/ Twinner Cattle Newsletter -- Spring 2002

Annual pre-sale gathering of twinner breeders, Wednesday February 6th

USDA-MARC will be holding their annual sale of twinner breeding stock on Thursday, February 7th. There is a change in location: unlike in years past the sale will not be held at MARC. Instead the sale will be held in Kearney, NE at the Kearney Livestock Commision. Consequently, different arrangements have been made for the Wednesday evening gathering of those with an interest in twinner cattle. We will meet on Wednesday evening, February 6th at the Ramada Inn restaurant in Kearney. I've reserved a room at the restaurant for our get-together (Persimmon room), starting at 7 pm. Those who desire can order dinner (“dutch treat”) off the cafe’s menu at 7:00 pm, and after we’ve had a chance to eat and visit there will be a short program. I'll share an abbreviated version of a talk I gave at the 2001 American Society of Animal Science meetings on management of twinning cattle. To get to the Ramada Inn take the Kearney exit off Interstate 80 and look for the Ramada sign (about three blocks to the north). They tell me you can't miss it. When you come in, just ask the host or hostess for the “twinner cattle” group or the Persimmon room and they'll point you in the right direction.

MARC twinner cattle sale, Thursday, February 7th

If you haven't already gotten a sale flier and catalog request postcard, you can obtain a catalog from MARC by sending a request to "MARC SALE CATALOG REQUEST, University of Nebraska, RLHUSMARC, P.O. Box 166, Clay Center, NE 68933-0166". Gordon Hayes informs me that this year's sale will include 12 twinner cows and 16 to 18 twinner bulls (23 bulls will be catalogged but not all will sell).

Not Baaaaad ! During the past year and a half two genes with profound effects on ovulation rate and litter size have been identified in sheep. The first to be identified was known informally as the "Inverdale" gene, with the name taken from the geographic location of the sheep. It was apparent from the original characterization of the sheep (reported in 1986) that the gene was on the X chromosome (ie. that could be deduced from the pattern of inheritance). This simplified the genetic mapping work by narrowing the search to one chromosome. Another interesting aspect of the gene was the effect of having 0, 1 or 2 copies of the Inverdale allele (the high ovulation rate form of the gene) versus having 2, 1, or 0 copies of the normal or common allele for typical ovulation rate. Ewes which were homozygous normal (ie. two common alleles) had typical ovulation rates of about 1.1 eggs shed per cycle. Ewes which were heterozygous (ie. one inverdale allele and one normal allele) had high ovuation rates of approximately 2 eggs per cycle. Interestingly, ewes which were homozygous for the Inverdale allele (ie. two Inverdale alleles) had abnormally developing, non-functional ovaries. The scientists mapping this gene exploited this by making matings of heterozygous ewes to rams with the Inverdale allele (since the gene is on the X chromosome and the ram has only one X, all daughters inherit the Inverdale allele from the sire in this mating). All resulting females offspring then fell into two clearly discernable categories: fertile (one normal allele and one Inverdale allele) or infertile (two Inverdale alleles). These easily distinguished phenotypes greatly simplified the genetic mapping. Once the gene was mapped to a narrow region of the sheep X chromosome the investigators turned to the wealth of information from the human genome project to identify genes predicted to reside in the corresponding region. Two genes with potential effects on cells of the ovary were examined, and a mutation with likely causative effect was found in one. The story was further solidified by the fortuitous identification of another, independent population of sheep with an X-linked, high ovulation rate phenotype. Examination of the same gene from these sheep revealed a different mutation, which like the first, would render the gene non-functional.

I'll save the story of the second gene for the next newsletter. The exciting thing about these discoveries for those of us who work with cattle is that mutations in these genes could be the basis for some of the variation in cattle ovulation rate and twinning rate. We have already done some preliminary work genetically screening some cattle with records of high twinning rate for mutations in the Inverdale gene. We have found one mutation, but it is doubtful that this mutation has any functional effect. We would like to broaden the screening, and that's a place where you can help. If you have a cow in your herd that has an exceptional reproductive record and is unrelated to the MARC population we'd ask you to consider providing us with a small tissue sample from her for collection of DNA. We can send you a mechanical punch that could be used to obtain a small, 1/4 inch circle of tissue from the ear. Of course, we'd prepay the return shipping on the punch and tissue sample. "Exceptional reproductive record" requires some definition. Our requirement would be that the cow in question have had 3 or more twin births and had a twinning rate of 50% or greater over her lifetime. If you have a cow that meets this profile and are willing to help us out, please get in touch with me using the contact information given below.

Marketplace:

Twinner females wanted: Mark Albrecht of Cozad, NE is interested in purchasing twinner females. You can contact Mark by phone at 308-784-2846 or 308-325-0669 or by email at .

I'm re-running this information on sires from whom semen is available. If you have a sire for whom semen is available and you'd like to list it in the next newsletter, please contact me.

Semen from twinner bulls:

USDA ID#928507, 26.8 twinning rate EBV (USDA), polled. Owner: Dave Serfling. Contact Dave Serfling at 507-765-2797.

USDA ID#888521, 48.0 twinning rate EBV (USDA), Owner: Daren Cyphers. Contact ABS Global Inc, 1 - 800 - ABS - STUD

USDA ID#949673, 42.8 twinning rate EBV (USDA). Owner: Daren Cyphers. Contact Hoffman A.I. Breeders, 801 - 753 - 7883.

USDA ID #918521, 50.7 twinning rate EBV (USDA), contact Sean Smith, 1211 240th Avenue, Thurman, IA 51654, 712-628-3005.

USDA ID#969549, 55.9 twinning rate EBV (USDA). Owner: Dave Serfling. Contact Dave Serfling at 507-765-2797.

USDA ID#969381, 67.3 twinning rate EBV (USDA), contact Brian Kirkpatrick, 5615 Longford Terrace, Madison, WI 53711, 608-271-6904.

USDA ID#998628, 64.0 twinning rate EBV (USDA), progeny test pending, contact Brian Kirkpatrick, 5615 Longford Terrace, Madison, WI 53711, 608-271-6904.

That's all I have for now. I look forward to visiting with those that can attend the meeting on the Wednesday, February 6th.


Brian Kirkpatrick

University of Wisconsin-Madison

1675 Observatory Drive

Madison, WI 53706

608-263-4323

608-262-5157 (fax)