Effects of daily propylene glycol drenching during the Ovsynch protocol on fertility and metabolic parameters in lactating dairy cows.

Negative energy balance (NEB) caused by restricted feed intake leads to body condition loss (BCS), increased metabolic stress and reduced fertility in dairy cows. Propylene glycol (PG) is a precursor of ruminal propionate for gluconeogenesis used to increase metabolic adaptation to the early postpartum period. The aim of this study was to determine the effects of daily drenching of PG during the fixed-time artificial insemination (FTAI) protocol on beta-hydroxybutyric acid (BHBA), glucose, adiponectin, insulin-like growth factor-1 (IGF1) concentrations, follicle size and pregnancy rate in dairy cows. Cows (n = 148) were randomly divided into two groups and received either 300 mL of PG (PG-OVS, n = 76) or 300 mL of water (CON-OVS, n = 72) each day of the Ovsynch protocol (GnRH-7 days-PGF2α -56 hours-GnRH-16-18-hour FTAI) between days 57 ± 3 to 67 ± 3 postpartum for the first service. Body condition scores (14 days before expected calving, at calving, on days 21 and 42 postpartum) were recorded. Blood samples were collected days 7 ± 3, 21 ± 3 postpartum, at the beginning of the Ovsynch (days 57 ± 3) and at the time of FTAI (days 67 ± 3) for measurements of BHBA, glucose, adiponectin and IGF1 concentrations. Ultrasonographic examinations were done to measure follicle size at the beginning of Ovsynch and FTAI and to determine pregnancy on days 30 and 60 following FTAI. There were no differences (p > .05) in glucose, adiponectin and IGF1 concentrations between the groups during the study. Although there was no difference (p > .05) in BHBA concentrations on postpartum day 7 ± 3, 21 ± 3 and 57 ± 3 between the groups, BHBA concentrations at the time of insemination was lower (p < .05) in the PG-OVS group (0.72 ± 0.03 mmol/L) than in the CON-OVS group (0.81 ± 0.03 mmol/L). Follicle sizes at the beginning of Ovsynch (PG-OVS, 14.5 ± 0.48 mm; CON-OVS, 14.3 ± 0.59 mm) and FTAI (PG-OVS, 17.8 ± 0.52 mm; CON-OVS, 17.7 ± 0.42 mm) were not different (p < .05). Pregnancy rate of the cows in the PG-OVS group (46.1%, 35/76) was higher (p = .05) than in the CON-OVS group (30.6%, 22/72) on day 30 following FTAI. In conclusion, decreasing serum BHBA concentrations at the time of FTAI by means of daily drenching of PG during the Ovsynch protocol, increased the pregnancy rate at first service in lactating dairy cows. On the other hand, blood glucose was not related with pregnancy rates in our study, probably as a result of our sampling time and more rapid fluctuations of blood glucose concentrations when compared to BHBA.

Utilization of olive mill wastewater for selective production of lipids and carotenoids by Rhodotorula glutinis.

Olive mill wastewater (OMW) is a zero-cost substrate for numerous value-added compounds. Although several studies on the production of lipids and carotenoids by Rhodotorula glutinis in OMW exist, none of them has specifically focused on the conditions for a target lipid or carotenoid. This study presents cultivation conditions that selectively stimulate the cell biomass, individual carotenoids and lipids. It was found that supplemental carbon and nitrogen sources as well as illumination affected cell biomass the most. High temperature, low initial pH, illumination, lack of urea and presence of glycerol stimulated the lipid synthesis. The highest total lipid content obtained in undiluted OMW supplemented with urea was 11.08 ± 0.17% (w/w) whilst it was 41.40 ± 0.21% (w/w) when supplemented with glycerol. Moreover, the main fatty acid produced by R. glutinis in all media was oleic acid, whose fraction reached 63.94 ± 0.58%. Total carotenoid yield was significantly increased with low initial pH, high temperature, illumination, certain amounts of urea, glycerol and cultivation time. Up to 192.09 ± 0.16 µg/g cell carotenoid yield was achieved. Torularhodin could be selectively produced at high pH, low temperature and with urea and glycerol supplementation. To selectively induce torulene synthesis, cultivation conditions should have low pH, high temperature and illumination. In addition, low pH, high temperature and urea supplementation served high production of ß-carotene. Up to 85.40 ± 0.76, 80.67 ± 1.40 and 39.45 ± 0.69% of torulene, torularhodin and ß-carotene, respectively, were obtained under selected conditions. KEY POINTS: • Cultivation conditions selectively induced target carotenoids and lipids • 41.40 ± 0.21% (w/w) lipid content and 192.09 ± 0.16 µg/g cell carotenoid yield were achieved • Markedly high selectivity values for torularhodin and torulene were achieved.

