Cholesterol requirement and phytosterols efficiency in semi‐purified diets of juvenile Pacific white shrimp Litopenaeus vannamei

Studies pertaining to cholesterol requirement are limited based on the levels evaluated and statistical analysis. Two trials were conducted to refine cholesterol requirement in Pacific white shrimp Litopenaeus vannamei feeds. The basal diet was supplemented with graded levels of cholesterol (ranging from 0.48 to 1.85 g/kg) in trial 1. Since the shrimp (initial weight: 0.24 g) growth response was very linear without reaching a plateau, it was not clear whether the requirement was met. Hence, a second trial was designed using eight diets designed with an increased range of cholesterol levels from 0.45 to 4.57 g/kg of diets. The shrimp (0.38 g initial weight) reached a final weight of (4.31–7.43 g) or per cent weight gain from 1,014%–1,874% (n = 4) after 6 weeks. Saturation kinetic model and broken‐line models with linear or quadratic ascending portions were used to evaluate dose–response relationships of feed efficiency (FE), thermal‐unit growth coefficient (TGC), whole‐body cholesterol (CHOL) and cholesterol deposition (CHOLD) against dietary cholesterol. The cholesterol requirement of shrimp was estimated at 1.9 (1.1–4.3) g/kg, 1.7 (1.1–3.4) g/kg, 2.5 (2.3–2.9) g/kg and 2.7 (2.4–3.1) g/kg of shrimp diet for FE, TGC, CHOL and CHOLD, respectively. Additionally, based on improved growth, the inclusion of phytosterol can serve as a partial replacement for cholesterol.     

Improving the Productivity of Bread Wheat by Good Management Practices under Terminal Drought

Drought‐induced damages in crop plants are ranked at top amid all losses instigated by diverse abiotic stresses. Terminal drought (drought at reproductive phase) has emerged as a severe threat to the productivity of wheat crop. Different seed enhancement techniques, genotypes and distribution of crop plants in different spacings have been explored individually to mitigate these losses; however, their interaction has rarely been tested in improving drought resistance in wheat. This study was conducted to evaluate the potential role of different seed enhancement techniques and row spacings in mitigating the adversities of terminal drought in two wheat cultivars during two consecutive growing seasons of 2010–2011 and 2011–2012. Seeds of wheat cultivars Lasani‐2008 (medium statured) and Triple Dwarf‐1 (dwarf height) soaked in water (hydropriming) or CaCl₂ (osmopriming) were sown in 20‐, 25‐ and 30‐cm spaced rows; just before heading, the soil moisture was maintained at 100 % field capacity (well watered) or 50 % field capacity (terminal drought) till maturity. Terminal drought significantly reduced the yield and related traits compared with well‐watered crop; however, osmopriming improved the crop performance under terminal drought. Among different row spacings, wheat sown in 20‐cm spaced rows performed better during both years of study. Wheat cultivar Lasani‐2008 performed better than cultivar Triple Dwarf‐1 under both well‐watered and stress conditions. Maximum net returns and benefit–cost ratio were recorded from osmoprimed seeds of cultivar Lasani‐2008 sown in 20‐cm spaced rows under well‐watered condition. Nonetheless, osmoprimed seeds of cultivar Lasani‐2008 sown in 20‐cm spaced rows were better able to produce good yield under terminal drought.     

Relationship between rhizosphere acidification and phytoremediation in two acacia species

Purpose

Phytoremediation is the most sustainable and economical strategy for reclamation of the salt-affected soils. In order to investigate the relationship between phytoremediation and rhizosphere acidification, two experiments (greenhouse and field) were conducted using two acacia species viz. Acacia ampliceps and Acacia nilotica.

Materials and methods

In greenhouse experiment, both the species were exposed to 100 and 200 mM NaCl concentrations in solution culture. The release of organic acids from plant roots was determined after 14 and 28 days of the salt treatment. Shoot and root ash alkalinity was determined after harvesting the plants. In field experiment, both the species were grown on a saline sodic soil for 2 years. After every 6 months, plant growth data were recorded and soil samples were collected from different soil depths for physicochemical analyses.

