Accuracy of pregnancy diagnosis and prediction of calving date in red deer using real-time ultrasound scanning

One hundred and sixty-two 18-month-old farmed red deer were used to test the accuracy of pregnancy detection and equations for predicting gestational age. Deer ranging from 30 to 110 days gestation were examined by rectal ultrasonography using a 5 MHz transducer while they were standing. Each scan was recorded on video tape for measurements of uterine diameter, amniotic sac diameters, crown-rump length, head length, head diameter, nose length, chest depth, chest width and placentome base-apex length and width. Fetal age was calculated from the mean of the age predictions derived from each dimension measured on individual deer, for 132 deer between 44 and 110 days gestation. All the hinds diagnosed as pregnant produced offspring, and all the hinds diagnosed as not pregnant failed to produce offspring. Between one and six fetal and uterine dimensions were measurable and the number measurable increased with fetal age. The mean error of calving date prediction in 132 deer was 0.97 days. The error of prediction when measurements were made between 44 and 60 days was 0.44 days, whereas between 61 and 80 days and between 81 and 110 days the errors were +0.95 and +4.72 days, respectively. The estimates of calving date were all within 13 days of the calving date.     

The effect of body condition, live weight, breed, age, calf performance, and calving date on reproductive performance of spring-calving beef cows.

Data from 321 spring-calving cows (mean calving date March 27) were used to assess the effects of body condition, live weight, cow age (from 4 to 13 yr), and breed (237 Hereford x Friesians and 84 Blue-Greys) and time of calving on the proportion of cows that became pregnant, the number of days from the start of mating to pregnancy, and calving interval. Mating started at turn-out to pasture in mid-May and lasted 9 to 10 wk. Body condition at calving and breed were the most significant animal factors affecting reproductive performance. Cows calving in higher body condition had shorter (P less than .001) calving intervals (11.2 d per unit of body condition at calving). Blue-Grey cows became pregnant in a higher proportion (90%) and calving interval was shorter (364 d) than in Hereford x Friesians (83%; 374 d). Body condition at the start of mating was less important and body condition at the end of mating had no effect. Live weight at calving and changes in live weight from calving to the start of mating and during the mating period had no significant effect. The proportion of cows becoming pregnant decreased significantly with age in Hereford x Friesian cows older than 7 yr. The variance in calving interval accounted for by calving date, body condition at calving, breed, and age was 42%.     

The effect of individual liveweight and condition of beef cows on their reproductive performance and birth and weaning weights of calves

AIM: To examine of the influence of liveweight (LW), condition (CS) and age of dam on inter-calving interval (ICI), date of calving, days from joining to calving, and birth and weaning weights of calves. METHODS: LW and CS were measured in a herd of mixed-aged (3-8 years) Hereford x Friesian beef cows on four occasions, annually, over a 3-year period from joining (the date bulls were introduced into the herd at the start of a restricted breeding season) in November 2000 to weaning in March 2004. The four dates of weighing and condition-scoring were joining (November), weaning (March), winter (June), and pre-calving (August). Calves were tagged, identified to their dam, and weighed within 24 h of birth, and at weaning. Date of calving, ICI and days from joining to calving were determined. RESULTS: The CS and LW of cows varied between years. LW increased in cows up to 6 years of age. Three-year-old cows had a longer ICI than older cows. Change in CS and LW from winter to pre-calving and pre-calving to joining were negatively correlated with ICI for younger cows but not for cows > or = 5 years (CS) and 6-8 years (LW) old. No difference in CS or LW precalving was evident between cows that subsequently became pregnant compared with non-pregnant cows, although cows that became pregnant gained more condition from pre-calving to joining than non-pregnant cows. Pregnant cows were heavier and had higher CS at joining than non-pregnant cows. CONCLUSIONS: Young cows, up to second-mating as 3-year-olds, would benefit from separate nutritional management from older cows, to ensure ICI and days to conception are kept at targeted levels. In addition, increasing CS from pre-calving to joining and higher LW and CS at joining resulted in higher pregnancy rates.     

