Estimates of the leaf area of forage peanut for use in morphogenetic assessment

Understanding the morpho-physiological responses of forage plants is critical for successfully managing pastures; however, there is no specific method for morphogenetically assessing Arachis pintoi. The present study aimed to develop and validate mathematical models to estimate leaf area in A. pintoi to enable assessments of leaf elongation and senescence. Two experiments were performed. The first experiment used 500 A. pintoi leaves to model leaf area. Three models were used: correlation, mechanistic and empirical. A total of 336 leaflets were collected to validate the models. For the second experiment, 786 leaflet pairs were collected to test the leaf symmetry. Leaf length (L), width (W) and area (A) were measured for each leaflet in both of the experiments. The model identity test was used. The leaflet area can be estimated using the following formula:  = W ×L × 0·25 × π. Experiment 2 showed that the initial leaflet pairs were equal, as were the terminal leaflet pairs. In conclusion, the mechanistic model should be used to estimate the leaf area for A. pintoi, and only half of each leaf can be measured.     

Impact of 24-h Cooling Prior to Freezing on the Survival of Domestic Cat (Felis catus) Epididymal Sperm

The aim of this study was to investigate the impact of a 24-h cooling period prior to freezing on domestic cat epididymal sperm viability. Fifteen tomcats were submitted to routine orchiectomy and sperm samples were retrieved from both epididymides in a Tris–glucose–20% egg yolk extender. For each tomcat, the diluted sperm was split into two equal volumes and cooled to 5°C at a rate of 0.5°C/min; one sample for 60 min (control) and the other for 24 h (cooled). After the cooling period, samples from both groups were frozen using an identical freezing protocol. Sperm samples were evaluated in three different periods: immediately after harvesting, after cooling at 5°C for 24 h (cooled group) and after freezing–thawing of control and cooled groups. Evaluations consisted of sperm motility and progressive status, sperm morphology and plasma membrane integrity (PMI) using two fluorescent probes. After cooling for 24 h, a decrease (p < 0.05) in sperm motility, progressive status and PMI was observed when compared to sperm samples immediately after collection. Comparing the results obtained after thawing, no difference (p < 0.05) was found regarding sperm motility, progressive status, PMI and sperm morphology between control and cooled groups. The results from the present study show that cooling cat epididymal spermatozoa at 5°C for 24 h prior to freezing does not lead to major damage of spermatozoa impairing the freeze–thaw process.     

Analysis of the mouse high-growth region in pigs

In the mouse, homozygous animals for the high growth mutation show a 30–50% increase in growth without becoming obese. This region is homologous to the distal part of pig chromosome 5 (SSC5). A previous genome scan detected several quantitative trait loci (QTL) in this region for body composition and meat quality using a three generation Berkshire × Yorkshire resource family. In this study, the effects on swine growth, fat and meat quality traits of three genes previously identified within the mouse high growth region were analysed. The genes studied were CASP2 and RIPKI domain containing adaptor with death domain ( CRADD ), suppressor of cytokine signalling 2 ( SOCS2 ) and plexinC1 ( PLXNC1 ). In addition, the influence of two other genes located very close to this region, namely the plasma membrane calcium-transporting ATPase 1 ( ATP2B1 ) and dual specificity phosphatase 6 ( DUSP6 ) genes, was also investigated. Single nucleotide polymorphisms were identified and used to map these genes to the QTL region on SSC5. Results indicate significant associations between these genes and several phenotypic traits, including fat deposition and growth in pigs. The present study suggests associations of these genes with swine fat and growth related traits, but further studies are needed in order to clearly identify the genes involved in the regulation of the QTL located on SSC5.     

