288 
BREEDING OF FARM STOCK. 
materials of the food is equally important for the formation 
of the fatty matter of the blood, whatever may be the form 
into which the animal system may convert it; and for this 
reason those animals which are best adapted for fattening are 
also best prepared to fulfil the first condition essential for the 
production of rich milk. 
We have now to consider the influence of the animal sys¬ 
tem upon the rich fatty matter circulating in its blood. The 
formation of milk is primarily dependent upon the activity of 
the mammary glands, which are naturally excited to action 
a short time prior to the birth of the offspring. The energy 
of these glands is naturally superior to the tendency which 
the animal possesses for the formation of fat; so much so, 
indeed, that when the food is deficient in oily matter fat 
which has been already formed is sometimes taken up again 
into the circulation and separated by the mammary glands in 
the milk. Thus we find that when these glands are acting 
in a healthy and energetic manner the fatty matter of the 
blood is freely separated by their agency, and we have a rich 
milk produced. In very many instances these glands have 
assumed an unnatural and torpid condition, have become 
less susceptible of the energy usually imparted by the birth 
of offspring, and have been influenced by it for a shorter 
period of time. In such cases, although the food may have 
been well prepared and the blood may travel through the 
vessels of the glands richly laden with the elements of milk, 
yet, from their torpidity, they may fail to appropriate it as 
milk, and the blood may pass on to yield its treasure toother 
parts of the body. Our great endeavour should therefore be 
to encourage a more active condition of these glands. These 
organs, in common with other parts of the system, are subject 
to hereditary influence, and much may be done in this di¬ 
rection to stimulate them to the performance of their natu¬ 
ral functions, whilst a neglect of this agency will increase 
and perpetuate an evil which considerably reduces the value 
of much of our breeding-stock. Not only may we hope that 
by judicious management these organs may again be raised 
to their natural standard of efficiency, but, like other parts 
of the animal system, become even more highly developed 
under the fostering care of man. Instances are by no means 
rare in which we observe in happy combination an aptitude 
for the formation of fat with sufficient energy of the mam¬ 
mary glands to produce a liberal supply of milk. Generally, 
in the case of cows, those that produce butter freely are sub¬ 
sequently found profitable for feeding for the butcher. With 
ewes thus distinguished the lambs thrive without extraneous 
