A set of Twins I never want again.

[JSchroeder]

How would the bull being a twin impact whether the cow he is bred to has twins?

There are millions of sperm in every breeding but if there aren't two eggs to fertilize, what difference does it make?

 

[DL]

How would the bull being a twin impact whether the cow he is bred to has twins?

There are millions of sperm in every breeding but if there aren't two eggs to fertilize, what difference does it make?

[size=10pt]It's all in the genes! Ya know it does take 2 to tango and we are talking big picture here not just one of a million sperm (which incidentally contains half the off springs DNA) vs one egg

recent studies have shown that infertility in some cattle is related to a small piece of Y chromosome in the females genome (we are not talking free martins) and as far as I know bull have chromosome #5 just like cows (see abstracts below). The bull does influence the twinning rate.

Summary of the MAR Cgenetics program to produce twinner cows. R. M. Thallman* and K. E. Gregory,

USDA/ARS, U.S. Meat Animal Research Center, Clay Center, NE.

The U.S. Meat Animal Research Center (MARC) initiated a program to select cows for increased twinning rate in 1981. Cows that had produced multiple sets of twins were purchased from commercial producers (96 cows) or were transferred from other projects at MARC (211 cows). Semen from 8 Swedish Friesian and 7 Norwegian Red bulls whose daughters twinned more often than normal was imported. Other foundation sires included sons of foundation cows and one Pinzgauer and one Charolais bull whose daughters twinned at high rates in another project at MARC. The herd is 24% Pinzgauer, 18% Simmental, 17% Holstein, 14% Swedish Friesian, 9% Hereford and Angus, 10% Norwegian Red, and 8% other breeds. Current herd size is 300 cows, half calving in spring and half in the fall. Twinning rate (TR) currently averages 50%. Ovulation rate (OR) is used as an indicator trait and is measured by counting corpora lutea via rectal palpation over six to eight estrus cycles prior to breeding heifers for the first time to calve at 30 months of age. The heritabilities of TR and OR are 0.09 and 0.10, respectively, with a genetic correlation of 0.75. Predicted breeding values (PBVs) are computed using multiple trait, repeated records model for TR and OR. Approximately 10 young bulls are progeny tested per year. Following measurement of their daughters’ OR, the best sires are mated to females with the highest PBVs to produce candidates for progeny testing. Response to selection for TR has averaged 2.5% per year. Tissue samples for DNA have been obtained from animals in the herd in 1994 and thereafter. In addition, semen samples were available from most of the sires used prior to 1994. Two quantitative trait loci (QTL) for TR and OR have been identified on chromosome 7 (approximately 60 cM apart) and one on chromosome 5. These three QTL account for about 15% of the genetic variance and are used together with residual polygenic effects in a two-trait model to compute marker adjusted PBVs, which have been used since 1998. Selection for TR has been effective, in spite of low heritability.

Confirmation of quantitative trait loci using a low-density single nucleotide polymorphism map for twinning and ovulation rate on bovine chromosome 5

Allan, M. F., L. A. Kuehn, R. A. Cushman, W. M. Snelling, S. E. Echternkamp, and R. M. Thallman 

Journal: Journal of Animal Science 2009 87: 46-56

Abstract: Traditional genetic selection in cattle for traits with low heritability, such as reproduction, has had very little success. With the addition of DNA technologies to the genetic selection toolbox for livestock, the opportunity may exist to improve reproductive efficiency more rapidly in cattle. The US Meat Animal Research Center Production Efficiency Population has 9,186 twinning and 29,571 ovulation rate records for multiple generations of animals, but a significant number of these animals do not have tissue samples available for DNA genotyping. The objectives of this study were to confirm QTL for twinning and ovulation rate previously found on BTA5 and to evaluate the ability of GenoProb to predict genotypic information in a pedigree containing 16,035 animals when using genotypes for 24 SNP from 3 data sets containing 48, 724, or 2,900 animals. Marker data for 21 microsatellites on BTA5 with 297 to 3,395 animals per marker were used in conjunction with each data set of genotyped animals. Genotypic probabilities for females were used to calculate independent variables for regressions of additive, dominance, and imprinting effects. Genotypic regressions were fitted as fixed effects in a 2-trait mixed model analysis by using multiple-trait derivative-free REML. Each SNP was analyzed individually, followed by backward selection fitting all individually significant SNP simultaneously and then removing the least significant SNP until only significant SNP were left. Five significant SNP associations were detected for twinning rate and 3 were detected for ovulation rate. Two of these SNP, 1 for each trait, were significant for imprinting. Additional modeling of paternal and maternal allelic effects confirmed the initial results of imprinting done by contrasting heterozygotes. These results are supported by comparative mapping of mouse and human imprinted genes to this region of bovine chromosome 5.

