Moose Antlers the fastest cells on earth

Totally off-topic but I like them...


Moose antlers are formed by the fastest-growing cells in nature. The main purpose of moose antlers is as a weapon for fighting for a mate, a period that generally only lasts from September to October. Therefore, antlers are unneeded after that point. The growth is prompted by the release of hormones that occurs around April or May, and each new set of antlers is generally increasingly larger than the last as a moose reaches its prime at around six years. After that, the cells in the antlers decrease in growth speed until the antlers eventually recede.


from Wise-Geek.

Alleles and Hardy Weinberg

Enter into the evolution debate, the Hardy-Weinberg law,  which is an algebraic equation that describes the genetic equilibrium within a population. It was discovered independently in 1908 by Wilhelm Weinberg, a German physician, and Godfrey Harold Hardy, a British mathematician and codified into a set of algebraic laws used primarily in population genetics.

 

The idea is, that in a large, random-mating population, the proportion of dominant and recessive genes tend to remain constant from generation to generation unless outside forces act to change it. This means that even the rarest forms of genes, from long ago in the ancestry of the species are preserved.

So if we know the number of individuals in any given population,looking back at the SvartHona example we know that they took 12  samples from their whole population.  Then the Hardy-Weinberg equation is applied to calculate the allele frequency over a period of time.

It is that last bit, that is always problematic, as you need the same starting point, which is why they often grow their specimens and start their calculations from that point.  With eggs like seeds, that is easy enough to do as they have relatively short incubation periods.

What's an Allele, understanding lethal poultry genetics.

Evolution is a change in the frequencies of alleles in the gene pool of a population.

A gene is a stretch of DNA or RNA  chemicals that determine a certain trait. DNA, or deoxyribonucleic acid, is like a blueprint of biological guidelines that a living organism must follow to exist and remain functional i.e. why a cow is  a cow and cat a cat.   DNA is also self-replicating.

RNA, or ribonucleic acid, helps carry out the DNA's instruction and while more  versatile than DNA, and capable of performing numerous, DNA is stabler and holds more complex information for longer periods of time.


In animal breeding, there is a controlled propagation of domestic animals in order to improve desirable qualities and typically the DNA traits (genotype) are unknown, so farmers have traditionally relied on phenotypes (appearance and characteristics) to modify domesticated animals to better suit human needs for centuries.

This is done via Selective breeding i.e. breeding a larger rooster against a medium size hen or vice or verse to get a large chicken.  Genetically this happens as genes mutate and can take two or more alternative forms based on the allele it receives from the parents.  For example, the gene for eye color has several variations (alleles) such as an allele for blue eye color or an allele for brown eyes etc.


An allele is found at a fixed spot on a chromosome and now thanks to genetic research scientists know where on the chromosome each point controls.  When you see Locus 32, that means that at Spot #32 was discovered to control X.  Locus being Latin for Spot or location.

As chromosomes occur in pairs, organisms always have two alleles for each gene — one allele for each chromosome in the pairing. Since each chromosome in the pair comes from a different parent, organisms inherit one allele from each parent for each gene and the two alleles inherited can either be the same (homozygous) or different (heterozygous).

The Swedish Black + the Silkie

Jamie Watter's Svart Hona Rooster

The Swedish Black chicken, shown, is for its dermal hyperpigmentation phenotype (it is all black).  While most have dark skin, like the Silkie and the Ayami Cemani, there are some that have lighter skin.

The paper by Anna M. Johannson in the Dept of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, in  Uppsala, Sweden, discusses this in depth.

I've taken some of the highlights of Ms Johannsson's paper and put them here.

If you want the whole paper, contact me and I will gladly send the PDF with her contact details as well if you would like to follow up with further questions about her findings.

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There are 11 Swedish local chicken breeds of which two, the SvartHona and the Hedemorahona are discussed, because these as the breeds that are notably all-black.  Ms Johannsson's study was really about the their comb colour, that can be categorized into three categories: red, semi-dark and dark.

