W. Senosy

Association between evaluation of the reproductive tract by various diagnostic tests and restoration of ovarian cyclicity in high-producing dairy cows

The uterine condition of clinically normal postpartum Holstein-Friesian dairy cows (n = 45) was evaluated once weekly (Weeks 3 to 7) by endometrial cytology, vaginal mucus collection device (VMCD), vaginoscopy, and ultrasonography to establish a relationship with postpartum resumption of ovulatory cycles. The time of first detection of the corpus luteum (CL) by ultrasonography and plasma progesterone concentration >or=1 ng/mL was recorded. By 49 d postpartum, 78% of the cows (n=35) had resumed ovarian function (CL group), whereas the remainder (n=10) had no CL (NCL group). There was a positive correlation between VMCD score and presence of fluid in the uterus in cows with a CL (P<0.01) during Week 3 postpartum but no significant correlation in cows without a CL. Percentage of polymorphonuclear leukocytes (PMN%) was higher in the NCL group (mean+/-SEM, 24.6+/-9.4%) than in the CL group (11.7+/-2.2%) during Week 5 postpartum (P<0.05). The PMN% (4.5+/-6.5%) and VMCD (0.5+/-0.5) scores during Week 5 in cows ovulating by Day 28 were lower (P<0.01) than the PMN% (15.0+/-14.3%) and VMCD (1.1+/-0.9) scores in those ovulating by Day 49. In conclusion, higher PMN% at 5 wk postpartum was associated with delayed resumption of ovarian cyclicity in high-producing dairy cows.

Influences of Metabolic Traits on Subclinical Endometritis at Different Intervals Postpartum in High Milking Cows

Seventy pluriparous high-yielding cows were used to investigate the impact of metabolic traits and body condition score (BCS) during early lactation on subclinical endometritis diagnosed at weeks 5, 6 and 7 postpartum (pp). Blood samples were collected from animals with no peripartum problems from the second (W2) to seventh (W7) weeks pp to estimate some blood metabolites including non-esterified fatty acids (NEFA), β-hydroxybutyric acid (BHBA), blood glucose, total cholesterol (T-chol) and blood urea nitrogen (BUN). Reproductive tract examination was carried out at weeks 5, 6 and 7 pp by endometrial cytology (percentage of polymorphonuclear cells; PMN%). Based on PMN%, animals having <5% were defined as subclinical endometritis group (ENDM group) while animals unaffected by endometritis were defined as no subclinical endometritis group (NOENDM group). Animals with endometritis during week 5 were identified as ENDM5, during week 6 identified as ENDM6 and during week 7 identified as ENDM7 or animals with no endometritis during weeks 5 (NOENDM5), 6 (NOENDM6) and 7 (NOENDM7) pp. Animals diagnosed at week 5; BUN and BCS were lower p < 0.05 in ENDM 5 than NOENDM5 group at W2, W4, W6 and W7. Cows diagnosed at week 6; T-chol was significantly higher (p = 0.05) in ENDM6 group (279.2 ± 12.5 mg/dl) than NOENDM6 group (246 ± 9.5 mg/dl) at W7. Moreover, blood glucose was significantly low (p < 0.05) in ENDM6 group when compared to NOENDM group at W4 pp (49.2 ± 1.8 vs 53.8 ± 1.3 mg/dl). BCS was significantly lower (p < 0.001) in animals suffered from endometritis during week 7 when compared to NOENDM7 cows at W3, W4, W5, W6 and W7. In conclusion, lower blood glucose, BUN and BCS could be a risk factor for cytologically diagnosed endometritis at weeks 5, 6 and 7 pp.

Association among energy status, subclinical endometritis postpartum and subsequent reproductive performance in Egyptian buffaloes

Sixty pluriparous, clinically normal buffalo cows (n=60) were used to investigate the relationships between metabolic status, subclinical endometritis and reproductive performance. Subclinical endometritis was diagnosed by endometrial cytology (EC) and ultrasonography (US) during weeks 4-9 postpartum (pp). A comparative assessment of these diagnostic approaches was made with respect to reproductive outcomes. Blood samples were collected on a weekly basis from weeks 4 to 9 in order to estimate some blood metabolites including blood glucose, total cholesterol, triglycerides, high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C). Reproductive tract examination was carried out weekly from weeks 4 to 9 by endometrial cytology (percentage of polymorphonuclear cells; PMN%) and Ultrasonography (detection of fluid in uterus regardless to its amount or echogenicity; FIU). The percentage of buffalo cow suffering from subclinical endometritis as diagnosed by endometrial cytology was significantly (P<0.01) higher in non-pregnant cows (80%) at weeks 4 and 5 (60%) pp when compared with pregnant animals (0). HDL-c concentration was significantly lower (P<0.05) in cytologically diagnosed ENDM group (15.4±0.7mg/dl) if compared to NOENDM group (25.0±3.1mg/dl) during week 4 pp. During week 5 pp, triglycerides concentration was significantly high (P<0.05) in ENDM group, as diagnosed by the presence of FIU (184.6±12.4mg/dl) if compared to NOENDM group (102.7±30.6mg/dl). Total cholesterol concentration was significantly lower (P<0.01) in ENDM group (51.9±0.5mg/dl) than that of NOENDM group (85.9±2.0mg/dl) during week 6 pp. In conclusion, Weeks 4 and 5 pp are the best times to identify cytologically diagnosed endometritis. Furthermore, glucose and total cholesterol indicated that energy status is not a risk factor for cytologically diagnosed subclinical endometritis in buffalo cows.

