Versuche zur Zyklussynchronisation bei Kühen aus Beständen rnit Fertilitätsproblemen und bei Hybriden zwischen Wisent und Rind mit der PRID-Spirale*

Inhalt: An 81 Versuchs- und 92 Kontrolltieren der Rasse “Potnische Schwarzbunte” aus 3 Problembetrieben wurde ein Versuch zur Sterilitätsprophylaxe rnit der PRID-Spirale durchgeführt. Anhand klinischer Befunde und Milchprogesteronwerten wurde die Untergruppe aus Kühen mit Ovardystrophie (18 Versuchs- und 22 Kontrolltiere) gebildet und extra ausgewertet. Der Behandlungsbeginn lag zwischen 60 und 80 Tage post partum. Die Versuchstiere wurden mit der PRID-Spirale 12 Tage lang behandelt, die Kontrolltiere erhielten Injcktionen rnit Kochsalzlösung und solche rnit Ovardystrophie wurden zusätzlich mit einer Eierstocksmassage behandelt. Die Versuchstiere wurden 56 und 72 Stunden nach Entfernung der Spirale blind besamt. Die Brunstin-duktionsrate betrug insgesamt 90,1%, bei denen rnit Ovardystrophie 77,7%. Die An-wendung der PRID-Spirale führte zur Verbesserung der Fertilitätslage. Die Gesamt-trächtigkeitsrate lag mit 87,6% bei den Versuchskühenüber derjenigen der Kontrollkü-he mit 79,3%. Die Behandlung der Tiere rnit Ovardystrophie erbrachte eine Gesamt-trächtigkeitsrate von 88,8% bei den Versuchs- und 72,7% bei den Kontrolltieren. Die Zwischentragezeit betrug bei den Versuchstieren 101,2 Tage und bei den Kontrolltieren 113,3 Tage (p ≤ 0,05). Bei den azyklischen Tieren lag die Zwischentragezeit bei 104,6 Tage bzw. 134,7 Tage (p ≤ 0,05). In einem anderen Versuch wurde 20 Hybriden zwischen Wisent und Hausrind rwecks Zyklussynchronisation die PRID-Spirale verabreicht. Die Brunstinduktionsrate betrug 66,6%, das Erstbesamungsergebnis nach Doppelbesamung 30%, die Gesamtträchtig-keitsrate nach dem Decken der umrindernden Kreuzungstiere rnit einem Bullen 90%. Die Deckperiode konnte verkürzt werden. Contents: Investigations on the synchronization of estrus cycle in cattle from farms with fertility problems and in cross-breeds between bison and cattle with a PRID-de-vice In 81 experimental and 92 control animals of the “Polish Black and White” breed derived from 3 farms with fertility problems an investigation was carried out for sterility prophylaxis using the PRID-device. Based on clinical findings and milk progesterone values cattle with ovarian dystrophy (18 experimental and 22 control animals) from a special group were used. The begin of treatment was between 60 and 80 days post partum. All experimental animals had received a PRID-device for a duration of 12 days. Control animals were injected with physiological saline solution and animals with ovarian dystrophy were treated additionally with ovarian massage. Experimental animals were inseminated 56 and 72 hrs after removal of the device. All animals taken, estrus was induced in 90.1% of the animals, while only 77.7% of animals with ovarian dystrophy came to estrus. Application of the PRID-device led to an improvement of fertility. Pregnancy rates in experimental animals were 87.6%, while only 79.3% of the control animals were pregnant. Treatment of animals with ovarian dystrophy resulted in 88.8% pregnancies for treated and 72.7% for control animals. Experimental animals were non-pregnant for a duration of 101.2 days, while control animals remained non-pregnant for 113.3 days (p < 0.05). Acyclic cattle had a non-pregnant period of 104.6 days and 134.7 days (p < 0.05) respectively. In a second experiment 20 cross-breeds between bison and domestic cattle were treated with a PRID-device for synchronization of the estrus cycle. The rate of estrus induction was 66.6%, the fertility after double insemination 30%, the total pregnancy rate improved after mating with a bull of animals that had not conceived to 90%.     

Conception rates to fixed-time artificial insemination of two oestrus synchronisation programmes in dairy heifers

AIM: To evaluate the conception rate to fixed-time artificial insemination (FTAI) of two oestrus synchronisation programmes in dairy heifers on eight farms over 2 years.

