Seasonal changes of DNA fragmentation and quality of raw and cold-stored stallion spermatozoa.

In this study annual fluctuations of DNA fragmentation and quality of cold-stored equine sperm were evaluated. Ejaculates were collected weekly during one year from 15 stallions. Ejaculate volume, sperm concentration and total sperm count were determined and semen was then extended and cold-stored for 48 h. Sperm motility was evaluated by CASA before and after 24 as well as 48 h of cold storage. In addition, the percentages of sperm with intact plasma membrane and acrosome (PMAI %) and with low intracellular Ca2+ level were determined in cold-stored semen (24 h, 48 h). SCSA™ was performed to assess mean DFI, SD of DFI and % DFI in raw frozen-thawed as well as in extended sperm after 24 and 48 h of storage. The month of semen collection affected (P < 0.05) all parameters evaluated in raw semen and all criteria except progressive motility as well as rapid cells in semen stored for 24 and 48 h, respectively. Ejaculate volume was higher and sperm concentration lower in summer compared to winter and motility lower in July than in any other month of the year (P < 0.05). In semen processed in April and stored for 24 h the percentage of rapid cells was improved compared to January and after 48 h of storage progressive motility (%) was higher in January and October than in July (P < 0.05). After 24 h of cold storage PMAI % was higher in October than in January and after 48 h values were higher in September compared to January and February as well as from April to July (P < 0.05). Regarding sperm with low intracellular Ca+2 level (%) after storage for 24 and 48 h, higher values were measured in winter and in October compared to April, June and July (P < 0.01). Seasonal changes in DNA fragmentation were most evident with respect to mean DFI. In raw frozen-thawed semen mean DFI was lower from August to November than in June and July (P < 0.001). Values were lower during winter compared to spring and early summer (P < 0.05) and lower in December than from April to September (P < 0.001). After 24 h of cold storage mean DFI was lower in September and October when compared to January, February, May, July and November (P < 0.05) and after 48 h storage mean DFI was reduced in spring and autumn compared to February, June and July (P < 0.05). In conclusion, a seasonal effect was evident on semen characteristics of raw and cold-stored sperm. Semen quality was impaired in midsummer when low sperm motility and viability were combined with an elevated DNA fragmentation and Ca2+ level of sperm.

Effects of an extension of the equilibration period up to 96 hours on the characteristics of cryopreserved bull semen.

This study was designed to investigate the effects of an equilibration period up to 96 hours and three extenders (AndroMed, OPTIXcell, and Triladyl) on the quality of cryopreserved bull semen and to evaluate, whether an extension of the equilibration time to 72 hours does affect fertility in the field. One ejaculate of 17 bulls was collected and divided into three equal aliquots and diluted, respectively, with the three extenders. Each aliquot was again divided into five parts and equilibrated for 4, 24, 48, 72, and 96 hours before freezing in an automatic freezer. Sperm motility, plasma membrane and acrosome integrity (PMAI), and DNA fragmentation index (% DFI) were measured during equilibration. In addition to the parameters measured during equilibration, the percentage of viable sperm cells with high mitochondrial membrane potential (HMMP) was measured immediately after thawing, and after 3 hours of incubation at 37 °C. Sperm motility was assessed using CASA, and PMAI, HMMP, and % DFI were measured using flow cytometry. Equilibration time did affect all parameters before freezing (P < 0.01), and also the extender affected all parameters except HMMP (P < 0.05). After thawing, all parameters except HMMP immediately after thawing were influenced by the equilibration period (P < 0.001), whereas all parameters except % DFI immediately after thawing were influenced by the extender (P < 0.001). The changes of semen characteristics during 3 hours of incubation were also dependent on the equilibration time and the extender used in all parameters (P < 0.01). In the field study, semen of nine bulls was collected thrice weekly, processed using Triladyl egg yolk extender, and frozen in 0.25 mL straws with 15 × 106 spermatozoa per straw. In total, the nonreturn rates on Day 90 after insemination (NRR90) of 263,816 inseminations in two periods were evaluated. Whereas semen collected on Mondays and Wednesdays was equilibrated for 24 hours in both periods, semen collected on Fridays was equilibrated for 4 hours in period one and equilibrated for 72 hours in period 2. No differences in NRR90 could be found (P > 0.05). In conclusion, extension of the equilibration time from 4 hours to 24-72 hours can improve motility and viability of cryopreserved semen after thawing. The extent of improvement in semen quality is dependent on the extender used. Prolongation of the equilibration period from 4 hours to 72 hours had no effect on fertility in the field.

Prenatal and early life exposure to traffic pollution and cardiometabolic health in childhood.

