Nutritive value of edible forage from two <Emphasis Type="Italic">Leucaena leucocephala</Emphasis> cultivars with different growth habit and morphology

The nutritive value of edible forage from Leucaena leucocephala cv. Cunningham (CUNN) and cv. CNIA-250 (CNIA) was determined during the rainy (R) and dry (D) seasons of Cuba without fertilization or irrigation. Forage was supplied ad libitum and the French system of total faeces collection was used for nutritive value determination and expression by using six adult castrated Pelibuey wethers for each determination. There were noticeable differences in the chemical composition and nutritive value between the two cultivars which were also influenced by year season. The highest protein and energy content were found in CNIA and during the rainy season which could also explain its higher forage intake and digestibility, while CUNN expressed higher DM and nutrient yield throughout the year, mainly due to advantages in tree size and morphology (higher ramification and proportion of leaves, and acceptable branch length). Quality and nutritive value results indicated that these Leucaena cultivars have a suitable potential as supplements for sustainable ruminant nutrition strategies during both seasons of the year; CNIA, because of its smaller height, is strongly recommended for agrosilvopastoral small ruminant browsing systems.     

Suspended culture evaluation of Pacific oyster Crassostrea gigas in a tropical estuary

The growth and survival of Crassostrea gigas were evaluated in hanging culture in the Chone River estuary (Bahía de Caráquez), Manabí province, Ecuador. Oyster seeds (~10 mm) were confined in lantern nets at a density equal to the occupation of half the surface of the basket base, until reaching commercial size (80 mm). A sample for oyster biometric, parasitic and bacterial analysis was obtained monthly. Temperature, salinity, oxygen concentration, seston and phytoplankton biomass were determined. At the end of the study, the oysters were analysed for heavy metal concentration. The commercial oyster production was extrapolated to estimate the possible economic performance of a family production module (a 7 × 7 m bamboo raft). The results show a great biological feasibility of culture of C. gigas with harvests of commercial size oysters in only 5 months and acceptable survivals (accumulated >70%, after 3 weeks of crop seed selection). The heavy metal concentrations and the parasitological and bacteriological analyses did not indicate levels of contamination. The economic projections suggest that, even with a profitability of 57%, the initially invested capital could be recovered within the first harvest.     

Canopy characteristics and tillering dynamics of Marandu palisade grass pastures in the rainy–dry transition season

The objective of this study was to evaluate the effect of pasture management during the rainy–dry transition season in Jaboticabal, Brazil, on the structural and tillering characteristics of Marandu palisade grass. The treatments were as follows: 15 cm sward height in the rainy season and ungrazed in the rainy–dry transition season (15/0); 25 cm sward height during the rainy season and fixed stocking rate of 2·5 AU ha^?1 during the rainy–dry transition season (25/2·5); and 35 cm sward height in the rainy season and fixed stocking rate of 2·5 AU ha^?1 in the rainy–dry transition season (35/2·5). There were more herbage mass, stem and dead herbage mass in treatments 25/2·5 and 35/2·5 than 15/0. Tiller appearance rate was greater in treatment 15/0 and tiller mortality rate was higher in treatment 35/2·5 compared to treatment 15/0. Tiller population stability index was 1 in treatment 15/0 and lower in treatment 35/2·5. Although treatment 15/0 showed favourable structural and tillering characteristics, it also has the lowest herbage mass. Treatment 25/2·5 can be regarded as an adequate management strategy for Marandu palisade grass, since it has similar herbage mass and better tillering characteristics than treatment 35/2·5.     

Potential of Limestone Tailings for Correction and Fertilization of an Oxisol in the Brazilian Savanna

ABSTRACT

Limestone mining industries produce large quantities of by-products that can generate environmental impacts if disposed inappropriately. This study aimed to evaluate the agronomic viability of limestone tailings as soil aciditys and the availability of Ca + Mg in an Oxisol. The experiment was carried out under a randomized complete design, in a 6 × 5 factorial scheme, with four replications. Six sources of limestone [Blended Limestone 1 (BL1), Unblended Limestone 1 (UL1), Blended Limestone 2 (BL2), Unblended Limestone 2 (UL2), Commercial Limestone (CC) and Pure Limestone (PL)] were studied at five application doses (0.0, 0.5, 1.0, 2.0 and 4.0 t ha^?1). During the incubation time of the soil, it was determined the active (pH) and potential acidity (H + Al), as well as the contents of Ca + Mg. It is concluded that the maximum efficiency dose for the limestone sources BL1, UL1, BL2 and UL2 was 4.0 t ha^?1, with responses higher than or equal to commercial limestone. Thus, these sources (BL1, UL1, BL2 and UL2) can be used as soil acidity correctors, since they have adequate reactivity and neutralization power, contributing positively and promisingly in the correction of both active and potential acidity, in addition to increasing the availability of Ca and Mg.     

