kappa-casein genotype markers: CHEESE

[cddexter]

One the bits I'll be tossing (ref thread on cleaning out files under General): This is from a company called Genetic Visions, based in WI (at the time the only lab doing E+ testing in North America). Sixteen years ago I used to deal with Mike Cowan, not sure he's still there. I used GV for the DNA testing that proved E+ existed and was red in Dexters, and proved that dun was NOT a standard dilute, nor E+ (as it is in Jerseys and Brown Swiss). In those days, tests were $60 each.

The original blurb was on the old heat sensitive fax paper and has almost faded away. They were a great company to deal with, and John Potter, on my recommendation, used them for the DNA work he did on the TYRP1 (brown/dun) study. He found them very helpful,. too. Since there is a rise in interest in Dexters for milk, and cheese has become of interest, thought this info might be useful.

From Genetic Visions:
Genes affecting milk yield and composition can have different forms. For example, the milk protein gene kappa-casein has two forms. One variant is commonly referred to as the A allele, whereas, the other form is denoted as the B allele. If the variants of a gene are associated with important traits, these 'genetic markers' can be used to indicate which animals are likely to have enhanced genetic value and which ones do not. This information can then be used to supplement pedigree information and may make your selection decision easier.

Kappa-casein variants of milk have been associated with differences in manufacturing characteristics. Milk from cows with kappa-casein genotype BB has been reported to yield more cheese and to have better cheese manufacturing characteristics than milk from cows kappa-casein genotype AA.

Our work at Genetic Visions, Inc. has shown that the effects of kappa-casein may differ by sire family. We compared PTAs for yield traits with kappa-casein genotype among sons of one elite Holstein sire. Within this sire family, sons with kappa-casein genotype BB had increased transmitting abilities for milk yield of 410 lbs. and there was a relative exchange fat for protein (8.15 lbs. more protein than fat).

All cattle will have one of the three kappa-casein genotypes: AA, AB or BB. The table (to the left) shows the approxi8mate distribution of genotype by dairy breed. The numbers may vary from herd to herd depending upon the sire used.

Market assisted selection can be applied to all animals regardless of age, sex or breed. However, the greatest application of genetic markers is when selecting among animals with similar or identical pedigrees or when lactation or performance information is lacking.

Breed AA AB BB

Holstein 67% 30% 3%
Guernsey 53% 40% 7%
Jersey 2% 25% 74%
Brown Swiss 11% 44% 45%

Genetic Visions, Inc., 200 S. Fish Hatchery Rd., Madison, WI 53711 ph [phone]

Carol back again: I think it would prove very interesting to determine which sires carried which alleles. With all the money it's amassing, I wonder if the assn. would be interested in paying for the tests for AI bulls (at least) in the interests of a service to its members. (and let's not get bogged down in petty fights about how one breeder might benefit to the detriment of another. This isn't about personalities, it's about what matters within the breed!). The assn. didn't cough up a dime for testing for pha, that cost fell on a few dedicated breeders who've never had recognition for their service. This would be a good time and place for the BoD to take responsibility for breed management....imo. Cheers, c.

[tonhou]

Sorry Carol, I don't quite get it. Kappa-casein is not beta-casein but another protein unrelated. I'm just a bit confused.

--Tony

[cddexter]

didn't know where to put it, can't figure out a new heading, so posted under this one. If you think it better, maybe I should move it somewhere else? Yes, not Beta, but Kappa. different protein. just thought the info might be useful as there has been some discussion about cheese lately, and this apparently strongly affects the volume. It's something I haven't seen discussed here, so thought it might be new info to most. cheers, c.

[Gorignak]

May have to draw us dumb ones pictures.....I have just touched on it as we expand our cheese knowledge.....then my eyes crossed and I heard a mental bearing start to squeal. I guess I came away with...like the Golden Rectangle in Art...there is a "golden ratio" that is best for curd formation and FIRMNESS......
.......to be continued.

[tonhou]

different protein. just thought the info might be useful as there has been some discussion about cheese lately, and this apparently strongly affects the volume

Certainly is of interest, thanks for bringing it up. I was just a bit slow on getting the drift. Shall do a little more research online.

--Tony

[carragheendexters]

Hi All,
here in Australia we can test for kappa casein and beta-lactoglobulin through the Uni of Qld. It certainly would be interesting to see what sort of results Dexters come up with. We have a local boutique cheese factory called the Small Cow Farm. They were Dexter breeders who tried to make a living from their cows. They had trouble getting relief milkers so never had a day off for years. Unfortunately now they are buying in milk to make their cheese. I've visited them and talked with them about their cheese making at a group meeting. They have a great setup, 3 cow dairy with the cheese factory the other side of the wall from the dairy.
They make the best Camembert, Brie and their marinated Fetta is to die for. They say that Dexter milk is best for soft cheeses, and the cheese is soooo white.
regards Louise

[tonhou]

Louise, somewhat off topic, but you don't know the layout/plan of the 3 cow dairy?

--Tony

[carragheendexters]

Hi Tony,
They had just the 3 angled milking stalls, walkthrough I think, though it was some years ago and my brain forgets lots. They milked about 15 cows. It was piped directly into the cooling vat on the other side of the wall of the dairy, with the cheese making facility all in the same area, then the maturing rooms all part of the complex. If you are interested I can get contact details for them, maybe an email address. They are really lovely people, I'm sure they could give you better details on the layout than what I can. Let me know if you want to follow up.
regards Louise

[Gorignak]

My size setup....ANY info would be great. We want to do the same if regulations don't choke us.
Here is another note....sorry, it touts the Guernsey, but will be interesting if Dexters have their own particular advantages.
From the WGCF:

Research carried out in USA has shown that 60% of Guernseys carry the Kappa Casein 'B' gene. This is of real economic benefit to cheese plants, giving a firmer curd, increased volume and better cheese characteristics. Recently a cheese made entirely from Guernsey milk was awarded the Silver Medal at the Royal Melbourne Show, Australia's most prestigious cheese show. Guernsey Milk Products, who entered the cheese, reported that 15.36 kg of cheese was made from 100 litres of pure Guernsey milk, whereas 10 kg is all that would normally be expected from "standard" milk in Australia.

Well, we know that Dexter milk is far from "ordinary"....so here's hoping that there are advantages for us