Effects of induced endometritis on uterine blood flow in cows as evaluated by transrectal Doppler sonography

This study was conducted to evaluate the effects of induced endometritis on uterine blood flow in cows. Transrectal Doppler sonography was performed on uterine arteries of six cyclic cows before and for 4 days after inducing acute endometritis by intrauterine infusion of 720 mg of policresulen, and for 4 days of the following estrous cycle. Time-averaged maximum velocity (TAMV) increased (p < 0.001) and pulsatility index (PI) decreased (p < 0.0001) within 1 h of policresulen administration, and did not change (p > 0.05) in the next 4 days of the same cycle. TAMV and PI values in the subsequent cycle did not differ (p > 0.05) from the values measured before infusion and showed no changes (p > 0.05) within the cycle. Blood flow parameters were not related (p > 0.05) to plasma concentrations of progesterone and estrogen. All cows showed an acute endometritis determined by histopathological findings of biopsy samples taken 1 day after infusion and fibrotic endometrial alterations detected in the subsequent cycle. No relationships were observed between fibrotic changes of the endometrium and uterine blood flow during either cycle. In conclusion, acute inflammation is accompanied by a rise in uterine blood flow, but fibrotic alterations do not seem to be related to Doppler sonographic findings.     

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.     

Effects of heat stress on the endometrial epidermal growth factor profile and fertility in dairy cows

The endometrial epidermal growth factor (EGF) profile is an indicator of uterine function and fertility in cattle. The present study aimed to investigate the effects of heat stress on the endometrial EGF profile and fertility in lactating Holstein cows. The endometrial EGF profiles of 365 cows in the Hokkaido and Kyushu regions were examined between June and September (heat stress period, n = 211) and between October and January (control period, n = 154). EGF profiles were investigated using uterine endometrial tissues obtained by biopsy 3 days after estrus (Day 3). The proportion of cows with an altered EGF profile was higher between June and September than between October and January (41.2 vs. 16.2%, P < 0.05). The effects of rectal temperature on Days 0 and 3 on the endometrial EGF profile were also assessed in cows (n = 79) between June and September in the Kyushu region. A single embryo was transferred to cow on Day 7 to evaluate fertility (n = 67). Regardless of the rectal temperature on Day 3, the proportion of cows with an altered EGF profile was higher (64.1 vs. 30.0%, P < 0.05) and the pregnancy rate after embryo transfer (ET) was lower (26.7 vs. 51.4%, P < 0.05) in cows with a rectal temperature ≥ 39.5°C on Day 0 than in cows with a rectal temperature < 39.5°C on Day 0. The present results indicate that alterations in the endometrial EGF profile induced by an elevated body temperature on Day 0 contributed to reductions in fertility in lactating dairy cows during the heat stress period.     

Melatonin and CIDR improved the follicular and luteal haemodynamics,uterine and ovarian arteries vascular perfusion,ovarian hormones and nitric oxide in cyclic cows

This study hypothesizes that melatonin with exogenous progesterone (CIDR) can improve follicular, luteal, ovarian and uterine haemodynamic of heat-stressed cows. Holstein cows (N = 12) studied for two spontaneous oestrous cycles during winter then divided equally during summer into the CIDR group received CIDR for 7 days and the melatonin group (Mel) received three injections of melatonin (75 mg/head) at the CIDR insertion, removal and ovulation days. Blood samples were collected to assay oestradiol (E2), progesterone (P4) and nitric oxide (NO). On day 0 (Ovulation), Mel had more small follicles (p < .05), higher ipsilateral and contralateral ovarian arteries (Ov.A.) peak systolic velocity (PSV), higher ipsilateral uterine artery (Ut.A.) PSV (p = .031) and blood flow volume (BFV), also Mel elevated contralateral Ut.A. PSV and BFV (p < .0001) but lowered contra Ut.A. pulsatility index (PI, p < .0001), E2 (p < .01) and NO (p < .0001). Mel increased the corpus luteum diameter (CL, p < .001), coloured area (p < .007) and P4 (p < .0001) on day 5 and reduced them (p < .05; p < .01) on Day 14. On day 10, Mel obtained CL diameter (p < .03) and coloured area (p < .002) of spontaneous that was higher than CIDR and decreased P4 (p < .003). Mel increased CL diameter, area and coloured area and decreased them thereafter. Mel increased the ipsilateral ovarian and uterine arteries PSV and BFV before ovulation and until day 8. Mel increased P4 and decreased NO until days 6 and 14. In conclusion, the improvement in follicular, luteal, ovarian and uterine haemodynamic and the decrease of NO production proved our hypothesis Melatonin doses higher than 75 mg/head is recommended to improve the heat-stressed cow's fertility.     