Biomarkers of bone development and oxidative stress in gilthead sea bream larvae fed microdiets with several levels of polar lipids and α‐tocopherol

Although dietary marine phospholipids are able to improve culture performance of marine fish larvae in a further extend than soybean lecithin, both types of phospholipids (PL) markedly increase oxidative risk. The inclusion of a fat‐soluble antioxidant such as the vitamin E α‐tocopherol could allow a better control of oxidative stress. The objective of this study was to determine the combined effect of graded levels of α‐tocopherol with different levels and sources of krill phospholipids (KPL) and soybean lecithin (SBL) on growth, survival, resistance to stress, oxidative status, bone metabolism‐related genes expression and biochemical composition of sea bream larvae. Sea bream larvae were completely weaned at 16 dph and fed for 30 days seven microdiets with three different levels of PL (0, 40 and 80 g kg^?1 diet) and two of α‐tocopherol 1500 and 3000 mg kg^?1 diet. Sea bream larvae fed diets without PL supplementation showed the lowest survival, growth and stress resistance, whereas increase in PL, particularly KPL, markedly promoted larval survival and growth. However, feeding SBL markedly increased TBARs and GPX gene expression increasing the peroxidation risk in the larvae. Besides, KPL inclusion improved incorporation of n‐3 HUFA and, particularly, EPA into larval tissues, these fatty acids being positively correlated with the expression of BMP‐4, RUNX 2, ALP, OC and OP genes and to bone mineralization for a given larval size class. The increase in dietary α‐tocopherol tends to improve growth in relation to the n‐3 HUFA levels in the diet, denoting the protective role of this vitamin against oxidation. Indeed, dietary α‐tocopherol decreased the oxidative stress in the larvae as denoted by the reduction in larval TBARs contents and gene expression of SOD and CAT, but not GPX. Thus, increase in dietary α‐tocopherol effectively prevented the formation of free radicals from HUFA, particularly EPA, but did not affect the incidence of bone anomalies or the expression of genes related to osteogenetic processes.     

Experimental transmission of the mild strain of Tomato yellow leaf curl virus (TYLCV) to Amaranthus dubius by Bemisia tabaci

Tomato yellow leaf curl virus (TYLCV) is a monopartite begomovirus from the Old World. The mild strain of this virus (TYLCV-Mld) was described for South America in Venezuela in 2007. Due to the potential risks of establishment of this virus in the field, six common weeds were evaluated for susceptibility to an isolate of TYLCV-Mld by using adults of Bemisia tabaci (Hemiptera: Aleyrodidae) to mediate viral transmission. In this work, detection based on PCR amplification with TYLCV specific primers showed Amaranthus dubius (Amaranthaceae) as the only infected weed. In A. dubius, viral symptoms were observed from 11.0?±?1.3?days post-inoculation and the transmission rate of TYLCV-Mld to this plant species was 83.3%. The successful back-transmission of TYLCV-Mld from A. dubius to tomato plants was demonstrated.     

Sulfated-polysaccharide fraction from red algae Gracilaria caudata protects mice gut against ethanol-induced damage

The aim of the present study was to investigate the gastroprotective activity of a sulfated-polysaccharide (PLS) fraction extracted from the marine red algae Gracilaria caudata and the mechanism underlying the gastroprotective activity. Male Swiss mice were treated with PLS (3, 10, 30 and 90 mg·kg(-1), p.o.), and after 30 min, they were administered 50% ethanol (0.5 mL/25 g(-1), p.o.). One hour later, gastric damage was measured using a planimeter. Samples of the stomach tissue were also obtained for histopathological assessment and for assays of glutathione (GSH) and malondialdehyde (MDA). Other groups were pretreated with l-NAME (10 mg·kg(-1), i.p.), dl-propargylglycine (PAG, 50 mg·kg(-1), p.o.) or glibenclamide (5 mg·kg(-1), i.p.). After 1 h, PLS (30 mg·kg(-1), p.o.) was administered. After 30 min, ethanol 50% was administered (0.5 mL/25 g(-1), p.o.), followed by sacrifice after 60 min. PLS prevented-ethanol-induced macroscopic and microscopic gastric injury in a dose-dependent manner. However, treatment with l-NAME or glibenclamide reversed this gastroprotective effect. Administration of propargylglycine did not influence the effect of PLS. Our results suggest that PLS has a protective effect against ethanol-induced gastric damage in mice via activation of the NO/K(ATP) pathway.     

