Effects of hypertonic dextrose and paraffin solution as non‐antibiotic treatments of clinical endometritis on reproductive performance of high producing dairy cows

The objective of this study was to compare the reproductive performance of cows affected by clinical endometritis (CE) following treatment with an intrauterine infusion of 50% dextrose solutions (DEX) and liquid paraffin (LP) as alternative therapies with routine treatments including PGF_2α injection and intrauterine infusion of oxytetracycline (OTC). Moreover, the reproductive indices of cows treated with endometritis were compared with those of healthy ones. At postpartum reproductive tract examination (28–35 DIM) in one Iranian dairy farm, cows with CE without any selection were assigned to four groups: (a) OTC, a common treatment in Iran, was administered (5 g) to 396 cows, (b) PGF₂α (PG) was injected to 496 cows, (c) dextrose solution (DEX): intrauterine infusion of 50% dextrose solution (200 ml) was done in 427 cows, and (d) liquid paraffin (LP) was administered (100 ml) to 423 cows via intrauterine route. We further assigned 2,233 clinically healthy cows to the control group. The incidence of endometritis was 41.6% in this study. Based on the results of reproductive indices including median days to first AI, days open (DO), first service conception rate, conception rate in 2nd and 3rd services, conception rate in all three services, pregnancy rate < 100 days and pregnancy rate < 200 days, except for median days to first AI in other reproductive indexes, reproductive performance was significantly lower in LP group compared with the healthy cows and other treatment groups (p < 0.05). Except for the first service conception rate and proportion of cows pregnant before 100 days in milk (DIM), there existed no significant difference between the DEX group and the control as far as reproductive performance is concerned (p ≥ 0.05). The first service conception rate was recognizably lower in DEX group compared with OTC and PG (p < 0.05). In conclusion, the use of a non‐antibiotic special solution of dextrose 50% is a good alternative to antibiotic agents concerning the treatment of CE in dairy cows.     

Comparative biochemical profiles,production and reproduction status of the post‐partum dairy cows with and without purulent vaginal discharge

Purulent vaginal discharge (PVD) is a prevalent uterine disease of dairy cows during the puerperium that affects the milk production and affects the profitability of farms. The objectives of this study were to evaluate the biochemical profile, the body condition score, the milk production of cows with PVD and the effects PVD on reproductive performance. A total of 338 Holstein dairy cows aged from 3 to 5 years, from three commercial dairy farms, from Brazil, were used. Blood samples were collected within 25 ± 3 days post‐partum from Holstein dairy cows without PVD (control cows, n = 242) and cows with PVD (n = 96), based on scoring of the vaginal discharge. The body condition score and milk production were recorded on the day of sampling. The biochemical profile encompassed albumin, urea, gamma‐glutamyl transferase, calcium, fibrinogen and cholesterol concentrations. The number of services per pregnancy was lower (p < 0.01), and the number of days until first insemination and the median time to pregnancy were higher in cows with PVD (p < 0.01) when compared with control cows. Milk production and body condition score were lower (p < 0.01) in cows with PVD than in control group. Cows with PVD had lower (p < 0.05) serum albumin, urea, calcium and cholesterol concentrations, and higher serum gamma‐glutamyl transferase activity and fibrinogen concentration than cows without PVD. Our results show that cows with PVD have changes in the biochemical profile and negative effects on production and reproduction performance.     

Efficacy of ozone as a novel treatment option for urovagina in dairy cows

Urovagina is detrimental to the health and fertility of cows worldwide. Surgery, the only known treatment, is not economically pragmatic to dairy practice, and it has some medical drawbacks. The objective of this study was to determine whether reproductive problems associated with urovagina could be alleviated through more practical and less‐invasive treatment options to allow successful conception and term‐pregnancy. Cows diagnosed with urovagina (n = 1219) were divided into three treatment groups, each containing an equal number of cows with mild, moderate and severe urovagina. The groups received one of three treatment options: saline (group A, n = 400), streptomycin (group B, n = 400) or ozone (group C, n = 419) flush, regardless of the severity of the urovagina condition within the group. The ozone treatment was found to be the most effective treatment modality, resulting in the shortest period of days open (95, 89 and 79 days in groups A, B and C, respectively; p < 0.05), the fewest number of inseminations until pregnancy (2.38, 1.84 and 1.63 in groups A, B and C, respectively; p < 0.05) and the smallest number of culled cows (20, 23 and 12 in groups A, B and C, respectively; p < 0.05). The ozone flush coupled with intracornual insemination presents an effective treatment option for urovagina that can lead to successful conceptions and pregnancies in dairy cows.     