It was noted by the owners of these birds over several generation.  The males in particular

Jean Cavanagh's BIS Black Bearded Silkie Blessing

have all three comb colours while females tend to have only red or dark combs.  (I could find no examples of these combs, sorry).

The appearance of a red comb points to the involvement of the Z chromosome in the trait. Additional observations from a bird owner, who is interested in genetics, showed that the inheritance of comb colour can mostly be explained as a Z-linked inheritance, but that there are exceptions that do not fit with a single Z-linked locus (Johansson cites, Swedish breeder Thomas Englund, in  personal communications).

The Fm and id loci are known to be involved in the dark pigmentation phenotype in the Japanese Silkie (Bateson and Punnett, 1911; Dorshorst et al., 2010) as well (see an example of the Silkie from my friend Jean).

The now living birds in both of these breeds originate from small relics of earlier larger populations.

What we want to do is map the  loci associated with the comb colour trait segregated within the two breeds. To do this we genotyped 12 Bohuslän-Dals svarthöna and Hedemorahöna with the 60k SNP chip produced by Illumina for the GWMAS Consortium (Groenen et al., 2011). An association study was performed on the genotypes given the recorded comb colour phenotype.  The huslän-Dals svarthöna originates from the northern part of Bohuslän in western Sweden (close to the Norwegian border -- see map below for the location of Bohuslan, taken from Yahoo Maps.)

What was discovered was that around 1899, a woman got the ancestors of the current population of this breed as a wedding gift. Her two sons inherited the flock,  and in 1958 a man got the birds from the two brothers (Olsson, 2004).  These black birds are said to have be common in this area in old times and there is a legend stating that they are the descendants of birds that sailors brought back from long tours overseas to a foreign country.

 More than that is not explored in the paper but the diversity and inbreeding of the two breeds was,  with the mean inbreeding coefficient (F)  considerably larger in the samples from  Hedemorahöna than in the samples from Bohuslän-Dals svarthöna, and so it was concluded by genetic testing  that the Bohuslän-Dals svarthöna (black Swedish)  individuals were not inbred despite expectations.  That conclusion was derived as their  F coefficient was  less than or close to  zero, which under the Hardy-Weinberg equilibrium means that the these birds  are more heterozygous (different and less inbred) than higher numbers.

 However  half the Hedemorahöna individuals had a F coefficient that was great 0.1 and most of these had F>0.2  (see the supplementary Table 3 in the Johansson paper), with the most inbred  Hedemorahönas had F=0.45. 

Bigger is Better

In the latest WATT Poultry newsletter they have a set of panellists talking about industry trends.  one that they all agreed on was the trend towards more and larger broilers will continue.  Large here is 8 pounds liveweight.

 

Ttypically that as a standard bred is a Jersey Giant, Orpington or Brahma.  But they are slow growers so the Barred Rocks are typically preferred.) broilers being produced will continue.  We had Brahmas and it did take 6 months to get to 11 pounds and we had him for Thanksgiving.  He was delicious.  We have never had Giants or Orps though a friend, Bob R.,  from Aberdeen, South Dakota,  wants to change that.  He sells a lot of Jersey Giants to the home market for just that purpose, keeping the "lookers" for his show pen.  If you are interested, go to their site, read about the Giant and see if one is in your future.  Bob btw is the Veep.

 

The reason is the cost advantage towards processing larger birds especially 9 pounders.  And there is one processing plant is getting 10 pounds birds. How does compute?  Well everything is larger and easier to clean i.e. process.  Most home birders like small single serving birds or if they have small kids, they go for the colourful and very pettable Silkies.  

 

The article continues that the "chase" towards bigger birds will until either the genetics or economics dictate otherwise.  In the meantime, increased chicken production over the next  2 two 3 years will come from more birds and heavier birds.

What's the Beef?

An economist speaking at the Oilseed and Grains Trade Summit,  said that the smaller cattle inventory, declining calf crops as well as smaller cattle supply have all resulted in a reduced cow slaughter obviously.  This has resulted in record low beef supplies... and record high prices.  Meaningful increases in beef production are at least 2 years away.  In the meantime, think chicken.