Effect of oestrous expression prior to timed artificial insemination with sexed semen on pregnancy rate in dairy cows.

The objectives of the study were to determine (1) oestrous expression rate and (2) the effect of oestrous expression prior to progesterone-based Ovsynch protocol on pregnancy rate in Holstein cows. All cows (n = 917) were subjected to 7-day progesterone-based Ovsynch protocol. In this protocol, cows that expressed oestrus before (HEAT1) the scheduled second GnRH were inseminated 20 h later after the onset of oestrus without GnRH administration. Cows that expressed oestrus after the second GnRH administration (HEAT2) or did not express oestrus (NOHEAT) received fixed-timed AI. Oestrous expression was determined by using activity-rumination monitoring system and all cows were inseminated with sexed semen. Oestrous expression rate prior to FTAI was 40.5% and the majority (p < .01) of oestrous expression were in HEAT2 compared with HEAT1 in both primiparous (71.8 vs. 28.1%) and multiparous cows (69.5 vs. 30.5%). The mean interval from intravaginal device removal to the onset of oestrus was 47.4 ± 0.9 h and 62.9 ± 0.5 in HEAT1 and HEAT2, respectively. Primiparous cows (47.7%) had a higher (p < .01) expression rate compared with multiparous cows (37.2%). Overall pregnancy rate was 37.4% and there was two-way significant interaction between parity and oestrous expression on pregnancy rate (p < .01). Both primiparous (48.1 vs. 35.8%) and multiparous cows (47.4 vs. 28.4%) that expressed oestrus had greater (p < .01) pregnancy rate compared with cows that did not express oestrus. There was no difference in pregnancy rates of HEAT1 and HEAT2 in both primiparous (44.7 vs. 49.5%) and multiparous cows (47.2 vs. 47.6%). Pregnancy rate was not influenced (p = .21) by milk production (high or low) in both primiparous (47.6 vs. 48.6%) and multiparous (54.9 vs. 42.1%) cows that expressed oestrus, respectively. In conclusion, cows showing oestrus before or after second GnRH of the Ovsynch protocol had greater pregnancy rate than cows not showing oestrus.

Phenotypic evaluation of mast cells in bovine mammary tissue and mastitis in the context of fibrosis.

This research paper addresses the hypothesis that mast cells (MCs) contribute to the formation of mammary fibrosis. MCs are important immune regulatory and immune modulatory cells that play major roles in the inflammatory process. Since there is no detailed knowledge, this research study aimed to comparatively investigate the presence, localization, and immunophenotypes of MCs in healthy and mastitic mammary tissues. A total of 264 mammary samples were evaluated for the examination of mast cells and fibrosis. The mean mast cell number in both acute and chronic mastitis samples were very significantly higher than the control group P < 0.001). A 7.9-fold increase in the number of mast cells was found when the chronic mastitis group was compared with the control (healthy) group. Immunohistochemistry revealed presence of all three immune phenotypes in control and mastitic mammary samples (tryptase + (MCT), chymase + (MCC) and both chymase and tryptase + (MCTC). The mean MCT, MCC, and MCTC numbers in the chronic mastitis group were found to be significantly higher than the control (P < 0.001 for all three phenotypes) but did not differ significantly between control and acute mastitis samples. When the mean numbers of MCT, MCC, and MCTC in the control group and chronic mastitis group were compared, a 10.5, 7.8, and a 4.1-fold increase was observed, respectively. The amount of connective tissue was strongly increased in tissues with chronic mastitis and a 3.01-fold increase was detected compared to the control group. A statistically significant relation was also found between the amount of fibrosis and the increased number of total MCs (P < 0.001).

Effect of delaying the time of insemination with sex-sorted semen on pregnancy rate in Holstein heifers.