Impact of Ovarian and Uterine Conditions on Some Diagnostic Tests Output of Endometritis in Postpartum High-Yielding Dairy Cows

The effect of ovarian predominating structures and uterine condition on the result of some diagnostic tools for the evaluation of endometritis was studied in postpartum (pp) Holstein-Friesian dairy cows (n = 58). Endometrial cytology (EC) and the evaluation of vaginal mucus by vaginoscopy or Metricheck were performed weekly from week 3 to 7 pp. The ovarian studies involved the predominating structures including cystic follicles with plasma progesterone (P(4) ; more or <1 ng/ml; >23 mm), corpus luteum (CL), pre-ovulatory follicles (10-23 mm) and small follicles (<10 mm). The uterine conditions comprised uterine involution, tonicity and fluid in uterus (FIU) regarding echogenicity extent. During week 5, the percentage of polymorphonuclear neutrophils (PMN%) was higher (p < 0.05) in animals with pre-ovulatory follicles (mean ± SEM, 26.3 ± 7.6%) than animals having CL (11.0 ± 3.6%). In cystic ovaries, during week 5, PMN% was higher (p < 0.05) in follicular cysts with low progesterone (P(4) < 1 ng/ml; 9.3 ± 2.6%) than those with high P(4) (P(4) ≥ 1 ng/ml; 1.5 ± 1.1%). Moreover, PMN% was higher (p < 0.01) in animals with non-involuted uterus (11.5 ± 7.4%) than those with involuted uterus (2.7 ± 0.6%) during week 7 pp. The animals that had abnormal mucus determined by Metricheck was higher in animals with atonic uterus than those with tonic uterus during week 6 (82.6% vs 51.5%; p < 0.05) and 7 (71.4% vs 25.7%; p < 0.01) pp. In addition, by vaginoscopy, the prevalence of animals with abnormal discharge showing small follicles (100%, 5/5) during week 3 pp and pre-ovulatory follicles (40.0%, 8/20) during week 5 pp was higher (p < 0.05) when compared to those having CL during week 3 (33.3%; 1/3) and week 5 pp (7.7%; 2/26), respectively. In conclusion, endometrial cytology, Metricheck and vaginoscopy were influenced by the predominating various ovarian structures and uterine condition in early pp high-yielding dairy cows.

Effect of dinoprost and cloprostenol on serum nitric oxide and corpus luteum blood flow during luteolysis in ewes

In this study we compared the effect of dinoprost and cloprostenol on changes of corpus luteum blood flow during luteolysis. Ten nonlactating cyclic ewes were synchronized with double PGF2α injections 11 days apart. At Day 10, the animals were classified into 2 groups and received the third dose of PGF2α after confirmation of the presence of a mature CL. The first group received (12.5 mg/im) dinoprost and the second group received (250 μg/im) cloprostenol. A color Doppler ultrasound scan was performed by the same operator according to the following timeline: 0, 0.5, 1, 2, 4, 6, 12, and 24 hours, then every 24 hours until Day 4). The size, morphology, and blood flow of the CL was evaluated during the regression. The results showed that regression of the CL did not differ between the dinoprost and cloprostenol groups. There was no significant effect on diameter of the CL in both groups, though the size of the CL decreased gradually and slowly. Pretreatment progesterone concentration did not differ between groups. The results showed that the nitric oxide level was significantly increased within half an hour after the dinoprost treatment, and was significantly decreased in the cloprostenol group after half an hour. The blood velocity was increased significantly half an hour after the dinoprost treatment and it was decreased in the cloprostenol-treated group. In conclusion, both cloprostenol and dinoprost affect CL by controlling the nitric oxide level and blood supply of the CL via different mechanisms to induce luteolysis.

Validation of a direct time-resolved fluoroimmunoassay for progesterone in milk from dairy and beef cows

The aim of this study was to validate a direct time-resolved fluoroimmunoassay (TR-FIA) for quantifying progesterone concentrations in milk during the bovine oestrous cycle. Holstein-Friesian and suckled and non-suckled Japanese Black cows were used to demonstrate the relationship between milk and plasma progesterone concentrations and to monitor progesterone profiles in milk and plasma during the oestrous cycle. The minimum detection level of the assay was 1.53ng/mL. Progesterone concentrations in milk and plasma changed in a similar manner throughout the oestrous cycle in dairy and beef cows, and milk and plasma progesterone profiles were significantly correlated (P<0.001). The study confirmed that a direct TR-FIA can be used to monitor the oestrous cycle in cattle and to quantify progesterone concentrations in whole milk.

