Variations in clinical presentation and anatomical distribution of gross lesions of African swine fever in domestic pigs in the southern highlands of Tanzania: a field experience

African swine fever is a contagious viral disease responsible for up to 100% mortality among domestic pigs. A longitudinal study was carried out to determine the clinical presentation and anatomical distribution of gross lesions in affected pigs in Mbeya region, Tanzania during the 2010 to 2014 outbreaks. Data were collected during clinical and postmortem examination by field veterinarians and using a structured questionnaire. A total of 118 respondents (100%) showed awareness about African swine fever. During previous outbreaks, the mortality rate was almost 100%, while in 2014 it was estimated to be less than 50%.The clinical picture of the 2010–2012 outbreaks was characterized by high fever, depression, inappetance, mucosal congestion, hemorrhages, erythematous lesions in different body parts, and abortion. Several internal organs including the kidneys, spleen, and liver were congested and edematous. During the 2014 outbreak, a number of pigs (49.7%) were asymptomatic when brought to slaughter slabs but were found to have African swine fever gross lesions at postmortem examination as compared to 12.3% in 2010–2012. Bluish discoloration, which is normally distributed on the non-hairy parts of the body, was not apparent in some pigs except at postmortem examination. Some pigs (36.1%) presented nasal and/or oral bloody discharges which were uncommon (9.1%) during previous outbreaks. Moreover, other gross features included enlarged dark red renal lymph nodes and spleen. Clinical signs such as anorexia, diarrhea, and pyrexia were mainly observed when affected pigs reached moribund stage. The majority of pregnant sows died without presenting abortions. In some litters, suckling piglets (3–6 weeks) survived from the disease. These findings indicated that in 2014, African swine fever outbreak in Mbeya region was characterized by a different clinical picture.     

The combined effects of the provision of feed and healthcare on nutrient utilization and growth performance of sheep during the early or late dry season

An on-farm study was conducted to determine the combined effects of the provision of feed and healthcare on nutrient use and growth performance of sheep during the early or late dry season. A total of 36 smallholder sheep farmers with a flock size of ≤7 was randomly selected within each of the three administrative regions in Northern Ghana. The sheep grazed on a heterogeneous natural pasture and offered crop residues as basal diet (control) or were additionally provided with a concentrate feed plus orthodox healthcare to control diseases and pests (CH) in a completely randomized block design. The provision of orthodox healthcare included scheduled control of endo- and ecto-parasites and administration of broad-spectrum antibiotics. Data was analyzed for the fixed effects of CH, season, or CH × season using the mixed model procedure of Genstats^®. The CH regimen had no effect (P = 0.098) on intake of natural pasture but pasture intake increased (P = 0.012) during the late dry season. Sheep on the CH regime had higher DM (P = 0.026) and N (P = 0.068) digestibility and improved ADG (P = 0.001) and feed conversion efficiency (P = 0.020) than those on the control. We hypothesize that improvements in growth performance of sheep on the CH regimen could be related to availability of nutrients for growth that will otherwise have been used for repair of damaged tissues caused by gastrointestinal parasites and ticks. Sheep on the CH regimen also had a higher concentration of fecal N during the late dry season when CP concentration was relatively higher than that in the early dry season (63.2 vs 60.9 g/day DM) when CP concentration of pasture was lower.     

Supplementation with linseed (<Emphasis Type="Italic">Linum usitatissimum</Emphasis>) cake and/or wheat bran on feed utilization and carcass characteristics of Arsi-Bale sheep

Thirty yearling male intact Arsi-Bale sheep with initial body weight (BW) of 15.5 ± 0.21 kg (mean ± SD) were used in 90 days feeding trial, 10 days digestibility trial followed by evaluation of carcass parameters at Bokoji, Ethiopia. The objectives were to evaluate effects of supplementation with linseed (Linum usitatissimum) cake (LSC), wheat bran (WB), and their mixtures at 2:1 and 1:2, respectively on feed intake, digestibility, daily BW gain, and carcass parameters. The five treatments included ad libitum feeding of natural pasture hay (control) and with daily supplementation of 300 g dry matter (DM) sole LSC, 2LSC:1WB mix, 1LSC:2WB mix, and sole WB. Six sheep were randomly assigned to each treatment using randomized complete-block design. Four sheep in each treatment were randomly selected and used for determination of digestibility and carcass characteristics using a completely randomized design. The intake of hay DM was higher (P < 0.001) for the non-supplemented sheep compared with the supplemented ones, but the contrary was true for total DM intake. Sheep in the control treatment lost BW (−1.5 g/day), while the supplemented ones gained 69.0–104.1 g BW/head/day. Digestibility of CP was higher (P < 0.001) for supplemented sheep as a result of higher (P < 0.001) CP intake. Slaughter weight, empty BW, and hot carcass weight were lower (P < 0.001) for sheep in the control treatment compared with the rest. Sheep supplemented with LSC and its mixtures with WB had better (P < 0.001) performance in daily BW gain than sole WB supplemented ones indicating the advantages of using supplements as mixed rations. Moreover, supplementation proved to be profitable, whereas feeding hay alone led to economic loss.     