Microsatellites reveal widespread predominance of an invasive over an indigenous <Emphasis Type="Italic">Bemisia tabaci</Emphasis> in Venezuela

The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is an important pest due to its capacity for producing strong infestations and transmitting plant viruses. The New World putative species of B. tabaci complex (NW) is the indigenous whitefly of the Americas, but only the invasive Middle East-Asia Minor 1 putative species of B. tabaci complex (MEAM1), commonly referred to as the “B biotype” was identified in a limited scope sampling in Venezuela. Similarly to MEAM1 invasions elsewhere, in this South American country there has been an increase in the geographic range and abundance of B. tabaci, and in the number of viruses that it transmits since the late 1980s. We estimated the diversity of B. tabaci to elucidate their role in the epidemiology of geminiviruses in Venezuela. Thirteen microsatellite loci were screened in samples collected from 19 localities in ten major agricultural states. A Bayesian clustering method (Structure) grouped the samples into two genetic groups. Control samples from whiteflies NW and MEAM1 and partial sequencing of the mitochondrial cytochrome oxidase I gene showed that our samples of B. tabaci populations from Venezuela fall within NW and MEAM1 groups. In this survey, MEAM1 was predominant over NW whitefly in a proportion of 35:1. No evidence was observed for gene flow between indigenous and invader whitefly. Altogether, our results stress the urgency for controlling the proliferation of the invasive whitefly.     

Induction of parturition with aglepristone in the Majorera goat

This study assessed the efficacy of aglepristone at inducing parturition in pregnant goats. Six experimental groups were defined: group A-5 (n = 12), group A-3.3 (n = 12), group A-2.5 (n = 12) and group A-1.5 (n = 12) in which goats were injected SC once with 5.0, 3.3, 2.5 and 1.5 mg of aglepristone per kg body weight of goat, respectively, group L (n = 11), which was treated IM with 3.75 mg of luprostiol; and group Ct (n = 11), which was injected SC with 1 ml of saline solution. Different parameters associated with parturition were thereafter investigated. In addition, plasma progesterone concentrations were defined after treatments till parturition. Aglepristone effectively induced parturition in all of the goats. In the A-5, A-3.3 and A-2.5 groups, the time to parturition was around 30-34 h, and the majority of goats (97.2%, 35/36) started kidding between 25 and 40 h after the aglepristone injection. However, the goats in group A-1.5 showed a significantly (p < 0.01) higher time to parturition (mean: 46.8 h). Overall, the incidence of dystocia registered in aglepristone-induced goats (20.8%, 10/48) and luprostiol-induced goats was not different from that observed after a spontaneous parturition. The percentage of live kids was very similar between A-5, A-3.3, A.2.5 and L groups (95.7, 95.3, 95.0 and 96.3%, respectively) but was higher that observed in the control (83.4%) and A-1.5 (81.2%) groups. In addition, no maternal mortality was registered in any groups. No changes in plasma progesterone were observed during the first 24 h after treatment, and high plasma progesterone concentrations were present at kidding (6.7, 5.5, 4.5 and 3.6 ng/ml for groups A-5, A-3.3, A-2.5 and A-1.5, respectively), confirming that aglepristone does not induce parturition via luteolysis. This study demonstrates that aglepristone can be used to induce parturition in goats with satisfactory efficacy, inducing pregnancy termination without direct or immediate modifications of luteal function.     

Testicular Neoplasms (Interstitial and Sertoli Cell Tumours) in a Domestic Ferret (Mustela putorius furo)

Unilateral testicular enlargement was detected in a 5‐years‐old domestic ferret during a routine sterilization. The right testicle showed two different types of proliferative lesions: (i) round nodules, well demarcated, showing a soft yellow tissue; (ii) white nodules, firm, with irregular‐shaped invaginations. Microscopically, the neoplastic proliferations were identified as an interstitial neoplasm and Sertoli cell tumour, respectively. The left testicle was small and showed intense testicular atrophy. Clinical evaluation of the ferret did not show any other apparent pathological processes. This study is the first case reporting the concomitant occurrence of a Sertoli cells tumour and an interstitial cell tumour in a domestic ferret.