In several studies conducted during the starting and fattening periods of broiler stock, and the starting and growing periods of laying stock, levels as high as 20-percent sugarcane molasses were utilized satisfactorily in practical-type diets by the birds. Variations obtained in the different studies were discussed. Caked litter resulted with population densities of 0.19 m.2 (2 feet2) per bird when a 20-percent molasses diet was used, while semi-caked litter resulted with a level of 15-percent molasses. These results imply that with densities of 0.09 m.2 (1 foot2), equivalent to practical management conditions, a level of 10-percent molasses in diets appears borderline. Further corroboration studies seem to be indicated, to determine and recommend the maximum economical level of molasses in the diet which will not result in a compact litter. Feed cost data and their relation to the efficiency of utilization in these studies were evaluated. Inconsistent experimental data from previous experiments is discussed. A new technique for the homogeneous dispersion of molasses is described.

A trial to determine the feasibility of using a cull dairy cow to rear her own calf and an additional adopted one was conducted at the Corozal Substation of the Agricultural Experiment Station, Mayagüez Campus, of the University of Puerto Rico. The data indicates these dairy culls can rear both calves satisfactorily to 8 months of age. The two groups in the experiment were subjected to two different treatments: (I), weaning the adopted calf at 4 months of age and feeding 4 pounds of concentrate, supplementary to grazing, for the subsequent 4 months while leaving their own calf with the dam until 8 months of age; and (II), nursing of the cow by both calves until weaning at 8 months of age. The analysis of the data indicates no benefit from weaning calves at 4 months of age. Although the adopted calves weaned at 4 months of age were 11.95 pounds heavier at 8 months than those that continued to nurse their foster mother until 8 months of age, costs of concentrate feeding and extra labor requirements more than offset the extra weight gains. The statistical analyses of the data for weight gains showed a significant difference in favor of own calves over adopted ones at all ages. The sex of calf had no effect on any of the weight gain comparisons. The rate of gain of the adopted as well as the own calves is presented. There were no adoption problems. The average calving interval for cows that freshened at least two times was 395.24 days. Twenty three cows showed reproduction failures, nine of which never freshened.

The results of these studies demonstrate that: 1, Coconut meal contains a high level of crude protein but is deficient in some of the essential amino acids, particularly lysine and methionine-cystine, required by poultry; 2, a caloric deficiency resulted in practical-type diets when a per unit substitution by coconut meal was made of yellow corn; 3, levels of coconut meal (expeller-process) as high as 50 percent were used satisfactorily by broilers in properly-balanced, practical-type, fattening diets; and 4, economic considerations, such as price and availability of ingredients, will determine the amount of coconut meal to incorporate in practical-type poultry feeds up to the limiting level of 50 percent.

USE OF HEAT LAMPS IN FARROWING PENS

The performance of the pigs of the 3/4 Duroc X 1/4 English Large Black Landrace line developed by the Station was compared with the performance of some imported animals. These imported pigs were from the Duroc, the Yorkshire, and the Hampshire breeds. The comparison and the evaluation of the animals was based on preweaning and postweaning characters. The preweaning characters considered were the number of pigs at farrowing, the number at 21 days, and at weaning age. The rate of gain, the feed efficiency, the back-fat thickness corrected to 200 pounds, and carcass evaluation were considered as postweaning characters. All the data obtained were submitted to analysis of variance and where the F values were significant, they were subjected to a Duncan Multiple Test to determine significance among the means. The overall evaluation of both preweaning and postweaning characters showed that the animals of the 3/4 Duroc X 1/4 English Large Black Landrace line of pigs were as good as any of the animals of the imported breeds with which they were compared, with the possible exception of the carcass evaluation, where the imported breeds gave somewhat better results. They were especially good in the number of pigs weaned, as well as in the weight at weaning time and in rate of gain.