Efficacy of Ozone and Other Treatment Modalities for Retained Placenta in Dairy Cows

Retained placenta is a worldwide recognized clinical condition in puerperal cows, which can significantly affect their health and fertility. Available treatment modalities are often of questionable efficacy or associated with time constraints, practicality or monetary considerations for their wide application in a routine dairy practice. The objective of this study was to compare and assess the efficacy of different treatment options, including a novel ozone treatment, for the retained placenta. Two hundred cows diagnosed with retained placenta were divided into five treatment groups, each receiving a different treatment option. Group A (n = 40) was given a combination treatment of intrauterine ozone and parenteral cephalexin; group B (n = 40) was given intrauterine ozone; group C (n = 40) was given a combination of parenteral cephalexin and intrauterine antibiotic tablets; group D (n = 40) was given only parenteral cephalexin and group E (n = 40) was given parenteral prostaglandins in 11‐day intervals. The control group (group Z, n = 200) included cows that gave birth without assistance and were not diagnosed with a retained placenta. The ozone treatment (groups A and B) was found to be the most effective modality resulting in the shortest period of days open, the smallest number of artificial inseminations until pregnancy, the smallest number of animals diagnosed with fever within 10 days post‐calving, the highest percentage of animals pregnant within 200 days after calving and the smallest number of animals culled because of infertility, when compared to the other treatment groups. The intrauterine ozone flush therefore has a potential as an efficacious and cost‐effective treatment option for retained placenta, with an overall positive effect on puerperal health and fertility in cows.     

Alterations in biochemical profiles and reproduction performance in postpartum dairy cows with metritis

The aim of the present study was to evaluate the biochemical profile and reproductive performance in postpartum dairy cows with clinical metritis. The research was carried out using performed on 213 pluriparous lactating cows from two dairy herds in southeast Brazil. Dairy cows were assigned into a group of healthy cows (n = 147) and cows with metritis (n = 66). Blood samples to assess serum albumin, cholesterol, fibrinogen, calcium, gamma-glutammyltransferase (GGT), aspartate aminotransferase (AST) and β-hydroxybutyrate (BHBA) concentrations were performed on day 8 ± 2 postpartum. Metritic cows had lower (p < .05) serum albumin, cholesterol and calcium concentration, and higher (p < .05) GGT and AST activity, and BHBA and fibrinogen concentrations when compared to the healthy group. The calving-to-conception interval and services per pregnancy were higher in metritic cows (p < .01) than in healthy cows and the conception rate at first service was lower in metric group (p < .01). Variable importance in projection plots demonstrated that cholesterol was the main discriminator between metritic and healthy cows. Our results indicated alterations in the biochemical profile and impaired reproduction performance in metritic cows.     

Comparison of Intrauterine Antibiotics versus Ozone Medical Use in Sheep with Retained Placenta and Following Obstetric Assistance

