Estrus detection and estrus detection aids.

There is no substitute for good management. Each animal should be identified carefully. The herds man should know all signs of estrus or impending estrus. In addition, for visual detection of estrus to be highly effective, sufficient time must be taken at least twice a day to catch animals with a short estrus period. Presently there are two visual aids to estrus detection which provide potential 24-h surveillance. One aid is a pressure sensitive device mounted on the back of each cow which can be triggered when the cow stands for mounting. The second one is a marking device worn by sexually aggressive animals which will stripe with colored ink the back of estrous animals as the marker animal mounts and dismounts. Both devices are effective when used properly. Other tests of changes in cervical mucus, vaginal characteristics, temperature, blood flow, and hormone changes in blood and milk are either not suffciently reliable or else simple enough yet to be practical aids for routine detection of estrus in dairy cattle. Milk progesterone can assist in characterizing problem cows.

[1]  C. J. Wilcox,et al.  Effect of estradiol-17beta on vaginal thermal conductance in cattle. , 1973, Journal of dairy science.

[2]  H. T. Gier,et al.  Factors Affecting Bovine Ovarian Activity after Parturition , 1968 .

[3]  R. Heap,et al.  Pregnancy diagnosis in cows; changes in milk progesterone concentration during the oestrous cycle and pregnancy measured by a rapid radioimmunoassay , 1973, The Journal of Agricultural Science.

[4]  D. Lang,et al.  A marking device for detecting oestrous activity of cattle , 1968 .

[5]  E. Linford.  Cervical mucus: an agent or a barrier to conception? , 1974, Journal of reproduction and fertility.

[6]  D. C. Blood,et al.  A study of oestrous behaviour and oestrus detection methods in a large commercial dairy herd. I. The relative efficiency of methods of oestrus detection , 1972, Veterinary Record.

[7]  Von B. Hoffmann,et al.  Progesteron in der Mitch: Radioimmunologische Bestimmung, Beziehungen zur Gelbkörperfunktion and Milchfettkonzentration* , 1973 .

[8]  J. Lauderdale.  Estrus Detection and Synchronization of Dairy Cattle in Large Herds , 1974 .

[9]  E. J. Stone,et al.  Estrus, Estrous Cycles, Ovulation Time, Time of Service, and Fertility of Dairy Cattle in Louisiana , 1959 .

[10]  D. Lamond,et al.  Chemical changes in cervical mucus from normal and ovariectomized cows treated with hormones. , 1969, Biology of reproduction.

[11]  L. Donaldson.  The efficiency of several methods for detecting oestrus in cattle. , 1968, Australian veterinary journal.

[12]  W. Thatcher.  Effects of Season, Climate, and Temperature on Reproduction and Lactation , 1974 .

[13]  R. Randel,et al.  Effects of various mating stimuli on the LH surge and ovulation time following synchronization of estrus in the bovine. , 1973, Journal of animal science.

[14]  Watson Jd,et al.  The anoestrous syndrome in new zealand dairy cattle. 2. Some factors influencing submission rates in Taranaki herds. , 1975 .

[15]  D. Schams,et al.  Zeitliche Beziehungen zwischen Brunstsymptomen, elektrischen Widerstandsveranderungen des Vaginalschleims, präovulatorischer Ausschüttung des Luteinisierungshormons and Ovulation beim Rind , 1972 .

[16]  D. C. Blood,et al.  A study of oestrous behaviour and oestrus detection methods in a large commercial dairy herd. II. Oestrous signs and behaviour patterns , 1972, Veterinary Record.

[17]  Kendrick Jw,et al.  PREPARATION OF TEASER BULLS BY PENECTOMY. , 1965 .

[18]  Watson Jd,et al.  The anoestrous syndrome in New Zealand dairy cattle. 1. A preliminary investigation. , 1973 .

[19]  S. J. Roberts,et al.  A review of postpartum ovarian activity and involution of the uterus and cervix in cattle. , 1969, The Cornell veterinarian.

[20]  W. E. Graves,et al.  Studies on the postpartum cow. , 1968 .

[21]  V. R. Smith,et al.  The Effect of Sterile Copulation on Time of Ovulation in Dairy Heifers , 1950 .

[22]  C. Pélissier.  Herd Breeding Problems and Their Consequences , 1972 .

[23]  N. Vandemark,et al.  Physiological aspects of fluids in female genitalia with special reference to cattle; a review. , 1957, American journal of veterinary research.

[24]  W. Hansel,et al.  Control of Ovarian Function in Domestic Animals , 1972 .

[25]  E. Schilling,et al.  Diagnosis of oestrus and ovulation in cows by pH-measurements intra vaginam and by apparent viscosity of vaginal mucus. , 1968, Journal of Reproduction and Fertility.

[26]  B. Hoffmann,et al.  [Progesterone in milk: determination by radioimmunoassay, relations to corpus luteum function and milk fat concentrations (author's transl)]. , 1973, Zuchthygiene.

[27]  T. Gimenez,et al.  Preparation of teaser bulls, rams and boars by penis and prepuce deviation. , 1973, Veterinary medicine, small animal clinician : VM, SAC.