cloprostenol and Body-Weight

The objectives of this study were 1. to determine the associations among circulating anti-Mullerian hormone (AMH), insulin like growth factor 1 (IGF1) and cadmium (Cd) concentrations of lactating Holstein cows at the time of superovulation and 2. to determine the effect of circulating AMH, IGF1 and Cd concentrations on the superovulatory response in Holstein dairy cows. Holstein cows (n = 30) were milked thrice daily and housed and fed in free stall barn as a separate group. All animals were synchronized for superovulation and flushed. Three blood samples for AMH, IGF1 and Cd analysis were collected prior to superovulation, at estrus and at the time of embryo collection. The concentrations of blood makers prior to superovulation were highly correlated to superovulatory response. Circulating concentrations of AMH, IGF1 prior to superovulation were negatively correlated to Cd concentrations (P < 0.05). There was no correlation between circulating concentrations of AMH and IGF1. The number of corpus luteum (r = 0.71), total embryo (r = 0.67), total transferable embryo (r = 0.51) and total grade 1 embryo (r = 0.5) were positively correlated to AMH concentrations (P < 0.05). There was a trend for negative correlation found between circulating cadmium concentrations and total grade 1 embryo yield (P < 0.1). When cows were classified into quartiles (Q) of circulating AMH concentration, number of corpus luteum, and total embryos, total transferable embryos and total grade 1 embryos yield was significantly different for AMH quartiles. The superovulatory response parameters evaluated were increased with increased AMH concentrations; particularly we observed a >2-fold difference between first and fourth AMH quartiles in total transferable embryo yield and total grade 1 embryo yield. In conclusion, circulating AMH concentration was strongly associated with superovulatory response. Measuring AMH before enrolling cows in superovulation programs will likely allow practitioners to improve numbers of embryos produced and, thereby, reduce costs per embryo produced.

Topics: Animals; Anti-Mullerian Hormone; Body Weight; Cadmium; Cattle; Cloprostenol; Embryo Transfer; Female; Follicle Stimulating Hormone; Insulin-Like Growth Factor I; Superovulation; Tissue and Organ Harvesting

We have previously shown that the number of ovarian follicles <4 mm in diameter can be increased by enhanced dietary intake in heifers. This study investigated the effect of the same dietary treatment on superovulatory response. The estrous cycles of 24 mature Hereford x Friesian heifers were synchronized by a standard progesterone plus prostaglandin protocol. The animals were fed with either 100% (group M, n = 12) or 200% (group 2M, n = 12) maintenance requirements for a 3-week period. Starting from day 4 of the synchronized estrous cycle, all the animals were superovulated using a standard 4-day FSH regime followed by an injection of GnRH analogue (GnRHa) to induce ovulation. Rectal ultrasound scanning was carried out to assess ovarian follicular populations at the start of FSH treatment and on the day of GnRHa injection, and to determine the number of corpora lutea 5 days after GnRHa injection. The body weight (BW) and body condition score (BCS) were recorded weekly and plasma samples were collected throughout the experimental period. There were no differences in either BW or BCS between two groups at the start of the experiment. The BW and BCS were maintained during the experiment in the group M, whilst animals in the group 2M showed a non-significant (P > 0.05) increase in BW and BCS. Circulating concentrations of insulin were significantly (P < 0.01) higher in heifers from the group 2M throughout the controlled feeding period. The group 2M had significantly (P < 0.05) more follicles 2-4 mm in diameter at the start of FSH treatment and more (P < 0.01) follicles >9 mm in diameter on the day of GnRHa injection, when compared with the group M. Similarly, 5 days after GnRHa injection there were significantly (P < 0.01) more corpora lutea in the group 2M (18.1+/-2.2) than in the group M (10.6+/-3.0). In addition, plasma progesterone concentrations following GnRHa injection were significantly (P < 0.01) higher in heifers from the group 2M. In conclusion, these results confirm that increased dietary intake can enhance the recruitment of ovarian follicles in heifers. This treatment may provide a valuable approach to improving superovulatory response in cattle.

