Semi-intensive production of Penaeus vannamei in Guatemala

SUMMARY Because marine shrimp species convenient for aquacultural purposes live mainly in warm-water environments, commercial shrimp farms are located principally along tropical and sub-tropical marine coastlines. Other than the South-East Asiatic countries, the Latin America countries are important shrimp producers that contribute in satisfying the international demand of marine shrimp. Part of the imported shrimp in Italy come from Guatemala, where the shrimp aquaculture (representing around the 88% of the total aquaculture production) is based mainly on the Pacific white shrimp (Penaeus vannamei). Common rearing procedures of one of the biggest marine shrimp farms operating in Guatemala are described. Some productive parameters of Penaeus vannamei brought out by semi-intensive system in earthen ponds are quantified. Productive data result in a uniform distribution of weight classes at different days after stocking, besides the growth trend and feed conversion ratio agree with the growth performance of Penaeus vannamei. Growth data, fitted on the von Bertalanffy model, present the maximum weight gain (0.13 g/day) 28 days after stocking. Shrimp survival after a grow-out period of 80 days in a 2.44-ha pond is around 56% and the gross yield turns out to be more than one ton per hectare. In conclusion, semi-intensive shrimp farming performed in Guatemala allows to have high productivities as well as a good quality product. On the other hand it must be highlighted that this kind of cultivation represents a risk for the environmental equilibrium along the coasts of tropical countries. RIASSUNTO Poiché le specie di gambero marino utilizzate a fini produttivi sono originarie principalmente degli ambienti con acqua a temperatura elevata, le aziende che producono questi gamberi sono situate maggiormente lungo le coste dei Paesi tropicali e sub-tropi- cali. Oltre ai Paesi del Sud-Est Asiatico, i Paesi dell’America Latina sono importanti produttori, che contribuiscono a soddisfare la domanda internazionale di gamberi marini. Parte dei gamberi importati in Italia proviene dal Guatemala, dove la produzione di gamberi, che rappresenta l’88% della produzione nazionale di acquacoltura, è basata principalmente sul gambero bianco del Pacifico (Penaeus vannamei). Vengono descritte le comuni procedure produttive di una delle più grandi aziende di gamberi marini operanti in Guatemala. Vengono inoltre valutati alcuni parametri produttivi del Penaeus vannamei, allevato con un sistema semi-intensivo all’interno dei bacini di questa azienda. I dati di peso risultano distribuiti uniformemente alle diverse epoche dopo la semina, inoltre l’andamento dei pesi e l’indice di conversione alimentare concordano con i parametri di crescita del Penaeus vannamei. I dati di crescita, stimati con il modello proposto da von Bertalanffy, evidenziano il massimo incremento di peso (0,13 g al giorno) al 28° giorno dalla semina. La sopravvivenza dei gamberi dopo un periodo di accrescimento di 80 giorni in un bacino di 2,44 ettari è di circa il 56% e la resa supera il quantitativo di una tonnellata per ettaro. Nel complesso l’allevamento di gamberi con sistema semiintensivo, condotto in Guatemala, sembra fornire un’alta produttività combinata con una buona qualità del prodotto finale. D’altronde deve essere considerato che questo sistema d’allevamento rappresenta un serio rischio per l’equilibrio ambientale lungo le coste dei paesi tropicali

Antimicrobial‐Resistant Enterococcus spp. in Wild Avifauna from Central Italy

Bacteria of the genus Enterococcus are opportunistic pathogens, part of the normal intestinal microflora of animals, able to acquire and transfer antimicrobial resistance genes. The aim of this study was to evaluate the possible role of wild avifauna as a source of antimicrobial‐resistant enterococci. To assess this purpose, 103 Enterococcus spp. strains were isolated from the feces of wild birds of different species; they were tested for antimicrobial resistance against 21 molecules, vancomycin resistance, and high‐level aminoglycosides resistance (HLAR). Furthermore, genes responsible for vancomycin, tetracycline, and HLAR were searched. E. faecium was the most frequently detected species (60.20% of isolates), followed by E. faecalis (34.95% of isolates). Overall, 99.02% of the isolated enterococci were classified as multidrug‐resistant, with 19.41% extensively drug‐resistant, and 2.91% possible pan drug-resistant strains. Most of the isolates were susceptible to amoxicillin/clavulanic acid (77.67%) and ampicillin (75.73%), with only 5.83% of isolates showing an ampicillin MIC ≥ 64 mg/L. HLAR was detected in 35.92% of isolates, mainly associated with the genes ant(6)‐Ia and aac(6′)‐Ie‐aph(2′’)‐Ia. Few strains (4.85%) were resistant to vancomycin, and the genes vanA and vanB were not detected. A percentage of 54.37% of isolates showed resistance to tetracycline; tet(M) was the most frequently detected gene in these strains. Wild birds may contribute to the spreading of antimicrobial‐resistant enterococci, which can affect other animals and humans. Constant monitoring is essential to face up to the evolving antimicrobial resistance issue, and monitoring programs should include wild avifauna, to