METHODS: The study was conducted in 2008 and 2010 on eight farms near Palmerston North, New Zealand. Nulliparous Friesian and Friesian×Jersey heifers (13–15 months of age) were randomly allocated to one of two oestrus synchronisation programmes. Group 1 (GPG+P4; n=330), received gonadotrophin-releasing hormone (GnRH) I/M on Day 0, a progesterone (P4)-releasing intravaginal device from Days 0–7, prostaglandin F_2α (PGF) I/M on Day 7 and a second dose of GnRH at the time of FTAI on Day 9. The second group (P4+PGF; n=343) received a P4-releasing intravaginal device from Days 0–7, PGF on Day 6 and FTAI on Day 9. Pregnancy was diagnosed from Days 42–52 by transrectal ultrasonography.

RESULTS: The overall conception rate was 52.4% and 54.8% for the GPG+P4 and P4+PGF groups, respectively. The odds of conception for the two treatments were not different (OR=0.90; 95% CI=0.67–1.23), nor was there any difference between groups in different years (p=0.58). Farm affected conception rate (p=0.002), but there was no interaction with treatment (p=0.92) .

CONCLUSIONS: This study has shown that an alternative synchronisation programme can produce similar results in terms of conception rate to the GPG+P4 treatment, currently commonly used in heifers. More research is required to establish whether other modifications to the GPG+P4 programme can produce similar results at lower costs, and to identify and quantify farm factors which affect the economic benefit of heifer synchronisation.

CLINICAL RELEVANCE: This study indicated that synchronising heifers with P4 and PGF resulted in conception rates equivalent to those resulting from a GPG+P4 treatment, but with reduced drug costs. However, because heifers in the GPG+P4 group received the second GnRH injection at the time of AI, they needed only three yardings as opposed to the four required for the heifers treated with P4 and PGF. Thus, the choice of programme for an individual farm will depend on that farm's circumstances, in particular the cost of yarding the heifers.     

A Bayesian meta-analysis of the effects of administering an intra-vaginal (CIDR) device in combination with other hormones on the reproductive performance of cycling,anoestrous and inseminated cows

AIMS: To evaluate the effectiveness of treatment programmes that included controlled internal drug-releasing (CIDR) devices containing progesterone (P4) in improving synchrony of oe- strus, and conception and pregnancy rates in cycling, anoestrous and inseminated dairy cows, using meta-analysis. To describe the difference in response between cycling and anoestrous cows to CIDR-based synchrony programmes.

METHODS: Scientific papers written in the English language between 1989 and 2002 that investigated the effects of treat- ment programmes including CIDR devices on reproductive per- formance in dairy heifers or lactating dairy cows were identified using a computerised literature search. The criteria for inclusion incorporated evidence that treatment allocation was completely randomised; the population studied was lactating dairy cows; and that data were available on submission, conception and pregnancy rates and their associated measures of variability. Re- productive outcomes from 25 synchrony trials (total n= 11,058 cows) were analysed. Summary measures of the effect of treat- ment on reproductive outcome were assessed using fixed- and random-effects Bayesian meta-analysis models.

RESULTS: Treatment programmes including a CIDR device increased the risk of submission in cycling cows (predicted Bayesian RR=2.86, 95% credible interval 1.46–5.67). Compared with controls, synchrony programmes including CIDR devices in cycling dairy cows had no effect on the risk of conception to first service post-treatment (predicted Bayesian RR=1.00, 95% credible interval=0.80-1.24). Compared with controls, synchrony programmes including CIDR devices had no effect on the risk of pregnancy throughout the mating period (pre- dicted Bayesian RR=1.02, 95% credible interval=0.89-1.17). In anoestrous cows, CIDR treatment had no effect on the risk of conception to first service post-treatment and no effect on the risk of pregnancy throughout the mating period, compared with anoestrous, untreated controls (predicted Bayesian RR=0.91 and 0.97, respectively; 95% credible interval=0.68–1.26 and 0.59-1.60, respectively).

CONCLUSION: The results of this meta-analysis showed that synchrony programmes using CIDR devices combined with other hormones reliably enhanced submission rates in lactat- ing dairy cows. The relatively small number of trials with data suitable for analysis and the heterogeneity of results at the indi- vidual trial level limited our ability to confirm either a beneficial or deleterious effect of treatment on conception or pregnancy rates. Further randomised, controlled trials to evaluate the ef- fectiveness of this form of reproductive therapy in commercial dairy farms are needed.     

Chlamydia infection in cats in New Zealand

Conjunctival swabs collected in 1991-92 from 333 pedigree and non-pedigree cats were tested for the presence of Chlamydia spp. antigen using an ELISA antigen kit. Forty (18.4%) of the 217 samples from cats with conjunctivitis were positive. Seven (6%) of 116 samples from cats which were in contact with cats with conjunctivitis but which showed no clinical signs at the time of sample collection were positive. Positive-testing cats were frequently from multi-cat households. Chlamydia spp. is present and associated with conjunctivitis in cats in New Zealand. Infection may occur concurrently with viral diseases. Feline calicivirus was recovered from 27 (21 with conjunctivitis) of 37 cats tested in five catteries. Four cats (with conjunctivitis) were FIV-positive.     

