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Is Man-O-Man Really Going to be a Sire of Sons?

This week LONGS-LANG OMAN OMAN (Man-O-Man) received outstanding indexes around the world (#6 TPI and #1 LPI) much like the rumours before this proof round had predicted (Read more – Man-O-Man Will He Turn Platinum?). Now many breeders  are again considering him for their breeding programs.  While we can totally support the principle of using the best sire to produce the next generation of AI bulls, we are not sure that Man-O-Man will be a great sire of sons.  Here’s our reasoning.

When you take a close look at Man-O-Man’s progeny, you find that 6 of his daughters worldwide have a higher gLPI  than he has. They are COMESTAR LAUTAMAI MAN O MAN, STANTONS MANOMAN EZRA, SEAGULL-BAY SHAUNA SATURN, BENNER MANOMAN JANESSE, DONNANDALE MANOMAN JAKARTA and STE ODILE MANOMAN MODEL SAPHIR. Three of these daughters have Estimated Breeding Values and three are younger and have Parent Averages.  What really stands out and catches our eye is that none of his sons (PA or EBV) have a higher gLPI than he has.  In fact  his highest gLPI son is almost 5% lower on his indexes than he is. It begs the question, “Will Man-O-Man ever have a son that indexes higher than himself?”

Proven Track Record

When we look at the current CDN Sires of Top 100 LPI Bulls, we find the following sires are proving themselves as sires of sons.

    the sire of Man-O-Man, has 6 sons in the top 100 in Canada with an average LPI of 2496.  This is by far the highest LPI average for sons! O Man has 15 genomically tested daughters worldwide higher than himself and 18 genomically tested sons worldwide  indexing higher than himself.(Ratio of 45% daughters to 55% sons).
    has the next highest son average LPI at 2137 on 11 sons.  Worldwide Bolton has 141 genomically tested daughters and 52 genomically tested sons higher than himself. (Ratio of 73% daughters to 27% sons).
    follows next.  He has 9 sons averaging 2023 LPI. On a global basis Baxter has 292 genomically tested females  and 191 genomically tested sons higher than himself.  (Ratio of 60% daughters to 40% sons).

These previous three sires have produced BOTH daughters and sons, who have surpassed them. Let’s look at another list that is producing top bull mothers but who have yet to produce a legacy son.

    139 daughters genomically tested worldwide higher than himself
    36 sons genomically tested worldwide higher than himself
    (Ratio of 80% daughters to 20% sons)
    91 daughters genomically tested worldwide higher than himself
    39 sons genomically tested worldwide higher than himself
    (Ratio of 70% daughters to 30% sons)
    379 daughters genomically tested worldwide higher than himself
    84 sons genomically tested worldwide higher than himself
    (Ratio of 82% daughters to 18% sons)

The anomaly is Bolton.  He ranks high for progeny average LPI on both the CDN List for Top 100 LPI Bulls (#2) and on the Sire of Top 1000 GLPI Cows (#3). However, his ratio indicates that he will work slightly better as the sire of bull mothers.

The Bullvine Bottom Line

The past foretells the future. Instead of running out to use Man-O-Man to produce that next great sire of sons, he is better used to generate that next great bull mother.  Also, instead of looking to use Man-O-Man sons as the next great sires of AI bulls, breeders  should perhaps  look at sons out of Man-O-Man daughters . History has shown that some bulls are meant to be bull mothers (Goldwyn, Planet and Shottle) and some bulls are more destined to be  sires of sons (AltaBaxter, and Oman). Man-O-Man’s numbers would indicate that he is going to be a better producer of bull mothers.


  1. Hi,
    I think you are looking at this incorrectly. First of all, other than the X/Y chromozone, a bull will pass on identical genetic material to females as males. So the idea of a bull that is best at siring bull mothers or best at siring sons has no real scientific backing. Secondly, the statistics you cite are very contrived. For example, Oman’s 55/45 male female split is likely like that way because many of his daughters would never have been tested genomically, not because of how he passes on his genetics. Of the other hand, Goldwyn has a strong 80/20 split because his daughters are put into situations where they get inflated proofs (remember what Missy’s numbers looked like at one point?). You even say that Planet is meant to be a bull dam sire. This is actually quite funny: Planet is not quite 10 years and has not had a single son proven. However, he is the sire to bulls that you may have heard of such as Observer or Bookem. His daughters indices are also likely higher than their true indices. For MOM specifically, you cite that he has 6 daughters ahead of him but no sons. First, MOM probably has an inflated proof in Canada, which means his own numbers are much too high. Secondly, citing that all 6 are females is not conclusive or really even meaningful. It is much too small of a sample. Also do not forget that you do not have access (as far as I know) to his sons that are still young and that, for many of the top cows/heifers, he was likely used in female sorted IVF, which would also result in a skew.

    I do hope that this was followable and logical. Sorry for the single paragraph.

  2. Could be an interesting discussion. I would never use Oman because of his low udder scores, but said that he would probably have better sons that are very useable.
    I don’t like Goldwyn because he isn’t a long lived bull and from a short lived family. But Goldwyn is one of the greatest type bulls ever, even though his pedigree isn’t. No rhyme or reason for Goldwyn in my opinion. Simply good bulls come from where ever with nothing backing them sometimes. I expect he will provide some great sons and daughters mixed to the right cattle who can provide very good cattle that can last a long time. Most of his daughters and sons will probably die early. Hey I would love to hear any explaination on why he proved to be so good on type.
    Johnny Stansell

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