Comparison between Cloprostenol-induced and Spontaneous Oestrus Fertility in Dairy Cows

A short calving to conception interval is of main importance to achieve high economic efficiency in dairy cow industry. In order to reduce this interval, several hormonal treatments have been put on the market, in which cloprostenol, a synthetic analogue of prostaglandin F2alpha (PGF2alpha). The aim of this study was to compare fertility of cloprostenol-induced oestrus to that of spontaneous oestrus in dairy cows. In a group of 525 cows, 280 (treated group) were administered 0.5 mg cloprostenol i.m. after transrectal corpus luteum (CL) detection, and inseminated at detected oestrus during the following week. The other 245 cows (control group) were inseminated during spontaneous oestrus. Whey progesterone concentrations were checked at treatment and at insemination in order to remove from the study cows whose P4 levels indicate a non-functional CL, or a lack of luteolysis respectively. Moreover, cows that were not inseminated due to genital problems were also excluded from this study. Conception (59% vs 54.5%) and calving rates (93.7% vs 93%) were not significantly different between the two groups.     

Bovine serum panel for evaluating foot-and-mouth disease virus nonstructural protein antibody tests.

A panel of 36 sera has been assembled from experimental cattle that had been infected by inoculation or contact exposure with 4 serotypes of foot-and-mouth disease virus (FMDV) with or without prior vaccination. Virus replication and persistence had been characterized in all of the animals. The proportion of the sera scored positive by 5 tests for antibodies to the nonstructural proteins of FMDV varied, suggesting that the panel can discriminate between the sensitivity with which such tests are able to identify infected cattle. Use of this panel will help in assessment of new tests and quality control of existing methods.     

The action of (S)-3-allyl-2-methyl-4-oxocyclopent-2-enyl (1 R)-trans-chrysanthemate, (S)-bioallethrin,on single neurones in the central nervous system of the leech,Hirudo medicinalis

Intracellular recordings from identifiable neurones in the leech segmental ganglion in high (20 mM) magnesium Ringer solution showed that (S)-3-allyl-2-methyl-4-oxocyclopent-2-enyl (1 R)-trans-chrysanthemate, (S)-bioallethrin, induced three phases of activity: (1) hyperexcitability; (2) repeated depolarisations accompanied by trains of action potentials; and (3) block of action potentials. A linear relation between log (time to onset) of both depolarisations and block and the log (applied dose) was observed over the range 3.44 × 10^?7–1.10 × 10^?3M. (S)-Bioallethrin was toxic to leeches at similar concentrations to those effective on isolated ganglia. The possible role of repeated depolarisations in the poisoning process is discussed.     

Efficacy of an intravaginal progesterone insert and an injection of PGF2alpha for synchronizing estrus and shortening the interval to pregnancy in postpartum beef cows, peripubertal beef heifers, and dairy heifers

The objective was to test the efficacy of an intravaginal progesterone insert and injection of PGF2alpha for synchronizing estrus and shortening the interval to pregnancy in cattle. Cattle were assigned to one of three treatments before a 31-d breeding period that employed artificial insemination. Control cattle were not treated, and treated cattle were administered PGF2alpha or an intravaginal progesterone-releasing insert (CIDR) for 7 d and treated with PGF2alpha on d 6. The treatments were applied in one of three experiments that involved postpartum beef cows (Exp. 1; n = 851; 56+/-0.6 d postpartum), beef heifers (Exp. 2; n = 724; 442.5+/-2.8 d of age), and dairy heifers (Exp. 3; n = 260; 443.2+/-4.5 d of age). Luteal activity before treatment was determined for individual cattle based on blood progesterone concentrations. In Exp. 1, there was a greater incidence of estrus during the first 3 d of the breeding period in CIDR+PGF2alpha-treated cows compared with PGF2alpha-treated or control cows (15, 33, and 59% for control, PGF2alpha, and CIDR+PGF2alpha, respectively; P < 0.001). The improved estrous response led to an increase in pregnancy rate during the 3-d period (7, 22, and 36% for control, PGF2alpha, and CIDR+PGF2alpha, respectively; P < 0.001) and tended to improve pregnancy rate for the 31-d breeding period for cows treated with CIDR+PGF2alpha, (50, 55, and 58% for control, PGF2alpha, and CIDR+PGF2alpha, respectively, P = 0.10). Improvements in rates of estrus and pregnancy after CIDR+PGF2alpha, were also observed in beef heifers. Presence of luteal activity before the treatment period affected synchronization and pregnancy rates because anestrous cows (Exp. 1) or prepubertal heifers (Exp. 2) had lesser synchronization rates and pregnancy rates during the first 3 d of the breeding period as well as during the entire 31-d breeding period. The PGF2alpha, and CIDR+PGF2alpha but not the control treatments were evaluated in dairy heifers (Exp. 3). The CIDR+PGF2alpha-treated heifers had a greater incidence of estrus (84%) during the first 3 d of the breeding period compared with the PGF2alpha-treated heifers (57%), but pregnancy rates during the first 3 d or during the 31-d breeding period were not improved for CIDR+PGF2alpha compared with PGF2alpha-treated heifers. In summary, the concurrent treatment of CIDR and PGF2alpha improved synchronization rates relative to PGF2alpha alone or control. Improved estrus synchrony led to greater pregnancy rates for beef cows and beef heifers but failed to improve pregnancy rates for dairy heifers.     