Factors affecting the success of resynchronization protocols with or without progesterone supplementation in dairy cows

The objective of this study was to investigate factors that influence the success of resynchronization protocols for bovines with and without progesterone supplementation. Cow synchronized and not found pregnant were randomly assigned to two resynchronization protocols: ovsynch without progesterone (P4) supplementation (n = 66) or with exogenous P4 administered from Days 0 to 7 (n = 67). Progesterone levels were measured on Days 0 and 7 of these protocols as well as 4 and 5 days post-insemination. Progesterone supplementation raised the P4 levels on Day 7 (p < 0.05), but had no overall effect on resynchronization rates (RRs) or pregnancy per artificial insemination (P/AI). However, cows with Body Condition Score (BCS) > 3.5 had increased P/AI values while cows with BCS < 2.75 had decreased P/AI rates after P4 supplementation. Primiparous cows had higher P4 values on Day 7 than pluriparous animals (p = 0.04) and tended to have higher RRs (p = 0.06). Results of this study indicate that progesterone supplementation in resynchronization protocols has minimal effects on outcomes. Parity had an effect on the levels of circulating progesterone at initiation of the protocol, which in turn influenced the RR.     

Mixed-breed twin production by contralateral direct-transfer of male embryos to beef cow recipients bred to GnRH-based, fixed-time AI

Two experiments were conducted to develop protocols for the use of fixed-time artificial insemination and embryo transfer (TAI and TET, respectively) to increase beef cattle productivity. Suckled beef cows were given GnRH (100 µg im) on Day − 10, and PGF (25 mg im) on Day − 3, with TAI on Day 0 (66 h later), and assigned to either embryo recipient (ER) or no embryo (NR) treatments on Days 6 or 7. Semen from Gelbvieh (GB) beef sires was used for TAI; sexed-male in vivo developed Holstein embryos (HO) were placed nonsurgically (TET) into the uterine horn contralateral to the corpus luteum. In Experiment 1, ovarian status of cows (n = 111; 69 ± 11 d postpartum; mean ± SD on Day 0) in Groups I and II was presynchronized with a single PGF treatment on Day − 24; Groups II and III received GnRH concurrent with TAI, and ER (n = 78) were selected from all groups on Days 6 or 7. Neither presynchronization nor GnRH affected rates of recipient selection, Day 45 pregnancy (43.2, 43.2, and 54.0% for Groups I, II and III, respectively), or calving (40.5, 37.8, and 43.2%). However, treatment with GnRH increased HO-birth rate (8.0, 14.0 and 24.0%; P < 0.05). In Experiment 2, cows (n = 99, 113 ± 10 d postpartum) were assigned on Day 7 to NR and ER, with and without hCG (2500 IU im), following a TAI protocol (as per Group III in Experiment 1). Treatment with hCG increased reproductive rate (1.16 vs 1.44 calves/calving; P < 0.05), but had no significant effect on rates of Day 45 pregnancy (45.3 vs 41.3%), calving (31.2 vs 37.0%) or HO-births (20.0 vs 26.0%). In summary, GnRH-based synchronization rates were 71.2% (based on circulating progesterone concentrations that were < 1.0 ng/mL on Day 0 and ≥ 1.0 ng/mL on Day 7); TET did not affect GB-birth rate, but more calves were produced by ER than NR cows (1.43 vs 1.02 calves/calving; P < 0.01); and weaned calf production was 53% greater for twin- than singleton-suckled cows (392 ± 25 vs 256 ± 11 kg/dam; mean ± SEM, P < 0.05). Therefore, GnRH-based TAI and TET protocols for mixed-breed twin production increased beef cow productivity.     

