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SECOND HALF of

"Bloodlines, Breed Structure, and the Influence of

Artificial Insemination in Dexter Cattle"
by Andrew Sheppy

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Line 5: Doesmead – Templeton Michaelmas Squeak (2043)

John Tuckey’s Doesmead herd was started in 1942, “one of the largest milking herds ever seen in Dexters” (p.155) [see photo below]. The Doesmead-bred Templeton Michaelmas Squeak became a significant AI bull. Though he goes back to a non-pedigree Jersey cross cow in his 5-generation pedigree, his progeny have “very few, if any, atypical characteristics”. One of his grandsons was exported to Denmark.

Line 6: Woodmagic – Woodmagic Mudstopper (8327 CM)

This is the only of the 8 lines founded on a cow, Woodmagic Mudstopper [photo below, from DCS UK Herd Book]. The herd, established by Beryl Rutherford in 1951, has had close breeding for many years so that “all Woodmagic animals are effectively sons and daughters of the same cow” (p.157). No bulldog calves have been produced by Woodmagic cattle as they have been exclusively “non-dwaf bred”, and the herd has been the source of dun coloured Dexters. The principal source of duns has been Mudstopper’s sire, Woodmagic Mole. Extensive exports of this line have been made to many countries, especially Canada and Denmark.

Line 7: Marsh – Marsh Warrior (1777)

Mr T.S. Pick established this herd in 1936, it surviving until 1965. Marsh Warrior was the DCS’s official AI bull 1964-66, coming from Grinstead breeding. He has few descendants today in the UK but a number in Canada, USA, Australia and New Zealand via Saturn of Knotting. Parkwood Harold, a son of Marsh Warrior, was exported to South Africa.

Line 8: Parndon – Melbry Duster (2034)

From 1949 to 1969, the Parndon herd was operated by W.R. Thrower. Sylvan Ebony, founder of the Doesmead line, was a Parndon herd sire for a number of years. Sheppy is critical of Thrower – “In scarcely a single year has the herd return and list of births been fully and correctly recorded in the normal manner. In the latter years…pedigree records were systematically falsified with cows in two…or three countries having the same name, Herdbook number and registration details” (p.159). Sheppy contends that Parndon Charley Pudding “was in fact half Guernsey” although he was registered as the son of a black Dexter bull and a red Dexter cow. Recessive white spotting in calves of his descendants confirm that he could not have been pure Dexter. Yet two sons, Parndon Bullfinch and Parndon Buster Finch were very extensively used via AI and the former went to the USA at a time when the national herd was relatively small. Parndon Buster Finch’s son, Melbry Duster [see photo to right, from DCS UK Herd Book], stood at AI in the UK and is founder of this eighth line. Sheppy also argues that an unregistered Dexter bull from a Scottish herd was substituted by Thrower for Parndon Buster Finch for a time in the late 1960s. This means that the sire of Melbry Duster cannot be verified and the purity of his line must be questioned.

Relationship of Lines

Based on an analysis of their 5 generation pedigrees, Sheppy concludes that apart from the case where Sylvan Ebony (Weatheroak line) is the great grandsire of Melbry Duster (Parndon line), “the eight representative line animals are remarkably little related…and can be treated effectively as separate bloodlines” (p.162). Note that this conclusion is based on 5 generation pedigrees, and does not take into account the extent to which all these pedigrees relate back to Ratcliffe Negro's Manager.

The Influence of Artificial Insemination

The Dexter Cattle Society UK decided in 1944 to make semen from registered bulls available for AI. This assists breeders to gain access to purebred semen but a narrowing of genetic material can result. An analysis of the 747 full pedigree registered females in the 1982 Herdbook showed that 46% came from the Woodmagic line, 29% from Weatheroak, 29% from Summerdale, 14% from Doesmead, 10% from Shadwell, with less than 10% from the remaining 3 lines. 3% of the cows had 6 lines in their pedigree, 15% had 5 or more lines, 33% had 4 or more, 55% had 3 or more. Only 83 cows were free of AI line ancestry. Sheppy concludes that in 1982 “the AI line animals were already having a disproportionately large influence on the breed” (p.164).  Further analysis of bulls registered in 1970, 1980 and 1990 showed that it had become difficult to find any bull without Sylvan Ebony in its pedigree and that the breed had become very mixed in bloodlines with very few pure line animals. In 1990, only two of the 185 bulls registered that year did not come from the 8 lines identified above.

Conclusion

The widespread use of AI in the UK has resulted in a major narrowing of the Dexter genetic resource. The spread of European stock globally has meant that “many of the impurities and potential problems have also been exported”  (p.165). “Should the breed be regarded only as that portion of the stock which is unquestionably pure old Dexter, in which case the breed is very rare indeed” (p.166).

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