This study outlines a new approach to reproductive tract treatment using ozone foam spray for certain ovine obstetrical problems, such as retained foetal membranes and possible uterine infections following obstetric assistance (OA), in comparison with classical antibiotics treatments. The study was conducted on 256 ewes from 11 sheep farms in north‐western Croatia. A total of 139 ewes were diagnosed with dystocia (DT) and 49 with retention of placenta (RP). Ewes with RP were treated either with ozone foam spray (Riger spray G; Novagen^®) applied into the body of the uterus for 2–3 s (first or RPO group; n = 24) or with two foaming, intrauterine tablets of oxytetracycline hydrochloride (Geomycin^® F) (second or RPA group; n = 25). The third and fourth groups consisted of ewes that received OA for dystocia (including ringwomb, foetal oversize and assistance of abnormal position and posture). The third group (DTO; n = 70) was treated with ozone foam spray, while ewes in fourth group (DTA; n = 69) were treated with antibiotics. The ewes in the control group (CTL) with physiological puerperium were randomly selected (n = 70) from all herds. Transrectal ultrasonography (transversal diameter of uterine horns) was used for the control of uterus regression on days 2 and 25 after parturition. There was a difference in transversal uterine horn diameter in the RP groups, that is RPO and RPA (5.40 ± 0.53 cm vs. 5.43 ± 0.40 cm), ewes with dystocia, that is DTO and DTA (5.37 ± 0.49 cm vs. 5.54 ± 0.60 cm) and ewes from the CTL group (4.98 ± 0.35 cm) one day after parturition. Average transversal uterine diameter of all groups at day 25 post‐partum was 1.80 ± 0.15 cm. The intrauterine ozone treatment in ewes with RP and after manual obstetrics attained similar results to spontaneously delivered ewes (CTL group), showed as the physiological regression of the uterus with a similar transversal diameter without the presence of lochia in the uterine lumen, indicating that this could be a novel potential alternative therapy.     

Reproductive Performance of Crossbred Dairy Cows in Different Production Systems in the Central Highlands of Ethiopia

The study was conducted to examine the fertility status of crossbred dairy cows in mixed crop-livestock production (MCLP), market-oriented specialized dairy production (MSDP) and urban dairy production (UDP) systems, including the Holetta Agricultural Research Center (HARC). Data on general farm management variables and reproductive histories were collected from study farms by questionnaire and from individual cow records. Age at first service and age at first calving were 29.58 months (n = 424) and 40.6 months (n = 348), respectively. Cows managed under UDP were younger at first service and at first calving (p<0.05). The mean intervals from calving to first service and to conception were 141.98 days (n = 284) and 185.02 days (n = 219), respectively. The mean calving interval for cows was 551.82 days (n = 258). Cows in MCLP had longer intervals from calving to first service and to conception and longer calving intervals than those managed under MSDP, UDP and HARC. First service conception rate (43.42%), number of services per conception (1.75) and pregnancy rate (79.29%) did not differ significantly between production systems. Reproductive performance was best in UDP followed by HARC and MSDP. The difference between MCLP and the rest points to particular difficulties in that system. To improve reproductive performance and economic benefit, there should be conservative stocking rate, sensible year-round feeding, a herd health plan, and sustainable extension service.     

Clinical endometritis with Trueperella pyogenes reduces reproductive performance and milk production in dairy cows

The aim of this study was to identify the impact of Trueperella pyogenes in cows with clinical endometritis (CE) on reproductive performance and milk production in affected cows. In total, 230 lactating Holstein dairy cows from six commercial dairy herds were sampled once between 28 and 33 days post-partum. Cows included in the present study did not receive antibiotic or anti-inflammatory treatments prior to the experimental period. Clinical endometritis (CE) was characterized as cow with vaginal mucus score = 3 (>50% of purulent vaginal discharge) and >18% polymorphonuclear neutrophilic leukocyte (PMNL). The body condition scores (BCS) and milk production were evaluated at the time of enrolment. The identification of isolated bacteria was carried out through the analysis of MALDI-TOF MS (matrix-assisted laser desorption ionization time-of-flight mass spectrometry). According to uterine health, three groups of dairy cows were formed: healthy control cows without T. pyogenes (n = 147), CE cows with T. pyogenes (n = 22) and CE cows without T. pyogenes (n = 61). CE cows with T. pyogenes had lower BCS, milk production and conception at first AI (p < .01) than CE cows without T. pyogenes and control cows. Furthermore, CE cows with T. pyogenes had higher (p < .01) service per pregnancy and had greater (p < .01) days to get pregnant than CE cows without T. pyogenes and control cows. This study demonstrates that CE cows with T. pyogenes had impaired reproductive performance and milk production when compared to cows without CE and CE cows without T. pyogenes. This information can contribute to a strategic treatment in cows affected by clinical endometritis, favouring the rational use of antibiotics on dairy farms.     