Survey of the prevalence and types of infertility in beef cows and heifers

Thirty to 180 days after natural mating to bulls, 8,184 beef cows and heifers were palpated rectally for pregnancy determination. Of these, 7,396 (90%) were pregnant and 815 (10%) were not pregnant. Regarding the nonpregnant cattle, 315 (38.7%) had a normal uterus and a functional corpus luteum, suggesting that they were cycling; the rest had palpable pathologic findings: 455 (55.8%) had ovarian inactivity and uterine atrophy; 16 (2%) had pyometra; 12 (1.5%) had a mummified fetus; 7 (0.9%) had chronic metritis; 6 (0.8%) had an involuting uterus; and 4 (0.5%) had adhesions of the uterus, ovaries, or a combination of both. For the purpose of comparison, the cattle were grouped according to age: group 1-1,035 nulliparous heifers 18 to 24 months of age; group 2-1,137 primiparous heifers 30 to 36 months of age; group 3-5,548 multiparous cows between 4 and 9 years of age; and group 4-464 cows 9 years of age or older. The pregnancy rates were 79.1, 72.2, 96.8, and 78.2, respectively, for these groups. The pregnancy rate for 4- to 9-year-old cows was significantly greater (P less than 0.05) than that for the other age groups.     

Ultrasonographic appearance of the uterus, placenta, fetus, and fetal membranes throughout accurately timed pregnancy in beagles.

Serial ultrasonographic examinations were performed on 8 Beagle bitches from 20 to 60 days pregnant to determine time of first detection, appearance, and sizes of selected features of pregnancy. Gestation was timed from the day of the preovulatory luteinizing hormone surge. Findings related to gestational age were consistent among bitches. Gestational ages at earliest detection of the following features were: chorionic cavity at day 20; placental layers in the uterine wall at day 22 to 24; zonary placenta at day 27 to 30; embryo and heartbeat at day 23 to 25; yolk sac membrane at day 25 to 28; allantoic membrane at day 27 to 31; choroid plexus of the brain at day 31 to 35; fetal movement at day 34 to 36; skeleton at day 33 to 39; bladder and stomach at day 35 to 39; kidney at day 39 to 47; and liver hypoechoic, compared with lung, at day 38 to 42. Extra-fetal structures were measurable from day 20 or 22 through day 48. Chorionic cavity diameter increased from 0.2 +/- 0.0 cm to 3.3 +/- 0.2 cm, outer uterine diameter increased from 0.8 +/- 0.03 cm to 4.8 +/- 0.2 cm, length of chorionic cavity or zonary placenta increased from 0.3 +/- 0.03 cm to 4.9 +/- 0.05 cm, uterine wall thickness increased from 0.3 +/- 0.03 cm to 0.8 +/- 0.01 cm, and placental thickness increased from 0.1 +/- 0.0 cm to 0.5 +/- 0.05 cm. Chorionic cavity diameter, outer uterine diameter, and placental length each increased at a linear rate through day 37, after which time, each had a marked plateau in growth. Of the extra-fetal structures, chorionic cavity diameter was the most accurate for estimation of gestational age. All of the fetal structures studied increased at an increasing (second order) rate. Crown-rump length increased from 0.3 +/- 0.05 cm on day 24 to 9.2 +/- 0.2 cm on day 48. Body diameter increased from 0.2 +/- 0.03 cm on day 24 to 4.6 +/- 0.15 cm on day 60. Head diameter increased from 0.8 +/- 0.05 cm on day 34 to 2.7 +/- 0.04 cm on day 60. Of the fetal structures, head diameter was the most accurate for estimation of gestational age.     