Supplemental l-Arginine Shortens Gestation Length and Increases Mare Uterine Blood Flow before and after Parturition

Supplementing diets with l-Arginine (Arg) improves female reproductive performance and reproductive blood flow in other species. The objectives of this study were to investigate uterine artery blood flow changes before and after parturition, and evaluate blood flow in Arg supplemented and control mares by Doppler ultrasonography. Sixteen light-horse mares began Doppler ultrasonography evaluation, 21 days before expected foaling date (EFD) and continued until day 7 postparturition. The mares under treatment (n = 8) were supplemented with 100 g Arg, once daily, beginning with 21 days before EFD. Blood flow measurements were calculated as pulsatility index (PI) and resistance index (RI) for both uterine arteries, either ipsilateral or contralateral; to uterine horn of established pregnancy; defined gravid uterine artery (GUA) and non-gravid uterine artery (NGUA), respectively. The mares under treatment had a shorter gestation length (337 ± 1.7 days) as compared to control (345 ± 2.1 days; P ≤ .05). No differences in gestation length were observed between groups when examined by age, parity, EFD, or sex of foal. Both GUA and NGUA uterine artery diameter decreased from the day before parturition to day 7 after parturition (P ≤ .001). During this time period, both PI and RI increased (P ≤ .01); indicating less blood flow. A treatment effect was observed with Arginine-treated mares having greater blood flow prepartum in the NGUA (P ≤ .001) and postpartum in the GUA (P ≤ .05), for both indices. The data demonstrated that supplementing mares with Arg shortened gestation length and increased uterine arterial blood flow before and after parturition.     

Milk progesterone enzyme-linked immunosorbent assay as a tool to investigate ovarian cyclicity of water buffaloes in relation to body condition score and milk production

Background

Application of assisted reproductive technologies in buffaloes is limited to some extent by farmers’ inability to detect oestrus because of its poor expression. The present study aimed at investigating reliability of a milk progesterone enzyme-linked immunosorbent assay (ELISA) to assess the ovarian cyclicity during post partum, oestrus and post-breeding periods in water buffaloes.

Methods

Progesterone concentrations were measured by an ELISA in milk of 23 postpartum buffaloes in relation to oestrus, pregnancy, body condition score (BCS) and milk production. Two milk samples were taken at 10 days intervals, every month starting from day 30 and continued to day 150 post partum. BCS and milk production were recorded during sample collection. Milk samples from bred buffaloes were collected at Day 0 (day of breeding), Days 10–12 and Days 22–24. Defatted milk was preserved at −80°C until analysis. Pregnancy was confirmed by palpation per rectum on Days 70–90.

Results

Seventeen buffaloes had 47 ovulatory cycles, one to four in each, 13 were detected in oestrus once (28 % oestrus detection rate). Progesterone concentration ≥1 ng/ml in one of the two 10-day-interval milk samples reflected ovulation and corpus luteum formation. The intervals between calving to first luteal activity and to first detected oestrus varied from 41 to 123 days (n = 17) and 83 to 135 (n = 13) days, respectively. Eight buffaloes were bred in the course of the study and seven were found pregnant. These buffaloes had a progesterone profile of low (<1 ng/ml), high (≥ 1 ng/ml) and high (≥ 1 ng/ml) on Day 0, Days 10–12 and Days 22–24, respectively. Buffaloes cycling later in the postpartum period had fewer missed oestruses (P < 0.05). Buffaloes with a superior BCS had a shorter calving to oestrus interval and produced more milk (P < 0.05).

Conclusions

Milk progesterone ELISA is a reliable tool for monitoring ovarian cyclicity and good BCS may be an indicator of resuming cyclicity in water buffalo.     

Effects of dietary soluble or insoluble fiber intake in late gestation on litter performance,milk composition,immune function,and redox status of sows around parturition