Reproductive performances of dairy cows in smallholder production system in Selalle, Central Ethiopia

A study was conducted to assess the reproductive performance and factors that influence reproductive efficiency of cows in smallholder dairy farms in Selalle, Central Ethiopia. Three hundred dairy farms (average herd size = 8) were visited and data on reproductive, breeding and management histories were collected and analysed. The overall geometric means for calving to conception interval (n = 382) and duration after last calving (n = 422) were 187 and 201 days in pregnant and non-pregnant cows, respectively. The least-squares mean calving to conception interval was higher (p < 0.05) in mixed crop–livestock production (MCLP) than in small urban dairy production (SUDP) systems and was lower (p < 0.01) in non-suckling than in suckling cows. District significantly influenced (p < 0.01) the least-squares mean duration after last calving and, among the districts, non-pregnant cows in Wuchale-Jida had the highest values, whereas cows in Sululta and Mulo had the lowest values. The overall average number of services per conception (±SD) and the first service conception rate were 1.6 ± 1.0 (n = 382) and 56% (n = 456), respectively. The prevalences of abortion, dystocia (assisted parturition), retained fetal membrane, vulval discharge/endometritis and pre-weaning calf mortality were 1.4%, 1.3%, 5.4%, 2.8% and 17.4%, respectively. The present estimates of extended calving to conception interval and duration after last calving indicate poor reproductive performances of cows in Selalle smallholder dairy farms. The pre-weaning calf mortality rate is highly significant. Accordingly, a further detailed investigation is necessary to identify and quantify the specific reproductive disorders and associated interacting factors attributing to such poor performance and to determine the causes and predisposing factors behind such high calf mortality.     

Combined GnRH and PGF2α Application in Cows with Endometritis Puerperalis Treated with Antibiotics

The investigations were carried out on a total of 70 cows with puerperal endometritis. In addition to intrauterine antibiotic treatment, 30 experimental animals were administered 20 μg GnRH analogue, buserelin, between days 10 and 12 post‐partum followed by 500 μg PGF_2α analogue, cloprostenol, 10 days later. Forty control cows were treated only with intrauterine antibiotics. Blood samples for progesterone determination were collected from the tail vein twice weekly until day 70 post‐partum. The first rise in progesterone level above 3.18 nmol/l occurred significantly earlier in the experimental than in control cows (21.6 ± 9.2 versus 27.8 ± 12.3 days; p ≤ 0.05). The duration of the first cycle post‐partum was 15.0 ± 4.3 days in experimental and 19.7 ± 7.3 days in control animals (p ≤ 0.05). However, no significant differences were observed in the occurrence of first oestrus post‐partum. The involution of the uterus was improved after hormone treatment. At day 42 post‐partum, completion of uterine involution was found in 93.3% of hormone‐treated cows and in 82.5% of those treated with antibiotic only (p ≤ 0.05). Clinical recovery was 96.6% in the experimental and 82.5% in the control group (p ≤ 0.05). First service pregnancy rate was significantly better in hormone‐treated than control cows (51.7 versus 36.4%; p ≤ 0.05). Total pregnancy rate and insemination index values were not significantly improved following GnRH and PGF_2α treatment. The average service period was 89.8 ± 21.2 days in cows after hormone treatment, and 112.6 ± 24.5 days in control cows. The difference was statistically significant (p ≤ 0.05). These results indicate, that the sequential GnRH and PGF_2α application in cows with puerperal endometritis positively affected ovarian function and uterine involution, resulting in improved fertility performance.     

