Hawk H W, Conley H H, Kiddy C A
J Dairy Sci. 1984 Feb;67(2):392-7. doi: 10.3168/jds.S0022-0302(84)81314-4.
Dogs trained to identify vaginal mucus samples and other fluids from estrous cows were used for further studies of estrus-related odors in milk. In the first experiment, milk was collected from 10 cows during estrus and luteal phase of the estrous cycle and tested in trials of 9 samples each; 1 or 2 of the samples were from estrous cows. Dogs responded to milk from estrous cows in 76% of the exposures to such samples with significant differences among cows and significant improvement by the dogs during the experiment. Responses to milk from luteal-phase cows, averaged 6%. In a second experiment, milk was frozen and thawed four times without decreasing the frequency of response to samples from estrous cows. In the third and fourth experiments, milk was collected from four cows on several days of the estrous cycle. After the dogs were trained to respond to milk from pre-estrous cows (1 or 2 days before estrus), they responded to 64% of these samples; after the dogs were retrained to not respond to milk from pre-estrous cows, they responded 21% of the time to milk obtained 1 to 3 days before estrus. In these two experiments, responses to milk from estrous cows averaged 83% and to milk from luteal-phase cows, 8%. Trained dogs can distinguish milk of pre-estrous cows from milk of either estrous or luteal-phase cows.
经过训练能够识别发情母牛阴道黏液样本及其他分泌物的狗被用于对牛奶中与发情相关气味的进一步研究。在第一个实验中，从10头母牛发情期和发情周期的黄体期采集牛奶，并在每次9个样本的试验中进行测试；其中1或2个样本来自发情母牛。在76%的此类样本暴露试验中，狗对发情母牛的牛奶有反应，不同母牛之间存在显著差异，且在实验过程中狗的反应有显著改善。对黄体期母牛牛奶的反应平均为6%。在第二个实验中，牛奶被冷冻和解冻4次，对发情母牛样本的反应频率并未降低。在第三个和第四个实验中，在发情周期的几天里从4头母牛采集牛奶。在狗经过训练对发情前母牛（发情前1或2天）的牛奶做出反应后，它们对64%的此类样本有反应；在狗经过重新训练不再对发情前母牛的牛奶做出反应后，它们对发情前1至3天获取的牛奶有21%的反应时间。在这两个实验中，对发情母牛牛奶的反应平均为83%，对黄体期母牛牛奶的反应为8%。训练有素的狗能够区分发情前母牛的牛奶与发情期或黄体期母牛的牛奶。
