خيارات البحث
النتائج 1 - 5 من 5
Relation among body condition score, serum urea nitrogen and cholesterol concentrations, and reproductive performance in high-producing Holstein dairy cows in early lactation
1992
Ruegg, P.L. | Goodger, W.J. | Holmberg, C.A. | Weaver, L.D. | Huffman, E.M.
Body condition scoring (using a 5-point with quarter-point divisions) was performed on 66 Holstein dairy cows that began their second or later lactation in August, September, or October 1988. Cows' body condition was scored beginning on postpartum day 4 (+/- 1) and subsequently at postpartum days (+/- 1) 18, 32, 46, 60, 73 and 87. Blood samples were obtained on the same dates. Reproductive health examinations were conducted by 1 of 2 veterinarians beginning at postpartum day 21. Reproductive performance was evaluated in relation to body condition score and serum urea nitrogen and cholesterol concentrations. Number of days to first recorded signs of estrus and first breeding were not related to body condition score at calving, amount of condition loss, cumulative 80-day milk yield, or 305-day fat corrected milk yield. Cows that calved with body condition score greater than or equal to 3.50 required more days to conceive. Cows losing > 0.75 points of condition had longer days of conception. Body condition score at calving and amount of condition lost were not related to services per conception or diagnosis of follicular cyst. Cumulative 80-day milk yield was not related to days to conception or services per conception. Cows that produced greater than or equal to the mean 305-day milk yield required more services and had longer days to conception than cows that produced < the mean 305-day milk yield. Cows with diagnosis of ovarian follicular cysts had greater cumulative 80- and 305-day milk yields than did cows that were not diagnosed with follicular cysts. Cows conceiving with less than or equal to 2 services did not differ in average daily milk production, body condition score, or serum urea nitrogen concentration from cows conceiving with > 2 services, but cows that conceived with less than or equal to 2 services had higher serum cholesterol values than did cows requiring more services.
اظهر المزيد [+] اقل [-]Synchronization of estrus in dairy goats treated with prostaglandin F at various stages of the estrous cycle
1992
Nuti, L.C. | Bretzlaff, K.N. | Elmore, R.G. | Meyers, S.A. | Rugila, J.N. | Brinsko, S.P. | Blanchard, T.L. | Weston, P.G.
Dairy goats were given IM injections of 12 micrograms of cloprostenol sodium on day 6 of the estrous cycle (prostaglandin F [PGF] 6, n = 22) or day 12 of the estrous cycle (PGF 12, n = 26). Mean +/- SE hours from injection to onset of behavioral estrus and proportion of goats responding were 46 +/- 4.2 (range, 12 to 88 hours) and 95% and 48 +/- 2.9 (range, 34 to 68 hours) and 100% for groups PGF 6 and PGF 12, respectively. There was no significant difference between the groups in mean time to onset of estrus, but variances about the means were different. Of the does in groups PGF 6 and PGF 12, 67 and 85%, respectively, had signs of onset of estrus between 36 and 60 hours after administration of PGF. Mean (+/- SE) hours from injection to time of peak concentrations of luteinizing hormone (LH) were 62 +/- 3.1 and 64 +/- 2.1 for groups PGF 6 and PGF 12, respectively. Of the does in groups PGF 6 and PGF 12, 86 and 100%, respectively, had LH peaks. Of the does in groups PGF 6 and PGF 12, 68 and 77%, respectively, had peak concentrations of LH between 48 and 72 hours after administration of PGF. All does in groups PGF 6 and PGF 12 had concentrations of progesterone > 1.0 ng/ml on the day of administration of PGF. Concentrations decreased to < 1.0 ng/ml by 48 hours after injection in all does except 1 in group PGF 6. Prostaglandin was equally effective for induction of estrus on day 6 or day 12 of the estrous cycle in dairy goats, but resulted in a more predictable time to estrus when injection was done on day 12.
اظهر المزيد [+] اقل [-]Plasma concentrations of luteinizing hormone and adrenocorticotropic hormone in blood collected during the luteal and follicular phases of the estrous cycle in cows
1992
Hegstad, R.L. | Johnston, S.D. | Pasternak, D.M. | Seguin, B.E. | Wheaton, J.E.