The objective of the study was to evaluate the interval from onset of oestrus to time of artificial insemination (AI) to obtain the optimum pregnancy rate with sex-sorted semen in Holstein heifers. Heifers in oestrus were detected and inseminated only by using heat-rumination neck collar comprised electronic identification tag at the age of 13-14 months. Heifers (n = 283) were randomly assigned to one of three groups according to the timing of insemination at 12-16 hr (G1, n = 97), at 16.1-20 hr (G2, n = 94) and at 20.1-24 hr (G3, n = 92) after reaching the activity threshold. The mean duration of oestrus was 18.6 ± 0.1 hr, and mean peak activity was found at 7.5 ± 0.1 hr after activity threshold. The mean interval from activity threshold to ovulation was 29.4 ± 0.4 hr. The overall pregnancy per AI (P/AI) was 53.0% at 29-35 days and 50.9% at 60-66 days after AI. There was a significant reduction between G1 (13.8 ± 1.4 hr) and G3 (7.9 ± 1.4 hr) related to the intervals from AI to ovulation time. Sex-sorted semen resulted in significantly higher P/AI at 29-35 days when heifers inseminated in G3 (60.9%) after oestrus than those inseminated in G1 (49.5%) and G2 (48.9%). In terms of fertility, when the temperature-humidity index (THI) was below the threshold value (THI ≤65) at the time of AI, there was a tendency (≤65; 57.2% vs. > 65; 47.1%) for high pregnancy rate. There was no effect of sire on P/AI. In addition, the interaction of the technician with the time of AI was found significant, and three-way interaction of technician, sire and time of AI was tended to be significant on pregnancy rate. Thus, in addition to delaying the time of insemination (between 20.1 and 24 hr) after oestrous detection, THI and experienced technician were also found to be critical factors in increasing fertility with the use of sex-sorted semen in Holstein heifers.

Fertility of lactating dairy cows inseminated with sex-sorted or conventional semen after Ovsynch, Presynch-Ovsynch and Double-Ovsynch protocols.

The objective was to compare pregnancy per artificial insemination (P/AI) with conventional (CS) or sex-sorted semen (SS) in dairy cows subjected to one of the three timed AI protocols. Cows (n = 356) were randomly assigned to synchronization with Ovsynch (OVS), Presynch-Ovsynch (PO) or Double-Ovsynch (DO) and inseminated on Day 77 ± 3 postpartum with either frozen-thawed SS (n = 182) or CS (n = 184) of the same bull. More cows were cyclic at the beginning of breeding Ovsynch increased (p < 0.01) with presynchronization and it was greater for DO than PO (OVS = 78.5%, PO = 85.1%, DO = 95.6%). Overall, P/AI for SS and CS increased with presynchronization (p < 0.05) on Days 31 (OVS = 35.5%, PO = 47.1%, DO = 48.3%) and 62 (OVS = 30.1%, PO = 43.8%, DO = 43.9%). Regardless of synchronization treatments, insemination with SS reduced P/AI (p < 0.02) on Days 31 (38.1% vs. 50.6%) and 62 (34.5% vs. 45.6%) compared with CS. No interaction was observed between synchronization treatment and type of semen for P/AI, although in cows receiving CS, P/AI was numerically greatest for PO (OVS = 42.0%, PO = 59.3%, DO = 49.0%), and in cows receiving SS, it was numerically greatest for those inseminated following DO (OVS = 27.9%, PO = 35.5%, DO = 47.6%). Thus, presynchronization improved P/AI in cows inseminated with sex-sorted or conventional semen.

Comparison of synchronisation and fertility after different modifications of the ovsynch protocol in cyclic dairy cows.