Protective effects of thymoquinone and l-cysteine on cadmium-induced reproductive toxicity in rats

This study was conducted to investigate the possible protective role of thymoquinone (TQ) and l-cysteine on the reproductive toxicity of male rats induced by cadmium chloride (CdCl2). Forty rats were divided into four even groups. The first group served as untreated control. The second, third and fourth groups received CdCl2, CdCl2 and TQ, and CdCl2 and l-cysteine, respectively for 56 days. Cd exposure caused spermatological damage (decrease sperm count and motility and increased the rates of sperm abnormalities), decrease serum testosterone level and increased oxidative stress. Histological alterations were also observed in the form of vascular and cellular changes in CdCl2 treated rats. The vascular changes were congestion of the blood vessels with interstitial edema in the testes, epididymis, seminal vesicle and prostate. The cellular changes were in the form of degenerative changes with presence of multinucleated giant cells in the lumen of seminiferous tubules, vacuolation and sloughing of the lining epithelium of the epididymis, seminal vesiculitis and prostatitis. Co-administration of TQ and l-cysteine with CdCl2 increased glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and testosterone and reduced lipid peroxidation (LPO) activity. In conclusion, our results showed that TQ and l-cysteine can ameliorate the deleterious effects of CdCl2 probably by activating testicular endocrine and antioxidant systems.

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.

Association between energy status early postpartum and subsequent embryonic mortality in high-yielding recipient cows.

High-yielding Holstein-Friesian recipients (n = 43) were used in order to investigate the relation between energy balance status during the early postpartum period and subsequent embryonic mortality after transferring good-quality frozen embryos. Blood samples were collected during the second, third, fourth, fifth, sixth and seventh weeks postpartum in order to measure energy status indicators. These indicators include β hydroxyl butyric acid (BHBA), non-esterified fatty acid (NEFA), total cholesterol (T-chol), glucose and blood urea nitrogen (BUN). Moreover, body condition scores (BCS) were assessed during the same period. Pregnancy diagnosis by ultrasonography at the 28th day postestrus and embryo viability was ascertained until 45 days postestrus in order to detect late embryonic mortality (LEM). The pregnancy rate on day 28 was 44.2% (19/43); however, five cows (11.6%) experienced LEM by day 45. Based on the non-return rate at day 24, non-pregnant animals, as diagnosed by ultrasonography, were allocated into animals with longer estrus intervals than 24 days (32.5%; mid-embryonic mortality (MEM) group) and animals returning to estrus by day 24 postestrus (23.5%; early embryonic mortality (EEM) group). At week 5 postpartum, BCS was significantly (P < 0.05) lower in the LEM group than that of pregnant (PREG), EEM and MEM groups. NEFA was significantly higher in animals that experienced LEM (LEM group) at week 7 postpartum (289.6 ± 47.0 µEq/L; P < 0.01) than that of PREG (196.8 ± 16.0 µEq/L), EEM (157.2 ± 18.6 µEq/L) and MEM groups (191.5 ± 14.4 µEq/L). In conclusion, lower BCS at week 5 postpartum and higher NEFAs at week 7 postpartum may be associated with subsequent LEM in high-yielding recipient cows.

Effects of propylene glycol on the metabolic status and milk production of dairy buffaloes

OBJECTIVES The study was designed to investigate the effects of drenching with propylene glycol (PG) on body condition, serum metabolites and milk production during the transition period of dairy buffaloes. MATERIAL AND METHODS Animals were randomly allocated to a control group (n=5) and a PG group of 10 buffaloes that were drenched with 500 ml of propylene glycol once daily from 10 (9±3) days prepartum until 2 weeks postpartum. Ultrasound measurements of backfat thickness (BFT) were performed weekly, while blood samples were taken at -4, -2, 2, 4, 6, and 8 weeks from parturition for estimation of hematological and biochemical metabolites. RESULTS At -4, -3, and -2 weeks from calving, BFT did not differ between the two groups, but decreased after calving and was higher for the control group than the PG group at weeks -1 and 1. Hematological analysis revealed insignificant changes between the two groups. Serum concentrations of non-esterified fatty acids (NEFA), β-hydroxybutyric acid (BHBA) and glucose did not differ between the two groups before parturition. At 2 and 4 weeks from parturition, NEFA was higher for the control group than the PG group. Serum concentrations of BHBA were higher at 2, 4, 6, and 8 weeks in control animals than in treated buffaloes. In contrast, the glucose level was significantly increased in PG group when compared to the control group at week 2 postpartum (p<0.05). Serum concentrations of total cholesterol, triglycerides, total proteins, albumin, and globulins did not differ significantly between the two groups (p>0.05). Serum enzyme activities of aspartate aminotransferase and γ-glutamyl transferase were significantly higher in the control than in the PG group. In treated buffaloes significantly (p<0.05) higher average 60-day milk yields were recorded (8.4±0.22 vs. 10.7±0.40 kg/day). Milk composition did not differ between the two groups. CONCLUSION AND CLINICAL RELEVANCE Drenching of dairy buffaloes with propylene glycol may reduce the risk of ketosis, improve the metabolic status, and increase the milk yield.