The objective of this study was to investigate the effects of dietary soluble fiber (SF) or insoluble fiber (ISF) intake in late gestation on litter performance, milk composition, immune function, and redox status of sows around parturition. A total of 60 Yorkshire sows were randomly assigned into three dietary treatments: normal level of dietary fiber (CON, 16.16% dietary fiber with 1.78% soluble fiber and 14.38% insoluble fiber), high insoluble fiber (ISF, 30.12% dietary fiber with 2.97% soluble fiber and 27.15% insoluble fiber), and high soluble fiber (SF, 30.15% dietary fiber with 4.57% soluble fiber and 25.58% insoluble fiber). Digestible energy and crude protein intake were comparable among treatments via adjusting feed intake from day 90 of gestation to parturition. After parturition, all sows were fed the same lactation diet. Results showed that litter performance of sows was not markedly affected by maternal fiber intake. However, sows fed ISF or SF diet had increased concentration of plasma mmunoglobulin G at day 107 (P < 0.05) and parturition (P < 0.01), and the SF diet had a tendency to increase fat content in both colostrum and milk relative to the CON diet. Furthermore, sows fed ISF diet had increased glutathione peroxidase activity (P < 0.05) at day 107, but decreased the plasma level of malondialdehyde at parturition (P < 0.05). High maternal SF intake tended to decrease the number of weaned piglets due to the increased preweaning mortality, as compared with sows fed the ISF diet. In conclusion, high fiber intake in late gestation may improve immune function and redox status, but differentially influenced the milk composition and preweaning mortality.     

Changes in the C-reactive protein and 13,14-dihydro-15-keto-prostaglandin F2α concentrations of uterine lavage samples after the administration of povidone-iodine in cows

Changes in the C-reactive protein (CRP) and 13,14-dihydro-15-keto-prostaglandin F_2α (PGFM) concentrations of uterine lavage fluid were examined in cows given an intrauterine povidone-iodine (PI) infusion. The mean polymorphonuclear leukocyte (PMN) ratios (the ratio of PMN to total cells) and CRP concentration of uterine lavage fluid on the day after the treatment were significantly (P<0.05) greater in the PI infusion group (PMN: 53.0 ± 32.7%, CRP: 50.2 ± 32.3 ng/mL) than in the non-treatment control group (PMN: 7.9 ± 21.9%, CRP: 17.2 ± 5.9 ng/mL), whereas there was no significant difference in the mean PGFM concentration between the two groups. The present findings suggest that the uterine CRP level is a useful biomarker of local uterine inflammation in cows.     

Quantitative analyses of insulin-like peptide 3 and sex steroid hormones in dominant follicles and corpora lutea during the estrus cycle and in follicular cysts in beef heifers

Insulin-like peptide 3 (INSL3) and sex steroids were measured in bovine dominant follicles and corpora lutea during the estrus cycle and in follicular cysts. Paired ovaries from beef heifers (n = 47) were classified, by their morphological features, either into four stages of the estrus cycle (Day 1 = day of ovulation, Day 20 = day of estrus) as Stage I (Days 1–4; n = 8), Stage II (Days 5–10; n = 10), Stage III (Days 11–17; n = 8), and Stage IV (Days 18–20; n = 11) or follicular cystic (n = 10). Cysts (n = 15) were subdivided into estrogen-active (n = 7) and estrogen-inactive (n = 8) cysts. INSL3, testosterone, and estradiol-17β concentrations in the dominant follicular fluid of Stage IV were higher than those in Stages II and III (P < 0.05). INSL3 concentrations in the cystic fluid were similar to those in dominant follicles at Stage IV, whereas testosterone and estradiol-17β concentrations were lower in cysts (P < 0.05). INSL3 content per estrogen-inactive cyst was higher than that of Stage IV (P < 0.05). INSL3 and progesterone concentrations in luteal tissue and contents per corpus luteum were higher in Stages II and III (P < 0.05). In conclusion, INSL3 secretion in bovine dominant follicles increased with maturation. Follicular cysts may retain the production of INSL3 during their formation but tend to lose the capacity for testosterone secretion. Estrogen-inactive cysts subjected to advanced atresia may accumulate more INSL3. INSL3 production in bovine corpora lutea is enhanced during maturation.     