Effects of Fishmeal Supplementation on Fertility and Plasma Ω-3 Fatty Acid Profiles in Primiparous,Lactating Beef Cows

A 2-yr study was conducted using 82 lactating, 2-yr-old, primiparous crossbred beef cows (yr 1, n = 40; yr 2, n = 42) to study the effect of fishmeal supplementation on reproductive performance. Cows were fed a corn silage-based diet supplemented with fishmeal (5% DM) or corn gluten meal (8.7% DM), beginning 25 d prior to the start of and continuing through the 90-d breeding season. Cows were artificially bred with semen from bulls of proven fertility 12 h after being detected in estrus. Jugular blood samples were taken from all cows on d 3 or 4, 9 or 10, and 15 or 16 following first insemination and analyzed for serum progesterone. During yr 2 of the study, additional blood samples were collected from four cows within each treatment group immediately before supplementation began (d 0) and at 7-d intervals for the first 35 d of supplementation. Plasma samples were analyzed for Ω-3 fatty acids. Serum progesterone concentrations did not differ between treatment groups following the first insemination (P>0.76). However, first service conception rates approached significance (NS; P=0.12) and tended to be greater for cows supplemented with fishmeal when compared with cows supplemented with corn gluten meal (76% vs 62%, respectively). Overall pregnancy rates at the end of the breeding season did not differ between the two treatment groups (P>0.64). In yr 2, within 7 d of supplementation, plasma eicosapentaenoate (EPA) and docosahexaenoate (DHA) were greater for cows supplemented with fishmeal (P<0.001). In conclusion, these data indicate that fishmeal supplementation alters plasma EPA and DHA (yr 2) and may improve first service conception rates in primiparous beef cows.     

Evaluation of reproductive tract infection during early post-partum period and its relationship with subsequent reproductive performance in high milk producing dairy cows

Clinically normal Holstein‐Friesian cows (n = 43) were used to establish a relationship between the evaluations of the uterine condition by vaginoscopy, Metricheck, endometrial cytology (EC) and ultrasonography (US) during post‐partum period (pp), and subsequent reproductive performance. The uterine status of the selected cows was evaluated by EC, Metricheck, US and vaginoscopy on a weekly basis from the third week (W3) to the seventh week (W7) pp. The animals were bred after a voluntary waiting period of 45–60 days pp and diagnosed for pregnancy status at 45 days after breeding by US. First service conception rate (FSCR) of bred animals was 32.6% (14/43). There was no significant difference in polymorphonuclear leucocyte percentage between conceived and non‐conceived cows during different weeks post‐partum. First service conception rate in animals with normal vaginal discharge as detected by Metricheck was significantly low when compared to those of abnormal discharge during W3 (2.3% vs 30.3%; p < 0.001) and W4 (4.7% vs 29.7%; p < 0.01) post‐partum. Using US, the number of pregnant cows having fluid in uterus (FIU) during W6 (p < 0.01) and W7 (p < 0.001) post‐partum was significantly lower (2/34, 4.7% and 1/43, 2.3%, respectively) than those that had no FIU (12/43, 27.9% and 13/43, 30.3%, respectively). Using vaginoscopy, FSCR in animals having abnormal discharge was significantly (p < 0.01) low when compared to that of normal discharge (2.4% vs 30.2%) during W5 and W6 post‐partum. In conclusion, Metricheck during W3 and W4 and detection of FIU by US and vaginoscopy during W6 and W7 pp can be used as good predictive tools to anticipate the future reproductive performance of dairy cattle.     

A cross-sectional study of bluetongue virus and Mycoplasma bovis infections in dairy cattle: II. The association between a positive antibody response and reproduction performance

