Insemination Period Research Articles

Study of morphological and cytological parameters indicating oestrus in Lemur fulvus mayottensis

AbstractLemur fulvus mayottensis females were presented each day to vasectomized males. A simultaneous study of parameters of vaginal smears, external genital organs, and the cervix was carried out on the same females. Results from the two methods allow the determination of oestrus, that is, the best period for artificial insemination.

Synchronization of estrus in cyclic beef heifers with the prostaglandin analog alfaprostol

Seventy-eight Hereford-Angus crossbred heifers were injected intramuscularly twice with 6 mg of alfaprostol b b Alfaprostol, 18,19,20-trinor-19-cyclohexyl-13,14 didehydro-PGF 2α-methylester, was supplied by Hoffman-LaRoche Inc., Nutley, NJ 07110. in 6 ml of propylene glycol. On each representative day of a 20-day estrous cycle (estrus = Day 0), either three or four heifers received their first injection. The second injection was given 12 days after the first, regardless of the response to the first injection. Thirty-nine heifers were not treated. The first alfaprostol injection reduced serum progesterone to less than 1 ng/ml in all heifers injected after Day 4. A total of 79.5% ( 62 78 ) of the heifers exhibited estrus by five days after the first injection. Average interval from injection to estrus was 63 hours. The second injection occurred on Days 6 through 16 for all but one heifer, with 75.6% ( 59 78 ) falling on Days 8 through 11 of the estrous cycle. Estrus was detected in 93.6% ( 73 78 ) of the heifers within five days after the second injection, with an average interval to estrus of 66 hours. Day of cycle at second injection did not affect the interval to estrus. Conception occurred in 79.4% ( 58 73 ) of the heifers inseminated in the five days after the second injection. Occurrence of estrus and conception was no different in treated heifers after five days of the insemination period than in nontreated heifers after 21 days of the insemination period, where 94.9% ( 37 39 ) were observed in estrus and 83.8% ( 31 37 ) conceived. Overall percent conception for a 55-day insemination period was 89.7 ( 70 78 ) for treated and 87.2 ( 34 39 ) for nontreated heifers. Day of cycle at first or second injection did not affect conception after the second injection. Some signs of estrus were observed in 11 of the 16 heifers injected before Day 5. A second trial to determine if alfaprostol induced luteolysis early in the cycle was conducted. Twenty purebred Angus, Hereford, or Simmental heifers received either one or two injections of alfaprostol on either Day 1, 2, 3, or 4. Only five heifers showed any signs of estrus, and the three that were inseminated did not conceive. Subsequent cycle length indicated that luteolysis occurred in only one heifer. Data suggest that alfaprostol is an effective luteolytic agent in cyclic beef heifers after Day 4 and that two injections 12 days apart will effectively synchronize estrus in heifers when distributed throughout the cycle at the first injection without affecting conception rate.

Insemination management for a one-injection prostaglandin F 2α synchronization regimen. I. One daily insemination period versus use of the a.m./p.m. rule

Following detection of estrus in a one-injection prostaglandin F 2α (PGF 2α) synchronization regimen, 261 dairy heifers were randomly inseminated (A.I.) either once between 0800 and 0900 h daily (a.m.) or about 12 h after detection of estrus (a.m./p.m.). During the regimen, 31.8 and 33.3% for the a.m./p.m. and a.m. groups, respectively showed estrus and received A.I. during the pre-PGF 2α period. The remaining heifers were injected with PGF 2α with 95.6% from a.m./p.m. and 96.5% from a.m. showing estrus and receiving A.I. within five days after PGF 2α. Pregnancy rates of 62.9% for a.m./p.m. and 62.0% for a.m. did not differ. Progesterone at the time of injection was similar between groups and was not correlated with either response to PGF 2α or fertility. Percentages of heifers in estrus <24, 25–48, 49–72, 73–96 and >96 after PGF 2α were 4.7, 30.2, 45.6, 14.3 and 5.3, respectively, with a mean time of 61.0±1.9 h. Satisfactory conception rate was attained with a.m. insemination.

