Prevalence of urovagina and its effects on reproductive performance in Holstein cows

Two hundred fifty-eight Holstein cows (n = 344 lactations) from seven dairy herds were examined every month by vaginoscopy and transrectal palpation to determine the prevalence of urovagina, to investigate its effects on fertility, and to determine some risk factors for urovagina. Accumulation of urine in the vagina of a cow was diagnosed as urovagina and was classified into mild (urine only on the floor of vagina), moderate (urine covering less than or equal to half portion of the external cervical os), or severe (urine covering more than half or whole portion of the external cervical os). In total, 26.7% of lactations had urovagina (mild 11.3%, moderate 11.0%, and severe 4.4%). Survival analysis was used to derive the case definition of clinically relevant urovagina based on the factors associated with increased time to conception. Only moderate (hazard ratio [HR] = 0.39) and severe (HR = 0.20) degrees of urovagina were associated with reduction in pregnancy rate and thus defined as clinically relevant urovagina. Cows with clinically relevant urovagina had decreased AI submission rate (HR = 0.52) and pregnancy rate (HR = 0.35), required more inseminations per conception (5 vs. 2; P < 0.001), had more days open (370 vs. 136; P < 0.001), and were more likely not to get pregnant by 210 d postpartum (odds ratio [OR] = 6.62) and to be culled for any reasons (OR = 5.32) or for reproductive reasons (OR = 9.54) compared with those in cows with no urovagina. Cows with clinically relevant urovagina had a higher risk of endometritis (36.4% vs. 9.2%; P < 0.001) compared with that in cows without urovagina. Cow, low BCS at first postpartum examination (OR = 2.85), endometritis within 60 d (OR = 2.50), and horizontal vulva (OR = 9.30) were risk factors for urovagina. In conclusion, 15.4% of lactations had clinically relevant urovagina that increased the risk of endometritis and had detrimental effects on fertility. Individual susceptibility, low BCS, and horizontal vulva increased the risk of diagnosing urovagina in Holstein cows.     

Factors affecting reproductive performance in Ontario dairy herds

Data were collected on reproductive, health and production events in 45 dairy herds in southwestern and eastern Ontario, Canada, from July 1990 to July 1993. Mean and median days in milk at first estrus, at first service, and at conception were 85.1 and 83.9, 94.0 and 88.9, and 126.3 and 115.5 d, respectively. The mean estrus detection rate was 48.3%, with a minimum of 28.4% and a maximum of 64.2%. The mean overall conception rate was 46.7%, with a minimum of 29.8% and a maximum of 70.7%. The most commonly used used therapeutic agents were GnRH (11.5% lactational incidence risk) and PG (13.1% lactational incidence risk). Estrus management accounted for the largest portion of PG use in the herds studied (69.4%). Results of a two sample t-test indicated no significant difference in reproductive performance among herds housed in free-stall compared with those housed in tie-stall barns. Multivariate linear regression models of 3 reproductive performance measures indicated that cows with ovarian cysts and/or increased peak milk production had significantly longer calving-to-first estrus and calving-to-conception intervals as well as lower conception rates than average producing cows without cysts. Cows with metritis were found to have significantly shorter calving-to-conception intervals but no detectable difference in conception rate or calving-to-first estrus interval than their herdmates. As lactation number increased reproductive performance improved. Cows that were observed in estrus earlier conceived earlier. Animals receiving uterine infusions had significantly longer calving-to-conception intervals and lower conception rates than their herdmates. There was no detectable difference in reproductive performance for cows treated with GnRH or PG compared with the nontreated cows. An increased estrus detection rate was associated with shorter calving-to-conception intervals and lower conception rates. Based on the range of performance in the study herds, the factors with the greatest potential influence on calving-to-conception interval in the average herd were the estrus detection rate and conception rate.     