The objectives of this study were to evaluate the effects of (1) double doses of PGF2α administration or (2) an exogenous progesterone (CIDR) applied concurrently with, or (3) the day after, first GnRH of Ovsynch (GnRH-1), on synchronisation and fertility during the Ovsynch protocol. All cows (n = 378) received the Ovsynch protocol (GnRH-7d-PGF2α-56h-GnRH-18h-TAI). The 'OVS' group (n = 105) received only the Ovsynch protocol. The 'OVS-PGF' group (n = 118, GnRH-7d-PGF2α-12h-PGF2α-44h-GnRH-18h-TAI) received an extra dose of PGF2α 12 h later on Day 7. The 'OVS-7CIDR' group (n = 78, GnRH+CIDR-7d-PGF2α-56h-GnRH-18h-TAI) received a CIDR for 7 days between GnRH-1 and PGF2α. In the 'OVS-6CIDR' group (n = 77, GnRH-24h-CIDR-6d-PGF2α-56h-GnRH-18h-TAI), CIDR was applied one day after GnRH-1 and removed 6 days later. When all cows were evaluated, the responses to GnRH-2 were higher (P = 0.005) in cows that responded to GnRH-1 (95.4%) compared to the cows that did not respond (87.6%). The pregnancy rates at 31 and 62 days for each group were 48.6% and 42.9% in the OVS, 54.2% and 52.5% in the OVS-PGF, 52.6% and 48.7% in the OVS-7CIDR, and 55.8% and 49.3% in the OVS-6CIDR groups. Thus, none of the three different treatments has an effect on increasing the out-comes of the Ovsynch protocol in cyclic lactating dairy cows.

Lack of complete regression of the Day 5 corpus luteum after one or two doses of PGF2α in nonlactating Holstein cows.

The early corpus luteum (CL) (before Day 6) does not regress after a single PGF2α treatment. We hypothesized that increasing PGF2α dose or number of treatments would allow regression of the early CL (Day 5). Nonlactating Holstein cows (N = 22) were synchronized using the Ovsynch protocol. On Day 5 (Day 0 = second GnRH treatment), cows were assigned to: (1) control (N = 5): no further treatment; (2) 1PGF (N = 6): one dose of 25 mg PGF2α; (3) 2PGF (N = 5): two doses of 25 mg PGF2α (50 mg) given 8 hours apart (second PGF2α on Day 5 at the same time as the other PGF2α treatments); (4) DPGF (N = 6): double dose of 25 mg PGF2α (50 mg) given on Day 5. Blood samples were collected to monitor progesterone (P4) profiles in two periods. In the first period (0 to 24 hours), there were effects of treatment (P = 0.01), time (P < 0.01), and an interaction of treatment and time (P = 0.02). Group 1PGF versus control was different only at 12 hours (P = 0.02). Cows treated with DPGF were different than control at 4 hours (P = 0.04), 12 hours (P < 0.01), and 24 hours (P < 0.01). Only cows treated with 2PGF had lower P4 than control during the entire period and low P4 (0.37 ± 0.17 ng/mL) at 24 hours, usually indicative of luteolysis. In the second period (Day 5 to 15 of the cycle), there were effects of treatment (P < 0.01), time (P < 0.01), and interaction of treatment and time (P = 0.002). Group 1PGF was not different than control from Day 5 to 13 and P4 was greater than control on Day 14 (P = 0.01) and 15 (P < 0.01). Circulating P4 in DPGF cows was lower than control from Day 7 (P = 0.05) through 12 (P < 0.01). Likewise, there were differences between control and 2PGF from Day 7 to 13, but not on Day 14 and 15. On Day 15, all PGF2α-treated groups had circulating P4 consistent with an active CL. Ultrasound evaluation confirmed that no CL from any group completely regressed during the experiment and no new ovulations occurred to account for functional CL later in cycle. In summary, a double dose of PGF2α (twice on Day 5 or 8 hours apart) can dramatically decrease P4, consistent with classical definitions of luteolysis; however, these CL recover and become fully functional. Thus, the Day 5 CL of mature Holstein cows do not regress even to two doses of PGF2α.

Pathological abnormalities after long-term administration of medroxyprogesterone acetate in a queen.

In this report, multiple abnormalities (bilateral ovarian cysts, cystic endometrial hyperplasia and pyometra (CEH-P), mammary adenoma, fibrosarcoma and cystic-papillary adenocarcinoma) identified in a queen continually administered medroxyprogesterone acetate (MPA) for 9 years are described. An 11-year-old domestic shorthair intact queen was presented for reduced appetite, polyuria, polydipsia, abdominal distension, and mammary mass. Pyometra was diagnosed based upon clinical, ultrasonographic and radiographic examinations. Mastectomy and ovariohysterectomy (OHE) were performed for treatment. Bilateral ovarian cysts were detected during OHE. Histopathologically, follicular ovarian cysts, CEH-P, and benign and neoplastic mammary lesions were identified. We suggest that, the pathological abnormalities may have been attributed to adverse effects of prolonged administration of MPA.