In a cross-sectional study to determine the possible relationship between a positive antibody test to bluetongue virus (BTV) or Mycoplasma bovis infections and reproductive performance of dairy cows, data were collected on 572 California dairy cows during December 1986 for analysis. Serum samples were tested using an enzyme-linked immunosorbent assay (ELISA). Data on reproduction variables were extracted from the individual cow sheets of the California Dairy Herd Improvement Association records and interfaced with the serological results for analysis.Similar data analyses for both BTV and M. bovis were performed to identify and quantitatively assess the association of the reproduction variables and each agent. These associations were evaluated unconditionally using the x ² for categorical variables and Student's t-test for continuous variables. Logistic regression analysis was used to determine if reproduction variables with significant unconditional associations remained significant when adjusted for the effects of possible confounding factors.Both the BTV and M. bovis ELISA antibody titres indicated exposure to the agents. The results of the multiple logistic regression analyses indicated that cows seropositive for BTV were significantly older at first calving (p<0.03). For M. bovis, seropositive cows were more likely to have longer intervals from calving to last service and longer intervals from calving to pregnancy diagnosis than seronegative cows (p<0.05). The other reproduction variables examined were not significantly associated with ELISA seropositivity.     

Reproductive performance of Holstein dairy cows in Iran

The objectives of the present study were to describe the current reproductive parameters of Holstein dairy cows in Iran and to determine factors which have a significant effect on reproductive performance with emphasis on high-producing dairy cows. Five large Holstein dairy herds from the major milk production areas of Iran were selected for this study. Reproduction data including parity of dam, calving date, days to first service, days open, number of services, dry period, and occurrence of diseases for cows that calved from 2004 to 2007 were collected from the herds' databases. To determine the effects of year and season of calving, disease status, level of milk production, and parity of dam on reproductive parameters, the proc-mixed procedure in SAS software was used. Overall, data about 8,204 lactation were collected for the study. Results showed that mean (±SD) days open, calving interval, and days to first service for study herds were 134 (±89), 403 (±86), and 67 (±38) days, respectively. Conception rates at the first service and the overall service-conception rate were 41.6% and 41%, respectively. The level of milk production and diseases had significant negative effects on days open and service per conception (P < 0.05); statistical analysis showed that for every 100-kg increase in milk yield, days open will increase by about 0.3 days. However, no significant effect of level of productivity was observed on days to first service. The results of this study indicate that high milk production is a risk factor for decreasing fertility in Iran, like many other parts of the world.     

Calm Temperament Improves Reproductive Performance of Beef Cows

Profitability of a beef operation is determined by the proportion of cows attaining pregnancy early in the breeding season and those that are pregnant at the end of breeding season. Many factors, including temperament, contribute to those reproductive parameters. The objective of this study was to evaluate effects of temperament on reproductive performance of beef cows. In Experiment 1, Angus and Angus‐cross beef cows (n = 1546) from eight locations were assigned a body condition score (BCS; 1 = emaciated; 9 = obese) and chute exit and gait score (1 = slow exit, walk; calm temperament; 2 = jump, trot or run; excitable temperament). Cows were grouped with bulls (1 : 25 to 1 : 30; with satisfactory breeding potential and free of venereal disease) for an 85‐day breeding season. Pregnancy status and stage of gestation were determined (transrectal palpation) 35 days after the end of the breeding season. Controlling for BCS (p < 0.01) and handling facility (p < 0.0001) and handling facility by temperament score interaction (p < 0.001), breeding season pregnancy rate was lower in excited versus calm cows [88.6% (798/901) vs 94.1% (607/645); p < 0.001]. Cows with an excitable temperament took 24 more days to become pregnant compared to calm cows (median days to pregnancy, 35 vs 59 days; p < 0.0001). In Experiment 2, Angus and Angus‐cross beef cows (n = 1407) from 8 locations were assigned scores for body condition and chute exit and gait (as described in Experiment 1) and assigned to bulls (breeding sound and free of venereal disease; 1 : 25 to 1 : 30) for 85 days. Pregnancy status was determined by transrectal palpation at 2 and 6 months after the onset of the breeding season. Controlling for BCS (p < 0.05), pregnancy loss was higher in excited versus calm cows [5.5% (36/651) vs 3.2% (20/623), p < 0.0001]. In conclusion, beef cows with an excitable temperament had significantly lower reproductive performance than calmer cows. The modified two‐point chute exit–gait scoring method was repeatable and identified cattle with an excitable temperament.     