Effects of evaporative cooling on reproductive performance and milk production of dairy cows in hot wet conditions

Fourteen animals of second and third lactation of Thai Friesian crossbred cows (87.5% Friesian × 12.5% Bos indicus) located at Sakol Nakhon Research and Breeding Centre, Department of Livestock Development, Ministry of Agriculture and Cooperatives, were divided randomly into two groups of seven each to evaluate the effects of evaporative cooling on reproductive and physiological traits under hot, humid conditions. Results indicated that installation of evaporating cooling in the open shed gave a further improvement in ameliorating heat stress in dairy cows in hot-wet environments by utilising the low humidity conditions that naturally occur during the day. The cows housed in an evaporatively cooled environment had both a rectal temperature and respiration rate (39.09°C, 61.39 breaths/min, respectively) significantly lower than that of the non-cooled cows (41.21°C; 86.87 breaths/min). The former group also had higher milk yield and more efficient reproductive performance (pregnancy rate and reduced days open) than the latter group. It is suggested that the non-evaporatively cooled cows did not gain benefit from the naturally lower heat stress during night time.     

Defining delayed resumption of ovarian activity postpartum and its impact on subsequent reproductive performance in Holstein cows

The objectives of this study were to derive a useful case definition of delayed resumption of ovarian activity, based on factors associated with reduced fertility, and to assess its impact on subsequent reproductive performance in Holstein cows (Bos taurus). Milk samples were collected twice weekly from 219 cows from four commercial herds, and whole-milk progesterone concentrations were determined with an enzyme-linked immunosorbent assay. Ovulation was considered to have occurred 5 d before the first rise of milk progesterone concentration above the basal level. Survival analysis was used to derive a case definition of delayed resumption of ovarian activity postpartum based on factors that were predictive of reduced pregnancy rate. First postpartum ovulation occurring beyond 35 d postpartum was associated with a reduced pregnancy rate (hazard ratio [HR] = 0.50; P < 0.001) and was defined as delayed resumption of ovarian activity; overall, 75 (34.9%) cows were in this category. These cows were more likely not to conceive on first artificial insemination (odds ratio [OR] = 2.85; P = 0.01) and more likely not to become pregnant within 100 d (OR = 3.30; P = 0.001) and 210 d (OR = 3.20; P < 0.001) postpartum compared with cows with normal resumption of ovarian activity. Furthermore, 13 (6%) cows that ovulated within 35 d postpartum had a prolonged (≥14 d) interval between either first and second or second and third luteal phases postpartum. A prolonged interluteal interval was also associated with a reduced pregnancy rate (HR = 0.35; P = 0.02). Days open (mean ± SEM) were greater (P = 0.0002) in cows with delayed resumption of ovarian activity (213 ± 13 d) and in cows with prolonged interluteal interval (220 ± 37 d) than in cows with normal resumption of ovarian activity (152 ± 9 d). In conclusion, first ovulation occurring beyond 35 d postpartum was defined as delayed resumption of ovarian activity, and the first ovulation occurring within 35 d postpartum but the absence of luteal activity ≥14 d between two consecutive luteal phases was defined as a prolonged interluteal interval; both abnormalities adversely affected the subsequent reproductive performance of Holstein cows.     

Effect of chromium methionine supplementation on lactation performance,hepatic respiratory rate and anti-oxidative capacity in early-lactating dairy cows

