Seed Shattering of Cañahua (Chenopodium pallidicaule Aellen)

Cañahua (Chenopodium pallidicaule Aellen) is a semi‐domesticated relative of quinoa (Chenopodium quinoa Willd.) with high nutritious quality. It is tolerant to frost, drought, saline soils and pests. One seed yield limitation is seed loss during the maturity stages. Two greenhouse experiments in Denmark and field experiments in Bolivia were carried out to determine seed shattering in landraces and cultivars with different growth habits. 15–21 % of the seed shattering in the fields took place whilst the plants still were flowering and 25–35 % during physiological maturity. Seed shattering varied between locations on the Bolivian Altiplano. Cañahua types with the semi‐prostrate growth (‘lasta’) had the highest seed shattering rate in the greenhouse experiments. The Umacutama landrace had lower seed shattering (1 %) than the cultivar Kullaca (7.2 %) both of the ‘lasta’ type. Under field conditions, the cultivar Illimani with the erect growth (‘saihua’) had the highest seed shattering rate (6.4–33.7 %) at both locations and at four different sowing dates. The Umacutama had the lowest rate (0.5–1.5 %). There were no significant differences between plants of the ‘lasta’ and the ‘saihua’ types. The landrace had significantly less seed loss than the cultivars. However, in the greenhouse, the landrace yield was approximately 25 % lower than the yields of the cultivars. In general, cañahua cultivars had higher yield compared to landraces, but also a higher seed shattering rate. Landraces may be used in breeding programmes to develop high‐yielding cultivars with reduced seed shattering.     

The Humus Content and Soil Biological Properties as a Function of Organic and Mineral Fertilization

There is a growing recognition for the need to develop sensitive indicators of soil quality that reflect the effects of land management on soil and assist land users in promoting sustainability of agro-ecosystems. Three soil enzymes (dehydrogenase, phosphatase and invertase) microbial biomass as biological variables and soil organic matter content (SOM) were investigated relative to fertilization and soil fertility (estimated by crop yield) at a long-term fertilization trial (Keszthely, Hungary). 0-34.7-69.4-104.1t farmyard manure (FYM) ha m 1 5 yr m 1 and the corresponding amount of mineral fertilizers (NPK) were applied in two different crop rotation systems. There were four straw and/or stalk incorporating treatments in the second crop rotation 'B'. Enzyme activities, microbial biomass and the amount of SOM were generally higher in the fertilized soils than in the unfertilized soils. The type of amendments (mineral, FYM or mixed) had significant effects only on the amount of SOM. The correlations among the biological variables and the crop yield were generally low (r < 0.250. The differences in field management resulted only in the invertase activity.     

Emerging issues in genomic selection

Genomic selection (GS) is now practiced successfully across many species. However, many questions remain, such as long-term effects, estimations of genomic parameters, robustness of genome-wide association study (GWAS) with small and large datasets, and stability of genomic predictions. This study summarizes presentations from the authors at the 2020 American Society of Animal Science (ASAS) symposium. The focus of many studies until now is on linkage disequilibrium between two loci. Ignoring higher-level equilibrium may lead to phantom dominance and epistasis. The Bulmer effect leads to a reduction of the additive variance; however, the selection for increased recombination rate can release anew genetic variance. With genomic information, estimates of genetic parameters may be biased by genomic preselection, but costs of estimation can increase drastically due to the dense form of the genomic information. To make the computation of estimates feasible, genotypes could be retained only for the most important animals, and methods of estimation should use algorithms that can recognize dense blocks in sparse matrices. GWASs using small genomic datasets frequently find many marker-trait associations, whereas studies using much bigger datasets find only a few. Most of the current tools use very simple models for GWAS, possibly causing artifacts. These models are adequate for large datasets where pseudo-phenotypes such as deregressed proofs indirectly account for important effects for traits of interest. Artifacts arising in GWAS with small datasets can be minimized by using data from all animals (whether genotyped or not), realistic models, and methods that account for population structure. Recent developments permit the computation of P-values from genomic best linear unbiased prediction (GBLUP), where models can be arbitrarily complex but restricted to genotyped animals only, and single-step GBLUP that also uses phenotypes from ungenotyped animals. Stability was an important part of nongenomic evaluations, where genetic predictions were stable in the absence of new data even with low prediction accuracies. Unfortunately, genomic evaluations for such animals change because all animals with genotypes are connected. A top-ranked animal can easily drop in the next evaluation, causing a crisis of confidence in genomic evaluations. While correlations between consecutive genomic evaluations are high, outliers can have differences as high as 1 SD. A solution to fluctuating genomic evaluations is to base selection decisions on groups of animals. Although many issues in GS have been solved, many new issues that require additional research continue to surface.     

