Mapping chicken production and distribution networks in Vietnam: An analysis of socio-economic factors and their epidemiological significances.

The growing chicken industry in Viet Nam has an increasingly important contribution to the country's food security, but its development requires careful planning to prevent disease risks. This study characterizes the chicken production and distribution networks in Vietnam and identifies potential factors that could promote disease emergence and transmission. Qualitative data were collected from interviews with 29 key informants from five stakeholder groups representing the main nodes from chicken production and distribution networks (PDN). Three main networks were identified based on production type: a colored broiler and spent hen network, a white (or exotic) broiler network, and an egg network. Colored chickens and spent hens are the most preferred commodity by vietnamese consumers and their PDN is composed of production units differing in their scale and management and with long distribution chains involving numerous small-scale independent stakeholders. Live bird markets plays a central role in this network, which is driven by consumers' preference for live chickens. The white chicken network presents an important duality, as it is composed of both a large number of independent household farms and traders operating independently with little chain coordination, and of large farms contracted by vertically-integrated companies. The egg PDN was the most organized network, being mostly controlled by large vertically-integrated companies. High level specialization and diversification of stakeholders is found in all three networks. Stakeholders' perceptions of the main factors promoting disease risk along the PDN were the low biosecurity in household farms and live bird markets, mobile traders, the informal slaughter of birds and the management of sick birds. Findings from this study can be used to plan future studies to support food system planners in the development of safer poultry production and distribution in Vietnam.

Effects of Stocking Density in Group Cages on Egg Production, Profitability, and Aggressive Pecking of Hens.

There is an increasing concern about welfare issues related to battery cages, which are commonly used in Vietnam, and requires a modified cage that improves hen welfare while retaining its economic and management advantages. We combined adjacent conventional cages to form group cages to examine the effects of stocking density on egg production, economic returns, and aggressive pecking of hens. The control group included triplicate conventional cages with four birds/single cage (12 hens per three cages) or 450 cm2 area per hen. Three group cage treatments were set up with 10, 12, and 14 birds per group cage or 540, 450, and 386 cm2 of floor area per hen, respectively. Compared to 14 birds per cage, hens housed at 10 birds per group cage had a higher hen-day production, consumed less feed, and thus had a better feed conversion ratio/dozen eggs. Reducing the stocking density to 10 birds per group cage resulted in additional production cost, but it was compensated for by a high egg income, and significantly decreased aggressive pecks. Group cages benefit hen performance, profitability, and welfare when decreasing the stocking density to 10 birds per cage with 540 cm2/hen.

Effects of medicinal plants mixture on growth performance, nutrient digestibility, blood profiles, and fecal microbiota in growing pigs.

BACKGROUND AND AIM: Alternative natural materials to antibiotics for improving digestive health and growth performance are needed due to strengthening regulations related to the use of antibiotic growth promoters. The study aimed to evaluate the effects of medicinal plants mixture (60% Bidens pilosa L., 15% Urena lobata L., 15% Pseuderanthemum palatiferum, 5% Ramulus cinnamomi, and 5% Star anise) as alternative growth promotors on animal health, nutrient digestibility, blood parameters, and growth performance of growing pigs. MATERIALS AND METHODS: The study was conducted, from April 2020 to June 2020, at a private pig production farm located in Cam Giang district Hai Duong Province, Vietnam. Forty-eight 10-week-old crossbred (♂Duroc×♀ [Landrace×Yorkshire]) pigs, average initial body weight 30.3±1.42 kg, were randomly allocated to four dietary groups, three replicate pens per experimental group, with 4 pigs/pen. For 7 weeks, the pigs were fed a basal diet supplemented with the mixture at levels of 0, 20, 40, and 60 g/kg of feed. RESULTS: Final body weight, average daily gain, average daily feed intake, and feed conversion ratio, as well as apparent total tract digestibility of dry matter, organic matter, crude protein, ether extract, and gross energy were not significantly influenced by the diets (p>0.05). Inclusion of the plant mixture decreased significantly red blood cell count, blood cholesterol, urea nitrogen, and low-density lipoprotein (LDL) concentrations (p<0.05) compared with the control diet. No diet effect was observed on fecal Escherichia coli, Salmonella spp., Clostridium spp., and total bacteria counts. CONCLUSION: The incorporation of the plant mixture into the diet of growing pigs reduced serum cholesterol, LDL, and urea concentrations with no adverse effect on performance and nutrient digestibility.

In growing pigs, nutritive value and nutrient digestibility of distillers' by-products obtained from two varieties of rice.

In South-East Asia, rice distillers' by-product (RDP) is a widely abundant feedstuff whose adequate incorporation into pig diets is still questionable. Especially, effects of RDP on nutrient digestibility of growing pigs fed corn-soybean meal-based diet are lacking. The objective of this study was to determine nutrient digestibility and energy value of ordinary (ORDP) and glutinous (GRDP) rice distillers' by-product in growing pigs. Two groups of 12 castrated crossbred barrows (Duroc × Landrace × Yorkshire), about 3 months old, 38 ± 1.04-kg initial body weight, were each allocated to a 15-day experiment in which pigs were divided into three isonitrogenous diet-groups. The animals were housed individually in metabolism cages for separated collection of feces and urine. Each diet-group was provided either a control corn-soybean meal diet or a diet in which corn and soybean meal were partly replaced by ORDP or GRDP at 15 or 30% on diet dry matter basis. Glutinous by-product especially showed higher levels in crude protein, neutral/acid detergent fiber, total branched-chain amino acids, and butyric acid. When compared to the control diet, ORDP tented to increase DM intake (P = 0.054) but decreased energy (P < 0.001) and crude protein (P < 0.04) digestibility, while GRDP decreased DM intake (P < 0.001). Both GRDP and ORDP products negatively affected digestibility of ether extract. The average digestible and metabolizable energy of ORDP and GRDP were 17.0 and 16.6, and 17.7, and 17.1 MJ/kg DM, respectively. In conclusion, these results show that both RDP, and especially GRDP, are highly valuable protein and energy sources for pig production.

Validation of a two-plate microbiological method for screening antibiotic residues in shrimp tissue.

Microbiological inhibition screening tests could play an important role to detect residues of antibiotics in the different animal food products, but very few are available for the aquaculture products in general, and for shrimps in particular. A two-plate microbiological method to screen shrimp for residues of the most commonly used antibiotics has been developed and validated according to criteria derived from the European Commission Decision 2002/657/CE. Bacillus subtilis was used as a sensitive strain to target antibiotics. Culture conditions on Petri plates (pH of medium) were selected to enhance the capacity of antibiotic detection. Antibiotic residues were extracted from shrimps using acetonitrile/acetone (70/30, v/v) before application on Petri plates seeded with B. subtilis. The method was validated using spiked blank tissues as well as antibiotic treated shrimps with enrofloxacin and tetracycline, two antibiotics often found to be used in shrimp production. For tetracyclines and (fluoro)quinolones, the detection capability was below the maximum residue limit (MRL), while it was around the MRL for sulfonamides. The specificity of the microbiological screening was 100% in all cases while the sensitivity and accuracy was 100% in almost all cases. The capacity of the method to detect contaminated samples was confirmed on antibiotic treated shrimps, analyzed in parallel with a confirmatory method (Liquid Chromatography coupled to mass spectrometry (LC-MS)).