Chromium may regulate dairy cow metabolism; a chelated formation of chromium methionine (Cr-Met) is available to the feed industry. The objective of this study was to investigate the effect of Cr-Met supplementation on lactation performance, hepatic respiratory rate and anti-oxidative capacity in early-lactating Holstein dairy cows. 64 multiparous cows were assigned to 16 blocks based on parity and milk yield and then the four cows in a block were randomly allocated to four treatment groups with 0, 4, 8 or 16 g/d of Cr-Met per cow supplemented to a basal diet. Cows were moved from an open dry lot to a naturally ventilated tie stall barn 2 weeks before treatment to adapt to this facility, fed and milked at 0630, 1400, and 1930 h every day. The experiment lasted for 12 weeks. Milk yield and composition were recorded weekly. Dry matter intake was measured every 2 weeks for a total of six times throughout the trial. The plasma variables were measured in weeks 4, 8 and 12 of the experiment. Supplementation of Cr-Met did not affect DM intake of cows. As the supplementation of Cr-Met increased, yields of milk, fat, energy corrected milk (P < 0.01) and lactose (P = 0.01) increased in a linear manner. In terms of plasma variables, insulin concentration decreased in a linear manner with Cr-Met supplementation. As for variables relating to hepatic respiration rate, concentrations of pyruvate and NAD in the plasma were increased in quadratic manners, and lactic dehydrogenase activity was linearly increased as Cr-Met feeding levels increased. Moreover, plasma glutathione peroxidase and superoxide dismutase activity were increased in a linear manner. In conclusion, our study suggested that Cr-Met supplementation improved lactation performance of early-lactating dairy cows through enhancing antioxidant capacity and hepatic cellular respiration.     

Reproductive performance in Ohio dairy herds in the 1990s

The objective of this study was to evaluate trends in reproductive performance in Ohio dairy herds during the 1990s. Stringent criteria for herd inclusion were applied to DHI records to ensure high quality and reliability of the data. The final data set contained 44,425 monthly herd summary records from 1772 herds from years 1992, 1994, 1996 and 1998. Outcomes of interest were calving interval length, calving-to-conception interval, days to first breeding, services per conception and first service conception rate. PROC MIXED in SAS (version 8.1) was used and the monthly records were treated as repeated measures nested within years and herds. First-order autoregressive covariance structure was used to model the covariance between the repeated measures within herds. The data were analyzed for the entire herd as well as for the first lactation cows separately. During the 1990s reproductive performance declined in Ohio dairy herds. Herd average calving interval lengthened from 13.6 to 14.1 months and calving-to-conception interval increased from 136 to 150 days between 1992 and 1998, respectively. Days to first service and number of services increased while first service conception rate declined on a herd level. The reproductive performance of first lactation cows, however, remained constant during this same period. Overall herd reproductive performance was associated with herd size and fat-corrected rolling herd average milk production (FCM). As milk yield increased, first service conception rate decreased and services per conception increased. Larger herds had lower first service conception rate and needed more services per conception, but they started breeding their cows earlier resulting in a slightly shorter calving interval and calving-to-conception interval compared to smaller herds.     

Reproductive performance of Farafra ewes in the subtropics

The present study was carried out to assess the reproductive performance of Farafra ewes—a breed with potential economic importance in the subtropics. A total of 262 ewes were categorized according to age, parity, and postpartum interval. Ewes were introduced for breeding in fall, winter and late spring seasons. Fertility, prolificacy, lamb birth weight, and ultrasonic fetal parameters were recorded. Results obtained showed that litter size was increased with age and parity. Lamb birth weight was affected by season. None of the parameters studied had a clear-cut effect on fertility. However, an interaction between season and parity was detected. Measurement of fetal size in the first half of gestation did not predict birth weight. The obtained data represents the first record of the reproductive performance of Farafra ewes in the subtropics, which could be used to anticipate their performance in different seasons.     

Economic consequences of reproductive performance in dairy cattle

The net economic value of reproductive efficiency in dairy cattle was estimated using a stochastic dynamic simulation model. The objective was to compare the economic consequences of reproductive performance scenarios (“average” and “poor”) of a cow having a good reproductive performance and to explore which reproductive factors have an important impact on economic efficiency. A “good” reproductive performance scenario was defined with 1 ovulation rate (POVU_i), 0.7 estrus detection rate (PEst), 0.7 conception rate (PCon), 0.03 incidence rate of postpartum disorders prolonging the ovarian cyclicity (CO), 0.2 incidence rate of postpartum disorders reducing conception (ME), 0.05 embryonic death rate (ED), and voluntary waiting period (VWP) of 9 wks pp (post partum). In the current situation of dairy cows in the Netherlands, an “average” reproductive scenario (0.95 POVU_i, 0.5 PEst, 0.5 Pcon, 0.07 CO, 0.27 ME, 0.07 ED and VWP of 12 wks pp) and a “poor” reproductive scenario (0.90 POVU_i, 0.3 PEst, 0.3 Pcon, 0.11 CO, 0.33 ME, 0.09 ED and VWP of 15 wks pp) were identified. A sensitivity analysis was performed by comparing changes of single effect of factors in a good and poor scenario with the average scenario. The mean net economic loss (NEL_i) compared with the good scenario was €34 and €231 per cow per year for the average and poor reproductive performance scenario, respectively. Increasing the calving interval resulted in greater economic loss. The important factors on the cost of reproductive efficiency were the involuntary culling cost and the return of milk production. Variation in PCon, PEst, ME, ED, and VWP had large impacts on economic benefits.     