Luteinizing hormone (LH) and ACTH concentrations were measured in plasma from 7 cows to determine whether ACTH secretion changes with the phase of the estrous cycle, and to determine whether any ACTH peaks are associated with LH peaks. Blood was collected every 5 minutes for 190 minutes during the luteal and follicular phases of the estrous cycle. Radioimmunoassays were used to measure ACTH and LH in plasma. Mean concentration of ACTH in all cows did not differ significantly between luteal (35.1 +/- 8.0 pg/ml) and follicular (37.5 +/- 9.4 pg/ml) phases of the estrous cycle. Mean concentration of luteal-phase LH of all cows (2.0 +/- 1.1 ng/ml) was significantly (P < 0.01) lower than mean concentration of follicular-phase LH (5.4 +/- 1.6 ng/ml). Frequency of peaks in ACTH concentration was low during the sampling period. Mean number of luteal-phase ACTH peaks (0.29 +/- 0.49) was not significantly different from that of follicular-phase samples (0.43 +/- 0.53). Unlike ACTH, mean frequency of LH peaks was significantly (P < 0.05) higher in plasma from cows in the follicular phase of the estrous cycle (2.9 +/- 0.7), compared with that from cows in the luteal phase (0.29 +/- 0.49).
اظهر المزيد [+] اقل [-]Long-term study of aerobic bacteria of the genital tract in breeding bitches
1992
Bjurstrom, L. | Linde-Forsberg, C.
The aerobic bacterial flora of the genital tract was characterized in 59 bitches in an 18-month study. The bitches represented 4 breeds and were from 3 kennels. Collection of vaginal swab specimens for bacterial culturing was performed every month, except during estrus when specimens were collected every week (n = 826). The capsule of the swab containing transport media was broken before specimen collection to moisten the tip, which helped to reduce the number of negative cultures. All bitches whelped at least once during the study and, thus, had known reproductive functions. Pregnancy rates, litter sizes, and pup mortality were within normal limits. Pasteurella multocida, beta-hemolytic streptococci group G, and Escherichia coli were the most common bacteria isolated. Although these species generally were isolated from mixed cultures, pure cultures were obtained from 18% of the specimens. There was a tendency for the various breeds to differ in their vaginal bacterial flora. The flora also varied during the reproductive cycle. Pasteurella multocida was isolated significantly more often during proestrus, estrus, metestrus, and pregnancy, than during anestrus and the postpartum period, and beta-hemolytic streptococci were isolated significantly more often during proestrus than during estrus, pregnancy, or the postpartum period. Staphylococcus intermedius was almost exclusively found after parturition. Culture results were negative for only 5.2% of specimens cultured. On the basis of our findings, bacterial culturing of vaginal swab specimens from bitches without signs of genital disease is of little value.
اظهر المزيد [+] اقل [-]Ultrasonographic appearance of the ovaries of dogs during the follicular and luteal phases of the estrous cycle
1992
Wallace, S.S. | Mahaffey, M.B. | Miller, D.M. | Thompson, F.N. | Chakraborty, P.K.
Ultrasonography of the ovaries of 10 bitches was performed daily, using a 7.5-Mhz transducer with a built-in stand-off pad, from the onset of proestrus until the onset of metestrus. Ovarian size, shape, location, echogenicity, follicular development, and apparent ovulation were monitored. Blood samples were collected twice daily for luteinizing hormone determination and daily for progesterone determination. Vaginal smears were made daily for cytologic evaluation. Ultrasonograms were evaluated independent of hormonal and cytologic data, and the day of ovulation was noted. Initially, the ovaries were uniform and had an echogenicity that was equal to or slightly greater than that of the renal cortex. Follicles appeared as focal hypoechoic to anechoic rounded structures. Ovaries were easier to identify as follicular development progressed. Ovarian size increased with time. Apparent ovulation was characterized by a decrease in number of follicles seen from 1 day to the next, but 1 or more follicles remained in at least 1 ovary of 7 of 10 bitches. The ovaries had an oval shape that became rounded after ovulation. At some time after ovulation, all bitches had cystic (anechoic) structures indistinguishable from follicles. These structures increased in echogenicity and decreased in size with time and may have been follicles that did not ovulate, corpora hemorrhagica, fluid-filled corpora lutea, or cyctic luteinized follicles. Time of ovulation determined by ultrasonography paralleled that predicted on the basis of hormonal data in 9 of 10 bitches and with cytologic findings in all bitches.
اظهر المزيد [+] اقل [-]