Nutrition and muscle mass

[milkmaid]

Long post very short, my animal science anatomy/physiology teacher (who taught at a vet school for 20+ years, if it makes any difference) gave me an article recently (regarding a study he'd done) on the impact of nutrition to the dam in early pregnancy affecting muscle mass in the offspring and amount of fat at slaughter. The study was done on sheep, but the same thing applies to cattle. For those who aren't familiar with muscle development - muscle is laid down early in gestation and while muscle cells can increase in size after birth, the number of muscle cells cannot.

The study had two groups; a control group fed 100% of daily requirements, and a nutrient restricted group fed 50% of daily requirements until halfway through gestation, and then both groups were fed 100% of daily requirements. At birth, the lambs from nutrient-restricted dams had heavier birthweights than the lambs from control ewes. Size overall was similar. At 100 and 140 days of age the lambs were ultrasounded and the lambs from nutrient-restricted dams had more backfat than the controls. At slaughter the lambs from restricted dams were heavier, but had a higher fat to body weight ratio than the lambs from control dams.

I found it quite fascinating... it may not make much difference to some of you, but in the western part of the U.S. cows are often run on rough rangeland and may not see hay until December or later, even when all that's left to eat is sagebrush and snow. They're usually first-trimester to early-second at that point and most folks figure the fetus is small and the dam doesn't need much in the way of nutrition. But where nutrition during gestation influences the composition of the calf at slaughter.....

It may also explain differences in carcass quality even with calves that have had similar management from birth to weaning and are from similar genetics.

Just thought y'all might find that interesting.

 

[kenny thomas]

Does it show a difference in intermuscular fat or just the overlaying fat?

 

[KNERSIE]

Claire, as you know I'm not against academic research, but I sometimes question the real life application of the results. Too often the goal with research is academic recognition and not to better the industry. The control groups often isn't genetically similar enough to the test group or the study ongoing enough to really make the findings above suspicion. Once the PhD is earned the project comes to an abrupt end.

That being said...

The oldtimers often calved just ahead of the grazing, meaning the breeding season coincides with the start of the good grazing season giving the cows a rising plane of nutrition and condition and also better nutrition during the early gestation when the bulk of the cell division takes place. This also just happens to be the way mother nature does it with the wild animals. Granted this doesn't always match your market or your area you live in, but then in nature migration plays such a big role that its seldom a problem while in commercial agriculture fences prevents that migration patterns with domesticated animals.

I am fascinated with peasant wisdom and research done to prove what the oldtimers did for centuries without academic papers or a statistical analysis is in my opinion always worth the money spent. If only more researchers focussed on the proven ways instead of trying to re-invent the wheel using only quantifiable data cattle breeding in general wouldn't have made all the mistakes of the last 60 years.

 

[milkmaid]

Does it show a difference in intermuscular fat or just the overlaying fat?

Backfat, kidney and pelvic deposition are mentioned in the study. I'll ask about marbling.

 

[TheLazyM]

I did like this post. It helped me put things in order. I've been trying to figure out a calving cycle and pros and cons off differnt conception times. I was thinking that a spring conception times was going to be harder on me for the fact of feeding expecting moms in my areas worst weather. I've tried to buy my bred cows to calve in the spring. My way of thinking was the grass and minaral blocks was surving 2 purposes the mom and the calf. Now it makes for sense to use the graze for the gestation of the calf. This is another tip I'll put in my book. Thank you.

 

[milkmaid]

Update: both backfat and intramuscular fat.

Knersie - I'd agree, but re this study and just FYI - fellow doing the study is 60+ and taught at a vet school for 20+ years; he's had his Ph.D for a long time. Wasn't one of those "need something to research" type of studies.

 

[jonbri55]

Thanks for the post MM. While I only raise bottle calves, I do raise meat goats and found this really interesting. I think I will try this in the fall when I breed my goats again. I usually wait until the last 2 months before I start feeding them grain. My goats will be kidding over the next 6 weeks and I will weigh them and compare with next year's crop. It should be interesting especially since I will be using the same buck again this fall.

Haven't seen a post from you in awhile, MM...school keeping you busy?

 

[Susie David]

MM...did the study mention which nutreients were restricted or was the whole daily requirement cut by 50%? DMc

 

[milkmaid]

It was the overall daily requirements that were halved for the test group, SD.

Yep school is keeping me pretty busy... I've got things like 2nd semester organic chemistry to occupy my time. Last semester with that though, biochem for the summer, and then I'm done with chemistry! (Can you tell I'm excited at the prospect?! LOL.)

*edited to fix typo*

 

[jonbri55]

My daughters have a friend who is on track for vet school...sounds like she has a lot to look forward to! :banana: Bet you can't wait to get home and work some cows on that big sorrel of yours! Organic chemistry in real life!
Your post was good-I will certainly change the way I feed my mommas!