Olar T T, Amann R P, Pickett B W
Biol Reprod. 1983 Dec;29(5):1114-20. doi: 10.1095/biolreprod29.5.1114.
Two experiments established the relationships among total scrotal width (TSW), daily spermatozoal production (DSP), daily spermatozoal output (DSO) and extragonadal spermatozoal reserves (EGR) of dogs ejaculated daily. In Experiment 1, 11 dogs (14 to 36 kg) were ejaculated daily for two 10-day periods and in Experiment 2, seven dogs (15 to 47 kg) were ejaculated daily for two 20-day periods. Approximately six daily ejaculations were required for stabilizing DSO. After the second period of daily ejaculations, dogs were castrated or killed and the testes were weighed and DSP and EGR were determined. In Experiments 1 and 2, DSP averaged 11.7 +/- 0.5 and 16.7 +/- 1.4 X 10(6) per gram of testicular parenchyma, respectively, or 369 and 594 X 10(6) per dog. DSP per gram of testicular parenchyma was not significantly correlated with parenchymal weight for the same testis in either experiment (r = 0.04 and 0.26). Mean (+/- SEM) EGR of dogs in Experiment 1 were 4024 +/- 368 X 10(6) and 4791 +/- 767 X 10(6) in Experiment 2. Approximately 63% of the EGR were contained in the caput and corpus epididymidis, 36% in the cauda epididymidis and 1% in the ductus deferens. DSO averaged 79 and 82% of DSP for the 2 groups of dogs. Based on combined data for all 18 dogs, TSW was correlated with testicular weight (r = 0.95; P less than 0.01), DSP (r = 0.82; P less than 0.01) and DSO (r = 0.75; P less than 0.01). Thus, measurement of TSW is a useful predictor of a dog's ability to produce and ejaculate spermatozoa.
两项实验确定了每日射精的犬的总阴囊宽度（TSW）、每日精子生成量（DSP）、每日精子排出量（DSO）和性腺外精子储备（EGR）之间的关系。在实验1中，11只犬（体重14至36千克）每日射精，共进行两个为期10天的阶段；在实验2中，7只犬（体重15至47千克）每日射精，共进行两个为期20天的阶段。稳定DSO大约需要每日射精6次。在每日射精的第二个阶段后，对犬实施阉割或处死，称取睾丸重量，并测定DSP和EGR。在实验1和实验2中，每克睾丸实质的DSP平均分别为11.7±0.5和16.7±1.4×10⁶，或每只犬为369×10⁶和594×10⁶。在任何一个实验中，同一睾丸每克睾丸实质的DSP与实质重量均无显著相关性（r = 0.04和0.26）。实验1中犬的平均（±标准误）EGR为4024±368×10⁶，实验2中为4791±767×10⁶。大约63%的EGR存在于附睾头和附睾体中，36%存在于附睾尾中，1%存在于输精管中。两组犬的DSO平均分别为DSP的79%和82%。根据所有18只犬的综合数据，TSW与睾丸重量（r = 0.95；P<0.01）、DSP（r = 0.82；P<0.01）和DSO（r = 0.75；P<0.01）相关。因此，测量TSW是犬产生和射出精子能力的一个有用预测指标。
