Efficacy of carprofen on conception rates in lactating dairy cows after subcutaneous or intrauterine administration at the time of breeding

Manipulation of the reproductive tract can cause inflammatory processes in the endometrium and release of cytokines and prostaglandins. It has been shown that PGF2α has direct negative effects on embryonic survival and development. Treatment with nonsteroidal antiinflammatory drugs (e.g., ibuprofen lysinate, flunixin meglumine) might improve pregnancy rates after embryo transfer in recipient heifers. The primary objective of this study was to evaluate the effect of a nonsteroidal antiinflammatory drug on reproductive performance in lactating dairy cows when administered at the time of first-service artificial insemination (AI) based on the hypothesis that uterine manipulation during AI might be similarly intense compared with embryo transfer in its effect on prostaglandin release. A total of 970 cows (333 primiparous and 637 multiparous) from 17 Holstein dairy farms were enrolled. On the day of first AI, cows were randomly allocated to 1 of 3 treatment groups. Cows of group 1 received 1.4 mg/kg of body weight (BW) of carprofen subcutaneously immediately after AI (SC group). In group 2, 1.4 mg/kg of BW of carprofen was administered into the uterus using a sterile disposable catheter 12 to 24 h after AI (IU group). Animals of group 3 remained as untreated controls. First AI conception rate was similar for the SC group (42.2%) compared with the untreated control group (45.1%). A binary logistic regression model for the odds of conception at first AI revealed a negative effect of an intrauterine administration of carprofen on conception rate (38.3%). Cows allocated to the IU group had a lower likelihood of being pregnant within 200 d in milk than cows in the control group. In summary, subcutaneous treatment with the nonsteroidal antiinflammatory drug carprofen at the time of AI did not influence conception rate, whereas an intrauterine administration of carprofen 12 to 24 h after first AI had a negative effect on first-service conception rate in lactating dairy cows

Association between transfer of passive immunity, health, and performance of female dairy calves from birth to weaning

The objective of this observational study was to compare calf health, average daily weight gain, and calf mortality considering the proposed categories of transfer of passive immunity (TPI) by the consensus report of Lombard et al. (2020). The consensus report defines 4 categories of passive immunity (excellent, good, fair, and poor) of calves obtained after colostrum ingestion. The association between the 4 TPI categories was analyzed on calf health (i.e., hazards for morbidity and mortality), and average daily weight gain (ADG) of female Holstein Friesian calves during the first 90 d of age. A further aim of this study was to examine the effects of calving-related factors, such as dystocia or winter season, on TPI status. We hypothesized that calves with excellent TPI have greater ADG, lower risks for infectious diseases such as neonatal diarrhea, pneumonia, and omphalitis, and lower mortality rates. This observational study was conducted from December 2017 to March 2021. Blood was collected from 3,434 female Holstein Friesian dairy calves from 1 commercial dairy farm. All female calves aged 2 to 7 d were assessed for TPI status by determination of total solids (TS) in serum via Brix refractometry by the farm personnel once a week. Passive immunity was categorized according to Lombard et al. (2020) with excellent (≥9.4% Brix), good (8.9–9.3% Brix), fair (8.1–8.8% Brix), or poor TPI (<8.1% Brix). For the analysis of ADG and calving ease 492 or 35 calves had to be excluded due to missing data. The distribution of calves according to TPI categories was as follows: 4.8% poor (n = 166), 29.5% fair (n = 1,012), 28.3% good (n = 971), and 37.4% excellent (n = 1,285). From the calving-related factors, parity of the dam, calving ease, birth month, calving assistance by different farm personnel, and day of life for TPI assessment were significantly associated with TS concentration. Out of 3,434 calves, 216 (6.3%) had diarrhea, and 31 (0.9%) and 957 (27.9%) suffered from omphalitis and pneumonia during the first 90 d of life, respectively. Overall, the morbidity during the preweaning period was 32.6% (n = 1,118), and the mortality was 3.1% (n = 107). The ADG was 0.90 ± 0.15 kg with a range of 0.32 to 1.52 kg. The Cox regression model showed that calves suffering from poor TPI tended toward a greater hazard risk (HR) for diarrhea (HR = 1.57, 95% CI: 0.92–2.69) compared with calves with excellent TPI. Calves suffering from TPI had a greater HR for pneumonia (HR = 2.00, CI: 1.53–2-61), overall morbidity (HR = 1.99, CI: 1.56–2.55), and mortality (HR = 2.47, CI: 1.25–4.86) in contrast to excellent TPI. Furthermore, calves with good and fair TPI had significantly greater HR for pneumonia (good TPI: HR = 1.35, CI: 1.15–1.59; fair TPI: HR = 1.41, CI: 1.20–1.65) and overall morbidity (good TPI: HR = 1.26, CI: 1.09–1.47; fair TPI: HR = 1.32, CI: 1.14–1.53) compared with the excellent TPI category. Average daily weight gain during the first 60 d of life was associated with TPI categories. Calves with excellent and good TPI status had ADG of 0.90 ± 0.01 kg/d and 0.92 ± 0.01 kg/d (mean ± SE), respectively. The ADG of calves with fair TPI status was 0.89 ± 0.01 kg/d, and calves suffering from poor TPI had 0.86 ± 0.01 kg/d. Average daily weight gain differed in calves with poor TPI compared with the other categories. Fair and excellent TPI differed additionally from good TPI. We found no statistical difference between the TPI categories fair and excellent. In conclusion, poor TPI was associated with higher morbidity and mortality during the first 90 d of life. Furthermore, calves with fair, good or excellent TPI had greater ADG

