Cambridge Herd -Research

[JamsHundred]

From the 1930's into the 1950's Cambridge University had a Dexter herd and registered with the prefix Research. Ownership was listed as the Animal Nutrition Research Institute, and would have been connected to the school of agriculture.

Was anything ever published on their research? Is anyone familiar with this research or any conclusions of the studies conducted?

Judy

[Duncan MacIntyre]

Does this help:-

Crossbreeding experiments with Dexter cattle were done at Cambridge University in 1953 by Sir John Hammond to determine the maternal effect on calf size and development of the offspring. The largest of the British breeds, South Devon, was bred by artificial insemination to Dexter females and South Devon females. The smallest of the British breeds, Dexter, was bred by artificial insemination to South Devon females and Dexter females.

The resulting birth weights comparing the cross-breds with the purebreds were as follows:

Dexter x Dexter 49.0 lb
South Devon x Dexter 51.0 lb
Dexter x South Devon 70.0 lb
South Devon x South Devon 105.0 lb

In Sir Hammond's experiments, conducted in 1953:

For the South Devon breed, the average size bull was 2,464 lb, the average size cow was 1,032 lb, pure bred calf birth weights ranged from 65 lb to 142 lb, the average birth weight was 100 lb

For the Dexter breed, the average size bull was 978 lb, the average size cow was 535 lb, pure bred calf birth weights ranged from 32 lb to 70 lb, the average birth weight was 52 lb.


Read more: http://dextercattle.proboards.com/threa ... z4in998O4O

[Louisa Gidney]

Original paper was:
Joubert, D. M. & Hammond, J. 1954. Maternal Effect on Birth Weight in South Devon X Dexter Cattle Crosses. Nature 174, 647-8
Cited in my thesis

[JamsHundred]

Thanks Louise and Duncan,

The first calf registered in DCS with the "Research" herd identifier was in 1935. So they were breeding Dexters for two decades. Isn't it interesting that the only reported research then would be with animals they had crossed and nearly 20 years after they first obtained Dexters.

Judy

[Louisa Gidney]

Judy - I found an official biography of John Hammond online. His research interests were in reproductive physiology and it's made clear that he chose Dexters as research animals as he could keep two cows for the cost of one larger commercial breed cow and so double the results obtained in the same timescale. He was a pioneer of artificial insemination and embryo transfer. He was not interested in Dexters per se. The Dexter X South Devon experiment was a follow up to crossing Shire horses and Shetland ponies.