SUPERFECUNDATION AND SUPERFCETATION 45 



development of this disease. Should lactation cease before 

 the end of pregnancy, the patient improves ; while six to eight 

 weeks after birth the disease becomes extensive (Friedberger 

 and Frohner). 



Calves borne by cows suffering with osteomalacia are often 

 in good condition, making it appear that lime salts for the 

 formation of the osseous frame of the foetus were furnished at 

 the expense of the mother. 



Cows in the second half of pregnancy often suffer with 

 indigestion; it being rare when they are fed properly. In 

 certain localities, however, where for economical reasons a 

 voluminous diet, often difficult of digestion, is furnished, 

 digestive disturbances in the pregnant animal result. 



9.— Superfecundation and Superfcetation. 



By superfecundation is understood the fertilization of two 

 or more eggs of one oestrum at short intervals ; this making it 

 possible that one ovum is fecundated by one bull and the 

 other ovum by another bull. At birth the mother bears two 

 young created by different males. In the cow this is ex- 

 ceedingly rare. 



By superfcetation we understand conception during preg- 

 nancy. This has been seen occasionally in the cow. As a 

 rule, the second conception induces abortion of the first 

 foetus ; but it happens that one calf is carried the full term, 

 and the other is aborted, that both calves are retained or both 

 foetuses are aborted. 