Comparative pharmacokinetics and pharmacokinetic/pharmacodynamic analysis by nonlinear mixed‐effects modeling of cefquinome in nonpregnant,pregnant, and lactating goats after intravenous and intramuscular administration

Cefquinome is a fourth‐generation cephalosporin that is used empirically in goats. Different physiologic factors like pregnancy or lactation could determine the pharmacokinetic behavior of drugs in the organism. The objectives of this study are to (a) compare the pharmacokinetics of cefquinome after intravenous and intramuscular administration in adult nonpregnant (n = 6), pregnant (n = 6), and lactating goats (n = 6), at a dose of 2 mg/kg, with rich sampling by nonlinear mixed‐effects modeling, (b) conduct a pharmacokinetic/pharmacodynamic analysis to evaluate the efficacy of the recommended posology in goats with different physiological states, and (c) determine the optimal posology that achieve a PTA value ≥ 90%, taking into account a T > MIC ≥ 60% of a MIC value ≤ 0.25 µg/ml, in the different subpopulations of goats for both routes. Gestation significantly increased Ka and V1, while reduced F0, Cl, and Q. On the other hand, lactation significantly increased V1 and reduced Tk0. Cefquinome concentrations achieved in placental cotyledon, amniotic fluid, and fetal serum indicate a minimal penetration across the placental barrier. Moreover, milk penetration of cefquinome was minimal. The total body clearance of cefquinome for goats was 0.29 L kg^?1 hr^?1, that is apparently higher than the reported for cows (0.13 L kg^?1 hr^?1) and pigs (0.16 L kg^?1 hr^?1). So, the optimal dose regimen for cefquinome after intravenous and intramuscular administration required higher dose and frequency of administration compared with recommendations for cows or pigs. Therefore, 2 mg kg^?1 8 hr^?1 and 5 mg kg^?1 12 hr^?1 could be used for IV and IM routes, respectively, for the treatment of respiratory infections caused by P. multocida and M. haemolytica, but only 5 mg kg^?1 12 hr^?1 by both routes should be recommended for Escherichia coli infections.     

Swine viscera preservation in hypersaturated salt solution after alcohol fixation as a preparation method for educational purposes

The use of live animals for educational purposes is an old practice that is still employed in teaching and research institutions. However, there are several objections to this practice, whether for ethical or humanitarian reasons. Surgical techniques teaching using anatomical pieces and/or preserved cadavers promotes greater learning efficiency, provides exercise repetition and increases the confidence and satisfaction of the students when compared to the use of live animals. The current work aimed to analyse the feasibility of using fresh swine urinary bladder and small intestines (jejunum), obtained from slaughterhouses, fixed in 99.8% ethyl alcohol (EA) and preserved in sodium chloride hypersaturated solution (SCHS) at 30%, for 7, 14 and 21 days, as an alternative method for surgical skills training (SST). Swine viscera, fixed in EA and preserved in SCHS, presented a realistic appearance, absence of odour and maintained the viable morphological characteristics during the performance of the operative techniques. Preservation solutions had low cost, were easy to acquire and did not offers risks to human health. Therefore, urinary bladders and small intestines fixed in 99.8% EA for 30 days and maintained in 30% SCHS at different periods were demonstrated as a good viable option as a preservation method for surgical skills training.     