Fertility control in a male rabbit using a deslorelin implant. A case report

[EN] Continuous low-dose release of the GnRH analogue deslorelin (Suprelorin, Peptech, Australia) causes a suppression of reproductive function in different species such as dogs, koalas, or kangaroos. No studies concerning the efficacy and safety in male rabbits have yet been conducted. A male rabbit with hypospadia was introduced to the Clinic for Animal Reproduction. The owner intended to keep it together with a fertile female rabbit. To avoid reproduction, a 4.7 mg deslorelin implant was injected subcutaneously. No negative reaction to implant placement was diagnosed by daily examination of the injection site for one week. To test the effectiveness of the treatment, blood samples were taken and the testes size was measured regularly. After an initial rise in testosterone levels for 14 d, a down regulation for seven month with values lower than 0.1 ng/mL was observed. In the same period, the size of the testes declined to 50 % of the original dimensions. Afterwards, both testes regained their former shape and size. Since it was not a stud rabbit, semen parameters were not determined. During the suppression of the reproductive function, no sexual activity was observed by the owners. These findings have yet to be proven by clinical trials with a sufficient number of animals, but this case indicates the efficacy of deslorelin implants in male rabbits.Arlt, S.; Spankowski, S.; Kaufmann, T.; Kostelnik, K.; Heuwieser, W. (2010). Fertility control in a male rabbit using a deslorelin implant. A case report. World Rabbit Science. 18(3). doi:10.4995/wrs.2010.819018

Effect of dose and frequency of prostaglandin F2α treatments during a 7-day Ovsynch protocol with an intravaginal progesterone releasing device on luteal regression and pregnancy outcomes in lactating Holstein cows