 

[JSchroeder]

I’m not sure what you bolded and underlined that section for, that’s referring to bulls that sire females that twin at a higher rate.  I realize that a twin bull will likely have an impact on his daughters. 

What I’m saying is that a bull that’s a twin really shouldn’t have much more of a chance to throw twins himself than any other bull.

 

[frostback]

Your right the bull would not throw more twins, but his daughters would.

 

[DL]

I’m not sure what you bolded and underlined that section for, that’s referring to bulls that sire females that twin at a higher rate.  I realize that a twin bull will likely have an impact on his daughters. 

What I’m saying is that a bull that’s a twin really shouldn’t have much more of a chance to throw twins himself than any other bull.

I know what you are saying - can you back it up with facts?

You are talking one cow - I am talking program - The impact of the bull may be felt a generation or 2 later - ie he sires a daughter she is more likely to have twins. if a person doesn't ever want to have twins again it would be prudent not to use a bull that was a twin or that sired twins

BTW there is science to show that bulls that are twins are less fertile than singlets-

 

[JSchroeder]

So if you knew what I was talking about why did you cite those studies that had nothing to do with what I was talking about?  Something doesn't make sense.

Yes, it takes a multi-ovulation for twins to happen (except for the obviously rare identical twin split embryo situation) and the bull’s semen (speaking of the physical semen, not the genetics in his offspring) doesn’t cause that.  If you're looking for medical facts, that's how it works in humans with fraternal twins.  The father being a twin has no impact on increased likelihood of having fraternal twins but does have an impact on the increased chances of twins in his daughters.  As mentioned, the father can't make his mate ovulate more than one egg.  Sure, it’s not cattle but as opposed to the two studies you cited, it’s contextual.

Edit: example...

Mating 1 - Twin bull bred to Big M’s cow
Mating 2 – Heifers from mating 1 bred to a twining bull
Mating 3 – Heifers from mating 2 bred to a twinning bull

All I was saying is that it really shouldn’t matter in mating 1 if the sire is a twin since there’s a couple million sperm in every ejaculate, it’s the amount of eggs they have to fertilize that matters.  I wasn’t saying anything at all about matings 2, 3, etc.  I thought my first sentence should have made that clear but if it didn't, I apologize.

Are you saying that a twin bull should sire more twins in mating 1 from that example?  Do you have studies to back that up?  The studies you cited were speaking of the increased rates of twinning in the females of those 2nd and 3rd levels in the above example.  And again, that doesn't contradict what I was talking about at all.

 

[jagerbeef]

We have had our own brood cows for 10 years now and never had a set of twins born.  This year with 9 cows that have calved we had three sets.  The first was out of a who made who heifer bred to rocky Balboa bull calf no top jaw, missing a section of back bone and part of his leg, his sister was missing part of back leg, both dead. Set #2 SOS cow bred to Dirty Harry 2, first calf out at 75# no problem, second calf came out backwards both alive.  The third set cow had a 105# bull calf that had a hole just in front of umbilical chord and the intestines came out vet sewed up and left two hours later she pushed out an undeveloped blob of a calf.  The first calf made it two days, but couldn't pee and died.  I was told that it was just my year. 

 

[bruiser]

Seems to me the heat last summer did more damage than we thought. Here in the Midwest I've talked to several producers who've had terrible calving rates, open cows that were 100% producers and abnormal things. Maybe weather has more effect than we suspect.

 

[firesweepranch]

Seems to me the heat last summer did more damage than we thought. Here in the Midwest I've talked to several producers who've had terrible calving rates, open cows that were 100% producers and abnormal things. Maybe weather has more effect than we suspect.

I know we had problems with fertility in the fall, and never had in the past. Going to several sales now, the rate of cows/heifers that took to the Fall AI date are EXTREMELY low (end of November), but bull bred several cycles later. I know the bad drought we had affected us, and other breeders in the area!