Reproductive performance and milk traits of F1 Romanov ewes

The objective of this study was to evaluate the effect of crossbreeding Awassi and Morkaraman ewes with Romanov sires on litter size and total productivity as reflected by reproductive performance and milk production in the ewes. Twenty-three Romanov × Awassi (RA) and 19 Romanov × Morkaraman (RM) ewes were used. All of the ewes were pregnant at the start of the study, and litter size at birth and at weaning (60 days) were recorded. Milk production was recorded weekly and milk composition was estimated as dry matter and fat percentage. Litter size at birth (RM: 1.89 ± 0.18; RA: 1.62 ± 0.15) and weaning (RM: 1.67 ± 0.20; RA: 1.46 ± 0.17), dam weight at lambing (RM: 50.2 ± 2.37; RA: 44.2 ± 1.98) and total productivity (RM: 29.9 ± 3.05; RA: 24.4 ± 2.54) were not influenced by breed-type. Lactation length and milk yield was relatively but not significantly higher in RA than RM ewes. Dry matter and fat percentage of milk were found to be similar for both breed-types. Results of the present study indicate that crossbreeding of Awassi and Morkaraman ewes with Romanov rams yielded similar performance in F1 ewes. When F1 ewe performance is compared with their pure breed maternal ancestor, it is concluded that reproductive performance is improved by crossbreeding with Romanov.     

Effects of soybean oil supplementation on performance,digestion and metabolism of early lactation dairy cows fed sugarcane-based diets

Sugarcane is an important forage source for dairy cows in tropical countries. However, it provides limited digestible fiber and energy intake, and fat supplementation can be a way to increase energy density and decrease dietary, non-fiber carbohydrates concentrations. We aimed to evaluate the performance, digestion and metabolism of dairy cows in early lactation fed different concentrations of soybean oil (SBO) in sugarcane-based diets. Fourteen primiparous (545±17.2 kg of BW) and eight multiparous (629±26.7 kg BW) Holstein dairy cows were used according to a randomized block design. After calving, diets were randomly assigned to cows within the two parity groups. Diets were formulated with increasing concentrations of SBO (g/kg dry matter (DM)): control (0), low (LSBO; 15.7), medium (MSBO; 44.3) and high (HSBO; 73.4). The study was performed from calving until 84 days in milk, divided into three periods of 28 days each. Dry matter intake (DMI) was affected quadratically in response to SBO addition with the greatest and lowest values of 19.0 and 16.0 kg/day for LSBO and HSBO diets, respectively. The digestibility of potentially digestible NDF was quadratically affected by SBO with the greatest value of 623 g/kg for LSBO diet. Both milk and energy-corrected milk (ECM) production were quadratically affected by SBO inclusion, with greatest ECM values of 27.9 and 27.3 for LSBO and MSBO, respectively. Soybean oil inclusion linearly decreased milk fat concentration by 13.2% from control to HSBO. The CLA t10,c12-18:2 was observed in milk fat only for MSBO and HSBO diets. Soybean oil inclusion did not affect plasma glucose or serum concentrations of total proteins, globulins, albumin, urea nitrogen, beta-hydroxybutyrate, non-esterified fatty acids or insulin. Serum concentrations of total cholesterol, triglycerides and low-density lipoprotein increased with SBO supplementation. Soybean oil inclusion in sugarcane-based diets for early lactation dairy cows from 15.7 to 44.3 g/kg DM can improve energy intake and performance; however, at 44.3 g/kg DM milk fat concentration and ECM decreased. Soybean oil inclusion at 73.4 g/kg DM adversely affected energy intake, fiber digestion and performance of early lactation dairy cows and is not recommended.     

