Manual Rupture Versus Transvaginal Ultrasound-guided Aspiration of Allanto-amniotic Fluid in Multiple Pregnancies: A Clinical Approach to Embryo Reduction in Dairy Cattle

To avoid the problems associated with twinning in dairy cattle, one of the embryos may be eliminated. This study compares the effect on pregnancy maintenance of two embryo reduction techniques, manual rupture (MR) and transvaginal ultrasound-guided aspiration (TUGA) of allanto-amniotic fluid, in Holstein-Friesian cows with multiple pregnancies. In the first experiment, 61 lactating cows bearing unilateral twins (n=27), bilateral twins (n=30) or triplets/quadruplets (n=4) were subjected to MR (n=45) or TUGA using a 17-G neddle (n=16) on day 28-34 of gestation. In 21 and 10 cows undergoing MR and TUGA embryo reduction, respectively, pregnancy loss occurred before day 90 (46.7 vs. 62.5%, P= 0.28). Through binary logistic regression, the type of pregnancy was identified as the only variable significantly affecting pregnancy maintenance (P=0.03). Based on the odds ratio, the risk of pregnancy loss was 4.1 times higher for unilateral twins than for bilateral twins (70.4 vs. 36.7%, respectively, P=0.01). No effect was detected on pregnancy maintenance of the technique used (P=0.17) or of the interaction technique by type of pregnancy (P=0.22). In the second experiment, a 22-G needle was used to perform TUGA on 22 lactating cows. The pregnancy loss rates were 44.4% (4/9), 18.2% (2/11) and 50% (1/2) for cows bearing unilateral twins, bilateral twins and triplets, respectively. The total pregnancy loss rate following TUGA using the 22-G needle tended to be lower than that using the 17-G needle (31.8 vs. 62.5%; P=0.06). Our results suggest that TUGA using a 22-G needle could be the method of choice to perform embryo reduction in cows carrying multiple pregnancies.     

Understanding forest transition in the Philippines: main farm-level factors influencing smallholder’s capacity and intention to plant native timber trees

The ‘when, where and how’ of decisions by smallholder upland farmers to plant trees as part of their use of natural, human and capital resources needs to be understood if policy support is to result in actual recovery of tree cover as part of a ‘forest transition’ trajectory. In large parts of the Philippines the turning point may be close. Data on resource access and tree planting decisions were gathered from a household survey, with a total of 148 respondents in four rural communities in Leyte Province in Central Philippines. Data were analysed using logistic regression analysis. Household-level results reveal that the outcomes of the decision-making processes primarily depend on the availability of land and access to remaining forest resources rather than socio-cultural or economic factors. The total area of land and number of parcels managed by the household plus security of land tenure through ownership was found to have a statistically significant effect on farmers’ decision to plant native timber trees. Access to surrounding natural forest is negatively associated with farmer tree planting.     

Evaluation of Nociception,Sedation, and Cardiorespiratory Effects of a Constant Rate Infusion of Xylazine Alone or in Combination with Lidocaine in Horses

This study aimed to evaluate the effects of a constant rate infusion (CRI) of xylazine or xylazine in combination with lidocaine on nociception, sedation, and physiologic values in horses. Six horses were given intravenous (IV) administration of a loading dose (LD) of 0.55 mg/kg of xylazine followed by a CRI of 1.1 mg/kg/hr. The horses were randomly assigned to receive three treatments, on different occasions, administered 10 minutes after initiation of the xylazine CRI, as follows: control, physiologic saline; lidocaine low CRI (LLCRI), lidocaine (LD: 1.3 mg/kg, CRI: 0.025 mg/kg/min); and lidocaine high CRI (LHCRI), lidocaine (LD: 1.3 mg/kg, CRI: 0.05 mg/kg/min). A blinded observer assessed objective and subjective data for 50 minutes during the CRIs. In all treatments, heart and respiratory rates decreased, end-tidal carbon dioxide concentration increased, and moderate to intense sedation was observed, but no significant treatment effect was detected in these variables. Ataxia was significantly higher in LHCRI than in the control treatment at 20 minutes of infusion. Compared with baseline values, nociceptive threshold increased to as much as 79% in the control, 190% in LLCRI, and 158% in LHCRI. Nociceptive threshold was significantly higher in LLCRI (at 10 and 50 minutes) and in LHCRI (at 30 minutes) than in the control treatment. The combination of CRIs of lidocaine with xylazine produced greater increases in nociceptive threshold compared with xylazine alone. The effects of xylazine on sedation and cardiorespiratory variables were not enhanced by the coadministration of lidocaine. The potential to increase ataxia may contraindicate the clinical use of LHCRI, in combination with xylazine, in standing horses.     

Commercial Breeding with Sexed Stallion Semen: Reality or Fiction?

Sorting stallion spermatozoa for the purpose of separating X- and Y-bearing spermatozoal populations has had significant advances in the past 10 years. However, current technology requires that the mare be close to the laboratory processing the semen. The development of procedures to cool and freeze sex-sorted sperm will be critical if this technology is to be embraced by the equine industry worldwide.     

Studying the function of ecosystem in preventing aeolian dust emission in the dryland areas of China

Aeolian dust emissions can cause many environmental hazards, like accelerating land degradation and desertification, polluting air, harming human health, and so on. The dryland areas of China (DAC) are hot spots of aeolian dust emissions. To date, many efforts have been paid to researching dust emissions processes and effects, but research studies on ecosystems' function in preventing dust emissions are still very limited. In this study, we investigated the function of DAC ecosystems in preventing dust emissions, and the corresponding driving factors through integrated wind erosion modelling system (IWEMS) modelling. The main results indicate that: (1) from 2001 to 2020, the ecosystems of DAC prevented the emission of dust ~40,554 Tg, approximately 15 times as much as the total actual dust emission (~2776 Tg); (2) the function of DAC ecosystems in preventing dust emissions was relatively strong in spring and winter; (3) grassland ecosystems had the strongest function in preventing dust emissions among all the land cover types, avoiding the emission of dust ~20,857 Tg over 2001–2020; (4) dust emission prevention function provided by the DAC ecosystems benefits almost every region of China, which provides a theoretical basis for formulating ecological compensation policies; and (5) the changes in dust emissions were dominated by wind speed in most areas of DAC.     

Biological characteristics and pathogenicity of avian Escherichia coli strains.

Fifty avian (chicken) pathogenic Escherichia coli strains (APEC) isolated from individuals suffering from omphalitis, septicaemia and swollen head syndrome, and 30 strains isolated from healthy chickens were studied regarding their biological characteristics such as serogroups, haemolysin, colicin, cytotoxin, toxin and siderophore production, adhesion capacity to in vitro cultivated cells, and absorption of Congo red dye. Serotyping demonstrated that most of the omphalitis and normal strains were untypable, whereas most of the septicaemic strains were either untypable or rough. There was no prevalent serogroup among the pathogenic strains studied. The capacity for adhesion and invasion of in vitro cultured cells (HeLa, HEp-2, KPCC), as well as the agglutination of different types of red blood cells and the LD50 of each strain were also evaluated. No correlation was observed between the biological characteristics and pathogenicity, except that colicin was characteristically produced by swollen head syndrome E. coli strains. No correlation was found between adhesion or haemagglutination patterns and pathogenicity. Only six of the 50 strains revealed invasive capacity and the strain that best invaded the cell lines was the one with the lowest LD50.