Topics: Animals; Body Composition; Body Weight; Buserelin; Cattle; Cloprostenol; Corpus Luteum; Diet; Dinoprost; Estrus Synchronization; Female; Follicle Stimulating Hormone; Insulin; Ovarian Follicle; Ovulation; Progesterone; Superovulation

The aim of this study was to determine whether sodium cloprostenol administered at a continuous low dosage induced luteolysis and polydipsia in early dioestrous bitches. Sodium cloprostenol was administered subcutaneously to greyhounds at doses of 4.04-5.19 microg/kg/day (treated group, n=5) or 0 microg/kg/day (control group, n=5) delivered by mini-osmotic pumps for 7 days. The treated bitches and two of the control bitches were in early dioestrus (Days 5-14, and 6 and 10, respectively) when the mini-osmotic pump was inserted (Day 0). Concentrations of plasmatic progesterone were measured in dioestrous bitches each day from Day -2 to 7, and then weekly until Day 90. Daily intake of water was ascertained in all bitches from Day -2 until Day 10, and their weight was measured on Days -2, 6 and 13. Biochemical analyses on plasma for concentrations of urea and glucose, and urinalyses were performed on all bitches before (Day -1), during (Day 4) and after treatment (Day 10). Concentrations of plasmatic progesterone declined dramatically and rapidly in treated bitches after Day 0 to <2.9 ng/ml but were not similarly affected in the dioestrous control bitches. However, in three of five treated bitches, concentrations of plasmatic progesterone increased to >1 ng/ml in the period from Day 10 to 90 indicating that luteolysis was incomplete. All treated bitches were polydipsic (intake of water >100 ml/kg/day) for 2-6 days during the period of treatment, and for 0-2 days immediately after treatment (Days 7 and 8). One control bitch was polydipsic on Days -2, -1 and 0. The treated bitches were also polyuric since they were hyposthenuric (<1.007, n=4) or isothenuric (1.010, n=1) on Day 4, their weight did not increase and no gastrointestinal or respiratory effects were observed. The control bitches were always hypersthenuric when measured during and after treatment (>1.021). Biochemical analyses of plasma and other data obtained from urinalyses did not reveal any differences between groups. This study indicated that sodium cloprostenol administered at a continuous low dosage induced polydipsia and suppressed luteal function in early dioestrous bitches.

Topics: Animals; Blood Glucose; Body Weight; Cloprostenol; Corpus Luteum; Diestrus; Dogs; Drinking; Female; Kinetics; Progesterone; Urea; Urinalysis

The effect of undernutrition on the ovulation rate of Merino ewes supplemented with lupins was examined in two experiments using a 2 x 2 factorial (low vs high nutritional plane x none vs supplemented) design. In both experiments, ewes were assigned at random to two equal-sized groups and differentially grazed for 8 weeks (low and high). In Experiment 1, flocks were recombined and managed as one group for 18 weeks and then divided into their original nutritional treatments 17 days prior to ovulation. Each of these groups was divided at random into equal-sized subgroups and one subgroup fed lupins for 10 days prior to ovulation. Restricting nutrition 6 months prior to ovulation resulted in a difference in mean liveweight between the low and high groups of 9.3 kg at the end of the 8-week period (P < 0.001). Ovulation rates per ewe were 1.06 +/- 0.07 (low, no supplement), 1.63 +/- 0.09 (low, lupin-supplemented), 1.28 +/- 0.09 (high, no supplement) and 1.57 +/- 0.08 (high, lupin-supplemented). The increase of 0.22 ovulations per ewe for the low vs high plane of nutrition without supplement was significant (P < 0.05). There was a significant interaction (P < 0.05) between previous nutrition imposed 6 months prior to ovulation and lupin supplementation, indicating that the ovulatory response to lupins was greater at the low compared with the high plane of nutrition (0.57 vs 0.29 extra ovulations per 100 ewes). In Experiment 2, the previous nutritional treatments were imposed for 8 weeks immediately before ovulation. Restricting feed intake in the low group resulted in a difference in mean liveweights between the two groups of 6.2 kg (P < 0.001) 6 weeks after the start of the nutritional treatments. Ovulation rates were 1.22 +/- 0.06 (low, no lupin supplement), 1.38 +/- 0.09 (low, lupin-supplemented), 1.67 +/- 0.08 (high, no lupin supplement) and 1.64 +/- 0.09 (high, lupin-supplemented). The effect of previous nutrition on ovulation rate was significant (P < 0.001) with 0.35 extra ovulations per ewe fed the high plane. Ewes in the low group responded to lupin supplementation with 0.16 extra ovulations per ewe (P = 0.06), whereas ewes previously fed on a high plane did not respond to the lupin treatment.