Estrus response and fertility after a single cloprostenol treatment in dairy cows with various ovarian structures

The objective of this study was to determine rates of estrus and conception in lactating multiparous Holstein cows given 500 μg of cloprostenol intramuscularly after detection of the following ≥ 60 d after parturition: a solid corpus luteum (CL), a CL with a nonechodense cavity ≤ 20 mm in diameter (CLcav), a luteal cyst (cavity > 20 mm in diameter and a luteinized wall > 3 mm in diameter), or a follicular cyst (cavity > 20 mm and a luteinized wall ≤ 3 mm in diameter). The estrus rates were 335/419 (80.0%), 183/223 (82.1%), 170/182 (93.4%), and 44/87 (50.6%), respectively (P < 0.0001), and the conception rates 30 to 36 d after insemination among the estrous cows with an apparently normal mucus discharge were 130/285 (45.6%), 44/141 (31.2%), 39/79 (49.4%), and 19/30 (63.3%), respectively (P < 0.002). Compared with a solid CL, a CLcav did not affect the estrus rate but significantly reduced the conception rate (P < 0.05), and the estrus rates were significantly higher and lower in cows with a luteal or follicular cyst, respectively (P < 0.05).     

Trace amounts of antibiotic exacerbated diarrhea and systemic inflammation of weaned pigs infected with a pathogenic Escherichia coli

The experiment was conducted to investigate the effects of trace amounts of antibiotic on growth performance, diarrhea, systemic immunity, and intestinal health of weaned pigs experimentally infected with an enterotoxigenic Escherichia coli. Weaned pigs (n = 34, 6.88 ± 1.03 kg body weight [BW]) were individually housed in disease containment rooms and randomly allotted to one of the three dietary treatments: nursery basal diet (CON) and two additional diets supplemented with 0.5 or 50 mg/kg carbadox to the nursery basal diet (TRA or REC), respectively. The experiment lasted 18 d with 7 d before and 11 d after the first E. coli inoculation. The E. coli F18 inoculum was orally provided to all pigs with a dose of 10¹⁰ colony-forming unit (CFU)/3 mL for three consecutive days. Fecal and blood samples were collected on day 0 before inoculation and days 2, 5, 8, and 11 postinoculation (PI) to test the percentage of β-hemolytic coliforms in total coliforms and complete blood cell count, respectively. Sixteen pigs were euthanized on day 5 PI, whereas the remaining pigs were euthanized at the end of the experiment to collect the jejunal and ileal mucosa and mesenteric lymph node for gene expression and bacterial translocation, respectively. Pigs in REC had greater (P < 0.05) final BW and lower (P < 0.05) overall frequency of diarrhea compared with pigs in the CON and TRA groups. Pigs in TRA had the lowest (P < 0.05) average daily gain and feed efficiency from day 0 to 5 PI, highest (P < 0.05) percentage of β-hemolytic coliforms in fecal samples on days 2 and 5 PI, and greatest (P < 0.05) bacterial colonies in mesenteric lymph nodes on day 11 PI compared with pigs in the CON and REC groups. Pigs in TRA had the greatest (P < 0.05) neutrophils on day 5 PI and higher (P < 0.05) white blood cell counts and lymphocytes than other groups on day 11 PI. Pigs in TRA had the greatest (P < 0.05) serum C-reactive protein on days 2 and 5 PI and serum tumor necrosis factor-α on day 5 PI, compared with pigs in the CON and REC groups. Pigs fed REC had increased (P < 0.05) mRNA expression of zona occludens-1 (ZO-1) and occludin (OCDN) and reduced (P < 0.05) interleukin-1 beta (IL1B), interleukin-6 (IL6), and tumor necrosis factor-alpha (TNFA) in ileal mucosa on day 5 PI, compared with the CON, whereas TRA upregulated (P < 0.05) mRNA expression of IL1B, IL6, and cyclooxygenase-2 (COX2) in the ileal mucosa on day 11 PI, compared with the REC. In conclusion, trace amounts of antibiotic may exacerbate the detrimental effects of E. coli infection on pig performance by increasing diarrhea and systemic inflammation of weanling pigs.     

Effect of polyoxyethylene and polyoxypropylene nonionic block copolymers on performance and recruitment of immune cell subsets in weaned pigs

Background

Because European-wide directives are restricting the non-clinical use of antibiotics as in-feed growth promotors in swine production, there is an intensive search for alternative strategies for control and prevention of losses among young pigs. With the growing knowledge of the porcine immune system and its endogenous modulation, it has been clearly established that exogenous immunomodulation using adjuvants and immune response modifiers (IRMs) represents an important prophylactic/therapeutic approach in the prevention/treatment of both stress- and microbial-induced disorders that accompaning weaning. However, it is essential to select a fully evaluated agent which may act either as a nonspecific IRM or synergistically as an adjuvant with vaccines. The synthetic macromolecules with a long history as adjuvant and IRM are nonionic block copolymers which consist of polyoxyethylene (POE) and polyoxypropylene (POP) molecules.