Fertilizing Capacity of Frozen Epididymal Sperm Collected from Dogs

The collection of epididymal sperm may be a valuable tool for canine reproduction especially since it can enable collection of cells after death of a valuable dog. The aim of the present study was to evaluate the viability of epididymal sperm after freeze-thawing. Epididymides were obtained from four adult dogs by elective orchiectomy. The caudal portion of the epididymides and part of the deferential ducts were squeezed by means of an anatomic clamp into a Petri dish containing either 0.9% saline solution (Group 1) or Ringer solution without lactate (Group 2). Samples were centrifuged at 800 ×  g for 10 min, the supernatant was removed and the pellet was diluted in one step with a Tris/citric acid/OEP (Orvus Es Paste) extender containing 7% glycerol and subjected to semen freezing. Oocytes were obtained from canine ovaries, after ovariohysterectomy. Only oocytes that were approximately 100 μm in diameter, with a dark ooplasm surrounded by three- or four-well formed cumulus cell layers were used for sperm testing. Frozen semen samples were thawed in a water bath at 70°C for 8 s and analysed at room temperature for sperm motility and velocity. Oocytes were incubated with spermatozoa in humidified atmosphere containing 5% CO₂ at 38°C for 18 h. Morphological and functional characteristics of spermatozoa were similar in both groups. However, the percentage of sperm cells bound to oocytes was significantly higher in Group 2 than in Group 1. This result suggests that the Ringer solution without lactate was a more suitable medium for collecting epididymal canine sperm than 0.9% saline.     

Modeling genetic differences of combined broiler chicken populations in single-step GBLUP

The introduction of animals from a different environment or population is a common practice in commercial livestock populations. In this study, we modeled the inclusion of a group of external birds into a local broiler chicken population for the purpose of genomic evaluations. The pedigree was composed of 242,413 birds and genotypes were available for 107,216 birds. A five-trait model that included one growth, two yield, and two efficiency traits was used for the analyses. The strategies to model the introduction of external birds were to include a fixed effect representing the origin of parents and to use unknown parent groups (UPG) or metafounders (MF). Genomic estimated breeding values (GEBV) were obtained with single-step GBLUP using the Algorithm for Proven and Young. Bias, dispersion, and accuracy of GEBV for the validation birds, that is, from the most recent generation, were computed. The bias and dispersion were estimated with the linear regression (LR) method,whereas accuracy was estimated by the LR method and predictive ability. When fixed UPG were fit without estimated inbreeding, the model did not converge. In contrast, models with fixed UPG and estimated inbreeding or random UPG converged and resulted in similar GEBV. The inclusion of an extra fixed effect in the model made the GEBV unbiased and reduced the inflation. Genomic predictions with MF were slightly biased and inflated due to the unbalanced number of observations assigned to each metafounder. When combining local and external populations, the greatest accuracy can be obtained by adding an extra fixed effect to account for the origin of parents plus UPG with estimated inbreeding or random UPG. To estimate the accuracy, the LR method is more consistent among scenarios, whereas the predictive ability greatly depends on the model specification.     

Effect of floor cooling and dietary amino acids content on performance and behaviour of lactating primiparous sows during summer