Topics: Animal Nutritional Physiological Phenomena; Animals; Body Weight; Cloprostenol; Estrus Synchronization; Fabaceae; Female; Food Deprivation; Ovulation; Plants, Medicinal; Progestins; Random Allocation; Sheep

Three groups of 40 parous Merino ewes were supplemented with 500 g of lupin grain/ewe/day for 7 days starting on either Day 3, 7 or 11 of the oestrous cycle and induced to ovulate by injecting cloprostenol on the sixth day of feeding. Supplementation with lupin grain significantly increased ovulation rate in all groups compared with corresponding controls by increasing the proportion of ewes with twin ovulations. Increases in ovulation rate did not depend on the stage of the cycle at which supplementation began or when during the luteal phase luteolysis was induced. It is concluded that the ovulatory response to lupin grain is initiated near the time of luteolysis.

Topics: Animal Feed; Animals; Body Weight; Cloprostenol; Estrus; Female; Ovulation Induction; Plant Proteins; Sheep

A field trial was conducted to assess the efficacy of a combined prostaglandin F(2)alpha analogue (cloprostenol) and dexamethasone treatment as an abortifacient in feedlot heifers. Heifers were grouped according to stage of gestation as follows: Group I, one to four months, n = 37: group II, four to six months, n = 40: group III, six to eight months, n = 40: group IV, one to eight months, n = 29. Heifers in groups I, II and III received a simultaneous intramuscular injection of 500 mug cloprostenol and 25 mg dexamethasone at the time of rectal palpation for pregnancy diagnosis. Heifers in group IV were subjected to rectal palpation for pregnancy diagnosis but received no treatments. Heifers were observed daily for two weeks for abortion and rectal palpations were done 50 days after treatment to determine reproductive status. HEIFERS ABORTING AFTER TREATMENT WERE AS FOLLOWS: Group I, 37/37; group II, 37/40, group III, 37/40; group IV, 0/29. In each of groups II and III there was one pregnancy and two cases of fetal mummification. The numbers of abortions in groups I, II and III were significantly different from that in group IV (P

Topics: Abortion, Induced; Animals; Body Weight; Cattle; Cloprostenol; Dexamethasone; Drug Combinations; Female; Pregnancy; Progesterone; Prostaglandins F, Synthetic

Two groups, each of 7 crossbred beef cows, which were suckling or not suckling calves, were fed a high quality food ad libitum for 3 months post partum. The non-suckling cows experienced regular ovarian cycles from 10--33 days post partum while the suckling cows did not do so until at least 14 weeks post partum. There was little difference between the groups in growth rate or in plasma glucose concentration. The plasma prolactin concentrations in the non-suckling cows showed a seasonal trend which paralleled ambient temperature and daylight hours; in the suckling cows this trend was less evident. Plasma LH concentrations were lower in suckling cows before Day 30 post partum but were similar thereafter. Most suckling cows also failed to experience oestrus or to exhibit LH release in response to an injection of oestradiol benzoate at about 6 weeks post partum. This failure, together with the earlier lower levels of LH in the suckling cows, is considered to be indicative of malfunction of the hypothalamic mechanism normally responsible for the establishment and maintenance of cyclic ovarian function.

Topics: Animals; Blood Glucose; Body Weight; Cattle; Cloprostenol; Estradiol; Estrus; Female; Lactation; Luteinizing Hormone; Ovary; Ovulation; Pregnancy; Progesterone; Prolactin