Methods

The aim of this work was to evaluate the effectiveness of POE-POP given as a single peroral dose on productivity parameters such as body weight gain, feed intake and feed conversion ratio, and systemic and intestinal immune parameters by assessing the proportions of CD45⁺ lymphoid cells, CD4⁺ and CD8⁺ T cells, and CD21⁺ B cells in the peripheral blood as well as the number of CD45RA⁺ naive lymphoid cells residing in the ileal mucosa in weaned pigs during a follow-up study 5 weeks after the treatment.

Results

Pigs treated with POE-POP had better feed intake (+ 14.57%), higher average body mass at the end of the experiment (20.91 kg vs. 17.61 kg), and higher body weight gain in relation to Day 0 (191.63% vs. 144.58%) as well as in relation to nontreated pigs (+ 18.74%), with a lower feed conversion ratio (− 30.26%) in comparison to the control pigs. A much lower diarrhea severity score (5 vs. 54) was recorded in pigs treated with POE-POP (− 90.74%) than in the control pigs. A higher average diarrhea severity (ADS) was recorded in the control pigs (1.54 vs. 0.14), whereas the treatmant group had much a lower ADS ratio (− 90.91%) after 35 days of the experiment. The pigs that were treated with POE-POP had an increased proportion of CD45⁺, CD4⁺ and CD8⁺ cells at Day 21 (at p < 0.05, p < 0.05 or p < 0.01, respectively), Day 28 (at p < 0.01, respectively) and Day 35 (at p < 0.01, p < 0.05 or p < 0.01, respectively) as well as of CD21⁺ cells at Day 28 (p < 0.05) and Day 35 of the experiment (p < 0.01). Also, these pigs had more numerous CD45RA⁺ cells in interfollicular (p < 0.05) and follicular areas (p < 0.01) of the ileal Peyer’s patches than did control pigs.

Conclusion

This property of POE-POP to induce recruitment of circulating and intestinal immune cell subsets in weaned pigs may allow the use of IRM-active block copolymers as adjuvants for vaccines, particularly those orally delivered and targeted to the gut-associated lymphoid tissues that are well known to promote rather tolerogenic than protective immune responses.     

Uterine morphology and function in postpartum mares

Ultrasonically detectable characteristics of the uterus and embryo and palpable uterine tone were assessed in 10 postpartum mares. A bright fern-like pattern of ultrasonic uterine echogenicity, outlining the endometrial folds, was observed for an average of 2.1 ±0.2 days following parturition (range, 1 to 3 days). Unexpectedly, the uterus was quiescent throughout the postpartum interval, based on daily one-minute contractility scans. Contractility was maximal on Days 12 to 15 of pregnancy in both postpartum (n=7) and nonparturient (n=7) mares. The mean diameter of ultrasonically detectable intrauterine fluid collections increased (P<0.05) abruptly between days 1 and 2 postpartum and gradually decreased (P<0.05) between days 4 and 7; no collections were detected after day 16. There was no effect of day on echogenicity of the intrauterine fluid collections; on all days, fluid was relatively black or nonechogenic, suggesting that puerperal endometritis was not a problem in this group. Because the increase in intraluminal fluid occurred after parturition and in temporal association with a decrease in diameter and tone of the uterus, the fluid collections apparently represented a physiologic influx from the involuting uterus rather than residual placental fluid. Involution of the horns was completed by day 27 (formerly nongravid horn) and day 31 postpartum (formerly gravid horn), based on failure to detect further significant decreases in diameter. However, the formerly gravid horn was larger (P<0.05) in diameter than the formerly nongravid horn on each of Days 1 to 35 postpartum (end of experiment), indicating residual effects on uterine size. When averaged over both horns, uterine diameters were larger on Days 0 to 24 (Day 0=day of ovulation) of pregnancy in postpartum mares than in nonparturient mares; by Day 25, diameters were similar between statuses. By approximately Day 6 of pregnancy, uterine contractility and ultrasonic endometrial exhotexture were similar between postpartum mares and nonparturient mares. Uterine tone was greater (P<0.05) in postpartum mares than in nonparturient mares on all days between Day 0 and 25. An unexpected, transient increase in uterine tone was detected on Day 5 of pregnancy in both postpartum mares and nonparturient mares. No differences were found between reproductive statuses in patterns of embryo mobility, the day of fixation of the embryonic vesicle (postpartum, Day 15.3 ±0.4; nonparturient, Day 15.0 ±0.3), and diameter of the embryonic vesicle on the day of fixation (postpartum, 22.1 ±1.4 mm; nonparturient, 19.4 ±l.6mm). However, mean uterine tone and mean horn diameters on the side of fixation were greater (cranial and middle cornual segments; P<0.05) or tended to be greater (caudal segment; P<0.1 ) on the day of fixation in postpartum mares than in nonparturient mares. In all postpartum mares, fixation occurred in the formerly nongravid horn. Enhanced uterine tone in postpartum mares may account for the occurrence of fixation on the same day for the two reproductive statuses, despite the larger uterus in postpartum mares.     

