CATTLE. 
125 
wrote in 1807, and since his day many improvements have taken place 
in the breeds of cattle ; and experience has proved, that the improved 
Yorkshire cow, in which the characters of the Durham and Holderness 
are mingled, unites the two qualities in high perfection. 
Reproduction, Rearing ami Fattening.— The heifer ought not to be 
permitted to breed until over two years old; the reason is obvious. 
Iter own system before this period is not sufficiently matured for the 
tax upon it — a tax which will be paid not only by the dam, but also by 
her progenjq for both will suffer from a deficiency in nutriment, the 
whole of which is necessary for the growth of the former, which during 
the second year is rapid. If the bull be kept separate from the herd of 
cows, the farmer may regulate the succession of calves almost at pleas- 
ure, so as to suit his pasture or his arrangements. The best time as it 
respects the mother, the calf, and the free supply of milk, is when the 
spring grass is beginning to shoot luxuriantly, affording a good and 
sufficient store of nutriment. It is true that veal and butter yield a 
better profit at an earlier period, but the breeder must judge in points 
of this nature from circumstances. The period of gestation in the cow 
is generally stated as nine calendar months, or 270 days; but there is 
often considerable variation of time. M. Tessier observes (in a memoir 
read to the Royal Academy of Sciences in Paris), that the shortest 
period, as far as his opportunities of observation enabled him to ascertain, 
was 240 days, the longest 321 ; the difference being eighty-one days.* 
This range of time is very extraordinary, and appears to depend on the 
care paid to the animal, and on its state of health ; by which the 
development of the calf is influenced through the sanguiferous system of 
the mother. With respect to the bull, he does not attain to a due degree 
of strength till two years old, and is in higher vigor at three ; but how 
long the breeder may keep him after that age must depend upon his 
own judgment, and a variety of circumstances. The cow seldom pro- 
duces more than a single calf, sometimes, however, twins, and very 
rarely three. In the case of twins, if they be respectively male and 
female, the female is generally, but not always, unproductive. 
It is sometimes desirable that the farmer should possess the power 
of controlling the ratio of the sexes in the animals he breeds. The 
wonderful ratio in which they are produced in nature, is one proof of 
the all-wise provisions of the Almighty in making them subject to 
certain laws. Many investigations have been made to show how far this 
is within the control of man. A dairy-man is particularly interested in 
the production of heifer calves, wherewith to increase his dairy stock ; 
a grazier may be equally desirous of producing bullocks for large weights 
and summer grazing; while a breeder for sale may be anxious to see a 
goodly proportion of bulls. How far he can control this production is 
a question of interest and importance. Hofkener, a German, made some 
calculations as regards the human species, which tended to show that 
where the father was younger than the mother, the proportion of male 
* In the Bulletin des Sciences, by the Soe. Philomatiquo, Paris, 1791, M. Tessier 
says, that out of ICO cows, some calved iu 241 days, and live in 308 ; giving a 
latitude of 67 days. — See Sir E. Home’s Paper on Phil. Trans. Part 1, for 1822. 