Reproductive Disorders of Crossbred Dairy Cows in the Central Highlands of Ethiopia and Their Effect on Reproductive Performance

The study was conducted to estimate the proportion of reproductive disorders and to determine factors affecting reproductive performance of crossbred dairy cows under four different production systems in the central highlands of Ethiopia. The principal postpartum reproductive disorders were retained fetal membranes (14.7%) and uterine infection (15.5%). Anoestrus was the major postpartum reproductive problem in the mixed crop–livestock production system (38.6%) and was significantly associated with this production system. Apart from anoestrus, the occurrence of reproductive disorders was not significantly associated with a production system. Most of the reproductive disorders occurred as a complex rather than as a single abnormality. Two or more abnormal conditions were seen in 11.4% of the cases. Each reproductive trait measured was affected adversely by reproductive disorders. Cows with reproductive disorders in each production system, lactation group and suckling and non-suckling group had longer intervals from calving to first service and to conception (p < 0.001) and required more services per conception (p < 0.001). Pregnancy rate and conception to first service were 84.7% and 51.7%, respectively, for cows without reproductive health problems; and 64.2% and 15.1%, respectively, for cows with reproductive disorders (p < 0.001). Overall, intervals from calving to first service were shorter (p < 0.05) than in younger cows. Intervals from calving to first service and to conception were longer in suckling than in non-suckling cows (p > 0.05). Cows with a good body condition score (>3.5) at calving had shorter calving to first service and conception intervals than cows in poor condition (p < 0.001). The results showed that reproductive abnormalities, coupled with poor body condition, are important factors that contributed to reproductive inefficiency. An appropriate reproductive health management, a reliable artificial insemination service and supplementary feeding could be the management options to reduce or alleviate some of the problems.     

Pre-breeding Ovaro–Uterine Ultrasonography and its Relationship with First Service Pregnancy Rate in Seasonal-Calving Dairy Herds

The objectives of the study were to characterize an ultrasound reproductive tract scoring (URTS) system to assess suitability for breeding in dairy cows, to describe the prevalence of these scores in commercial dairy herds and to examine their relationship with subsequent fertility. Ultrasound examinations (7797) were performed on 5751 Holstein–Friesian cows prior to breeding in 62 seasonally calving herds over 2 years. Data recorded from images of both ovaries and the uterus were combined into a six point scoring system and the prevalence of cows with cystic ovarian follicles and uterine abscesses and adhesions was recorded separately. The prevalence of ovulatory cows which had completed uterine involution (score 1), or had mild (2) or moderate endometritis (3) was 62.5%, 21.7% and 2.2%, respectively. The prevalence of anovulatory cows with moderate endometritis (4), ovulatory cows with pyometra (5) and anovulatory cows which had completed uterine involution (6) was 3.3%, 2.2% and 8.1%, respectively. The interval between calving and examination differed between cows with each of the scores 1, 2, 5 and 6 (61, 46, 53 and 50 days, respectively, p < 0.05) but not between cows with scores 3 and 4 (37 and 35 days, respectively). Ovulatory cows which had completed uterine involution (score 1) had a higher likelihood of pregnancy to first service than ovulatory or anovulatory cows which had not completed uterine involution (p ≤ 0.10). The prevalence of cows with cystic ovarian follicles or abscesses or adhesions of the reproductive tract was 3.9% and 1.2%, respectively. In conclusion, 29% and 11% of cows in seasonally calving and breeding dairy herds had not completed uterine involution or were anovulatory prior to the mating start date, respectively. Both conditions, detected using a URTS system, significantly reduced first service pregnancy rate in these pasture-based dairy herds.     

The effects of calving to first service interval on reproductive performance in normal cows and cows with postpartal disease

The relationships between the calving to first service interval and several measures of reproductive performance were evaluated in 1738 lactation records from cows in 32 southern Ontario Holstein herds. Lactation records were divided into three mutually exclusive health categories based on the cows' postpartal disease histories.

