Growth Pattern of Bulls - When are they 'Fully Matured'? At what age do they express their muscling potential?

          I always enjoy calls that come from folks interested in learning more about the British White breed.  Oftentimes, the questions asked of me leave me pondering the question to myself of how I can better answer those questions next time around.  Recently, the question/observation was posed that full muscle expression in bulls wouldn't generally show itself until they were further on the road to maturity.  I was hesitant in that regard, as my first thought was that by yearling age the muscling attributes of a bull should be well visible.  I found myself looking back through photos of various bulls, particularly the ones that I've seen grow to maturity myself or via photographs, which really amounts to just a handful of bulls.

After looking through those photos, I came to the conclusion that the muscling potential really ought to be clear by yearling age under optimal nutrition for the frame score of the animal in question.  And even during the bull's months as a calf at his dam's side, the muscling potential is apparent.  Most often, if the animal is expressing more muscle definition than its peers, it's noticeable; if much less definition than the others, that's fairly noticeable as well.  Pictured to the left is an Elvis sired bull calf that did receive his sires muscling in the rump; he grew up to be J.West's Big Mac, and was the most like his sire, Elvis, of any of Elvis' sons to date, including his good-natured disposition.

That said, without a doubt as the bull matures that muscle expressed in youth continues to increase tremendously as the years pass -- but the basic structure, the basic muscle expression remains the same.  What follows are some photos of my senior herd bull, J.West's Elvis.  Unfortunately, I haven't been able to locate calf photos of him, I didn't take as many pictures back then and didn't have the benefit of a digital camera.  Nonetheless, from the time he was born, he was quite a distinctively made and handsome youngster; thus the name Elvis that was given him. 

I've also included the different weights taken on Elvis over the years, which illustrate quite well for me the transformation of my good-natured, short and chunky, handsome bull calf  into the mature and hefty Frame Score 2/3 herd bull he is today.  Elvis' hip height measure was taken by Gerald Fry when Elvis was just over 48 months of age and he stood 51" over his hook bones.  This puts Elvis at somewhere between a Frame Score 2 and Frame Score 3, depending on charting sources. 

J.West's Elvis was born March 10, 2003, with a recorded birth weight of 76 lbs. using a taped chest measure.  It's possible it was lower, as I didn't hold the tape snugly back then as is recommended for the best weight estimate.  Elvis was weaned in fall of 2003 with an actual wean weight of 438 lbs on the 28th of November.  His dam, Halliburton Adios, a Popeye daughter, weighed 846 lbs on that same day and she was almost exactly 3 years old.   Elvis was her second calf. 

The next weight I can locate on Elvis is from November 12, 2004, and this photo of Elvis' Rump is from November of 2004 -- at 20 months of age.  His weight was 856 lbs., practically a doubling in size over the prior 12 months.  Unfortunately, I can't locate any other photos of him from this group, it predates my switch to a digital camera.  Hopefully, I'll locate the Kodak disc one of these days that the photo came from.

My next actual weight on Elvis was Feb. 16, 2005, at 23 months old, and he had reached 980 lbs., a gain of about 40 lbs. a month, and not bad with  zero grain concentrates that winter.  The photos below were taken in May of 2005 when Elvis was about 26 months old.  He was fully expressing his  muscling - but still had much, much growing ahead of him.

Unfortunately, I don't have another recorded weight on Elvis until May 15, 2008.  At 5 years of age he had reached a weight of 1715 lbs.  The next weight recorded was on December 18, 2009, at what I'm sure is his peak mature weight of  1785 lbs.  He is pictured below at about this same time.  And if you compare the photo below and the one above, the muscle expression is very much the same, just extraordinarily increased.

The growth of Elvis from a 2 year old to his 6th year can  better seen in this March 2009 video of Elvis below.  He does seem to have expressed more muscling with age, he is almost twice as heavy, but he has also laid on a lot of fat at this stage, which can add to perceived muscling in most mature bulls.  In Elvis's case, there is definitely muscle defining him in every way, with the fat cover adding to his natural gifts, although he has lost that bloom of youth and the sharpness of his muscling - I think he perhaps should have to work a bit harder!  Elvis is a 100% grassfed bull, he has high genetic Feed Efficiency, and there's never been a day when he was not well fit.