The study was conducted by assigning cows to weekly cohorts. On any given day, the
214 employees were only handling a single GnRH product. The first GnRH was administered when
215 cows went through the palpation rail on Tuesday morning. On Thursdays afternoons, cows were
216 administered GnRH when they were in the rotary milking parlor. There would be only one
217 GnRH product and this product alternated weekly so that it was matched with the GnRH product
218 given 9 d earlier. Cows stayed on the same treatments but the product that was used on Tuesday
219 on the rail was not the same as the product that was used two days later (Thursday) on the rotary.
220 We did the experiment in this manner so that treatment administration was simpler and more
221 compliant. An alternative design where cows were individually assigned to treatment (instead of
222 cohorts) was initially considered. Although the treatment of individual cows (and not cohorts) is
223 probably a superior experimental design, we abandoned the design because of the logistical
224 concerns that it created