Effect of Repeated Use of Progestagen-PMSG Treatment for Estrus Control in Dairy Goats out of Breeding Season

Contents In order to analyze the effects of repeated use of progestagen-PMSG treatment, estrus and pregnancy results have been analyzed for 1989 in a Saânen dairy goat herd in which breeding takes place each year out of season after FGA/PMSG treatment. After the first 1989 treatment (169 goats), percentage of goats showing estrus and kidding have been lower for 59 multiparous than for 46 primiparous and 64 nulliparous females. Moreover, when 38 goats are treated for a second time in 1989, 44.7% exhibited estrus vs 71.0% after the first treatment (P < 0.05). The PMSG binding level before the 1st 1989 treatment is higher for multiparous (17.5 ± 23.1%) than nulli and primiparous (-0.06 ± 0.7 and 1.2 ± 1.9%) and is increased for all parities after treatment (23.2 ± 26.4 after vs 5.7 ± 15.0% before, P < 0.01). For nulliparous and primiparous females; PMSG binding levels are not different for pregnant or not pregnant nulliparous and primiparous goats. On the opposite, PMSG binding rates are higher in non pregnant (25.7 ± 23.3) than in pregnant multiparous goats (6.5 ± 15.9) (P < 0.01). However, when the binding rate is ≤ 5.12% (computerized distributions) multiparous goats exhibit estrus and pregnancy at levels not different from nulliparous or primiparous females (% estrus 95.8 vs 100 or 97.8%, % pregnancy 66.7 vs 70.3 and 63.0% respectively). Repeated use of PMSG during the female life or during one given year leads to active immunization against PMSG (as measured by percentage of binding of PMSG in plasma) decreasing the efficiency of ovarian stimulation out of breeding season. Inhalt: Einfluß einer wiederholten Progestagen/PMSG Behandlung zur Östruskontrolle außerhalb der Paarungssaison bei Milchziegen Um den Einfluß wiederholter Progestagen-PMSG-Behandlung zu prüfen, wurden Östrus und Trächtigkeitsergebnisse in einer Saanen Ziegenherde für das Jahr 1989 analysiert. Bei den untersuchten Tier en wird die Bedeckung jedes Jahr außerhalb der Saison nach FGA/PMSG-Behandlung vorgenommen. Nach der ersten Behandlung 1989 (169 Ziegen) war der Prozentsatz Ziegen, die einen Östrus zeigten und ablammten, bei 59 multiparen niedriger als bei 46 primiparen und 64 nulliparen Tieren. Darüber hinaus zeigten von 38 Ziegen nach einer zweiten Behandlung 1989 zu 44,7% einen Östrus gegenüber 71% nach der ersten Behandlung (p < 0,05). Die Bindungsfähigkeit für PMSG war bei der ersten Behandlung bei den multiparen Tieren höher (17,5 ± 23,1%) als bei nulli- und primiparen Tieren (-0,06 ± 0,7% und 1,2 ± 1,9%) und stieg für alle Tiere nach der Behandlung an (23,2 ± 26,4% nach zu 5,7 ± 15,0% vor der Behandlung, p < 0,01). Die PMSG Bindungsfähigkeit war nicht unterschiedlich bei tragenden und nichttragenden nulli- und primiparen Tieren. Dagegen waren die PMSG Bindungsraten bei nichttragenden Ziegen (25,7 ± 23,3%) höher als bei tragenden multiparen Tieren (6,5 ± 15,9%) (p < 0,01). Wenn allerdings die Bindungsraten unter 5,12% (Computerverteilung) sinkt, zeigen multipare Ziegen Östrus und Trächtigkeitsraten, die sich von multiparen und primiparen Tieren nicht unterscheiden (Östrus < 95,8% gegen 100 bzw. 97,8%; Trächtigkeit: 66,7% gegen 70,3 bzw. 63%). Wiederholter Gebrauch von PMSG, auch schon eine Applikation innerhalb eines Jahres führt zur Immunisierung gegenüber PMSG (gemessen an dem Prozentsatz Bindungsvermögen im Plasma) und senkt die Effektivität der ovariellen Stimulation außerhalb der Saison.     