BACKGROUND: Prenatal exposure to traffic pollution has been associated with faster infant weight gain, but implications for cardiometabolic health in later childhood are unknown. METHODS: Among 1418 children in Project Viva, a Boston-area pre-birth cohort, we assessed anthropometric and biochemical parameters of cardiometabolic health in early (median age 3.3 years) and mid- (median age 7.7 years) childhood. We used spatiotemporal models to estimate prenatal and early life residential PM2.5 and black carbon exposure as well as traffic density and roadway proximity. We performed linear regression analyses adjusted for sociodemographics. RESULTS: Children whose mothers lived close to a major roadway at the time of delivery had higher markers of adverse cardiometabolic risk in early and mid-childhood. For example, total fat mass was 2.1 kg (95%CI: 0.8, 3.5) higher in mid-childhood for children of mothers who lived <50 m vs. ≥200 m from a major roadway. Black carbon exposure and traffic density were generally not associated with cardiometabolic parameters, and PM2.5 exposure during the year prior was paradoxically associated with improved cardiometabolic profile. CONCLUSIONS: Infants whose mothers lived close to a major roadway at the time of delivery may be at later risk for adverse cardiometabolic health.

[Sonographic diagnosis of pregnancy and determination of fetal number and gestational age in ewes]. / Sonographische Trächtigkeitsunter- suchung und Bestimmung von Anzahl und Alter der Feten beim Schaf.

The aim of the present study was to evaluate accuracy of transabdominal ultrasonography for pregnancy diagnosis, determination of fetal number and estimation of gestational age in ewes. A total of 1068 ewes from 8 different flocks (Swiss White Alpine n = 379, Swiss Black-Brown Mountain n = 189, Oxford-type n = 164, Ostfriesian n = 154, Texel n = 104, Lacaune x Osfriesian crossbred n = 78) was investigated using an Ovi-Scan™ ultrasound scanner with a 3.5 MHz 170° mechanical axial probe (BCF Technology Ltd., BelIshill, Great Britain). Scanning was performed transabdominally at the right inguinal region in ewes restrained in standing position. Sonographic findings were compared with lambing data recorded by the farmers. Included in the analysis were all ewes that, at the time of examination, were not pregnant and those that were pregnant between 26 and 110 days with a known lambing date and number of lambs born (n = 882). The sensitivity of pregnancy diagnosis was 97.8% and the specificity 97.6% (overall accuracy 97.8%, n = 853). Sensitivity and specificity for discrimination between single and multiple pregnancies was 95.8% and 90.5% (overall accuracy 93.9%, n = 752), respectively, when multiples were defined as positive. Discrimination between twins and triplets reached a sensitivity of 86.0% and a specificity of 99.5% (overall accuracy 98.0%, n = 458) when triplets were defined as positive. Considering a gestation period of 150 days, the mean deviation of the estimated to the effective day of gestation at examination was 5.6 ± 5.0 days (n = 781). The correlation between estimated and true gestational age was very high (r=0.936, P<0.0001). In conclusion, a highly accurate and efficient diagnosis of pregnancy with reliable estimation of fetal number and age is possible using an Ovi-Scan™ ultrasound scanner by an experienced examiner.

Reproductive performance of Lacaune dairy sheep exposed to artificial long days followed by natural photoperiod without and with additional progestagen treatment during the nonbreeding season.

This study compared the reproductive performance of Lacaune dairy ewes exposed to a light program and subsequent male introduction without (n = 36) or with (n = 36) an additional 6-day progestagen treatment during the nonbreeding season. All ewes were exposed to extended day length (16 hours light and 8 hours darkness) for 77 days during winter (December 15 until March 2) followed by increasing natural photoperiod. At the end of the photoperiodic treatment, three blood samples were collected 6 days apart for progesterone (P4) analysis to determine cyclic activity. One half of the ewes were additionally subjected to a 6-day progestagen treatment in combination with PGF2α and eCG at insert withdrawal. Rams fitted with marking harnesses were introduced to females for 45 days and marked ewes recorded. Ewes exposed to the light program only were joined 40 days after the end of photoperiodic treatment, and ewes with additional progestagen treatment were joined 1 day after insert removal (40-44 days after the end of photostimulation). Lambing data were recorded and fertility (percentage of ewes lambing, lambing rate, and litter size) assessed to the first service period and overall. Mean serum P4 concentrations were similarly (P > 0.05) low in both groups (0.4-0.7 ng/mL vs. 0.4-0.6 ng/mL). On the basis of elevated P4 levels (>1 ng/mL), evidence of luteal activity was found in 27.8% of the ewes at the end of the light program. Estrus response was equally high (97.2%) and estrus distribution highly synchronized in progestagen-treated ewes (91.7% within 4 days). In ewes exposed to the light program only, estrous activity was recorded within 4 days (six ewes), from Day 8 to Day 17 (17 ewes) and from Day 19 to Day 25 (12 ewes) after joining. The percentage of ewes that lambed to the first service period was higher (P < 0.05) in ewes exposed to the light program only than that in the group additionally treated with progestagen/PGF2α/eCG (94.4% vs. 69.4%). Overall, the percentage of lambing ewes was similar in both groups (97.2% and 94.4%), and lambing rates (1.4-1.9) and litter sizes (1.9-2.1) were high and not influenced (P > 0.05) by the treatment. In conclusion, this study reports that exposition of Lacaune ewes to artificial long days followed by natural day length and male introduction is highly effective to induce fertile estrous activity during the nonbreeding season and offers a reliable and practical alternative to hormonal manipulation for out-of-season breeding in sheep.