Processing index of barley grain and dietary undigested neutral detergent fiber concentration affected chewing behavior,ruminal pH,and total tract nutrient digestibility of heifers fed a high-grain diet

The objective of this study was to investigate the effects of processing index (PI) of barley grain and dietary undigested neutral detergent fiber (uNDF) concentration on dry matter (DM) intake, chewing activity, ruminal pH and fermentation characteristics, total tract digestibility, gastrointestinal barrier function, and blood metabolites of finishing beef heifers. The PI was measured as the density after processing expressed as a percentage of the density before processing, and a smaller PI equates to a more extensively processed. Six ruminally cannulated heifers (average body weight, 715 ± 29 kg) were used in a 6 × 6 Latin square design with three PI (65%, 75%, and 85%) × 2 uNDF concentration (low and high; 4.6% vs. 5.6% of DM) factorial arrangement. The heifers were fed ad libitum a total mixed ration consisting of 10% barley silage (low uNDF), or 5% silage and 5% straw (high uNDF), 87% dry-rolled barley grain, and 3% mineral and vitamin supplements. Interactions (P < 0.01) of PI × uNDF were observed for DM intake, ruminating and total chewing time, and DM digestibility in the total digestive tract. Intake of DM, organic matter (OM), starch, and crude protein (CP) did not differ (P > 0.14) between low and high uNDF diets, but intakes of NDF and acid detergent fiber were greater (P = 0.01) for high uNDF diets regardless of barley PI. Heifers fed high uNDF diets had longer (P = 0.05) eating times (min/d or min/kg DM) and tended (P = 0.10) to have longer total chewing times (min/kg DM) than those fed low uNDF diets. Additionally, heifers sorted (P = 0.01) against long particles (>19 mm) for high uNDF diets but not for low uNDF diets. Altering PI of barley grain did not affect (P > 0.12) total volatile fatty acid (VFA) concentration, molar percentages of individual VFA, or duration of ruminal pH < 5.8 and <5.6. Total VFA concentration was less (P = 0.01), acetate percentage was greater (P = 0.01), and duration of ruminal pH < 5.8 and <5.6 was less (P = 0.05) for high compared with low uNDF diets. Digestibility of DM, OM, and CP was greater (P = 0.02) for low vs. high uNDF diets with PI of 65% and 75%, with no difference between low and high uNDF diets at PI of 85%. Blood metabolites and gastrointestinal tract barrier function were not affected (P ≥ 0.10) by the treatments. These results suggest that increasing dietary uNDF concentration is an effective strategy to improve ruminal pH status in finishing cattle, regardless of the extent of grain processing, whereas manipulating the extent of barley processing did not reduce the risk of ruminal acidosis.     

