EFFECT OF 17?-HYDROXYPROGESTERONE 17-n-CAPROATE ON THE REPRODUCTIVE PERFORMANCE OF CATTLE

Abstract

Embryonic death has been shown to be a direct cause of lowered fertility in repeat-breeding cows. In a study of 104 such animals, Tanabe and Casida (1949) reported that 66 per cent of the cows with no clinical detectable abnormality had fertilized ova. At 34 days those having normal embryos had decreased to 23 per cent. Since these ova lived for a time after fertilization, it is reasonable to believe that embryonic death may have been due to failure of the embryo to implant in the uterus. This failure could have resulted from the fact that the uterus was not prepared for implantation. One of the conditions essential for the implantation of ova in the uterus appears to be a secretory condition of the endometrium, and this depends largely on progesterone. Insufficient available progesterone a t the time of nidation could be a major cause of "repeat breeders."The object of this study was to determine the effects of the administration of progesterone on reproductive efficiency in normal cows. Experimental ProcedureAll the females in the University of Idaho dairy herd were given a rectal examination at estrus when the animal was due for first breeding. Animals in which the ovaries were of normal size ( 2 to 4 cm. in diameter for cows and 1.5 to 3 cm. for heifers), with a single, well-developed Graafian follicle, and free from detectable infection and disease, were considered to be ready for breeding.After the animals were bred, alternate cows were treated with a reposital type of progesterone, while the other animals were not treated and were used as controls. The treated group received 100 mg. of a reposital progesterone intramuscularly on days 2, 3, 4, 6, and 9 after the first breeding only. This dosage level and time interval were determined from the success of preliminary work at the Idaho station in the treatment of repeat-breeder cows. Twenty females having had from 4 to 9 infertile services each to a male of known fertility were treated with a reposital progesterone (Johnson, 1955). Sixteen of the animals conceived on first breeding, 3 on second, and 1 on third breeding after treatment, giving a breeding efficiency of 80.0 per cent. Results and DiscussionOne hundred and fifteen females of the Holstein and Jersey breeds were given a rectal examination at estrus during which the animal was due for first breeding and were considered ready for breeding. Forty-eight of the animals were treated with a reposital-type progesterone a t first service. Thirty-three conceived at first service, a breeding eficiency of 68.7 per cent. Eleven of the animals conceived at second service, 2 a t third, and 577

Egg Transfer in Sheep. Factors Affecting the Survival and Development of Transferred Eggs

“…This theory receives some support from the fact that in cattle Hawk, Wiltbank, Kidder & Casida, 1955), sheep and pigs (Robertson, Casida, Grummer & Chapman, 1951 ;Perry, 1954), the peak incidence of embryonic mortality occurs at about the time when the corpus luteum would be beginning to regress if the animal were not pregnant. Progesterone therapy has been used in cattle in an attempt to correct this deficiency, and different workers have claimed widely differing degrees of success from such treatment (Herrick, 1953;Dawson, 1954; Wiltbank, Hawk, Kidder, Black, Ulberg & Casida, 1956;Johnson, 1958 Samples of about a litre of blood were obtained from the jugular veins of Suffolk ewes on the 15th day of pregnancy. These animals were representative of each of the N2, N5, S¡¡ and S5 groups described above, and they were all slaughtered on Day 18, at which time counts were made of the number of embryos and corpora lutea that were present.…”

Influências da condição corporal e atividade ovariana sobre a taxa de prenhez de vacas de corte suplementadas com progesterona de longa ação após a IATF

“…Os resultados reportados sobre o efeito da suplementação de P4 no início do diestro são divergentes, variando de resultados positivos (JOHNSON et al, 1958;ROBINSON et al, 1989), resultados neutros (VAN CLEEFF et al, 1991;STEVENSON et al, 1991;ARNDT et al, 2009;GARCIA-ISPIERTO et al, 2012;COLAZO et al, 2013;MONTEIRO et al, 2014;MARQUES et al, 2014) e também resultados negativos (VAN CLEEFF et al, 1996;PARR et al, 2014). No entanto, estes estudos apresentaram muitas diferenças entre categoria animal (primíparas vs pluríparas), métodos para aumentar a concentração de P4, início da suplementação de P4 relativo ao dia da IA e número de animais utilizados nos trabalhos.…”

“…Diversos estudos avaliando a suplementação com P4 por meio de dispositivos intravaginais de P4 em vacas de leite também não indicaram aumento na P/AI (VAN CLEEFF et al, 1991;STEVENSON et al, 1991;ARNDT et al, 2009;GARCIA-ISPIERTO et al, 2012;COLAZO et al, 2013;MARQUES et al, 2014). Monteiro (2014) JOHNSON et al, 1958;ROBINSON et al, 1989).…”

<b>Efeito da administração de progesterona após a IATF no desenvolvimento do concepto e na taxa de prenhez em búfalas lactantes</b>

“…São conflitantes os dados encontrados na literatura sobre os benefícios dos tratamentos com P4i sobre ambiente uterino e o desenvolvimento do embrião. Também, existem ainda poucas informações que indiquem o melhor momento e a dose ideal para o tratamento com P4 após a IA.Alguns estudos apontam efeito positivo da suplementação com P4 na fertilidade Johnson et al (1958),. verificaram que vacas que receberam subsequentes doses de 100 mg de P4i nos dias 2, 3, 4, 6 e 9 após a inseminação apresentaram maior taxa de concepção que vacas não tratadas.…”