Fifty nine primiparous sows PIC Camborough 23 were distributed in a completely randomized 2 × 2 (with and without floor cooling × two dietary treatments) factorial design with 16 sows/treatment, each sow being considered as an experimental unit. Four replicates of sixteen sows each were used during the trial with the objective of evaluating the effects of floor cooling and the use of dietary amino acid contents on their performance and behaviour during summer. The sows were distributed among the treatments according to body weight and backfat thickness after farrowing. The sows were maintained in the experiment until weaning at 21 days of lactation. The two experimental diets supplied the same levels of crude protein (22%), metabolizable energy (ME; 14.65 MJ/kg) and levels of essential digestible AA relative to digestive lysine and differed according to the digestible lysine to ME ratio (0.75 vs. 0.82 g/MJ of ME). The temperature of the water circulating in the cooled floor was maintained at about 17 °C. Based on the average minimum and maximum temperatures (21.5 and 29.5 °C) obtained during the experimental trial, it can be assumed that the sows were exposed to periods of heat stress. The replicate and the interaction between replicate and treatment effects on all the measurements were not significant. Similarly, no effect of diet or interaction between diet and floor cooling system was found for all criteria measured. An effect (P < 0.05) of floor cooling on average daily feed intake was observed and floor cooling sows showed a higher average (P < 0.05) digestible lysine (61.5 vs. 51.8 g/d) and ME (78.2 vs. 65.9 MJ/d) intakes. The sows submitted to floor cooling showed, consistently, higher absolute values for average weight (+ 8.5 kg) and backfat (+ 0.75 mm) at weaning, compared with the control sows. The sows submitted to the cooled floor showed a shorter (P < 0.01) weaning-to-oestrus interval. The piglet and litter's daily weight gain (DWG), average weight at weaning (AWW) and total weight gain during lactation (TWG) were higher (P < 0.01) for the floor cooling sows. The floor cooling sows showed a higher (P < 0.01) daily milk production. The respiratory rate and rectal temperature values were lower (P < 0.01) for the floor cooling sows. There were differences (P < 0.01) on the cutaneous temperatures measured on the different parts of the sow's body, with the animals submitted to the cooled floor having lower values. The sows submitted to floor cooling spent less (P < 0.01) time in lateral recumbency inactive, more time nursing (P < 0.05) and more time feeding (P < 0.01) compared with control sows. The floor cooling under the sows increased daily feed intake and lysine intake, leading to a lower body weight loss, a lower weaning-to-oestrus interval and also improved nursing behaviour of the sows, leading to a higher milk production and, consequently, higher weight gains of piglets and litter during the lactation period.     

Experimental assessment of the contribution of plant root respiration to the emission of carbon dioxide from the soil

The contributions of root and microbial respiration to the total emission of CO₂ from the surface of gray forest and soddy-podzolic soils were compared under laboratory and field conditions for the purpose of optimizing the field version of the substrate-induced respiration method. The magnification coefficients of respiration upon the addition of saccharose (k _mic) were first determined under conditions maximally similar to the natural conditions. For this purpose, soil cleared from roots was put into nylon nets with a mesh size of 40 μm to prevent the penetration of roots into the nets. The nets with soil were left in the field for 7–10 days for the compaction of soil and the stabilization of microbial activity under natural conditions. Then, the values of k _mic were determined in the root-free soil under field conditions or in the laboratory at the same temperature and water content. The contribution of root respiration as determined by the laboratory version of the substrate-induced respiration method (7–36%) was lower compared to two field versions of the method (27–60%). Root respiration varied in the range of 24–60% of the total CO₂ emission from the soil surface in meadow ecosystems and in the range of 7–56% in forest ecosystems depending on the method and soil type.     

Antiproliferative Activity of Fucan Nanogel

Sulfated fucans comprise families of polydisperse natural polysaccharides based on sulfated L-fucose. Our aim was to investigate whether fucan nanogel induces cell-specific responses. To that end, a non toxic fucan extracted from Spatoglossum schröederi was chemically modified by grafting hexadecylamine to the polymer hydrophilic backbone. The resulting modified material (SNFuc) formed nanosized particles. The degree of substitution with hydrophobic chains was close to 100%, as estimated by elemental analysis. SNFfuc in aqueous media had a mean diameter of 123 nm and zeta potential of −38.3 ± 0.74 mV, as measured by dynamic light scattering. Nanoparticles conserved their size for up to 70 days. SNFuc cytotoxicity was determined using the MTT assay after culturing different cell lines for 24 h. Tumor-cell (HepG2, 786, H-S5) proliferation was inhibited by 2.0%–43.7% at nanogel concentrations of 0.05–0.5 mg/mL and rabbit aorta endothelial cells (RAEC) non-tumor cell line proliferation displayed inhibition of 8.0%–22.0%. On the other hand, nanogel improved Chinese hamster ovary (CHO) and monocyte macrophage cell (RAW) non-tumor cell line proliferation in the same concentration range. The antiproliferative effect against tumor cells was also confirmed using the BrdU test. Flow cytometric analysis revealed that the fucan nanogel inhibited 786 cell proliferation through caspase and caspase-independent mechanisms. In addition, SNFuc blocks 786 cell passages in the S and G2-M phases of the cell cycle.