Evaluation of functional muscle anatomy scalability in the canine hind limb

In contrast to other mammals, the large variation in dog sizes is not accompanied by any significant genetic re-organization. In order to study the relationship between body mass, limb length and the functional anatomical muscle parameters of the canine hind limb, a large dataset comprising of muscle masses, optimal muscle fibre lengths and physiological cross-sectional area's (PCSA) were acquired for twenty-five muscles in ten dogs of sizes varying between 20 kg and 52 kg. The potential of body mass and limb length for reliably scaling individual muscle masses, optimal muscle fibre lengths and PCSA's were examined. For the majority of the muscles of the canine hind limb, neither body mass nor limb length were reliable scaling parameter for either muscle masses, PCSA's and optimal fibre length. These results indicate the need of a breed-specific approach to musculoskeletal modelling in future canine musculoskeletal research.     

The effect of photoperiod and melatonin on plasma prolactin concentrations in female guanaco (Lama guanicoe) in captivity

The present study examined the effects of different photoperiods and melatonin treatment on plasma prolactin concentrations in guanacos, a South American camelid, in captivity. Fourteen adult female guanacos, not gestating or lactating and isolated from males, were studied. The control group was exposed to natural daylight, during short days (N = 7, 10L:14D) and long days (N = 7, 16L:8D). The treatment group (N = 7, 10L:14D) received melatonin implants every 23 days for 6 weeks during long days. Blood samples were taken at intervals of 1 week for 3 weeks, starting the third week of treatment. Prolactin concentrations were measured using competitive ELISA. Plasma concentrations of prolactin in non-lactating female guanacos have seasonal changes, with a higher concentration (p < .001) in short days (3.50 ± 2.24 ng/ml) than long days (1.10 ± 0.91 ng/ml). Melatonin treatment significantly decreases (p < .05) plasma concentrations of prolactin on the 21st day after the treatment. These findings are the first report of an endogenous circannual rhythm of plasma prolactin concentration and the action of melatonin treatment on prolactin secretion in this wild camelid.     

Use of dimethylformamide to cryopreserve alpaca semen previously incubated with collagenase

The objective of this study was to evaluate the effect of collagenase and two final dimethylformamide (DMF) concentrations (4% and 7%) on alpaca frozen-thawed sperm quality. A total of 25 ejaculates from 5 alpaca were obtained using electroejaculation. Each individual ejaculate was evaluated and then diluted 4:1 in a solution of 1 mg/ml collagenase in HEPES-TALP medium and incubated for 4 min at 37°C. Subsequently, samples were diluted in TRIS-fructose-citric acid-egg yolk and cooled to 5°C. Then, each sample was divided in two aliquots and DMF at final concentration of 4% or 7% was added, equilibrated for 1 hr at 5°C and frozen over liquid nitrogen vapours. A Kruskal–Wallis test was used to evaluate the sperm morphometry, and Completely Random Block designs were used to analyse sperm motility, viability, membrane function and acrosome status. After collagenase incubation, none of the samples showed thread formation, and sperm parameters were preserved. Non-progressive motile sperm were higher (p < .05) in equilibrated samples (4% DMF: 31.8 ± 8.3% and 7% DMF: 36.3 ± 11.8%) compared to raw (10.1 ± 4.3%) and frozen-thawed semen (4% DMF: 9.7 ± 1.8% and 7% DMF: 7.5 ± 3.2%). Sperm membrane function, membrane integrity and intact acrosomes were higher (p < .05) in raw semen (40.1 ± 12.2%, 94.6 ± 3.2% and 91.3 ± 8.1%) compared to frozen-thawed samples (4% DMF: 19.8 ± 4.7%, 53.2 ± 2.7%, 65.7 ± 8.7% and 7% DMF: 20.4 ± 4.5%, 54.1 ± 1.4%, 64.6 ± 9.1%). Length of the sperm head was lower in frozen-thawed samples, being statistically different with 4% DMF compared to pre-freezing samples. The ratio between acrosome and head areas was greater (p < .05) in frozen-thawed samples. Incubation of raw alpaca semen with collagenase decreased the thread formation without affecting sperm quality. Frozen of collagenase treated alpaca semen with 4% or 7% DMF did not preserve the sperm parameters in thawed samples.