Reproductive efficiency in grazing lactating dairy cows under a programmed reproductive management system

OBJECTIVE: To evaluate the effectiveness of a reproductive management program consisting of combinations of Ovsynch/TAI and prostaglandin (PG) F(2alpha) treatments in Holstein dairy cows under a pasture-based dairying system. DESIGN: Field trial. PROCEDURE: A total of 1177 cows in 8 commercial dairy farms were randomly allocated to control and treatment groups. Treatment group cows received one of two interventions depending upon the number of days postpartum (DPP) before the planned start of breeding. Cows more than 50 DPP by the planned start of breeding received the Ovsynch/TAI treatment, consisting of gonadotrophin releasing hormone (GnRH) - PGF(2alpha)- GnRH plus timed artificial insemination. Cows between 40 and 50 DPP received a PGF(2alpha) treatment followed by oestrus detection and, if the cow was not seen in oestrus, the cow received a second PGF(2alpha) 14 days later. Control cows were submitted to twice a day heat detection followed by artificial insemination. The experimental period was the start of the breeding season plus 21 days for cows over 50 DPP at the start of breeding, and was 40-61 DPP for cows that calved later and passed their voluntary waiting period after the start of the breeding season. RESULTS: Submission rate was higher for the treated group than for the control group (84.9% vs. 55.1%; P < 0.0001), as was the conception rate (51.0% vs. 46.1%; P < 0.03). Due to farm variations, pregnancy rate was similar in both groups (38.5% vs. 28.2%; P > 0.1). Within the treated group, conception rate and pregnancy rate of the cows inseminated after a PGF(2alpha) were higher than for timed artificial inseminated cows (51.4% vs. 32.6%; P < 0.001), and (37.8% vs. 32.6%; P < 0.001). CONCLUSION: A programmed reproductive management protocol may improve reproductive efficiency in dairy farms with seasonal breeding, by increasing submission and conception rates at the beginning of the breeding season and/or at the end of the voluntary waiting period. Fertility of cows bred after a PGF(2alpha) synchronised heat was greater than after an Ovsynch/TAI protocol.     

Innate factors causing differences in gene flow frequency from transgenic rice to different weedy rice biotypes

BACKGROUND: The compatibility and outcrossing rates between transgenic rice and weedy rice biotypes have been studied in some previous cases. However, few studies have addressed the reasons for these differences. The present study compared the compatibility and outcrossing rates between transgenic rice and selected weedy rice biotypes using manual and natural crossing experiments to elucidate the key innate factors causing the different outcrossing rates. RESULTS: Hybrid seed sets from manual crossing between transgenic rice and weedy rice varied from 31.8 to 82.7%, which correlated directly with genetic compatibility. Moreover, the significant differences in the quantity of germinated donor pollens and pollen tubes entering the weedy rice ovule directly contributed to the different seed sets. The natural outcrossing rates varied from 0 to 6.66‰. The duration of flowering overlap was the key factor influencing natural outcrossing. Plant and panicle height also affected outcrossing success. CONCLUSION: From this study, it is concluded that the likelihood of gene flow between transgenic rice and weedy rice biotypes is primarily determined by floral synchronisation and secondarily influenced by genetic compatibility and some morphological characteristics. Copyright © 2011 Society of Chemical Industry     

绵羊同期发情研究进展

同期发情是动物繁殖生物技术之一,同超数排卵和胚胎移植一并已广泛应用于养羊业生产,大大地提高了羊生产力。文章就国内外绵羊同期发情技术的研究方法及其效果作以论述。     

Comparison between two progesterone sources and two oestradiol formulations in a Heatsynch protocol for postpartum cycling dairy cows in pasture

To compare an injectable progesterone (MAD-4) with an intravaginal device (IPD), and natural O17 with synthetic oestradiol (OB) in a synchronisation protocol, 51 cows were divided into four groups. Each group was treated with one of the two sources of progesterone and one of the two oestradiol formulations. Oestrus behaviour, follicle diameter, and pregnancy rates were evaluated. Oestrus behaviour (p = 0.902), numbers of cows in oestrus (p = 0.917), follicle diameter (p = 0.416), and pregnancy rates (p = 0.873) were similar among the four groups. More cows in the group treated with the IPD and OB scored > 200 oestrus behaviour points compared to the other groups (p = 0.038). A longer interval between the end of treatment and oestrus was observed among cows treated with MAD-4 than cows given the IPD (p = 0.030), but no differences were found between animals receiving the two oestradiol formulations (OB and O17). While the use of MAD-4 requires further testing, similar responses to natural oestradiol observed in the present study could allow the use of this formulation in reproductive protocols because it is not associated with the potential human health risks of OB.