Pregnancy Loss in Dairy Cattle: Relationship of Ultrasound,Blood Pregnancy‐Specific Protein B,Progesterone and Production Variables

Objectives were to determine associations between percentage pregnancy loss (PPL) in dairy cattle and: (i) pregnancy diagnosis by ultrasonography; (ii) pregnancy diagnosis by serum pregnancy‐specific protein B (PSPB) concentrations, with or without serum progesterone concentrations; and (iii) production and environmental factors. This study included 149 822 pregnancy diagnoses conducted over 13 years in Holstein‐Friesian cows in Hungarian dairy herds. The following were determined: PPL in cows diagnosed pregnant by transrectal ultrasonography 29–42 days after artificial insemination (AI; n = 11 457); PPL in cows diagnosed pregnant by serum PSPB 29–35 days after AI (n = 138 365); and PPL and its association with serum progesterone concentrations, PSPB and production/environmental variables. The definition of PPL was percentage of cows initially diagnosed pregnant based on ultrasonography or PSPB, but not pregnant when examined by transrectal palpation 60 –70 days after AI. The PPL was lower (p < 0.001) in cows following ultrasonographic vs PSPB diagnosis of pregnancy at 29–35 days (8.1 vs 19.3%, respectively), but was higher in cows following ultrasonographic pregnancy diagnosis on 29–35 vs 36–42 days (8.1 vs 7.1%, respectively, P < 0.05). Furthermore, 72.9% of pregnancies with ultrasound‐detected morphological abnormalities resulted in pregnancy loss. As a subset of PSPB data, a fully quantitative PSPB assay was used for 20 430 samples; PPL in cows with a high PSPB concentration (>1.1 ng/ml) was lowest (15.0%), whereas cows with low concentrations of both PSPB and progesterone (0.6–1.1 and <2 ng/ml, respectively) had the highest PPL (76.3%; p < 0.0001). Furthermore, PPL was higher in cows with advanced parity and with high milk production, when ambient temperatures were high, although body condition score (BCS) had no effect on PPL. Finally, there were no significant associations between serum PSPB and environmental temperatures or number of post‐partum uterine treatments.     

Distribution patterns of mast cells in the uterus of pregnant Meishan pigs

The present study was performed to investigate the numerical distribution of mast cells (MCs) in the uteri of pregnant Meishan pigs to explore the functions of MCs in pig pregnancy. The uterine samples from pregnant (on days 15, 26 and 50 of gestation) pigs were obtained respectively and stained with toluidine blue. The results were as follows: MCs were constitutively located in the uterus of the Meishan pig, with the distribution varying with gestational stages. On days 15 and 26 of gestation, MCs were mainly distributed around the blood vessels and uterine glands within the endometrium. On day 50 of gestation, MCs were mostly distributed in the myometrium. These results indicated that uterine MCs possibly have versatile functions in pig pregnancy.     

High incidence of abortions and congenital deformities of unknown aetiology in a beef herd

In 1980, 16 abortions or stillbirths occurred and 26 deformed calves were born in a beef herd of 115 Friesian cross Hereford cows mated to Charolais bulls. The deformities were principally arthrogryposes with contractures, particularly of the forelimbs, and various skull abnormalities. Following investigation it was considered highly unlikely that hereditary causes, infectious agents or a nutritional deficiency were responsible. The most likely cause was exposure to an unidentified teratogen early in pregnancy.     

超声断层扫描观察苏北犬胚胎和胎儿发育

用5MHz线阵探头对14只母犬从配种后18d开始，每2d用B超探查1次；配种后36～48d，每3d探查1次；48d以后，于52、57d各探查1次。结果表明，于配种后18～22d确诊7只犬妊娠，7只空怀。有3只犬分剐在配种后24、36、39d发生流产。观察胎囊、胎儿、胎心、胎动、胎儿脏器、胎儿骨骼出现时间和测量胎囊大小、冠臀长、胎儿身长、头长、双顶径、胸深和心区大小，证明胎囊大小、胎儿冠臀长、身长、头长、双顶径、胸深与胎龄呈显著正相关。在配种后18～30d，观察子宫暗区大小可预测胎龄。在配种32d以后，观测胸深、双顶径或头长。可精确预测胎龄。     

The effect of metritis and subclinical hypocalcemia on uterine involution in dairy cows evaluated by sonomicrometry

