Vol. 21 No. 9 (2023)

Respiratory disease complex has emerged as a major challenge for the poultry industry. Pathogens and co-infections in respiratory disease complex such asviruses (AIV, IBV, ILTV, NDV, aMPV) and bacteria/mycoplasma (APG, ORT, APEC, MG) were anattractive research topics worldwide. In Vietnam, the etiology of respiratory diseases has only been noticed in the last few years. Due to its novelty, by molecular biology technique, this study was conducted to detect several pathogens in chickens suffering from respiratory diseases in northern Vietnam. There were 127/157 (80.9%) of the samples positive for at least 1 out of 9 viruses, bacteria/mycoplasma (AIV, IBV, ILTV, NDV, aMPV, APG, ORT, APEC, MG). Of those 127 positive samples, the highest frequency (100/127) was the co-infections between viruses and bacteria. Among 51 co-infection patterns, 41/51 patterns were the co-infection between 2-6 agents.

Avian metapneumovirus(aMPV) is a newly recognized respiratory pathogen in Vietnam but has currently received less interest from veterinary scientists. In continuation of the previous published studies, this study aimed to describe some characteristics of seroprevalence of antibodies against Avian metapneumovirus according to flock size, infected breeds, and variation of antibody titers between age- groups. The indirect ELISA technique detected the presence of specific antibodies against aMPV in 130/359 samples (36.2%) randomly collected from 29 chicken farms (without history of using vaccine against aMPV) in 10 provinces in northern Vietnam. Chickens belonging to all flock sizes had specific aMPV antibodies ranging from 24.8%-63.2%. Meat type birds of many breeds had natural antibodies against aMPV of 8.2% for broiler chickens, 35.0% for hybrid chickens and 48.8% for native chickens. Of the sero-positive sera, the antibody titers against aMPV of chickens from 4 age-groups were variable in a relatively wide range, from 102.6to 104.2.

The study was conducted to evaluate the influence of breed, body condition score (BCS- Body condition scores), ovary volume and the largest follicle size on some parameters related to the number and quality of bovine oocytes (classify as A, B level were good oocytes and C, D level were not good oocytes). The results showed that there was no significant difference on the average number of follicles on the ovary surface, the number of oocytes obtained, and the ovary volume between the cattle breeds but the average mass of follicles/ovary. Specifically, the average volume of follicles/ovary in Yellow cattles (6.11g) was higher than in Dairy cattles (2.66g, P <0.05). BCS did not affect the mean follicle size, mass, and the total number of follicle obtained. Ovarian mass, the largest follicle size had an influence on the total number of follicles and the number of oocytes obtained. Ovaries with a mass of 5-10g having the average total number of follicles, the total number of A, B and C, D follicles accounted for the highest number (11.21 follicles; 3.9 and 6.51 oocytes). Similarly, the number of A-B and C-D oocytes obtained from the ovary with the largest follicle size ranged 3-7mm were 4.06 and 7.09, respectively (P <0.005).

This study was conducted to describe the cumulative egg production curves and determine the best model to estimate the cumulative egg production of Mia hens raised at Hadinco livestock farm, Son Tay Town, Hanoi from June 2021 to May 2022. The cumulative egg production was recorded from 23 weeks (the zero-week egglaying) to 74 weeks of age (51 weeks of the egglaying) from 300 Mia hens. Nine nonlinear models were used to be fitted the data of cumulative egg production of Mia hens. The upper asymptotic cumulative egg production at 52 weeks of egglaying was 85.98 eggs. The number of eggs produced (NEPt) reached the maximum at the 9th week of egglaying (2.57 eggs per hen per week). Lopez function appeared best to describe cumulative egg production of Mia hens with the highest coefficient of determination (99.91%) and the lowest AIC (377.74), BIC (392.99), and SER (0.45). These results suggest that Lopez functions can be applied to estimate the cumulative egg production, number of eggs per hen per week of other local chicken breeds that similar egg production as the Mia hens.

