fertility

[knabe]

Has anyone followed lines where say a bull didn't pass a fertility exam and the fertility of full sibs or half sib females and their progeny's fertility, notably males?

ie, if a bull failed on motility, or count, and failed repeated tries, ie not an isolated occurence, and by chance he sired 2 females, has anyone followed fertility?

basically the question is i have identified a line that basically has only two direct daughters, the line is alive, the phenotype is unique and prepotent, and the cows are longlived and productive, though one daughter only has females.

 

[aj]

I have always heard that under selection pressure that you cull for poor fertility but you couldn't really select for good fertility. Thats interesting.

 

[blackcows]

Knabe,

Is your concern that if you continue with the lineage you may be breeding for poor fertility?  If so I would say it may be a valid concern but without knowing the exact cause for the poor fertility of the sire I certainly wouldn't give up on the line.  Many other factors could have contributed to poor semen quality like nutrition, environment, or injury.  If you cull open cows the line would eventually work it's way out of the herd over time anyway.

Mike

 

[knabe]

Knabe,

Is your concern that if you continue with the lineage you may be breeding for poor fertility?  If so I would say it may be a valid concern but without knowing the exact cause for the poor fertility of the sire I certainly wouldn't give up on the line.  Many other factors could have contributed to poor semen quality like nutrition, environment, or injury.  If you cull open cows the line would eventually work it's way out of the herd over time anyway.

Mike

ditto on the first sentence.  the cows seem fertile and uh, extremely productive.

 

[GONEWEST]

Knabe,

What do you think of the line of reasoning that says if infertility were highly heritable, since  infertile cows would not be able to produce as many offspring and therefor over time would have eliminated themselves from  the gene pool?

 

[knabe]

to me, low heritability means more genes, or phenotypic ones.  for me, turnover to next breeding is probably the least appreciated trait from wildebeasts.