Commercial small-scale chicken farms managed as all-in-all-out but operating with low standards of hygiene/biosecurity are increasingly common in Vietnam. These conditions facilitate the transmission of gastrointestinal helminths. However, there are no published data on helminths in these systems. We aimed (1) to determine the prevalence/burden of gastrointestinal helminths in small-scale commercial flocks in the Mekong Delta region and (2) to investigate the association between worm burdens and birds' weight and disease status. Randomly selected chickens (n = 120) from 'normal' flocks were investigated at the end of their production cycle (~18 weeks), as well as 90 chickens from 'diseased' flocks with signs of respiratory and/or severe disease. The gastrointestinal tract of chickens was dissected and all visible helminths were identified and counted. A total of 54.2% and 54.4% normal and diseased chickens contained helminths. Among colonised birds, the diseased ones harboured a higher mass of helminth worms than normal (healthy) birds (3.8 ± SD 8.6 g vs. 1.9 ± SD 6.3 g, respectively). Eight species were identified, including nematodes (Ascaridia galli, Cheilospirura hamulosa and Heterakis gallinarum), cestodes (Hymenolepis, Raillietina cesticillus, Raillietina echinobothrida, Raillietina tetragona,) and one trematode (Echinostomatidae). Heterakis gallinarum was the most prevalent helminth (43.3% and 42.2% in normal and sick chickens, respectively), followed by A. galli (26.7% and 41.1%). Colonised chickens weighed 101.5 g less than non-colonised birds. Colonisation was higher during the rainy months (May-November) for both H. gallinarum and A. galli. Anthelminthic usage was not associated with reduced helminth burdens. We recommend upgrading cleaning and disinfection and limiting access to ranging areas to control helminths in small-scale chicken flocks.

Background: Alternative materials for antibiotics used in white leg shrimp farming were extensively investigated. The promising effects of plant based extracts in controlling aquaculture diseases has been reported elsewhere. This study was conducted to examine the effect of Solanum procumbens Lour. extract on survival, growth performance, innate immunity and protection against acute hepatopancreas necrosis disease caused by Vibrio parahaemolyticus (VpAHPND) in white leg shrimp. Methods: From March 2021 to September 2021, four difference diets were examined including the supplementation of S. procumbens L. extract at 0.0%, 0.5%, 1.0% and 1.5%. After 30 days of culture, the experimental shrimp was examined for survival rate, growth responses, innate immune parameters and mortality as challenged with VpAHPND. Result: The results indicated shrimp fed diets with and without S. procumbens L. extract supplementation showed no significant differences in survival and growth performances. However, the innate immune parameters were likely increased in shrimp fed diets at 1.0% and 1.5% extract supplementation and shrimp fed diets at 1.0% and 1.5% extract supplementation reduced the accumulate mortality of VpAHPND challenged shrimp by 47.6%. S. procumbens L. could be a potential material for enhancing innate immunity of white leg shrimp and can protect shrimp from AHPND infection.

Commercial small-scale chicken farms using all-in-all-out production but operating with low standards of hygiene/biosecurity are increasingly common in Vietnam. These conditions facilitate transmission of gastrointestinal helminths. However there are no published data on these parasites in these systems. The aims were: (1) to determine the prevalence/burden of gastrointestinal helminths in small-scale commercial flocks in commercial small-scale flocks in the Mekong Delta region; and (2) to investigate the association between worm burdens and birds’ weight and disease status. Randomly selected chickens (n=120) (‘normal’ flocks) were investigated at the end of their production cycle (∼18 weeks), as well as 90 chickens with signs of respiratory and/or severe disease. The gastrointestinal tract of chickens was dissected and all visible helminths were identified. 54.2% and 54.4% healthy and diseased chickens contained helminths. Diseased, colonized chickens harboured a higher mass of helminth worms (3.8 ±SD 8.6g) than colonized, healthy chickens (1.9 ±6.3g). Eight species were identified, three nematodes (Ascaridia galli, Cheilospirura hamulosa and Heterakis gallinarum), four cestodes (Hymenolepis, Raillietina cesticillus, Raillietina echinobothrida, Raillietina tetragona,) and one trematode (Echinostomatidae). Heterakis gallinarum was the most prevalent helminth (43.3% and 42.2% in healthy and sick chickens, respectively), followed by A. galli (26.7% and 41.1%). Colonized chickens weighed 101.5g less than non-colonized birds. Colonisation was significantly higher during the rainy months (May-November) for both H. gallinarum and A. galli. Anthelminthic usage was not associated with reduced helminth burdens. We recommend upgrading cleaning and disinfection and limiting access to ranging areas to control helminth infections in small-scale commercial chicken flocks.

All-male giant freshwater prawns (AMGFPs) have been a popular crop cultivated in the Mekong Delta, Vietnam, due to their proven production efficiency compared to all-female or mixed-sex prawn cultures. However, the crucial water quality factors impacting AMGFP aquaculture efficiency have yet to be elaborately investigated. Two separate experiments were randomly arranged with three replicates to evaluate the effects of salinity or alkalinity on the growth and survival of AMGFP juveniles during the grow-out period. The results show that the prawn survival rate in the salinity range of 0–15‰ varied from 66.1 to 74.8％ and in a salinity range of 0–5‰ was relatively low compared to the range of 10-15‰; however, the difference was not significant among salinities after 90 days of culture (p > 0.05). All the prawn growth performance parameters significantly decreased with increasing salinities of 0, 5, 10, and 15‰ after 30, 60, and 90 days of culture (p < 0.05). Notably, the prawn yield did not significantly differ between salinities of 0 and 5‰ (p > 0.05), and both were significantly higher than those at salinities of 10 and 15‰ (p < 0.05) after 90 days of culture. In addition, the survival rate reached 82.5–84.4％ and did not significantly differ among alkalinities of 80, 100, 120, 140, and 160 mgCaCO3 L−1. However, the growth performance parameters and yield of AMGFPs at an alkalinity of 160 mg L−1 were significantly higher than those at lower alkalinities (80, 100, 120, and 140 mg CaCO3 L−1) after 90 days of culture. Therefore, it is recommended that a salinity range of 0–5‰ and alkalinity of 160 mgCaCO3 L−1 is optimal for the growth-out culture of AMGFP juveniles.

Sourced breeders from domesticated broodstocks have played an essential role in the steady development of shrimp culture in many countries. In the present study, two experiments were performed in Tra Vinh province, Vietnam, to compare the culturing benefits of sourced breeding stocks from domesticated and non-domesticated Penaeus monodon broodstock. The first 90-day experiment was randomly arranged with three repetitions in six earthen ponds (1,500–2,000 m2). Experimental shrimp (PL12) were stocked at a density of 20 ind. m−2. The second experiment was randomly designed with three repetitions in six composite tanks (6.0 m3). PL15 of experimental shrimp were cultured at a density of 30 ind. m−2 for 120 days. Grobest pellet feed (40 % protein) was used in both experiments. At experiment termination, the mean weight (26.09 g) and length (15.68 cm) under pond culture, as well as respective values of 15.57 g, and 13.21 cm under tank culture, for D-shrimp were significantly higher than those of W-shrimp (p<0.05). Similarly, the survival rate (84.33 %), FCR (0.98), and yield (3,558 kg ha−1) under pond culture, as well as the survival rate (87.59 %) and yield (470 g m−3) under tank culture, of D-shrimp were significantly better than those of W-shrimp (p<0.05). These results prove that the grow-out culture of shrimp postlarvae from domesticated broodstocks resulted in superior performance to those from wild broodstocks.