Mexican poppy (Argemone mexicana) control in cornfield using deep learning neural networks: a perspective

Mexican poppy (Argemone mexicana) is a widespread noxious annual weed associated with crops such as corn (Zea mays L.), and this weed is persistent because it produces a seed bank. This invasive weed species must be controlled even in the dry season because Mexican poppy has a deep-reaching root system, which taps water from deep soil layers. Cases of a human death caused by Mexican poppy seeds in South Africa, India, and other Eastern countries were reported from the early years of the twentieth century. However, when weeds are controlled uniformly instead of site-specific or precision farming method across the spatially variable fields, there are environmental pollution challenges. Site-specific weed control techniques have gained interest in the precision farming community over the last years mainly because of Global Positioning System (GPS) applications, and a controlled measure of herbicides are applied where there are weeds in the field, and areas with more clusters of weeds receive the correct amount of herbicide application. Mexican poppy has prickles and is a nuisance to farmers, and herbicides represent a severe health hazard to humans due to chemical concentrations in water. For that reason, we propose the design of a site-specific weed control plan to use a row-guided robot to detect and identify weeds with accuracy, control speed timeously, and spray herbicides with a high level of precision and automation. These robotics methods are reported to be environmentally conscious, and economically efficient with less labour and management. The proposed method of deep learning neural networks, which use row-guided robots, a machine is trained on multiple images to identify weeds automatically from the main crop, and release a controlled measure of herbicides based on weed location and density, and spray weeds on-the-go upon emergence.     

Shear-wave splitting and implications for mantle flow beneath the MELT region of the east pacific rise

Shear-wave splitting across the fast-spreading East Pacific Rise has been measured from records of SKS and SKKS phases on the ocean-bottom seismometers of the Mantle Electromagnetic and Tomography (MELT) Experiment. The direction of fast shear-wave polarization is aligned parallel to the spreading direction. Delay times between fast and slow shear waves are asymmetric across the rise, and off-axis values on the Pacific Plate are twice those on the Nazca Plate. Splitting on the Pacific Plate may reflect anisotropy associated with spreading-induced flow above a depth of about 100 km, as well as a deeper contribution from warm asthenospheric return flow from the Pacific Superswell region.     

Genetic Fingerprinting of Potato Varieties from the Northwest Potato Variety Development Program

The Northwest Potato Variety Development (NWPVD) Program has released 45 improved potato varieties since 1985. Thirty-four potato varieties, four breeding clones and two advanced selections from NWPVD Program, and six commonly-grown potato varieties were fingerprinted using 32 simple sequence repeat (SSR) markers and 12,808 single nucleotide polymorphism (SNP) markers. Of 32 SSR markers, 29 exhibited significant polymorphism across all the 46 potato clones studied. A total of 143 alleles were observed with an average of 4.6 alleles per SSR marker. These markers span all 12 chromosomes of potato, with a maximum of five markers from chromosome VIII and minimum of one marker from chromosome VI. The polymorphic information content (PIC) and expected heterozygosity (H_e) of the SSR markers ranges between 0.18 to 0.75 and 0.20 to 0.78, respectively. Based on PIC, H_e, and ease of scoring, we recommend a set of eight SSR markers: STG0016, STI0004, STI0012, STI0023, STI0030, STI0033, STM1016 and STM1104 for fingerprinting NWPVD varieties. Out of 12,808 SNPs, 88.8% resulted in reliable three cluster diploid calling of which 87.8% were polymorphic. Tetraploid calling resulted in 44.2% of SNPs of which 94.5% were polymorphic. Our study provided fingerprinting resources for the NWPVD varieties and can be used in issues related to intellectual property rights, ownership, trademark and diversity analysis.     