Our objective was to evaluate the effect of 3 different Ovsynch protocols on progesterone (P4) and pregnancies per artificial insemination (P/AI), where all cows received a P4 releasing intravaginal device (PRID) from d 0 until d 8. We hypothesized that (1) both modified PGF2α treatments lead to decreased P4 at the second GnRH treatment (G2), resulting in greater P/AI, (2) the treatment effect is influenced by the presence of a corpus luteum (CL) at the beginning of the protocol, and (3) potential vaginal discharge caused by the PRID does not have a negative influence on fertility. Lactating Holstein cows (n = 1,056) were randomly assigned to 1 of 3 treatment groups on a weekly basis (n = 356; control: d 0, 100 µg of GnRH + PRID; d 7, 25 mg of dinoprost; d 8, PRID removal; d 9, 100 µg of GnRH). Cows in the second group (n = 353) received an Ovsynch protocol with a double dose of PGF2α (DoubleDose: d 0, 100 µg of GnRH + PRID; d 7, 50 mg of dinoprost; d 8, PRID removal; d 9, 100 µg of GnRH). Cows in the third group (n = 347) received an Ovsynch protocol with a second PGF2α treatment 24 h after the first one (2PGF: d 0, 100 µg of GnRH + PRID; d 7, 25 of mg dinoprost; d 8, 25 mg of dinoprost and PRID removal; d 9, 100 µg of GnRH). All cows had their ovaries scanned to determine the presence of a CL at the beginning of the Ovsynch protocol. Vaginal discharge score (VS) was evaluated at PRID removal. All cows received timed artificial insemination approximately 16 h after G2. Pregnancy diagnosis was performed via transrectal ultrasonography (d 38 ± 3 after timed artificial insemination) and rechecked on d 80 ± 7 after timed artificial insemination. Blood samples were collected on d 0, 7, and 9 of the protocol to determine P4 concentrations. Treatment affected P4 at G2. Progesterone was lower for 2PGF and DoubleDose cows compared with cows in the control group (control 0.35 ± 0.02 ng/mL; DoubleDose 0.29 ± 0.02 ng/mL; 2PGF 0.30 ± 0.02 ng/mL). Overall, P/AI did not differ among treatments. We found, however, an interaction between treatment and CL at the first GnRH treatment. Cows lacking a CL at the first GnRH treatment in the 2PGF group had greater P/AI (47.9%) compared with the same type of cows in the DoubleDose group (32.7%). We observed an effect of VS on P4 concentration at d 7. We found an increase in P4 with greater VS. Vaginal discharge score at PRID removal tended to have a positive effect on P/AI at d 38 (VS0: 36.5%; VS1: 41.3%; VS2: 49.7%). In conclusion, the addition of a second PGF treatment on d 7 and 8 of a 7-d Ovsynch protocol increased luteal regression and decreased mean P4 at G2. Cows treated with PGF2α 2 times 24 h apart showed greater P/AI, compared with cows treated with an increased dose of PGF2α

Effect of a progesterone-releasing intravaginal device (PRID) for 8 days during a modified Ovsynch protocol on pregnancy outcomes in lactating Holstein cows

Our objective was to evaluate the effect of a progesterone-releasing intravaginal device (PRID) in a 7-d Ovsynch protocol on pregnancy per artificial insemination (P/AI) and pregnancy loss, compared with a standard 7-d Ovsynch protocol without progesterone supplementation. We hypothesized that progesterone supplementation during an Ovsynch protocol would increase P/AI and decrease pregnancy loss. Data were collected on lactating Holstein cows (n = 716) that either received a 7-d Ovsynch protocol (control: d 0, 100 µg of GnRH; d 7, 500 µg of cloprostenol; d 9, µg of GnRH; n = 360) or a modified Ovsynch protocol with addition of a PRID (PRIDsynch; d 0, 100 µg of GnRH + PRID; d 7, 25 mg of dinoprost; d 8, PRID removal; d 9, 100 µg of GnRH; n = 356). All cows received timed artificial insemination (TAI) approximately 16 h after the second GnRH treatment. Pregnancy diagnosis was performed via ultrasonography on d 38 ± 3 after TAI and rechecked on d 80 ± 7 after TAI. Reproductive performance differed between treatments, with PRIDsynch cows having greater (38.9%) P/AI compared with control cows (31.7%) at d 38 ± 3 and also at d 80 ± 7 (34.6% vs. 28.9%, for PRIDsynch and control cows, respectively). Pregnancy loss did not differ among treatments

Evaluation of laboratory and on-farm tests to estimate colostrum quality for dairy cows

The objectives of this study were to evaluate different analytical methods to determine colostrum quality in dairy cattle, including one laboratory-based method (ELISA) and 4 on-farm tests. We hypothesized that the colostral IgG concentration using different analytical methods, such as ELISA (mg/mL), digital Brix refractometer (% Brix), colostrometer (specific gravity and mg/mL), an outflow funnel (seconds), and a lateral flow assay (mg/mL), were highly correlated with the reference method, radial immunodiffusion (RID; mg/mL) and would generate comparable results. Colostrum samples were collected from 209 Holstein Friesian cows on 2 commercial dairy farms in Germany. Colostrum weight and colostrum temperature were measured. Test characteristics, such as optimum thresholds, sensitivity, specificity, and area under the curve (AUC) were determined using a receiver operating characteristic curve analyses for each test. Out of 209 colostrum samples assessed by RID, 186 (89%) samples had high quality (≥50 mg IgG/mL), while 23 colostrum samples (11%) showed poor quality with IgG concentrations less than 50 mg/mL. The mean IgG concentration (±SD) was 101.3 ± 45.9 mg/mL and the range was 6.0 to 244.3 mg/mL. The Pearson correlation coefficient (r) between RID and ELISA was r = 0.78. In comparison to RID, Pearson correlation coefficients for the on-farm tests were: r = 0.79 (digital Brix refractometry), r = 0.58 (colostrometer: specific gravity), r = 0.61 (colostrometer: temperature corrected), r = 0.26 (outflow funnel) and r = 0.43 (lateral flow assay), respectively. The optimal threshold to identify high-quality colostrum using ELISA was 50.8 mg/mL with sensitivity 91.3%, specificity 92.3%, and AUC of 0.94. For the on-farm tests sensitivity ranged from 95.7% (Brix refractometry) to 60.9% (lateral flow assay). Specificity ranged from 88.6% (lateral flow assay) to 75.9% (colostrometer: temperature corrected). The AUC ranged from 0.93 (Brix refractometry) to 0.73 (outflow funnel). Based on the AUC, ELISA (0.94) and Brix refractometry (0.93) can be considered highly accurate. In conclusion, the ELISA is accurate to assess colostrum quality. Regarding the on-farm tests only the digital Brix refractometer and the colostrometer were adequate to determine colostrum quality

