Vitrification with Glutamine Improves Maturation Rate of Vitrified / Warmed Immature Bovine Oocytes

The current study examined the protective effects of l ‐glutamine and cytochalasin B during vitrification of immature bovine oocytes. Oocyte vitrification solution (PBS supplemented with 10% FCS, 25% EG, 25% DMSO and 0.5 m trehalose) was the vitrification control. Treatments were the addition of 7 μg/ml cytochalasin B, 80 mm glutamine or both cytochalasin and glutaminine for 30 s. After warming, oocytes were matured in vitro for 24 h, fixed and stained with Hoechst (33342) for nuclear maturation evaluation. l ‐glutamine improved the vitrified/warmed immature bovine oocytes viability (32.8%), increasing the nuclear maturation rates compared to other treatments and the no treatment vitrified control (17.4%). There was, however, no effect of cytochalasin B on in vitro maturation (14.4%).     

Growth response of 98 barley (Hordeum vulgare L.) genotypes to elevated CO2 and identification of related quantitative trait loci using genome‐wide association studies

Elevated CO₂ (eCO₂) concentrations can stimulate crop growth, but little is known about intraspecific variability in the response to eCO₂ and the underlying genetics in cereals. Field experiments over two years with 98 barley genotypes were conducted in open‐top chambers (OTCs) under ambient CO₂ (400 ppm) and eCO₂ (700 ppm) concentrations. At crop maturity, different fractions of aboveground biomass (AGB) were measured, and genome‐wide association studies (GWASs) were conducted to identify quantitative trait loci (QTL). Averaged across all genotypes, eCO₂ significantly enhanced AGB by 15%, while the increase in culm and ear biomass alone was not significant. The AGB response to eCO₂ of the individual genotypes ranged from c. ?36% to +95% compared with ambient CO₂ (aCO₂), showing a large variability of growth responses. In GWAS, 51 associations between SNP markers and the relative changes (eCO₂/aCO₂) in biomass were detected on different chromosomes. Loci potentially involved in biomass alterations under eCO₂ were identified. The wide range of variability in responses might be exploited by marker‐based breeding for climate‐resilient barley.     

Pregnancy Rates to Fixed Embryo Transfer of Vitrified IVP Bos indicus,Bos taurus or Bos indicus × Bos taurus Embryos

The pregnancy rates obtained after the transfer of cryopreserved in vitro‐produced (IVP) embryos are usually low and/or inconsistent. The objective of this study was to evaluate the pregnancy rates of Holstein, Gyr and Holstein × Gyr cattle after the transfer of vitrified IVP embryos produced with X‐sorted sperm. Seventy‐two Gyr and 703 Holstein females were subjected to ovum pickup (OPU) sessions, followed by in vitro embryo production using semen from sires of the same breeds. Embryos (1636 Holstein, 241 Gyr and 1515 Holstein × Gyr) were exposed to forskolin for 48 h prior to vitrification. The pregnancy rate achieved with Gyr dam and sire was 46.1%, which was similar (p = 0.11) to that of Holstein dam and Gyr sire (40.3%). Crossing Gyr dams with Holstein sires resulted in a pregnancy rate of 38.9% and did not differ (p = 0.58) from the pregnancy rate obtained with the cross between Holstein dams and Gyr sires. The rate obtained with Holstein dam and sire was 32.5%. The average pregnancy rate was 36.6%, and no difference was found in the proportion of female foetuses (88.8%, in average) among breeds (p > 0.05). In conclusion, transfer of cryopreserved X‐sorted embryos represents an interesting choice for dairy cattle. Despite the small differences between pregnancy rates, we highlight the efficiency of this strategy for all of the racial groups studied.     

New compounds active against resistant cattle ticks (Boophilus spp.): Relationship between structure and activity within the group of cyclic amidines

A series of cyclic amidines is described, many of which are highly active against resistant cattle ticks, Boophilus spp. The preferred compound is clenpyrin, 1-butyl-2-(3,4-dichlorphenylimino)pyrrolidine which paralyses the cattle ticks and inhibits their egg-production.     

Pathological investigations of pigs with porcine multisystemic wasting syndrome (PMWS)

Extract

Pathological changes and immunohistochemical (IHC) examination for porcine circovirus-2 (PCV-2) in nine weaner pigs from a property with PMWS are reported. The pigs were in moderate to poor body condition, and several had diarrhoea and noisy respiration. The outstanding pathological changes related to microscopic lesions in lymphoid tissues, including lymph nodes, palatine tonsils, Peyer's patches, peribronchial lymphoid aggregates and spleen. While there was variability of expression of change between and within cases, the main features of lesions could be summarised as depletion of lymphoid cells, infiltration of histiocytes (often syncytial), and the presence of botryoid intra-cytoplasmic inclusion bodies in macrophages. The changes in lymphoid tissue were typical of those described in PMWS. Also characteristic of this syndrome were histiocyte-dominated cellular inflammatory infiltrates in kidney, liver and lung. There was strong correlation between IHC positivity for PCV-2 and the lesions in lymphoid, pulmonary and renal tissues. Concurrent diseases that are probably promoted by immune suppression may complicate the diagnosis of PMWS. In the present cases, salmonellosis, attaching and effacing Escherichia coli infections, and secondary bacterial bronchopneumonia were identified.     

Corn growth and nitrogen nutrition after additions of biochars with varying properties to a temperate soil

The effects of biochar properties on crop growth are little understood. Therefore, biochar was produced from eight feedstocks and pyrolyzed at four temperatures (300°C, 400°C, 500°C, 600°C) using slow pyrolysis. Corn was grown for 46 days in a greenhouse pot trial on a temperate and moderately fertile Alfisol amended with the biochar at application rates of 0.0%, 0.2%, 0.5%, 2.0%, and 7.0% (w/w) (equivalent to 0.0, 2.6, 6.5, 26, and 91 t biochar ha⁻¹) and full recommended fertilization. Animal manure biochars increased biomass by up to 43% and corn stover biochar by up to 30%, while food waste biochar decreased biomass by up to 92% in relation to similarly fertilized controls (all P < 0.05). Increasing the pyrolysis temperature from 300°C to 600°C decreased the negative effect of food waste as well as paper sludge biochars. On average, plant growth was the highest with additions of biochar produced at a pyrolysis temperature of 500°C (P < 0.05), but feedstock type caused eight times more variation in growth than pyrolysis temperature. Biochar application rates above 2.0% (w/w) (equivalent to 26 t ha⁻¹) did generally not improve corn growth and rather decreased growth when biochars produced from dairy manure, paper sludge, or food waste were applied. Crop N uptake was 15% greater than the fully fertilized control (P < 0.05, average at 300°C) at a biochar application rate of 0.2% but decreased with greater application to 16% below the N uptake of the control at an application rate of 7%. Volatile matter or ash content in biochar did not correlate with crop growth or N uptake (P > 0.05), and greater pH had only a weak positive relationship with growth at intermediate application rates. Greater nutrient contents (N, P, K, Mg) improved growth at low application rates of 0.2% and 0.5%, but Na reduced growth at high application rates of 2.0% and 7.0% in the studied fertile Alfisol.