The objective of this study was to examine the effects of metritis and subclinical hypocalcemia on reduction of uterine size in dairy cows using ultrasonography and sonomicrometry. Four piezoelectric crystals were implanted via laparotomy into the myometrium of the pregnant uterine horn of 12 pluriparous Holstein Friesian cows 3 weeks before the calculated calving date. Sonometric measurements were conducted daily from 2 days before parturition (= Day 0) until Day 14 after calving and then every other day until Day 28. Distances between adjacent crystals were expressed in relation to reference values obtained before calving. The diameter of the formerly pregnant uterine horn was measured using transrectal B-Mode sonography starting on Day 10. Cows were retrospectively divided into the following groups: cows without metritis (M–; n = 7), cows with metritis (M+; n = 5), cows with normocalcemia (SH–; Ca > 2.0 mmol/l on Days 1 to 3; n = 5) and cows with subclinical hypocalcemia (SH+; Ca < 2.0 mmol/l in at least one sample between Days 1 and 3; n = 7). Metritis did not affect (P > 0.05) sonometric measurements, but the diameter of the formerly pregnant horn was larger (P ≤ 0.05) between Days 15 and 21 in M+ cows than in M‒ cows. Reduction in uterine length in hypocalcemic cows was delayed (P ≤ 0.05) between Days 8 and 21 compared with normocalcemic cows, but the uterine horn diameter was not related to calcium status. In conclusion, both diseases affected reduction of uterine size until Day 28. Cows with metritis had a larger uterine diameter, possibly attributable to accumulation of lochia, and cows with subclinical hypocalcemia had delayed reduction of uterine length, presumably related to reduction of myometrial contractility.     

Trächtigkeitsfeststellung beim Rind mit dem Echolot-Verfahren

Pregnancy detection in cows by pulse mode ultrasound
Two commercially available pulse mode ultrasound instruments for pregnancy detection in cows were examined by testing 50 pregnant Friesian cows twice weekly. Absolutely reliable results were obtained after d 181 ("Cow-Tone") and d 221 of pregnancy (Preg-Alert 7 respectively. A newly constructed instrument ("HK-Rheintechnik") operating with greater wavelength (0,7 MHz) was tested in a similar fashion on 62 pregnant cows. Zt produced absolutely reliable results from d 135 of pregnancy on, i.e. 46 days sooner than the best of the commercial instruments tested .     

Health, welfare and fertility implications of the use of bovine somatotropin in dairy cattle

Twenty-two Friesian and Friesian cross Ayrshire cows and 16 first lactation heifers were paired. Twenty were injected subcutaneously with 500 mg recombinant bovine somatotropin (sometribove) and 18 with a placebo at fortnightly intervals, starting 80 (+/- 7) days after calving, through the winter of 1986-87. The cows' weights and changes in condition, milk yields, milk solids, health and fertility were recorded regularly. Compound cake was fed at a fixed stepped rate according to the number of days since the cow calved. Silage was available on an easy-feed basis. Ten cows had their daily silage intake measured. Sometribove treated cows produced on average 27.7 kg of milk per day, 4.5 kg more than the controls. Treated heifers produced 23.5 kg per day, 2.5 kg more than the controls. Milk quality was unchanged. Treated cows gained weight during the trial, but not by as much as the controls. Control heifers also gained weight but the treated heifers lost, on average, 3 kg. Local reactions at the injection site were not felt to be of welfare concern, nor was the general effect of the extra milk production. A small number of treated animals experienced mastitis and had poorer fertility but the differences were mostly not statistically significant. If bovine somatotropin should become licensed for use in Britain it is recommended that clear guidelines should be issued on the management practices necessary for economic success and for the welfare of the treated animals.     

Reproductive consequences of deficiency of uridine monophosphate synthase in Holstein cattle

Cattle heterozygous for deficiency of uridine monophosphate synthase required more breeding services per calving when mated to other heterozygotes than did matings of normal cattle. Gestation length, number of breeding services per calving, and days from breeding to pregnancy examination were monitored on 759 complete gestations, 76 false-positive pregnancy diagnoses, 14 false-negative pregnancy diagnoses, and 413 negative pregnancy diagnoses in a dairy herd between 1983 and 1987. For complete gestations, 15 heterozygote x heterozygote matings required 3.13 +/- 0.37 breeding services per calving, which was significantly more than the 2.05 +/- 0.05 breeding services required for normal x normal matings; gestation length and days from breeding to pregnancy examination were similar between mating types. For false-positive pregnancy diagnoses, females diagnosed pregnant, but subsequently found not to be pregnant, 5 heterozygote x heterozygote matings averaged 51 +/- 23 days of gestation, which was less than the 93 +/- 6 days required for 71 normal matings; services and days from breeding to pregnancy examination were similar between mating types. All false-negative pregnancy diagnoses, females diagnosed not pregnant but later found to be pregnant, were made on cattle with normal matings. For negative pregnancy diagnoses, heterozygous matings averaged 0.3 more breeding services per examination than normal matings.     