Results and discussion

The results of greenhouse study indicated higher rhizosphere acidification by A. ampliceps than A. nilotica in terms of release of citric acid, malic acid, and tartaric acid along with ash alkalinity. The comparison of both the species in the field indicated higher amelioration in the soil properties like pH_s, EC_e, SAR, bulk density, and infiltration rate by A. ampliceps than A. nilotica.

Conclusions

It is concluded from these studies that A. ampliceps is more suitable species than A. nilotica for the phytoremediation of the salt-affected soils due to its higher rhizosphere acidification potential.

     

Concurrent vaccination of goats with foot and mouth disease (FMD) and peste des petits ruminants (PPR) booster vaccines

Foot and mouth disease (FMD) remains subclinical and self-limiting in small ruminants, but risk of spread of infection to susceptible cohorts is of great epidemiological significance; therefore, small ruminants must be included in vaccination campaigns in FMD endemic regions. Three groups of goats already immunized against peste des petits ruminants (PPR) were vaccinated with FMD and PPR vaccines alone or concurrently. The specific antibody response against three FMD virus strains and PPR virus were evaluated by competitive enzyme-linked immunosorbent assay (cELISA). Goats concurrently vaccinated with PPR + FMD vaccines had significantly (p < 0.05) higher antibody titers to two serotypes of FMD virus at 28, 45, and 60 days post-immunization compared to goats vaccinated with FMD vaccine alone, while goats vaccinated with PPR vaccines alone or PPR + FMD vaccines concurrently showed similar antibody kinetics against PPR virus up till 60 days post-vaccination. Overall, antibody kinetic curves for all three tested strains of FMD virus and PPR virus were similar in vaccinated groups during the course of experiment.     

Genetic variation in drought tolerance at seedling stage and grain yield in low rainfall environments in wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)

Genetic architecture of seedling drought tolerance is complex and needs to be better understood. To address this challenge, we developed a protocol to identify the most promising drought-tolerant genotypes at the seedling stage in winter wheat. A population of 146 recombinant inbred lines (F₉) derived from a cross between wheat cultivars, ‘Harry’ (seedling drought tolerant) and ‘Wesley’ (seedling drought susceptible) were used in this study. All genotypes were sown in three replications in a randomized complete block design under controlled conditions in a greenhouse. Seven traits were scored and grouped into tolerance traits; days to wilting, leaf wilting, and stay green and survival traits; days to regrowth, regrowth, drought survival rate, and recovery after irrigation. Three selection indices were calculated (1) tolerance index, (2) survival index, and (3) drought tolerance index (DTI). The same set of genotypes were also tested for grain yield in two low rainfall environments for two seasons. High genetic variation was found among all genotypes for all seedling traits scored in this study. Correlations between tolerance and survival traits were weak or did not exist. Heritability estimates ranged from 0.53 to 0.88. DTI had significant phenotypic and genotypic correlations with all seedling traits. Genotypes were identified with a high drought tolerance at the seedling stage combined with high grain yield in low rainfall. Breeding for tolerance and survival traits should be taken into account for improving winter wheat drought tolerance at seedling stage. The selected genotypes can be used for to further improve drought tolerance in high yielding wheat for Nebraska.     

Bacillus subtilis B21 and Bacillus licheniformis B26 improve intestinal health and performance of broiler chickens with Clostridium perfringens‐induced necrotic enteritis