Nghiên cứu được tiến hành để đánh giá các chỉ tiêu sinh lý và sinh hóa máu của 4 giống vịt địa phương ở Miền Bắc Việt Nam. Tổng số 115 mẫu máu của vịt Cỏ, Pất Lài, Nà Tấu, Trời được thu thập từ các tỉnh Hà Tây, Lạng Sơn, Điện Biên và Bắc Ninh để xác định các chỉ tiêu nghiên cứu. Số liệu được phân tích bằng mô hình tuyến tính GLM và xử lý thống kê bằng phần mềm SAS. Hầu hết các chỉ tiêu sinh lý và tất các các chỉ tiêu sinh hóa có sự sai khác thống kê giữa các giống vịt (P <0,05). Cụ thể, số lượng, thể tích hồng cầu, bạch cầu lâm ba và ái kiềm ở vịt Cỏ; thể tích trung bình và khối lượng hemoglobin trong một hồng cầu ở vịt Pất Lài; số lượng bạch cầu ở vịt Pất Lài và vịt Trời, bạch cầu trung tính ở vịt Nà Tấu và vịt Trời được tìm thấy cao hơn so với các giống khác. Protein tổng số và hàm lượng albumin ở vịt Cỏ, Pất Lài và hàm lượng globulin ở vịt Nà Tấu cao hơn so với ở các giống vịt khác. Giới tính ảnh hưởng đến hầu hết các chỉ tiêu sinh lý và sinh hóa máu. Sự tương tác giữa giống và giới tính được quan sát thấy ở hầu hết các chỉ tiêu nghiên cứu (P <0,05).

The study was carried out from June 2021 to May 2022 to investigate the usage and bioactive compounds of indigenous plants commonly used in pig production. A total of 120 pig raising households in 3 provinces Hai Duong, Bac Giang, and Hoa Binh in Northern Vietnam were selected for interview using the preprepared questionnaires. After the survey, 16 potential plant species from studied regions were collected for determining their bioactive compounds and antioxidant capacity. Results showed that thirty-nine indigenous plant species were used as feed supplement for raising pigs in surveyed households, in which 5 indigenous plants, viz.Ipomoea batatas(86.67%), Bidens pilosa(55.83%), Uurena lobata(48.33%), Pseuderanthemum palatiferum(42.50%), and Wedelia chinensis(41.67%) were mainly used. Indigenous plants were used for different purposes such as improving animal health (69.12%), anti-inflammatory agents (41.03%), providing dietary fiber (38.46%), treatting diarrhea disease (28.21%), and enhancing animal product quality (25.64%). The higher content of polyphenols was found in 5 indigenous plants, i.e. Camellia sinensis, Manilkara zapota, Mangifera indica, Phyllanthus urinaria,and Psidium guajava, with polyphenol content ranging from 15.43 to 120.8 mgGAE/g DM. Moreover, 5 indigenous plants having stronger antioxidant activity were Camellia sinensis, Phyllanthus urinaria, Psidium guajava, Mangifera indica, and Ramalus cinnamomiand they showed better DPPH free radical scavenging activity with IC50 values less than 11.83 μg/ml. The research could serve as basis for selecting potential plants as herbs containing high polyphenol content and antioxidant activity for testing on live animals for various purposes.

The aimsof this study wereto investigate the pathological features and tisue tropism of classical swine fever virus (CSFV) in the internal organs of the naturally infected pigs in some provinces inNorth Vietnam. Necropsy was performed on 8 CSFV infected pigs at differentagesto observe the gross lesions, collect specimens for histopathological study and detect viral antigen by immunohistochemistry. The gross findings included haemorrhages, inflamation in lymph system, spleen margin infarction, petechialor diffusehaemorrhages in various organs. The microscopic lesions weremainly hyperemia,haemorrhages, lymphoid deleption, necrotic and vascular cuffing in most internal organs. Immunohistochemical examination revealed thepresent of CSFV antigen in all 12 organs with high virus load in lymph nodes, spleen, lung and kidney. This is the first report about tissue tropisms of CSFV in the infected pigs by using IHC method inNorthVietnam.These results suggested the circulating virus was high virulent and induced acute disease form in the infected herds.