Effects of a combination of fibrolytic and amylolytic enzymes on ruminal enzyme activities,bacterial diversity,blood profile and milk production in dairy cows

We hypothesised that adding a combination of fibrolytic and amylolytic enzymes to the diet of early-lactation dairy cows would improve rumen enzyme activity and bacterial diversity, promote energy metabolism, and benefit milk production in cows. Twenty multiparous early-lactation (90 ± 5 d) Holstein cows with similar body conditions were randomly allocated to control (CON, n = 10) and experimental (EXP, n = 10) groups in a completely randomised single-factor design. The CON was fed only a basal total mixed ration diet, and the diet of the EXP was supplemented with a combination of fibrolytic and amylolytic enzymes at 70 g/cow/d (cellulase 3 500 CU/g, xylanase 2 000 XU/g, β-glucanase 17 500 GU/g, and amylase 37 000 AU/g). The experiment lasted 28 days, with 21 days for adaptation and 7 days for sampling. Enzyme addition increased the activity levels of α-amylase and xylanase, and the ammonia-N concentration (P < 0.05) tended to increase the activity of β-glucanase (P = 0.08) in rumen fluid. However, there was no significant difference in the rumen bacterial richness and diversity, phylum (richness > 0.1%) or genus (richness > 1%) composition between the CON and EXP groups (P > 0.05). A tendency of difference was found between CON and EXP (R = 0.22, P = 0.098) in principal component analysis. Ten genera showed different abundances across the CON and EXP groups (linear discriminant analysis effect size, linear discriminant analysis > 2). EXP increased the ratio of albumin to globulin and the concentrations of total cholesterol and low-density lipoprotein cholesterol (P < 0.05) and tended to increase triglycerides (P = 0.09) in blood. Milk yield, 3.5% fat-corrected milk yield and energy-corrected milk yield increased with enzyme supplementation (P < 0.05). The production levels of milk fat and lactose increased, but the percentage of solids, not fat and protein, decreased in EXP (P < 0.05). Although the DM intake was not affected, the feed efficiency tended to increase (P = 0.07) in EXP. In conclusion, dietary supplementation with a mixture of fibrolytic and amylolytic enzymes on multiparous early-lactation dairy cows increased α-amylase and xylanase activity levels in rumen fluid, enhanced milk performance and tended to improve the feed efficiency in cows.     

Genome-wide associations for investigating time-dependent genetic effects for milk production traits in dairy cattle

Phenotypic variation in milk production traits has been described over the course of a lactation as well as between different parities. The objective of this study was to investigate whether variation in production is affected by different loci across lactations. A genome-wide association study (GWAS) using a 50-k SNP chip was conducted in 152 divergent German Holstein Friesian cows to test for association with milk production traits over different lactations. The first four lactations were analysed regarding milk yield, fat, protein, lactose, milk urea nitrogen yield and content as well as somatic cell score. Two approaches were used: (i) Wilmink curve parameters were used to assess the genetic effects over the course of a lactation and (ii) test-day yield deviations (YD) were used as a normative approach for a GWAS. The significant effects were largest for markers affecting curve parameters for which there was a statistical power <0.8 of detection even in this small design. While significant markers for YDs were detected in this study, the power to detect effects of a similar magnitude was only 0.11, suggesting that many loci may have been missed with this approach in the present design. Furthermore, all significant effects were specific for a single lactation, leading to the conclusion that the variance explained by a certain locus changes from lactation to lactation. We confirm the common evidence that most production traits vary in the degree of persistency after the peak as a result of genetic influence.     