This study investigated the influence of Bacillus‐based probiotics on performance and intestinal health in broiler challenged with Clostridium perfringens‐induced necrotic enteritis. One‐day‐old Arbor Acre (n = 480) were randomly assigned to four treatments with 10 cages of 12 birds: (a) basal diet negative control (NC), with no probiotics nor antibiotics formulated to contain 2,930 and 3,060 kcal/kg with 24.07 and 15.98% CP, for starter and finisher diet, respectively, (b) basal diet + enramycin (5 mg/kg), an antibiotic growth promoter (AGP); (c) basal diet + Bacillus subtilis B21 at 2 × 10⁹ CFU per g (BS); (d) basal diet + Bacillus licheniformis B26 at 2 × 10⁹ CFU per g (BL); growth performance, intestinal morphology, intestinal lesion scores, short‐chain fatty acids (SCFAs) and mucosal barrier tight junction's (TJ) mRNA expression were assessed. NC‐ and BL‐fed groups showed higher (p = 0.005) average daily feed intake from d1 to d21 than AGP and BS, whereas BS‐ and AGP‐fed groups showed higher average daily weight gain from d22 to d42 and d1 to d42 of age. Higher mortality rate of (12.5%) and lower of (5.5%) were recorded in AGP and NC fed‐groups respectively, lesion score was higher in BS and BL than in AGP, while no lesion was observed in NC group, results revealed higher duodenum and jejunum villus height to crypt depth (VH:CD) compared with NC and BS. Probiotics‐fed groups showed higher total (SCFAs), acetic and butyric acid concentrations at d21 post‐challenge (PC) than other groups. The expression of claudin‐1 was upregulated in duodenum (d7) PC and in jejunum (d7) and (d21) PC in BL group, while at d21 PC, the expression of occludens was higher in jejunum and ileum by AGP and BL. The present study indicated both BS and BL have some similarity with AGP in preventing or partially preventing NE effect in broilers.     

EVALUATION OF NUTRITIONAL COMPOSITION OF PLANT SPECIES OF SOONE VALLEY IN PUNJAB,PAKISTAN

The key component for global sustainability is plant diversity, an essential for living sources on this planet. An investigation was carried out in the Soone Valley, Punjab, Pakistan to determine the nutritional value of plant diversity in relation to requirements of grazing ruminants therein. Various parameters such as moisture content, crude protein, mineral matter, fat fiber content, dry matter, nitrogen free extractable substances, and net energy were evaluated in this investigation. Results showed that various plant species studied exhibited fluctuation in all parameters in this valley. Correlation studies also indicated that various parameters showed negative as well as positive significant relationships with various parameters of soil in this valley. The information will be useful in further conservation program. A. farnesiana was negatively correlated (?0.335) with protein and mineral matter (?0.048). Significant correlations of different plant species regarding nitrogen- phosphorus- potassium (NPK) were recorded with net energy. Various variables studied in this investigation demonstrated their importance to be used in further conservation, research, and grazing livestock programs.     

基质类型及烯效唑对不同秧龄晚稻机插质量和产量的影响

为明确基质类型及烯效唑对不同秧龄晚稻秧苗生理特征及本田期生长发育特性的影响,确定适宜晚稻机插育秧的基质类型、烯效唑浸种措施及秧龄,该研究以嘉58为供试晚稻品种,以2种代表性育秧介质(营养土和轻型无土育秧基质)为研究对象,采用2种(清水浸种和25 mg/L烯效唑浸种)外源生长调控措施,阐明了不同育秧介质和烯效唑浸种对不同秧龄晚稻秧苗生理特征、机插质量的影响及调控技术。结果表明,随晚稻秧龄延长,秧苗地上部分干物质量显著增加,叶片SPAD值和根系活力先增加后降低;水稻全生育期延长,大田生育期缩短。采用烯效唑浸种可提高秧苗素质,浸种处理秧苗茎基宽约增加0.1~0.2 mm,株高显著降低,叶片SPAD值和根系活力显著提高。短秧龄条件下烯效唑浸种对秧块质量和机插质量影响较小,长秧龄条件下烯效唑浸种可有效提高成苗率和大田基本苗数,降低漏插率和伤秧率。采用营养土育秧时最适机插秧龄为18 d,轻型无土基质育秧适宜机插秧龄为18~24 d。秧龄大于24 d时,烯效唑浸种可提高营养土育秧晚稻有效穗数和每穗粒数,增加晚稻产量,且秧龄越长,烯效唑浸种的增产效果越显著。烯效唑浸种对轻型无土基质育秧的产量影响较小。采用轻型无土育秧基质培育机插晚稻秧苗,产量高于常规营养土处理,适宜晚稻机插育秧。研究结果可为提升晚稻种植机械化水平提供重要参考。