[Fertility after treatment with Eazi-breedTM CIDR G for 6 or 12 days outside the breeding season in Lacaune dairy sheep]. / Fruchtbarkeit nach 6- und 12-tägiger Behandlung mit Eazi-breed™ CIDR® G ausserhalb der Zuchtsaison beim Lacaune Milchschaf.

This study compares the fertility after short- and long-term synchronization using a progesterone intravaginal device in Lacaune dairy sheep outside the breeding season. For the experiment 108 Lacaune sheep were treated with Eazi-breed™ CIDR® G intravaginal devices (Pfizer Animal Health, Zürich) for 12 days (Group L, n = 60) or 6 days (Group K, n = 48) in combination with eCG (Group L) or with eCG and 125 µg Cloprostenol (Group K) at device removal. Thereafter the ewes were kept together with rams for 60 days, ewes in estrus were recorded and the fertility was assessed after lambing. Blood progesterone concentration was measured at device application, withdrawal and 14 days later. Results show that neither treatment nor parity had an influence on estrus rate (Group L 91.7 %, Group K 93.8 %, nulli- and pluriparous animals 96.9 % and 90.8 %, respectively). Group L showed a tendency towards a better first cycle lambing rate and a significantly (P < 0.05) higher overall lambing rate compared to sheep of Group K (71.7 % vs. 60.4 % and 83.3 % vs. 72.9 %). Pluriparous ewes had higher (P < 0.05) lambing rates and greater (P < 0.05) numbers of lambs born per synchronized ewe than nulliparous sheep for the first cycle (75.0 % vs. 46.9 % and 1.4 ± 1.0 vs. 0.9 ± 1.1) as well as for the overall service period (92.1 % vs. 46.9 % and 1.7 ± 0.8 vs. 0.9 ± 1.1). Fourteen days after insert withdrawal progesterone concentrations were higher (P < 0.05) in Group L than in Group K (7.7 ± 4.3 vs. 5.6 ± 2.7 ng/mL) and in nulli- compared to pluriparous (9.1 ± 5.6 vs. 5.7 ± 2.1 ng/mL) ewes. In conclusion, the overall lambing rate was higher after long-term compared to short progesterone treatment and nulliparous ewes were less suitable for estrus induction outside the breeding season.

Dans ce travail, on étudie la fertilité chez de brebis de race Lacaune lait après une synchronisation des chaleurs de courte et de longue durée au moyen d'un pessaire intra vaginal à la progestérone. Pour cela, 108 brebis Lacaune lait ont été traitées pendant 12 jours (groupe L, n = 60) ou 6 jours (groupe K, N = 48) avec un pessaire vaginal Eazi-breed™ CIDR® G (Pfizer Animal Health, Zürich) en combinaison avec 500 IE d'eCG (groupe L) respectivement 500 IE d'eCG et 125 µg de Cloprostenol (groupe K) au moment du retrait du pessaire. Par la suite, les brebis ont été détenues pendant 60 jours avec des béliers, les chaleurs ont été relevées ainsi que la fertilité après l'agnelage. Le taux sanguin de progestérone a été mesuré lors de la mise en place et du retrait du pessaire ainsi que 14 jours plus tard. Les résultats montrent que ni le traitement ni le nombre de gestations antérieures n'avaient d'influence sur le taux de chaleurs (groupe L 91.7 %, groupe K 93.8 %, brebis nulli- et pluripares 96.9 % respectivement 90.8 %). Les brebis du groupe L montraient, un taux de mise bas tendentiellement meilleur lors du premier cycle et au total significativement plus haut (P < 0.05) que celles du groupe K (71.7 % par rapport à. 60.4 % et 83.3 % par rapport à 72.9 %). Les pluripares avaient, lors du premier cycle et en général, des taux de mise-bas plus élevés que les nullipares (75.0 % contre 46.9 % respectivement 92.1 % contre 46.9 %, P < 0.05) ainsi qu'un nombre d'agneaux plus élevé par brebis synchronisée (1.4 ± 1.0 contre 0.9 ± 1.1 respectivement 1.7 ± 0.8 contre 0.9 ± 1.1, P < 0.05). Quatorze jours après le retrait du pessaire, les taux de progestérone étaient plus élevés dans le groupe L que dans le groupe K (7.7 ± 4.3 contre 5.6 ± 2.7 ng/mL) aussi bien chez les nulli- que chez les pluripares (9.1 ± 5.6 contre 5.7 ± 2.1 ng/mL). En résumé on constate que le taux de mise-bas était meilleur après un traitement long qu'après un traitement court et que les brebis nullipares étaient moins adaptées à la synchronisation des chaleurs hors de la saison de reproduction.