Relationships between the calving to first service interval and the first service conception rate, number of services per conception and open interval were similar for all three health categories. The first service conception rate was lower and the average number of services per conception higher in cows first bred before 60 days when compared to cows first bred after 60 days. The relationship between the calving to first service interval and the open interval indicated that for each day that breeding was delayed the open interval was extended by 0.86 days.

It appeared that overall conception rates may be lower for cows first bred very early or very late, but differences in the overall conception rate were only significant for cows experiencing a reproductive tract infection. Unless very expensive semen is being used, it is suggested that disease free cows be bred at the first heat occurring after 40 days postpartum, and that cows experiencing postpartal disease be bred at the first heat occurring after 60 days postpartum.

     

Differential expression of ISG 15 mRNA in peripheral blood mononuclear cells of nulliparous and multiparous pregnant versus non‐pregnant Bos indicus cattle

Embryonic mortality is found to be the main source of reproductive wastage in domestic ruminants. Many genes are involved in the growth and development of the embryo, and the interferon‐stimulated gene 15 (ISG 15) is one of the major gene stimulated by interferon tau, the maternal recognition of pregnancy signal in ruminants. In this study, both genomic and cDNA sequences of ISG 15 from Bos indicus (Deoni breed) were amplified and characterized. The genomic sequence of Deoni ISG 15 exhibited 99% identity with Bos taurus and 97% identity with that of Bos mutus and Bubalus bubalis. Moreover qRT‐PCR analysis revealed constitutive expression of the ISG 15 mRNA in peripheral blood mononuclear cells of Deoni heifers and multiparous cows during early pregnancy. Fourteen Deoni heifers and fifteen multiparous Deoni cows were synchronized for timed AI by CIDR‐Ovsynch protocol, and six animals were kept as cyclic control in each group. Blood samples were collected on days 7, 14, 16, 18, 21, 30 and 45 from the day of AI. Pregnancy was confirmed by plasma progesterone level through ELISA. A significantly higher expression of ISG 15 mRNA was found on day 16 (p < .05) and day 18 (p < .05) of pregnancy in nulliparous heifers. Although in multiparous Deoni cows ISG 15 expression was greater in pregnant cows, difference was statistically non‐significant. The result of this study indicates that ISG 15 gene expression is upregulated during 16–18 days of pregnancy and could be used as an early pregnancy marker in dairy cows especially in heifers.     

Effect of flunixin meglumine treatment during and after embryo transfer on the pregnancy rate in cattle

This study aimed to determine the effect of flunixin meglumine treatment during and after the transfer of in vivo produced embryos to Angus (cows) and Holstein (cows and heifers) breeds of cattle on pregnancy rate. Holstein cows were used as donors in the study. A double dose of prostaglandin F2α was administered to the recipient animals for synchronization. Uterine flushing was performed in donors on day 7 after artificial insemination. A total of 295 transferable embryos were obtained. These embryos were transferred to Angus cows (n = 85), Holstein heifers (n = 80) and Holstein cows (n = 130). After the transfer, these animals were divided into three subgroups. The first subgroup (TI) was administered flunixin meglumine during embryo transfer, and the second subgroup (TII) was administered flunixin meglumine both during embryo transfer and on days 8 and 9 after the transfer. The third subgroup (TIII) was not administered anything and it was considered the control group. Pregnancy examination of the recipients was performed on days 30–35 after the transfer using real-time ultrasonography. The pregnancy rates after embryo transfer were found to be 43.52% in Angus cows, 42.5% in Holstein heifers, and 24.61% in Holstein cows (p < .05). When the animals were not classified according to breed, the pregnancy rates in subgroups TI, TII and TIII were found to be 29.29%, 45.10% and 29.79%, respectively (p < .05). In addition, the pregnancy rates were higher in TII and TIII subgroups of Angus cows and Holstein heifers compared to that of Holstein cows (p < .05). As a result, the pregnancy rates obtained after embryo transfer in Angus cows and Holstein heifers were found to be higher than that in Holstein cows. In addition, it was concluded that the administration of flunixin meglumine during and during/after embryo transfer has a positive effect on pregnancy rates in Angus cows and Holstein heifers.