Improved synchrony of estrus and ovulation with the addition of GnRH to a melengestrol acetate-prostaglandin F2alpha synchronization treatment in beef heifers

The objective of this experiment was to determine the effect of a GnRH injection within a melengestrol acetate (MGA)-PGF2alpha (PGF) estrus synchronization protocol on follicular dynamics and synchronization of estrus. Pubertal crossbred beef heifers (n = 34) were randomly assigned to one of two treatments. Both treatment groups were fed MGA (0.5 mg x hd(-1) x d(-1)) for 14 d and injected (i.m.) with PGF (25 mg of Lutalyse) 19 d after MGA withdrawal. Melengestrol acetate was delivered in a feed supplement of 1.8 kg x hd(-1) x d(-1). Seventeen heifers received an injection of GnRH (100 microg Cystorelin) 12 d after MGA withdrawal and 7 d before PGF. The control group (n = 17) received only MGA-PGF. Estrus was detected four times/d for 7 d beginning on the day PGF was injected. Transrectal ultrasonography was performed daily on eight heifers from each treatment to monitor ovarian activity and characterize changes in follicular dynamics after MGA withdrawal and until ovulation after PGF. Each of the GnRH-treated heifers either ovulated or had a luteinized dominant follicle following GnRH and subsequently initiated a new follicular wave (8/8, 100%). All GnRH-treated heifers (17/17, 100%) and 94% of controls (16/17) exhibited estrus after PGF. Estrus was exhibited over a 132-h period (12 to 144 h) for control heifers compared with 60 h (48 to 108 h) for GnRH-treated heifers. The peak synchronized period for both treatments was between 48 and 72 h after PGF, during which time 76% (13/17) of the GnRH-treated heifers exhibited estrus compared with 63% (10/16) for controls. Seventy-one percent (12/17) of the GnRH-treated heifers exhibited estrus from 48 to 60 h after PGF, compared with 38% (6/16) for controls (P < 0.05). In summary, injection of GnRH within a 14- to 19-d MGA-PGF protocol increased the synchrony of estrus during the synchronized period and concentrated the period of detected estrus. This protocol may offer potential for the fixed-time insemination of replacement beef heifers.     

应用杆状病毒载体在昆虫细胞表达马立克氏病病毒Meq基因

将源于马立克氏病病毒 ( MDV) GA株的 Meq基因克隆到杆状病毒转移载体质粒 p Blu Bac4中强有力的多角化蛋白启动子 ( PPH)之后 ,经与线性化的 Bac-N-Blue TMDNA共转染于昆虫细胞系 SF9,获得了重组杆状病毒。使用重组痘病毒表达的 Meq制备的单抗 ,对重组杆状病毒感染的 SF9细胞及其裂解物分别进行间接免疫荧光试验、Western blotting和免疫沉淀试验 ,结果发现 :( 1 )本表达系统产生的 Meq可被原制备的单抗所识别 ;( 2 )在感染细胞中 ,Meq蛋白仅局限于细胞核内 ,而且随着感染后时间的增加 ,具有从核质向核仁和核膜转移的趋向 ;( 3 ) Western blotting和免疫沉淀试验均证实重组杆状病毒感染细胞裂解物中出现有 2条特异带 ( 60 0 0 0处 )。结果表明 ,杆状病毒 /昆虫细胞系统用于表达外源蛋白是可行有效的     

Strategies for empowering the local people to participate in forest restoration

Within various parts of the tropics and temperate regions, there are increasingly more efforts towards reforestation or restoration. Interventions in the tropics however, have not adequately addressed the needs of local people compelling them to degrade forests. We conducted a study in and around Mabira Forest Reserve in Uganda with the aim of assessing locally proposed restoration techniques and conditions for empowering local people to raise their willingness to participate in forest restoration practices. We specifically set out to; (i) identify proposed techniques to restore the degraded forests, and (ii) determine the pre-conditions for supporting local people’s participation in restoration activities. Data were collected using individual semi-structured interviews, focus group discussions and participatory forest surveys. The findings show that the local people mainly engaged in practices that address their needs concurrently. The most reported practices include: planting trees on farm, enrichment tree planting in the forest, control of soil erosion, and control of invasive alien species. The main pre-conditions for their participation in forest restoration is assurance for more access to forest resources. The efficiency of local people in restoration will be enhanced by strengthening their capacity for collaborative forest management, raising their awareness on restoration, building their capacity, as well as continuous monitoring by forest managers.