112 Produce of Calves by a Herd of Cows. 



cost is trifling; its carriage light, since a waggon will convey 

 enough gypsum to dress 30 acres of grass. It is a manure, too, 

 that abounds in all parts of England — hardly a county is destitute 

 of it in some form or other ; and there is no extensive district to 

 be found in which large breadths of land are not benefited by its 

 judicious application. 



XV. — On the means of calculating the number of Cahes which 

 ivill probably be produced by a herd of Cows. By Earl 

 Spencer. 



It would be a considerable practical advantage to breeders of 

 cattle, and particularly to those who purchase cows, if there were 

 any means of ascertaining whether a cow was certainly in calf at 

 an early period of her gestation. I have found that what I be- 

 lieve to be the ordinary rule among farmers, viz., that when a 

 cow has not returned to the bull for six weeks after she has been 

 bulled she is certainly in calf, is by no means to be depended 

 upon ; and having observed, as I thought, that this was the case 

 in my herd of cattle, I resolved in the beginning of the year 

 1837 to ascertain with accuracy, first, whether a cow, not having 

 returned to the bull for six weeks, was either certainly or to a 

 very high degree of probability in calf ? and secondly, if it should 

 prove that this was not the case, at what length of time after she 

 had been bulled this certainty might be assumed. The result, I 

 am sorry to say, has been to prove that the cessation of taking the 

 bull for six weeks is so far from indicating with any certainty that 

 a cow is in calf, that, in my herd at least, very nearly half the cows 

 who have gone six weeks will prove not to be in calf^ and more- 

 over that there is no period at which a man can feel the certainty 

 required. 



I am aware other modes of ascertaining this fact have been 

 suggested by a very able and experienced veterinary surgeon, in 

 the Journal of our Society. He stated that by placing your ear 

 close to the cow's flank you may at a very early period of her ges- 

 tation hear the double pu'lsation of the foetus, and be satisfied 

 whether she is in calf or not. I have tried this frequently with 

 cows not only at early but at late periods of their gestation, but I 

 must confess that my sense of hearing has hitherto never been 

 sufficiently acute to perceive the slightest intimation of the exist- 

 ence of the foetus. I have tried the use of a stethoscope, but from 

 want of practice in the management of the instrument, or from 

 some other cause, I have with this also been equally unsuccessful. 

 I have also seen a surgeon well accustomed to the use of a stetho- 

 scope try it and fail as completely as myself. As to the other 

 modes of examination which are suggested in the same paper, in 



