64 Keport of Department of Animal Husbandry of the 



An increase in the fuel value from below 30,000 Cal. to more 

 than that amount, for cows giving about 22 lbs. of milk, was 

 followed by about the usual shrinkage in milk flow or less. A 

 reduction of the fuel value from above to below 30,000 Cal. was 

 followed by twice the usual shrinkage. 



An increase in the fuel value when above 30,000 Cal., for cows 

 giving about 24 lbs. of milk, resulted in a maintenance of the 

 milk yield without shrinkage. A reduction of the fuel value to 

 not less than 30,000 Cal., was followed by about twice the usual 

 shrinkage in milk. 



PROTEIN. 



In general, changes in the amount of protAi within ordinary 

 limits produced less effect than changes in the amount of total 

 nutrients. On the whole the diminution in milk flow was less 

 when the amount of protein was increased than when it was re- 

 duced. 



On the average for all records when the protein was increased, 

 those including also an increase of total nutrients show no fall- 

 ing oft' in milk production, those with but little change in 

 nutrients show a normal diminution or less, those with a reduc- 

 tion of nutrients show a shrinkage greater than usual. On the 

 average for all records when the protein was reduced those 

 with an increase of total nutrients show less than the usual 

 decrease in milk production, those with but little change of 

 nutrients show about the normal shrinkage, those with a reduc- 

 tion of nutrients show a falling off at twice the normal rate. 



The average of those records where there was an increase of 

 protein without change in amount of total nutrients shows an 

 increased cost of production. There was no increase in the cost 

 of production, on the average, when the protein was reduced 

 without change in amount of nutrients. 



A reduction in the amount of protein, when the ration con- 

 tained less than 2 lbs. per day per 1000 lbs. live weight, was fol- 

 lowed by about twice the usual shrinkage in milk flow. An in- 

 crease in the amount of protein when less than 2 lbs. was, in 

 general, followed by less than the usual shrinkage. 



