Carcass Yields

[onthebit]

I am hearing conflicting reports on the comparisons of carcass yields between carrier and non carriers....Does anyone know of studies that have been done?

[kansasdexters]

Hi Charlotte,

In order to do a fair comparison, you would want to feed out several steers with essentially the same pedigree, differing only in the fact that one group carried the chondro gene and the other group did not. I've collect data on all of the steers we have processed in the past four years and we have both chondro-carriers and chondro-free steers in that data. Most of our steers are chondro-free, so the number of chondro-carriers steers to compare them with is quite limited. What we have seen in our own herd is that the chondro-free steers typically finish (fatten and ready) by 26-27 months old, they have a live weight of 750 to 900 pounds and they have a hanging weight that is 58 to 63% of their live weight. The chondro-carrier steers typically finish (fatten and ready) by 24-25 months, they have a live weight of 550 to 700 pounds and they have a hanging weights that are 55 to 60% of their live weight.

But that doesn't tell the whole story --- because the chondro-carrier steers have less bone, and the actual pounds of meat yielded from the carcass ends up being very close (within 10 pounds) of the meat yielded from the carcass of a chondro-free animal that had a live weight 100 pounds greater than his chondro-carrier brother.

Patti

[onthebit]

Thanks Patti. I would have thought the carriers would be heavier boned?

[kansasdexters]

Carriers have smaller skeltons (smaller frames) so there is actually less bone.

[onthebit]

So there might be an advantage if you were strictly looking for beef animals since they finish a couple months earlier. Something to ponder!

[Clive]

Sept 20, 2010 11:24:23 GMT -5 onthebit said:

I am hearing conflicting reports on the comparisons of carcass yields between carrier and non carriers....Does anyone know of studies that have been done?

I've got stats from a group animals which show liveweight, hookweight and kg's of meat (without offal).

All were steers. Most were medium framed non-shorts, just 2 were chondro-carrier shorts.

The hookweight on the shorts was just 1% lower than the non-shorts.

The amount of meat achieved from the non-shorts averaged 118kg's, and the two shorts produced only 92 and 96 kg's. Although the percentages worked out similar, that's not enough meat for us. The worst percentage-wise were a few quite tall, lanky steers. But they still produced more actual meat than the shorts. So, depends whether you want percentages or meat!

The shorts went to the abattoir at 24 months and the non-shorts average age was 27 months. That may be an advantage but as we spring calve, it's a disadvantage because they will go to the abattoir just when the grass has started to grow and they are full of winter rations! We are only concerned with how many winters they have to be on the farm for, and that is always 2, whether short or non-short. Taking them later has the advantage for us that they are taken straight off fresh growing grass, so the beef will be better (and healthier).

But they're all good and what flavour!

[cddexter]

Morning, Clive..I agree. Actually I have seen results from three 'studies'. Veronica Schofield in England, Wes Patton in the US, and Piet Wilke in South Africa all did their own comparisons. Veronica is a well-read and very experienced breeder with genetics training; Wes and Piet are both breeders and university profs (Wes was a dept. head, Piet was Dean of Ag). All three came up with the same results: You get a better overall yield with non-dwarfs.

However, having said that, because the succession after the baby stage is bone growth, muscle development, and then fat cover, and the three growth stages overlap somewhat, AND because bone growth seems to stop sooner in dwarfs, dwarfs are already into the fat cover stage while their non-dwarf counterparts are still building muscle. I guess one would have to figure out costs vs. yield to see if there really was an advantage either way.

In the meantime, I've learned something new this year. I used to calve in the spring, and kill at around 22-27 months. This had me feeding over two winters, and using the spring and irrigated summer grass to fatten, along with a small addition of grain (approx. 5 lbs/day for 30 days). The butcher didn't want to hang them more than two weeks because they didn't have enough fat cover. This year, they were all just sort of 'out there doing their thing', I didn't take hay off because the fields need redoing and the yield would haven't been worth the labour to have a contractor come in and bale for me, so I just left the dozen or so cattle I still have, to roam wherever on the 40 acres. We had a really dry spring and summer, and while the grass grew okay it died off early and never came back. I figured there was enough feed out there, and let nature take it's course. I just slaughtered a three year old bull, and he was well covered. I asked the butcher about this, and he said the dry grass gave the animal more value because the wet grass is mostly water in bulk. He hung for three weeks, the butcher said he was very tender, and I tried a sirloin steak last night and it was one of the best for years. Hmmm...if you don't mind the pun--food for thought. ;Dregards, c.

[Clive]

Yes, I've read reports that say that dry standing grass maintains it's nutritional value; it doesn't have to be green. But I'm not sure that's the same over here in the UK though, we don't get dry standing grass very often! Too much rain and maybe different grasses.

[hrfohio]

Actually, I've read that -aside from Vit A and E- hay retains nutritional value, even when not green. But I would think standing grass would be different because the plant is going through the entire growth cycle. (e.g. protien rises through the growth phase, but once the plant goes to boot, the protien drops dramatically and the plant starts shifting nutrients to the root system.)

I'd think grass that has died is mostly starches. I know grasses that are under drought can have flushes of sugar from any rain and some species will concentrate nitrates (sometime to dangerous levels). Drops in temperature to below 40 degrees will also cause a flush in sugars.

If you want to find more information about it, you could google foundered horses on pasture. That is a group of people who are very motivated to completely understand what happens to forages in the very short durrations (e.g. if the temps fall below 40 degrees, they need to keep the horse off the pasture till a couple hours of sun have driven the sugars lower again).