Management practices associated with reproductive performance in Holstein cows on large commercial dairy farms

As a result of the increase in herd size and the intensification of production, the complexity of reproductive management has been growing in dairy herds. The aim of our study was to examine the associations of management practices and reproductive performance in Holstein cows on large commercial dairy farms. Management practices applied to cows were surveyed between 22 May and 6 November 2015 in 34 large Holstein-Friesian dairy herds in Hungary. Individual data of 23 784 cows that calved between 1 January 2014 and 31 December 2014 in the surveyed herds were gathered. Associations between the management practices and the reproductive parameters were analyzed by mixed effects models. Regarding heat abatement we found that ventilation with sprinklers was associated with the shortest breeding interval (P<0.01), the shortest calving to conception interval (P<0.01), and the highest odds of being pregnant by 200 days in milk (P<0.01). Solely ventilation showed similar (P>0.05) results to lack of heat stress protection. It was also revealed, that lack of a well-established voluntary waiting period (VWP) or a VWP shorter than 50 days was associated with less days to first service (P<0.01), shorter breeding interval (P<0.01) and calving to conception interval (P<0.05), as well as higher odds of carrying a calf by 200 days in milk (P<0.01) compared with those using a VWP of at least 50 days. Those farms that applied transrectal ultrasonography were more likely to use ventilation with sprinklers (P<0.05), hormonal synchronization (P<0.01) and to perform early pregnancy diagnosis followed by pregnancy recheck (P<0.05). The application of transrectal ultrasonography with one of the aforementioned practices was associated with reduced days to first service (P<0.05), shorter breeding interval (P<0.05) and higher odds of pregnancy at 200 days in milk (P<0.05). Our study highlights the management practices most closely related to improved reproductive performance, which are, therefore, suggested to be applied on dairy farms, considering the local circumstances of the individual farms.     

妊娠期妇女生殖道大肠埃希菌感染与妊娠不良结局分析

目的探讨妊娠期妇女生殖道大肠埃希菌感染对妊娠不良结局的影响。方法回顾性分析2011年1月至2013年12月在石家庄市第四医院住院孕产妇共2 053例,进行阴道分泌物细菌培养,对大肠埃希菌培养阳性组与正常对照组的妊娠结局进行分析,以探讨妊娠合并生殖道大肠埃希菌感染与围产期并发症的关系。结果在2 053例围产期妇女中,无致病菌组（对照组）为1230例,大肠埃希菌培养阳性组（感染组）为103例,总患病率为5.02%。感染组与对照组的绒毛膜羊膜炎的发生率分别为78.64%、12.20%（P〈0.01）,产褥感染率分别为24.27%、3.41%（P〈0.01）,新生儿黄疸的发生率58.25%、12.36%（P〈0.01）,胎膜早破率分别为11.65%、10.57%（P〉0.05）,早产率分别为3.88%、3.09%（P〉0.05）,胎儿窘迫的发生率2.91%、2.76%（P〉0.05）,低体重儿的发生率1.94%、2.03%（P〉0.05）。结论妊娠期妇女生殖道大肠埃希菌感染与绒毛膜羊膜炎、产褥感染及新生儿黄疸的发生相关,孕期及早发现、诊断、治疗妊娠期妇女生殖道大肠埃希菌感染是有重要意义。     

Low peripheral progesterone and late embryonic/early fetal loss in suckled beef and lactating dairy cows

