Statistical Analysis
All variables were tested for normality using the
Shapiro-Wilk test (Shapiro and Wilk, 1965) and
transformed into logarithm form to normalize their
frequency distribution, when necessary. Then, data
were processed by ANOVA using the GLM procedure
of SAS (SAS Institute, 1999) for repeated measures.
The variation attributable to the fat supplementation
was tested. The variation attributable to fat supplementation,
time of sampling, and their interactions was
tested for milk, protein, and fat yield and milk energy
output. Individual animal variation within treatment
was used as the error term. When significant effects
were found (at P < 0.05), Student’s t-test was used to
locate significant differences between means.