Insemination management for a one-injection prostaglandin F 2α synchronization system. II. One versus two inseminations following detection of estrus

Following detection of estrus in an estrus synchronization system, 216 dairy heifers were inseminated (A.I.) randomly either soon after detected estrus (1X) or soon after detected estrus and again 10 to 12 h later (2X). Average h from detection of estrus to A.I. was 1.8±0 for 1X and 1.1±0 and 11.1±0.4 for 2X. During the regimen, heifers were checked visually for estrus daily for five consecutive days with 16.0 and 17.3% showing estrus and receiving A.I. in the 1X and 2X groups, respectively. Those not seen in estrus were injected with 25 mg PGF 2α with observations for estrus and A.I. continuing for five more days. Response rates as indicated by estrus following prostaglandin F 2α (PGF 2α) were 74.7 and 75.8% for 1X and 2X, respectively. Percentages of heifers in estrus <24, 25 to 48, 49 to 72, 73 to 96 and >96 h after PGF 2α were 3.7, 22.8, 47.1, 15.4 and 11.0, respectively. Based on rectal palpation for pregnancy between 45 and 60 days after A.I., conception rates of 70.2% for 1X and 68.6% for 2X did not differ significantly (P>0.05). Progesterone concentrations at injection for heifers not responding to PGF 2α were lower than was seen in responding heifers (2.7 vs 5.8 ng/ml) (P<0.01). Data from the present experiment supports the conclusion of an earlier experiment that satisfactory conception can be achieved with a single, established daily insemination period.

Effects of dam age, prepartum nutrition and duration of labor on productivity and postpartum reproduction in beef females.

Sixty-two, 2-yr-old heifers and 65 cows, 4 to 7 yr old, were assigned randomly at 60 d before the median predicted calving date to a factorially designed study. Main effects were: age of dam (heifer or cow), moderate (M) or high (H) precalving feed level (110 or 135% of National Research Council recommendation) and short (S) or prolonged (P) duration of Stage II of parturition. After calving, all dams were placed in the same range pastures and received supplemental hay and a grain-salt mix until adequate range forage was available to produce weight gains in the lactating dams. Dams were bred in a 45-d artificial insemination period. Calving difficulty scores and duration of labor (Stage II) were greater (both P less than .01) in heifers than in cows; calf birth weight (P less than .01), calf vigor at birth (P less than .05) and calf gains birth to weaning (P less than .01) were higher in cows. Effect of gestation feed level on precalving, calving and postpartum data were nonsignificant. Eighty-two percent of the S females were given obstetrical assistance and 15% of the P females required assistance at parturition (P less than .01). More S dams exhibited estrus by the beginning of the breeding season than P dams (91.4 vs 81.7%, P less than .10), and October pregnancy of S dams was higher than P dams (89.5 vs 75.6%, P less than .05). Interaction effects of dam X duration of Stage II were not significant, but short duration of labor had beneficial effects on postpartum reproduction in both dam age groups. Results of this study indicate prolonged labor may result in depressed subsequent reproduction in beef dams.

The fertility of heifers consuming red clover silage

AbstractThe fertility of forty‐two heifers offered either red clover silage or grass silage prior to and during the period of insemination was compared. Pregnancy rate to first service was significantly higher (P &lt; 0·25) on red clover silage at 76% compared with 43% on grass silage. Pregnancy rates from a mating period covering three oestrus cycles were similar on the two silage diets. The ratio of services to pregnancies was lower on red clover silage (1·2) than on grass silage (2·2). In a subsidiary trial with twenty‐three heifers, pregnancy rate to first service on red clover silage was 78%.There was no evidence to indicate that herd fertility is depressed by red clover silage.

Reproductive Performance of White Leghorns Provided Fluoride

Two trials were conducted to determine if added sodium fluoride in the drinking water of chickens would result in any deleterious effects on reproduction. In both trials 120 individually caged Single Comb White Leghorn hens (SCWL) were used. Experimental groups consisted of a control group which received no fluoride and three treated groups which received 100 parts per million (ppm) fluoride during either the growing period (0 to 20 weeks), production period (from 20 weeks on), or continuously from day 1. In Trial 1 broiler-breeder males that had not been treated with supplemental fluoride were used as the source of semen for artificial insemination. In Trial 2 half the SCWL cockerels used had been treated with 100 ppm F in the drinking water from day 1.The reproductive characteristics measured were egg production, fertility, duration of fertility, and hatchability of fertile eggs. No deleterious effects due to fluoride exposure at the 100 ppm level in the drinking water were observed in the reproductive performance of either pullets or cockerels. Egg production in both trials decreased slightly during the insemination periods in all experimental groups of pullets. Birds hatched from the various treatment groups in Trial 1 were raised to 4 weeks of age, and no effects of fluoride on progeny growth were noted.