Pregnancy failure during placentation in lactating dairy cows was associated with low concentrations of serum progesterone. Beef cows have greater serum progesterone and less pregnancy failure. Experiment 1 determined that reduction of serum progesterone affected late embryonic/early fetal loss in suckled beef cows. Cows (n = 40) received progesterone from two new or used controlled internal drug releasing devices, replaced every 5 d, beginning on Day 28 of gestation (mating = Day 0); CL were enucleated on Day 29. Retention of pregnancy was 77% in treated cows and 97% in 78 control cows (P < 0.05). Experiment 2 determined how pregnant, lactating dairy cows with high or low progesterone concentrations during Days 28-34 differed in luteal function or in serum progesterone during replacement therapy. Luteal tissue from such cows was assayed for progesterone and expression of mRNA for genes of endothelin and prostaglandin (PG) systems. Secretion of progesterone and prostaglandins by dispersed luteal cells was determined during incubation with LH, endothelin-1, or arachidonic acid. Neither luteal progesterone nor mRNAs for endothelin or prostaglandin systems differed. Endothelin-1 inhibited secretion of progesterone more (P < 0.05) in luteal cells from cows with low versus high serum progesterone, when incubated with arachidonic acid. Secretion of prostaglandin F₂α was increased and that of 6-keto-PGF₁α decreased by endothelin-1 in vitro. Serum progesterone during replacement was lower (P < 0.05) for cows with low than high serum progesterone at lutectomy. Thus, clearance, more than luteal production, determined peripheral progesterone in pregnant, lactating dairy cows.     

Prevalence, risk factors for and impact of subclinical endometritis in repeat breeder dairy cows

The aim of this study was to determine the prevalence and risk factors for subclinical endometritis (SE) and its effects on fertility in repeat breeder dairy cows. Dairy cows of parity 1 to 5 that were artificially inseminated (AI) 3 or more times (selected cows were artificially inseminated an average of 3.9 times) were examined at 190 ± 40 days in milk, and clinically normal cows (n = 77) were selected based on the absence of abnormal discharges on external inspection and the absence of abnormal findings on transrectal palpation and ultrasonographic examination. Endometrial samples were collected from the uterus by using the lavage technique in the luteal phase of the estrus cycle. Collected samples were centrifuged and a drop of sediment was streaked on to a clean microscopic slide and stained with Giemsa. The percentage of polymorphonuclear cells (neutrophils) was counted for each specimen. The analysed data showed that the average amount of neutrophils was 3.1% (0-9) in the selected cows. Abnormal calving (dystocia, twin births, and abortion), retained placenta, and postpartum uterine infections were associated with an increase in prevalence of SE. Subsequently, SE was significantly associated with a decrease in conception rate in the next AI. Conception rate in the next AI was 5% for cows (n = 38) with SE (≥ 3% neutrophil), and 47% for cows (n = 34) without SE (< 3% neutrophil) (P = 0.001). The prevalence of cytologically diagnosed SE (≥ 3% neutrophil) was 52.7% (n = 38). In conclusion, abnormal calving, retained placenta, and postpartum uterine infections may be associated with an increase in prevalence of SE and subsequently, SE may decrease reproductive performance and increase the incidence of repeat breeder syndrome.     

Mycoflora of cervicovaginal fluids in dairy cows with or without reproductive disorders

Fungal infection of reproduction system of dairy cattle have not been received much more attention. The aim of this study was to determine the fungal infection of Holstein dairy cows with reproductive disorders or healthy. Fungal isolates of cervicovaginal fluids of 176 Holstein dairy cows were collected by using the double rod swabs for cervix and the sterilized cotton swabs for discharges of vagina. They were evaluated for fungal infections. The treatment group included 70 dairy cows with reproductive diseases, such as abortion, repeat breeder, endometritis, metritis, retention of fetal membrane, dystocia, cervicitis, and vaginitis. The control groups were included 42 healthy non-pregnant cows and 64 pregnant cows. Isolates of fungi were obtained from cervix and vagina of 27.1% and 28.6% of treatment group, 26.7% and 31.2% of pregnant cows, and 33.3% and 21.4% of healthy non-pregnant cows, respectively, indicating no significant differences. It is showed that the cervix and vagina of the treatment group have been infected by six different mycotic isolates. However, the cervix and vagina of pregnant and non-pregnant healthy cows in control group were infected with 5, 6 and 5, 4 different fungal agents, respectively. Penicillium and yeast were the most common isolated agents. Regarding to the result of this study, it is concluded that fungal infections can occur in cervicovaginal cavity of Holstein dairy cows with or without reproductive diseases.     

