Section 14 — Animal Genetics and Breeding 



embryonal development connected with the 

 maternal organism; (b) hereditary peculiarities 

 of paternal and maternal organisms. 



When crossing birds with contrasting produc- 

 tiveness and constitution (egg-producing and 

 double-purpose breeds) the progeny mostly 

 inherits egg productiveness and physiological 

 earliness from the paternal organism and live- 

 weight, hatchability and fattening characters 

 from maternal organism. 



While selecting fathers and mothers with 

 similar productiveness and constitution (double- 

 purpose poultry breeds) we observe that in- 

 breed mating and interbreeding do not result in 

 the regular paternal or maternal influence on 

 live- weight. 



Only daughters are inclined to inherit live- 

 weight from mothers and even less so from 

 fathers. 



High meat qualities are inherited by the prog- 

 eny particularly from the paternal organisms. 

 The above-mentioned regularities in hereta- 

 bility of characteristics when selecting poultry 

 of contrast or similar breeds are efficiently used 

 by poultry breeders in their work. To produce 

 highly productive hybrids of double-purpose 

 breeds, parental forms are selected from egg- 

 producing breeds or strains, and maternal — 

 only from double-purpose ones. For the develop- 

 ment of hybrids, growing for meat, paternal 

 and maternal forms are selected from special 

 double-purpose breeds and strains. In this case 

 the parental form should have high meat quali- 

 ties which positively correlate with the live- 

 weight, and the maternal form should have 

 high egg production and vigorous constitution, 

 which is characterized by high vitability, hatch- 

 ability, intensive metabolism and by some 

 interieur features (development of thumus). 



14.37. Diallel Crosses of Inbred Lines of Egg-type 

 Poultry Repeated over Locations and Years. 

 I. The Relative Importance of Different Kinds 

 of Genetic Effects. L. H. Baker and R. B. 

 Arvidson (Des Moines, U.S.A.). 



The now classical concepts of general and 

 specific combining ability have been extensively 

 applied in evaluating inbred lines of corn. 

 However, all published evidence concerning the 

 relative importance of these genetic effects in the 

 fowl may be of limited value, since it has all been 

 based upon results from individual performance 

 tests. 



Because genotype and environment have inter- 

 acting effects on the phenotypic expression of 

 quantitative characteristics, the data from a 



specific experiment pertain only to the genetic 

 variance of the population with reference to the 

 environment (s) actually sampled by the experi- 

 ment. Therefore, points of major interest in the 

 design and analysis of a hybrid breeding program 

 are: 



(1) The consistency of estimates of general and 

 specific combining ability variances from 

 experiments repeated over a series of 

 locations and years, 



(2) Estimates of variance in genetic and recip- 

 rocal effects defined as averages for the 

 totality of environment pertinent to the 

 destiny of the genetic populations studied, 

 and 



(3) The relative importance of additive and 

 specific effects in lines selected over years. 



The study reported here represents an attempt 

 to evaluate these points of interest and compare 

 the results obtained with estimates of genetic and 

 reciprocal effects available from other studies in 

 the fowl. 



14.38. A Case of Hairlessness in Cattle. V. Derlogea 



(Bucarest, Rumania). 



Two calves of the Pinzgau breed ($ and ^) 

 hairless were born in 1962 in the Nasaud county 

 — Cluj region. Their birth weight was normal 

 and except the above-mentioned characteristic, 

 they did not present any other phenotypical 

 peculiarity. Beginning with their second week of 

 life, they suffered from repeated indigestions, lost 

 weight and died, one 52 days old, the other but 

 16 days old. 



As compared to the previously described cases 

 of semilethal allopecy (Surrarer, Hut and Saun- 

 ders), these calves presented the particular 

 characteristic that even their eyelids and tail- 

 end were bare of hair. 



The histologic cross-sections through their 

 skin showed very rarely distributed hair follicles, 

 the sheaths of which were much enlarged and 

 distorted resembling small lodges in which the 

 hair roots were coiling around several times. 

 There was a total disturbancy as regards the 

 orientation of the follicles and an utter impossi- 

 bility for the hair to push towards the exterior 

 (Fig. 2). 



Breeding history. The mothers of these calves 

 were daughters of an imported Pinzgau bull 

 used in the A. I. Centre of the Nasaud county. 

 These cows were at their first calving. Their mat- 

 ing had taken place in the conditions of moun- 

 tainous pasture land where they had been put 

 together with three bulls of the same herd, two of 

 which were closely related with the cows, one 

 even being a half-brother. 



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