unknown or mistaken. It would be near impossible to predict a full grown height on an animal without knowing how old it is. With really young calves it can be difficult to figure out the difference between 1-4 months but as cows approach a year old, the horns can give a you really good indication of age. Pay attention to the horns in yearlings and older cattle.
The “miniature” height designation is different depending on who you talk to. IMCBR says the animal must be under 42” at three yrs old. Pretty much every other registry has a height differential between cows and bulls of roughly 2”… so a miniature bull in this case is anything under 44”.
When one parent of a calf is chondro positive but the calf is not, it’s not accurate to assume that you’d still average the parents heights to get the calfs adult height estimate. You must first add the non-chondro height back to chondro positive parent before averaging the parents heights. So a 38” chondro bull would be approximately 43” or 5” taller for the sake of averaging the parents heights in this example. Often times, a chondro positive calf will grown to be similar in height to its chondro positive bull parent and slightly larger if the chondro positive parent is the dam.