Induction of lactation in dry dairy dattle.

Abstract Lactation was successfully induced in 14 of 15 non-pregnant cows treated for 7 days with twice daily subcutaneous injections of 15 mg oestradiol-17β and 37.5 mg progesterone. The successfully induced cows were first machine-milked about 8 days after the end of treatment and, although they milked for as long as their naturally calving identical twins, produced significantly less milk, fat and lactose. Augmenting the basic regimen with Opticortenol or thyrotrophin-releasing hormone produced no advantage. Plasma and milk hormone analyses were conducted and used to study the onset of lactogenesis and possible meat and milk residues. Ten of the 15 treated cows showed frequent oestrous activity and 4 became lame. Pregnancy rates after an 8-week insemination period were 69% and 93% for treated and control cows, respectively. It is concluded that the technique is unlikely to gain wide acceptance in the form used here.

DIFFERENCES IN STARFISH OOCYTE SUSCEPTIBILITY TO POLYSPERMY DURING THE COURSE OF MATURATION

During the course of starfish oocyte maturation, the optimum period for insemination is between germinal vesicle breakdown and the first polar body formation. The rate of polyspermy increases with increasing time intervals between the first polar body formation and sperm addition, although the fertilization membrane is formed normally in all oocytes. As long as polyspermy is prevented, however, the oocytes remain viable even after the formation of second polar bodies. Thus, it is postulated that there is some mechanism (s) of protection against polyspermy between the first sperm entry and the fertilization membrane formation. The mechanism(s) may be gradually lost after the first polar body formation and disappear completely after the second polar body formation.

ARTIFICIAL INSEMINATION IN DENMARK BY FROZEN DONOR SEMEN SUPPLIED FROM A CENTRAL BANK

A central semen bank in Denmark supplied deep-frozen semen. Selection of donors, freezing technique, and practical details about transport of specimens are described. In one of the gynaecological departments supplied with frozen semen, 22 out of 30 patients who had artificial insemination became pregnant. The advantages and disadvantages of using frozen semen are discussed.

SYNCHRONISATION OF OESTRUS IN BEEF CATTLE ARTIFICIAL BREEDING PROGRAMS USING PROSTAGLANDIN F2α

PGF2alpha either as a subcutaneous injection (8 or 10mg) or intrauterine infusion (dose 5 mg) successfully synchronised oestrus in beef cattle AI programs. The beef cattle programs were managed by 1 of the following 2 systems. 1. Two 10-day insemination periods, 1 for the first and the second for the repeat inseminations. Oestrus was detected and oestrus cows inseminated for the first 4 days of the first period. On the fifth day all cows not inseminated were treated with PGF2alpha. The treated cattle came into oestrus and were inseminated over the following 2 to 5 days. 2. Two PGF2alpha treatments 10 days appart followed by two 4-day insemination perids. During the first 4-day period, cows exhibiting synchronised oestrus were inseminated. Cows returning to oestrus were inseminated during the second 4-day period, about 18 days after the first, period. Synchronisation of oestrus was not sharp, oestrus being distributed over 7 days, with the majority of cows being in oestrus on the third (42.3%) and fourth (22.4%) days. The route of administration of PGF2alpha (injection or infusion) did not effect oestrus synchronisation. PGF2alpha by either route of administration did not effect the fertility of cows inseminated at either the synchronised or subsequent oestrus. Pregnancy rates at the synchronised oestrus were higher when cows were inseminated after dectection of oestrus than when they were inseminated without reference to oestrus at a fixed time 3 days after PGF2alpha treatment (mass injection). Oestrus synchronisation greatly reduced the input of time, labour and feed required during the total program. However, oestrus synchronisation did not alter the overall efficiency of artificial breeding programs measured in terms of the proportion of cattle entering a program that were inseminated and became pregnant. The main problem encountered was drug wastage through unknowingly treating cows and heifers that were not cycling.

