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

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

Rooster sperm pellet cryopreservation protocols: effect of step variations on the qualitative parameters of post-thawed sperm

The cryopreservation of sperm into pellets is not the preferred way to package avian semen but is quick and easy to do and does not require sophisticated technology. The aim of this study was to evaluate rooster sperm viability and mobility and the incidence of normal cells and sperm injuries in post-thawed pelleted sperm. The outcomes of different pelleting protocols were evaluated, which varied according to the parameter combinations used in each of the critical steps of the freezing process and in the thawing conditions which differed in methodology and temperature. The protocols employing 6% DMA showed the highest values of thawed sperm mobility. The most favourable thawing method in terms of sperm mobility was using the hot-plate at 60 °C, followed by the water-bath at 50 °C. The protocols resulting in the best sperm quality parameters employed a 1:2 dilution rate, a 30-min equilibration time at 4 °C, 6% DMA, and thawed 80 mL pellets using the water-bath at 50 °C or the hot-plate at 60 °C. According to the parameters evaluated, rooster sperm was highly susceptible to damage caused by the freezing-thawing methodology, although the survival rate of normal sperm cells still reached 39%, with 32% recovered mobility with respect to fresh sperm samples

From the Semen Collection Method to the Hatchlings: The Use of Cryopreserved Sperm from Pheasants Fed an Antioxidant-Enriched Diet

A widely used approach to preserving genetic diversity in birds involves the cryopreser- vation of semen. In this process, cells are subjected to physical and chemical stresses, but not all cell species respond equally. Many studies have been published on the freezing–thawing of sperm cells from a wide variety of domestic and wild species, on issues ranging from the sperm quality to different protocols, fertilisation success rates, etc. Nevertheless, very little information is available on the common pheasant. To fill this gap, the aim of this study was to describe the pheasant semen collection method, evaluate some qualitative parameters of sperm from males fed an antioxidant- enriched diet, and to test the in vivo fertilising capacity of the cryo-preserved semen. The freezing protocol employed involved pellets thawed by the hotplate method. Dimethylacetamide was used as a cryoprotectant at a final concentration of 6%. A total of six AIs were performed at 3-4-day intervals on a total of 40 females with doses of 35 × 106 of normal live thawed sperm. Males receiving the enriched diet produce more abundant and concentrated ejaculates. Freeze–thawed sperm lost 85% of their initial mobility, and diet influenced neither sperm mobility nor viability. The enriched diet did improve the number of normal freeze–thawed cells and was associated with a lower sperm fracture incidence. Regardless of the dietary group, frozen–thawed sperm resulted in a fertility rate of 30%, with 8-9 chicks hatching for every 100 eggs incubated

Overview of Native Chicken Breeds in Italy: Conservation Status and Rearing Systems in Use

The ongoing loss of domestic animal breeds around the world is occurring at an alarming rate. Thus, the registration and preservation of native breeds is of great importance. The aim of this study, which forms part of a conservation program, was to provide an overview of the conservation statuses of native Italian poultry breeds being reared by local breeders in Italy. The data collected by means of a census questionnaire demonstrate the low population sizes of these breeds in Italy and highlight the need for campaigns aimed at publicizing and promoting the benefits of native breeds with the goal of increasing population sizes. Identifying strategies to facilitate breeders’ access to pure breed birds is also essential, and would require collaborative efforts of university research centers, public entities, and breeders

Genetic Diversity of 17 Autochthonous Italian Chicken Breeds and Their Extinction Risk Status

The preservation of genetic variability of autochthonous poultry breeds is crucial in global biodiversity. A recent report revealed small breed size and potential risk of extinction of all native Italian poultry breeds; therefore, a correct assessment of their genetic diversity is necessary for a suitable management of their preservation. In this work, we provided an overview of the contribution to poultry biodiversity of some Italian autochthonous breeds reared in conservation centers devoted to local biodiversity preservation. The level of genetic diversity, molecular kinship, inbreeding, contribution to overall genetic diversity, and rate of extinction of each breed were analyzed with a set of 14 microsatellite loci in 17 autochthonous chicken breeds. To evaluate genetic variability, total number (Na), and effective number (Ne) of alleles, observed (Ho) and expected (He) heterozygosity, and F (Wright’s inbreeding coefficient) index were surveyed. The contribution of each analyzed breed to genetic diversity of the whole dataset was assessed using MolKin3.0; global genetic diversity and allelic richness contributions were evaluated. All the investigated loci were polymorphic; 209 alleles were identified (94 of which private alleles). The average number of alleles per locus was 3.62, and the effective number of alleles was 2.27. The Ne resulted lower in all breeds due to the presence of low-frequency alleles that can be easily lost by genetic drift, thus reducing the genetic variability of the breeds, and increasing their risk of extinction. The global molecular kinship was 27%, the average breed molecular kinship was 53%, and the mean inbreeding rate 43%, with a self-coancestry of 78%. Wright’s statistical analysis showed a 41% excess of homozygous due to breed genetic differences (34%) and to inbreeding within the breed (9%). Genetic variability analysis showed that 11 breeds were in endangered status. The contribution to Italian poultry genetic diversity, estimated as global genetic diversity, and ranged from 30.2 to 98.5%. In conclusion, the investigated breeds maintain a unique genetic pattern and play an important role in global Italian poultry biodiversity, providing a remarkable contribution to genetic variability