Progesterone concentration in defatted milk of dairy cows in early pregnancy.

Progesterone concentrations have been measured in defatted milk of British Friesian cows of four herds during the oestrus cycles (other than short cycles) immediately before artificial insemination (AI) at oestrus and immediately after AI (in non-pregnant cows), and during early pregnancy. Differences in mean progesterone concentrations between herds were significant (P less than 0.05) on all days within the day 10-18 period after AI, both in pregnant and in non-pregnant, inseminated cows but were not significant between pregnant and non-pregnant cows within herds until day 17 or 18. It is concluded that up to this time (that of luteolysis in non-pregnant cows) undefined factors, variable among herds, can have a much greater influence on the rate of progesterone secretion by corpora lutea and consequent progesterone concentration in plasma and milk than does the presence of conceptuses. Maximum mean progesterone concentration reached during early pregnancy in two herds did not differ significantly; it was reached in the 11-15-day period in one herd but not until 46-50 days in the second. Mean progesterone concentration declined after day 90.     

Calving outcomes for cows diagnosed pregnant or nonpregnant by per rectum examination at various intervals after insemination

Early pregnancy diagnosis could be associated with decreased diagnostic accuracy or increased fetal loss, which might lead to increased culling. We determined the relationship between pregnancy diagnosis at various intervals after artificial insemination and subsequent calving for cows from five dairy herds in California. Palpations were done by either of two experienced veterinarians. Cows diagnosed pregnant at a first pregnancy examination 41 days or less after insemination were significantly less likely to subsequently have a calf than were cows diagnosed later.     

Practical uses of ultrasound in early pregnancy in cattle

Using a 'real-time' ultrasound scanner with a 3.5 MHz rectal transducer, a herd of 80 Friesian cows were scanned at weekly intervals during early pregnancy to assess the accuracy of pregnancy diagnosis, and the accuracy of twin detection. The growing fetuses were also measured to determine the relationship between crown-rump length and age. The accuracy of detection of pregnancy was inversely proportional to the age of the cow (r -0.967), the accuracy of detection of twinning was 100 per cent and there was strong correlation between fetal crown-rump length and age (r 0.98).     

Plasma progesterone and gonadotrophin concentrations following norgestomet treatment with and without cloprostenol in beef cows

Twelve Hereford cross Friesian cows received subcutaneous implants containing 6 mg norgestomet and intramuscular injections of 5 mg oestradiol valerate and 3 mg norgestomet. Six of the cows also received 0.5 mg cloprostenol eight days later and all implants were removed on day 9. When treatment was commenced between days 3 and 5 of the ovarian cycle, luteal function was not prevented although the luteal phase was shortened in some cases. When treatment was commenced between days 8 and 14 of the cycle progesterone concentrations remained above basal levels for five to seven days. Cows with corpora lutea that were given cloprostenol underwent rapid luteolysis. It is concluded that oestradiol valerate does not control luteal function adequately, particularly if administered early in the cycle, and this may explain failure of oestrus synchronisation in some cases. Administration of prostaglandin 24 hours before norgestomet implant removal may improve the degree of oestrus synchronisation in groups of cyclic cows.     