Effects of Dietary Quebracho Tannin on Performance Traits and Parasite Load in an Italian Slow-Growing Chicken (White Livorno Breed)

Tannins have shown numerous biological activities and are very appreciated in food animal production, especially for their antimicrobial, antiparasitic, antioxidant, anti-inflammatory and antivirus effects. The aim of the present study was to evaluate the effect of two levels of dietary Quebracho tannin (QT) on growth and performance traits, and possible effects on intestinal parasite load in Italian White Livorno pullets. A 140-day trial was carried out on 180 35-day-old females, fed on two levels of dietary QT inclusion: 0%, 1% and 2%. Birds were reared under free-range conditions. Dietary Quebracho tannin may be used up to 1% in growing female White Livorno chickens without any adverse effects. The results observed in this study on the use of dietary QT at 2% might have not reflected the real effect on performance traits due to the initial inclusion of dietary QT at 3%. Nevertheless, by reducing QT to 2%, a progressive normalization of body weight gain, feed intake and feed conversion ratio was observed, resulting in compensatory growth. QT was demonstrated to drastically reduce fecal outputs of Nematodes eggs (Ascaridia spp. and Heterakis spp.) and Coccidia oocytes (Eimeria spp.). The inclusion of 2% produced highly dry droppings

Cryopreservation of pheasant semen: effect of dilution ratio and cooling time on spermatozoa viability and mobility

Aim of the present study was to investigate the cryopreservation of pheasant semen by adopting the freezing/thawing protocol by Tselutin et al. (1999) with some modifications. Semen was collected by abdominal massage twice a week. Evaluations were performed on pooled semen from fifteen males (Phasianus colchicus mongolicus). Two semen dilutions (DIL) with Lake diluent (1:2 and 1:3, v/v; Lake, 1968) and two equilibration times (ET) at 5°C (10min and 30min) before dimethylacetamide (DMA) addition, were tested. Assessment of sperm mobility was performed by Accudenz methodology according to Froman’s procedure (1997) and viability by eosin/nigrosin staining. As expected, viability and mobility were strongly affected by the freezing/thawing procedure. ET did not affect mobility while influenced live sperm percentage during the DMA equilibration (DMA-Eq). Semen/diluent ratio significantly (p<0.001) modified the mobility parameter and the highest progressive movements of spermatozoa were obtained with the most diluted semen in each critical step of the cryopreservation procedure. In conclusion, for pheasant semen cryopreservation, the 1:3 dilution ratio can be considered appropriate and the cooling time up to 30 minutes not crucial for the spermatozoa mobility and viability. Nevertheless, the deleterious effect of freezing/thawing procedure reduced live thawed spermatozoa to 24% and forward motility to 89% of the initial movement capacity

Breast meat traits of Muscovy ducks fed on a microalga (Crypthecodinium cohnii) meal supplemented diet

A trial was conducted in order to increase the docosahexaenoic acid ( DHA) content in the meat of Muscovy ducks ( Cairina moschata domestica L.) fed on a diet supplemented with the microalga Crypthecodinium cohnii. 2. Two diets were provided to 48 male and 48 female ducks, belonging to an Italian rural strain during the last 3 weeks of life: a maize - soybean based diet as the control diet and the same diet supplemented with 5 g/ kg microalga meal. 3. Dietary treatment did not induce differences in growth performances and slaughter traits. Similarly, chemical composition, colour, pH, oxidative stability and sensory characteristics of breast muscle were not influenced by the diet. 4. A significant increase of DHA content in breast meat of ducks fed on the Crypthecodinium cohnii enriched diet was observed

Distribution and consistency of Ancona and Livorno poultry breed in Central Italy

Nowadays most of the Italian chickens’ breeds are replaced with commercial hybrids characterised by higher productive performance. However, the safeguard of biodiversity and consequently the genetic variability are a very important issue, and for this reason, it is fundamental to include local strains in preservation programs. In Italy, the poultry Genealogic Book has been recently constituted, and includes 22 chicken breeds. The diffusion of these strains is strictly linked to the territory of origin, in particular in the Central Italy, the Ancona and Livorno chicken breeds are the mainly widespread ones. The aim of this study was to determine the consistency and the characteristics of the farms involved in the farming of Ancona and Livorno chicken breeds in Central Italy. A survey to analyse the facilities, the human resources and the chicken population consistencies was conducted in the farms of Abruzzo, Lazio, Marche, Tuscany and Umbria regions. All the investigated farms can be identified as ‘hobby-farms’ being small scale ones and leading the breeding of Ancona and Livorno chickens as a secondary business. The survey also confirmed that the presence of the strains depends on the region: 100% of Marche farms bred Ancona whereas, in Tuscany the Livorno breed is the most common.Highlights A survey in centre Italy was carried out to determine the consistency of Ancona and Livorno chicken breeds; The Ancona and Livorno chickens breed were reared in small scale farms; The widespread of the breeds depend on the region: Ancona breed is most present in the Marche region while the Livorno is mainly bred in Tuscany