Harvest management based on leaf stage of a tetraploid vs. a diploid cultivar of annual ryegrass

Leaf stage‐dependent defoliation is linked to the plant's physiological status and may be a more suitable criterion than time‐based intervals for harvesting forage grasses, but no reports of research with annual ryegrass (Lolium multiflorum Lam. var. westerwoldicum) were found. To address this, a 2‐year field study was carried out at Raymond, MS, on a Loring silt loam soil (fine‐silty, mixed, thermic Typic Fragiudalfs). Forage production, morphological characteristics and nutritive value responses to defoliation based on leaf stage (2, 3 and 4 leaves per tiller) and two residual stubble heights (RSH; 5 and 10 cm) of a tetraploid (“Maximus”) vs. a diploid (“Marshall”) cultivar of annual ryegrass were quantified. Forage harvested, in 2011, increased linearly as leaf stage increased from 7.3 to 8.8 Mg/ha, but during 2012 was least (7.0 Mg/ha) at 3‐leaf stage and similar at the other two leaf stages (7.6 Mg/ha). Tiller density was less for Maximus (1,191 tillers/m²) than for Marshall (1,383 tillers/m²). Leaf blade proportion decreased with increasing leaf stage and was greater by 9% for Maximus than for Marshall. Generally, forage nutritive value became less desirable with increasing leaf stage. There was a dichotomy in forage harvested and nutritive value responses, but maximum forage productivity was achieved when annual ryegrass was defoliated at the 4‐leaf stage interval.     

Influence of dietary palm oil supplementation on serum lipid metabolites, carcass characteristics, and lipid composition of carcass tissues of growing ram and ewe lambs.

The objective of this research was to determine the influence of dietary palm oil supplementation on carcass characteristics and lipid composition of tissues from growing lambs. Twenty-eight Suffolk x Hampshire lambs were weaned at 60 d of age (average 36 kg BW) and assigned to a 2 x 2 factorial arrangement consisting of diet (control [NPO] or 10.6% added dietary palm oil [PO]) and sex (ram vs ewe). The NPO diet (77% forage and 23% concentrate) contained 11.2% CP and 2.66 Mcal of ME/kg. Palm oil replaced molasses in the PO diet. Lambs were individually given ad libitum access to feed for 60 d to a final BW average of 50.1 kg. Lipid composition of the longissimus muscle and corresponding subcutaneous (s.c.) adipose tissue was determined by gas-liquid chromatography (GLC). Lambs fed PO were fatter (P less than .01) than lambs fed NPO (.77 vs .56 cm, s.c. fat). Diet had no effect on cholesterol content of lean tissue; however, feeding PO increased the saturated fatty acids of lean tissue. The s.c. fat from lambs fed PO had less (P less than .01) cholesterol (64.79 vs 89.67 mg/100 g) and more saturated fatty acids than that from lambs fed NPO. Ewes were fatter (P less than .01) than rams, yet they had less cholesterol content in the s.c. adipose tissue (68.71 vs 85.74 mg/100 g). High amounts of dietary palm oil fed to growing lambs caused changes in fatty acid deposition and cholesterol metabolism and may be a useful investigative tool to study lipid metabolism in growing ruminants.(ABSTRACT TRUNCATED AT 250 WORDS)     

Simultaneous histochemical determination of three fiber types in single sections of ovine, bovine and porcine skeletal muscle

Classification of muscle fiber types involves tedious comparisons of serial muscle tissue sections. Procedures that would incorporate pertinent histochemical properties into one simplified assay for the successful differentiation and determination of fiber types were evaluated using muscle samples from three different species (ovine, bovine and porcine). For ovine and porcine muscle tissue, the best staining procedure involved initial preincubation of the tissue section at 4.35 (for ovine) and 4.30 (for porcine) followed by incubating for succinate dehydrogenase (SDH) activity, then staining for myofibrillar adenosine triphosphatase (ATPase) activity after an acid preincubation and, finally, counterstaining with hematoxylin. For bovine muscle tissue, the procedure involves first incubating for SDH activity, after which the section is incubated at pH 4.15 and then stained for myofibrillar ATPase activity after an acid preincubation, with a concluding counterstaining using hematoxylin. These procedures permit successful differentiation and identification of three fiber types (beta R, alpha R and alpha W) from a single section of muscle tissue with approximately a 65% saving in time and materials. The results of histochemically typing muscle fibers in a single tissue section stained with these techniques were similar to those obtained with the traditional methods comparing serial sections.