ARTIFICIAL INSEMINATION OF BEEF CATTLE

A system for the artificial insemination fo beef cattle was described. The system involved preparation of the cattle and facilities, visual oestrous detection twice a day, drafting each morning and insemination of oestrous cows twice a day. The AI program was evaluated during the course of the program and at pregnancy test 35 to 90 days after the end of the insemination period. The insemination period was from 25 to 60 days depending on efficiency, with programs from 25 to 35 days being favoured. Results for 12218 first inseminations (65.9%) and 2222 second inseminations (57.8%) in 56 AI programs compared favourably with results in dairy AI. Pregnancy rates in lactating cows (70.5%) were significantly higher than in nonlactating cows and heifers (66.1%). Overall efficiency of well-managed AI programs were represented by 63% of cows put into a program becoming pregnant in a 29-day insemination period. Seventy-two per cent of the cows put into the program were inseminated yielding an 88% pregnancy rate. The efficiency of visual oestrous detection was 95% but this estimate did not include false positives. Efficiency of AI programs were effected by management, nutrition, infection, inseminators, facilities and the origin and type of cattle put into a program. Environmental factors such as handling, stress and thunderstorms did not effect efficiency except via a nutritional effect.

Investigation and Treatment of the Infertile Male

The investigation of 117 infertile couples in a clinical practice is reported. Results of testicular biopsies were categorized as follows: Type 1 normal testis; Type 2 germinal cell aplasia; Type 3 germinal cell arrest; and Type 4 sloughing effect. A diagnosis of block in the epididymis or vas was made by injecting saline up the vas toward the urethra and by finding inspissated spermatozoa in the distended tubules of the epididymis. (This method was later replaced by radiologic evidence of the patency of the vas by vasography and epididymography.) 2 men were found to have Klinefelters syndrome. Local surgical conditions associated with infertility were noted in 7 cases. There were 36 infertile men with seemingly normal semen. A strongly positive Kibricks macroagglutination test was found in the plasma of 9 of these men and similar antibodies were noted in 5 of their wives. Of the 22 men with aspermia an obvious explanation existed in 8 cases (e.g. Klinefelters syndrome retrograde ejaculation mechanical obstruction). The sloughing effect was noted in 11 of the 14 men without an obvious cause for aspermia. Oligospermia was diagnosed in 60 men. Testicular biopsies in 21 of these cases revealed the sloughing effect in 10 specimens germinal cell arrest in 3 and aplasia in 8. Of the 29 oligospermic men treated with fluoxymesterone 14 showed improved sperm density and all showed improved motility. Sustained improvement in sperm density was observed in 11 of the 25 men treated with clomiphene. Only patients who showed sloughing off in the biopsy had improvement with either treatment method; however sloughing did not always predict an improvement in sperm density. The persistently oligospermic man may be helped by artificial insemination of centrifuged semen or by pooling concentrated sperm. Plasma antisperm antibodies can be washed off spermatozoa and a concentrated specimen of semen injected directly into the cervix. Pregnancy has been achieved in 3 of the 12 cases where this method was tried. Finally in cases with a positive Kibricks reaction in the wifes plasma prednisone can be administered to the woman over the period of artificial insemination with washed spermatozoa. This has achieved 1 pregnancy to date in this series.

Iso-antibody formation against rabbit spermatozoa and its effect on fertility.

Isoantibody formation against rabbit spermatozoa and its effect on fertility were studied in 14 rabbits (9 known fertile 5 virgin). All animals received weekly injections of epididymal spermatozoa suspended in sodium alginate for 10 weeks prior to the 1st insemination and prior to each succeeding insemination. In addition intravaginal sperm alginate-soaked tampons were introduced. 10 or 11 days following the last injection rabbits were mated (on the 1st occasion) or artifically inseminated (on subsequent occasions) after the injection of human chorionic gonadotrophin. A high rate of infertility was encountered in the control animals when they were mated with fertile bucks in the 1st insemination period. After the 4th and final insemination 98.7% of 75 eggs recovered from 9 saline-injected rabbits were fertile. Only 2 of 27 eggs recovered from immunized rabbits were fertile. 4 sperm-injected rabbits (apparently sterile) produced detectable antibodies but all of the control and remaining immunized rabbits showed negative serum titers and at some stage in the study were fertile. Antibody against homologous epididymal spermatozoa was stimulated by injection of rabbit spermatozoa suspended in sodium alginate as revealed by the high levels of isoantibody against rabbit spermatozoa and suppressed fertility. The high titers also suggested that isoantigenicity depends largely on a suitable adjuvant a sufficient injection schedule and an adequate immunological assay. Cultured antigen-exposed vaginae of the immunized females revealed no antibody to spermatozoa.

Studies on the artificial insemination in the rat. IV. On the optimum period of insemination in the rats kept under the artificially reversed day and night

Studies on the artificial insemination in the rat. IV. On the optimum period of insemination in the rats kept under the artificially reversed day and night