Produce of Calves by a Herd of Cows-. 



115 



On the 21st of October, 1839, I calculated that I should have 

 40 live calves previous to the 1st of August, 1840. I had 48. 



I have made several other calculations of the same kind to test 

 my principle, but it would be tedious to state any more of them. 

 This last is the one in which the event has differed the most from 

 the expected result. It will be seen that in all these trials of my 

 system I must have included in my calculation all the cows 

 bulled up to the day of making it, for the period over which the 

 calculation extends equals the ordinary time of the gestation of a 

 cow, and therefore I think the accuracy with which the result of 

 the calculations has agreed with the event proves that a Table of 

 Odds may be constructed, which upon any given number of cows 

 will prove tolerably correct. 



It is so obvious that it is hardly necessary to state how I make 

 these calculations. Taking the first Table I have given, for in- 

 stance, I divide the sum total of the cows in calf by the sum total 

 of the numbers in each of the previous columns, and the deci- 

 mals which will be the product of such divisions will show the 

 probability of a cow proving in calf who shall not have returned 

 to the bull at the end of each week respectively. This process I 

 apply to ascertain the probabilities in the other Table. I then 

 multiply the number of cows who have gone 21 weeks by the 

 decimal belonging to this column ; the number who have gone 

 18 weeks and not 21, the number v/ho have gone 17 and not 

 1 8, and so on, by the decimals respectively belonging to these 

 columns. I add the products of these multiplications together, 

 and the sum total gives the probability of the whole list : I mean, 

 it gives the probable number of cows who will prove in calf. 

 From this must be deducted the number who will probably not 

 produce live calves, according to the allowance to which I have 

 referred above. With respect to the other Table, I treat it in the 

 same manner, and assume the probable number of cows to go six 

 weeks as if they had actually gone that period, and add it to the 

 first column of the first-mentioned Table. 



If I thought that the observations which I have made would 

 apply to cattle generally, as well as they appear to have done to 

 my own herd, I should think them of considerable use ; but I do 

 not think this is likely to be the case. My object in breeding is 

 to breed bulls, and I am therefore constantly in the habit of per- 

 severing in the attempt to procure calves from cows, and by bulls 

 who are so uncertain as breeders that a farmer in ordinary cir- 

 cumstances would have put them to feed and have sold them to a 

 butcher long before I do. But I think that, if any breeder will 

 take the trouble to make the same sort of observations with respect 

 to his herd which I have with respect to mine, he will very soon 

 arrive at full as great accuracy in the results as myself. I am 



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