Relationships between cytology, bacteriology and vaginal discharge scores and reproductive performance in dairy cattle

The objective was to compare three diagnostic approaches for intrauterine infection and inflammation: scoring of vaginal contents; quantification of percentage of nucleated cells that were polymorphonuclear leukocytes (PMN) following endometrial cytology; and intra-uterine bacteriology. Dairy cows (n = 303) were examined twice, Days 28 (D28) and 42 (D42), where Day 0 = day of calving. Associations between gross vaginal inflammation scores, uterine cytology, and bacteriology, and subsequent reproductive performance were examined using multivariable models. There was fair agreement at D28 (Kappa = 0.29), but only slight agreement at D42 (Kappa < 0.15), between PMN% and gross vaginal inflammation score. Cows were categorized as having PMN% in the highest quartile (H), or not (L), at both D28 and D42; therefore, cows were categorized as PMNLL, PMNLH, PMNHL, or PMNHH. Cows in the highest PMN% quartile at both time periods were slower to conceive (P < 0.001) than those in all other quartiles (mean ± SEM 32.2 ± 2.3, 37.0 ± 5.3, 40.8 ± 4.1, and 55.3 ± 7.3 d from start of breeding to conception for PMNLL, PMNLH, PMNHL, and PMNHH PMN% cows, respectively). Milk yield was greater (P = 0.001) in cows in the lower quartiles for PMN% at D28 and D42 (i.e., PMNLL) than those in the PMNHH and PMNHL categories, with PMNLH intermediate (P = 0.001). We concluded that PMN% was a better predictor of reproductive performance than either intra-uterine bacteriology or gross vaginal inflammation score. Cows in the highest quartile for PMN% at both D28 and D42 had lower pregnancy rates, took longer to conceive, and had a lower milk yield than those in the lower PMN% categories.     

Reproductive performance of partial gonadectomized male African catfish, Clarias gariepinus broodstocks

This study was conducted to evaluate the effect of partial gonadectomy on reproductive performance of male Clarias gariepinus broodstock. Testes from C. gariepinus broodstock were surgically removed; 25% of the testes (Treatment 1), 50% of the testes (Treatment 2), 75% of the testes (Treatment 3), and removal of the sperm from the testes sac using syringe after the abdominal cavity had been cut open (Treatment 4) {control}. The incisions were sutured and the fish kept inside separate concrete tanks for 4 mo. The incisions closed up within 8 to 9 wk of surgery. The postsurgical survival of C. gariepinus was 100%, indicating the efficiency of the surgical procedure. There was no significant difference (P > 0.05) in sperm production, percentage fertilization, hatchability and survival of the larvae using sperm derived from regenerated testes of the partially gonadectomized C. gariepinus and nongonadectomized C. gariepinus. It also reveals that partial gonadectomy could not alter the quality of sperm production of C. gariepinus. Sperm derived from regenerated testes performed effectively for fertilization of eggs. Based on the results of this study, the removal of 75% of testes during partial gonadectomy proved to be the best as the total number of spermatozoa was more than that of other methods and the sperm was able to fertilize more eggs. Hence the removal of 75% of testis during partial gonadectomy of C. gariepinus is recommended based on the results of this study.     

Reproductive performance in female common hamsters

We monitored individual reproductive timing and output in a common hamster population in Vienna over a 3-year period. Animals were live-trapped, weighed, individually marked, and reproductive status was determined at capture. Costs of reproduction were investigated by measuring body condition shortly before hibernation and overwinter survival. Our results indicated that early emerging females had more litters and weaned more offspring per season. Body mass throughout the active season did not differ significantly between females with high and low reproductive output. High reproductive output seemed to affect the duration of the active season. Successful females had a longer postreproduction period before hibernation than less successful ones, probably serving to balance the costs of reproductive effort by extended preparation for hibernation. Also, females that had emerged early in spring and had high reproductive success were more likely to survive the subsequent winter. Hence, we found female common hamsters to vary strongly in maternal investment capacity and to tailor reproductive strategies accordingly.