Treatment of cystic ovarian disease in dairy cattle

Fourty-four Holstein Friesian cows diagnosed as having ovarian follicular cysts from rectal palpation of the ovaries and observation of estrous behavior were used for the present experiments. Of the 16 cows injected intramuscularly (i.m.) with 110 mg of depot-progestins containing 100 mg of 17alpha-hydroxyprogesterone caproate and 10 mg of progesterone in oil, 8 cows responded with conception with 103 +/- 53 days in average after the treatment. The 8 cows not responding to depot-progestins were injected i.m. with 6,000 MU of HCG on the 10th day after the treatment. As a result, 2 cows of them conceived within 72 days in average after the initial treatment. Of the other 16 cows injected i.m. with 100 mg of progesteron in oil, 3 cows conceived. Interval between the treatment and conception was 36 +/- 9 days in average. In the 11 cows which failed to respond to progesterone treatment, an intramuscular injection of 6,000 MU of HCG on the 5th day after treatment resulted in conception of 7 cows within 42 +/- 10 days in average after the first treatment. Of the remaining 12 cows which received an i.m. injection with 10,000 MU of HCG, 4 cows responded with conception with 64 +/- 51 days in average after treatment. No remarkable rise in serum progesterone levels was observed either 10 days after depot-progestins injection or 5 days after progesterone treatment. Serum progesteron levels increased distinctly after HCG injections. The combined treatment with 100 mg of progesterone and 6,000 MU of HCG at 5 days interval gave the most successful results and this treatment was effective even when performed long after calving. Thus this method of treatment of cystic ovarian disease may be recommended for practical application.     

Gamma Interferon Production and Plasma Concentrations of Pregnancy‐Associated Glycoproteins 1 and 2 in Gestating Dairy Cows Naturally Infected With Neospora caninum

Gamma interferon (IFN‐γ) production and cross‐breed pregnancy have been attributed a role in protecting dairy cows infected with Neospora caninum against abortion. Plasma levels of pregnancy‐associated glycoproteins‐1 (PAG‐1) are a marker of placental/foetal well‐being and of PAG‐2 is an abortion risk indicator in chronically N. caninum‐infected animals. The present study examines, in cross‐breed pregnancies, interactions between IFN‐γ production and levels of PAG‐1 and PAG‐2 in non‐aborting naturally Neospora‐infected dairy cows. Data were obtained from 60 pregnant Holstein‐Friesian cows: 44 Neospora‐seropositive and 16 Neospora‐seronegative; 12 became pregnant using Holstein‐Friesian semen and 48 using Limousin semen. Blood samples were collected on Days 40, 90, 120, 150, 180 and 210 of gestation. Gamma interferon was only detected in the plasma of nine of the 44 Neospora‐seropositive cows, all of them became pregnant using Limousin semen. Through GLM procedures, in cows inseminated with Limousin semen and Neospora‐seropositive cows showing no IFN‐γ production, PAG‐1 concentrations were high and increased throughout gestation compared to the levels detected in cows inseminated with Holstein‐Friesian semen and Neospora‐seropositive cows producing IFN‐γ, respectively. In Neospora‐seronegative cows and in Neospora‐seropositive cows showing no IFN‐γ production, significantly increased PAG‐2 concentrations were observed on gestation Day 120. Our findings indicate that IFN‐γ production correlates negatively and the production of antibodies against N. caninum is uncorrelated with plasma PAG concentrations during gestation in Neospora‐infected dairy cows. Accordingly, IFN‐γ production could be linked to the transplacental migration of tachyzoites, which may cause a reduction in PAG levels.     

Pregnancy diagnosis in cattle by measuring vaginal electrical resistance

The results of early pregnancy diagnosis using a milk progesterone assay and a measurement of electrical resistance of the vaginal mucosa made on 135 dairy cows in two herds are compared. The tests were carried out on the day of insemination and 21 days later. Ninety-eight cows were diagnosed as pregnant by both tests. Of these, 92 calved and there were 6 cases of suspected embryonic mortality. Thirty animals were diagnosed as non-pregnant by both tests and none calved. One cow, diagnosed as non-pregnant by the vaginal electrical resistance method, calved later. Of the remaining 6 cows, 4 had extended postparturition anoestrus, one had cystic ovarian disease and another had a long oestrus cycle.The results of this study suggest that measurements of the electrical resistance of the vaginal mucosa in dairy cows may have a part to play in on-farm pregnancy diagnosis.