Body temperature around induced estrus in dairy cows

The overall objective of this study was to study the influence of induced estrus on body temperature, comparing 5 distinct intervals around induced estrus and to determine the diurnal pattern from 4 ± 1 d before to 4 ± 1 d after induced estrus. Sixteen estrous cycles of 9 postpartum dairy cows were synchronized with 2 injections of PGF(2α), 10 d apart. After the second PGF(2α) injection on d 10, temperature loggers were inserted into the vaginal cavity for a 12 ± 1-d period. Two days later, a third dose of PGF(2α) was injected to induce estrus. After confirmation of a corpus luteum, loggers were removed on d 5 ± 1. Observation of estrus, rectal palpation, and ultrasound scanning to determine ovulation were carried out every 4 ± 1h, beginning at 12h after the third PGF(2α) injection. Blood samples from the vena coccygea mediana were collected twice daily from d 11 to 12 and every 4 ± 1h after the third PGF(2α) injection until ovulation. Vaginal temperature was recorded every 5 min and averaged to hourly means for the following 5 periods: 1) 48 h preceding the third PGF(2α) injection, 2) from the third PGF(2α) injection to first signs of estrus, 3) estrus to ovulation, 4) a 4-h interval in which ovulation occurred, and 5) a 96-h post-ovulation period. High body temperatures (39.0 ± 0.5 °C) and low progesterone (P4) concentrations (<0.5 ng/mL) were observed during estrus, whereas low body temperatures were observed from PGF(2α) injection to estrus (38.6 ± 0.3 °C) and around ovulation (38.5 ± 0.2 °C), respectively. An association between body temperature and serum P4 concentrations did not exist. However, P4 concentrations on d 11 and 12 were high (5.0 ± 1.5 ng/mL) and decreased (0.9 ± 0.2 ng/mL) after ovulation. Diurnal temperature rhythms were similar before and after estrus. Vaginal temperature before estrus (d 11 and 12) was slightly (0.1 °C) higher compared with the post-ovulation period

Determination of ceftiofur derivatives in serum, endometrial tissue, and lochia in puerperal dairy cows after subcutaneous administration of ceftiofur crystalline free acid

Puerperal uterine infections are often associated with decreased reproductive performance in dairy cows. Routine treatment protocols include the systemic administration of antibiotics. Antibiotic drugs, however, should be administered daily over at least 5 d. The objective of this study was to determine concentrations of ceftiofur derivatives in serum, endometrial tissue, and lochia after subcutaneous administration of ceftiofur crystalline free acid in 6 clinically healthy puerperal dairy cows with normal parturition. Samples were taken immediately before treatment, 2 h after, and then every 24 h over a 7-d period. Concentrations of ceftiofur derivatives were quantified using an HPLC assay. In serum and endometrial tissue, ceftiofur derivatives could be detected above the reported minimum drug concentrations required to inhibit relevant pathogens such as Escherichia coli and Arcanobacterium pyogenes over a 7-d period. Concentrations of desfuroylceftiofuracetamide at 5 d after administration of ceftiofur crystalline free acid were 1.21±0.61 μg/mL in serum, 0.86±0.61 μg/mg in endometrial tissue, and 0.96±1.15 μg/mL in lochia. In lochia, mean concentrations of ceftiofur derivatives also remained above the minimal inhibitory concentration of relevant pathogens, but showed greater variations between cows