Ovarian and uterine arteries blood flow waveform response in the first two cycles following superstimulation in cows

To investigate the ovarian and uterine blood flow responses, hemodynamic, circulating ovarian hormones and nitric oxide (NO) after end of treatment by Folltropin. Holstein Friesian (12) cows previously synchronized with CIDR underwent Doppler ultrasound after administrating of FSH daily for 4 days in eight injections started on day 10 of the second ovulation (day −5). Oestradiol (E2), progesterone (P4) and nitric oxide (NOMs) were measured. During the follicular phase, follicle area and antrum area of the second cycle reached maximum value on the day of ovulation compared with that in the first cycle, while during the luteal phase, both showed a pattern of increase and decrease. The luteal area and total coloured area increased till day 10 in the first and second cycle. The first cycle ipsilateral ovarian artery (Ov.A) had higher pulsatility (PI) (p = .001), resistance (RI) (p = .001), peak velocity (PSV) (p = .009) and lower end-diastolic velocity (EDV) (p = .003) compared with the second cycle. The increased ipsilateral Ov.A PSV (p = .009) was accompanied by lower EDV. The first cycle ipsilateral middle uterine artery (MUA) had higher PI (p = .001) and RI (p = .001), with lower PSV (p = .001) and EDV (p = .001). It was concluded that blood flow of ovarian and middle uterine arteries changed after the end of superstimulation as the increased ipsilateral Ov. A and MUA PSVs accompanied by lower EDV and both Doppler indices that reflect the amount of ovarian and uterine blood flow waveform.     

Effect of a single injection of gonadotropin-releasing hormone (GnRH) and human chorionic gonadotropin (hCG) on testicular blood flow measured by color doppler ultrasonography in male Shiba goats

Although color Doppler ultrasonography has been used to evaluate testicular blood flow in many species, very little has been done in goat. Eight male Shiba goats were exposed to a single intramuscular injection of either gonadotropin-releasing hormone (GnRH group; 1 µg/kg BW) or human chorionic gonadotropin (hCG group; 25 IU/kg BW). Plasma testosterone (T), estradiol (E2) and inhibin (INH) were measured just before (0 hr) and at different intervals post injection by radioimmunoassay. Testis volume (TV) and Doppler indices, such as resistive index (RI) and pulsatility index (PI) of the supratesticular artery, were measured by B-mode and color Doppler ultrasonography, respectively. The results indicated an increase in testicular blood flow in both groups, as RI and PI decreased significantly (P<0.05), but this increase was significant higher and earlier in hCG group (1 hr) than in the GnRH group (2 hr). A high correlation was found for RI and PI with both T (RI, r= −0.862; PI, r= −0.707) and INH in the GnRH group (RI, r=0.661; PI, r=0.701). However, a significant (P<0.05) correlation was found between E2 and both RI (r= −0.610) and PI (r= −0.763) in hCG group. In addition, TV significantly increased and was highly correlated with RI in both groups (GnRH, r= −0.718; hCG, r= −0.779). In conclusion, hCG and GnRH may improve testicular blood flow and TV in Shiba goats.     

Assessment of Uterine Vascular Perfusion During the Estrous Cycle of Mares in Connection to Circulating Leptin and Nitric Oxide Concentrations

The objective of this study was to find difference in vascular perfusion of uterine horns or uterine body throughout the estrous cycle and their relation to circulating nitric oxide and leptin concentrations. Five cyclic mares were subjected to transrectal Doppler ultrasonography and blood sampling for 18 days. Area of color and power Doppler modes was measured in pixels. Day (P = .0001) of the estrous cycle and ovulation (P = .0001) influenced uterine blood flow. Uterine body blood flow directed away from the transducer (blue, P = .0001) increased from day −5 until day 0 (day of ovulation), and its power (P = .0001) blood flow increased from day −6 until day 0; then, both decreased until days 12 and 10, respectively. Conversely to the contralateral uterine horn, ipsilateral uterine horn blood flow directed away from the transducer (blue, P = .0001) increased from day −5 until day −1, and its power (P = .0001) blood flow increased from day −6 until day 0; then, both decreased until day 10. Nitric oxide concentrations (P = .0001) attained two major peaks; the first on day −3 and the other persisted from day 2 until day 5. Leptin concentrations increased (P > .001) with a maximum value on day 0 and then decreased until a minimum value on day 9. In conclusion, during the estrous cycle, ipsilateral uterine horn and uterine body blood vessels had similar blood flow. Both leptin and nitric oxide played a role during follicle growth, ovulation, and corpus luteum development and modulated uterine blood flow before and after ovulation.