The objective of this study was to evaluate effect of stocking density on growth performance and surface temperature of different body parts in broilers. A total of 1000 one-day-old broiler chicks (Ross 308) were assigned to two treatments in a completely randomized design. The stocking density treaments were (1) 9 chicks/m2(SD 9) and (2) 13 chicks/m2(SD 13). Each treatment had 20 replicate pens (50% female and 50% male/pen). The experimental results showed that there was no difference in average daily weight gain between two treatments (P >0.05). However, broilers in the SD 9 group had a better feed conversion ratio than those in the SD 13 group (P = 0.048). The survival rate of broilers in the SD 9 group (99.8%) was greater (P <0.001) than that of broilers in the SD 13 group (95.8%). Moreover, the body surface temperature of broilers in the SD 9 group (32,3C) was much lower (P = 0.003) than that of broilers in the SD 13 group (36.0C). A similar trend was also observed for the shank and neck surface temperature of broilers (P <0.05). Briefly, the stocking density of 9 broilers/m2improved the feed conversion ratio, survival rate and body surface temperature of broilers as compared with the stocking density of 13 broilers/m2.

Diarrhea in pre-weaning piglets is one of the most common diseases in modern pig production, causing high mortality, reducing growth rate and increasing treatment costs. This prospective study on a commercial pig farm was conducted to identify the diarrhea prevalence, the factors associated with diarrhea, and the effect of diarrhea on weaning weight of piglets. The results showed that the proprtion of cumulative diarrhea for 21 days in suckling piglets was 36.70% (95% CI 32.91-40.62) with a mortality rate of 0% (95% CI: 0-0.59). Neonatal piglets experienced diarrhea from 1 day of age (11.86%), peaked at day 5 (22.6%), then gradually decreased and kept at a low level from 11 days of age to weaning. There were 3 factors associated to diarrhea in suckling piglets including birth weight of piglets, diarrhea inflicted sows and metritis inflicted sows. The factors of diarrhea duration and birth weight were related to maternalassociated weaning weight of piglets.

This study aimed to evaluate the effect of dietary nanocurcumin on growth performance, carcass yield, meat quality and blood physiological parameters of Ross 308 chicken. A total of 120 one-day-old Ross 308 chickens were randomly allocated into two treatments: (1) control group fed basal diet and nanocurcumin group feda basal diet supplemented with 200 mg nanocurcumin per kg. Each group was replicated three times. The results showed that supplemntation with nanocurcumin in the diet did not affect the survival rate, daily gain, body weight, daily intake, carcass yield and meat quality (P >0.05). The feed conversion ratio in nanocurcumin group (1.32) was lower than in the control group (1.36) (P <0.05). Proportions of abdominal fat, the weight of the liver, heart and spleen were not different between control and nanocurcumin groups (P >0.05). Dripp loss, pH and meat tenderness did not significantly different, except b* values of breast (P <0.05). Hematological parameters in nanocurcumin group were higher than those in control group (P <0.05), except lymphocytes proportion.

Nghiên cứu này được thực hiện trên gà trống lai F1(♂Đông Tảo x ♀Lương Phượng) từ 7 đến 13 tuần tuổi nhằm đánh giá ảnh hưởng của bổ sung bột quế đến khả năng sinh trưởng và một số chỉ tiêu sinh hoá, sinh lý máu gà. Tổng số 90 con gà được chia ngẫu nhiên vào 3 lô, mỗi lô 30 con. Từ 7 tuần tuổi gà được nuôi bằng các khẩu phần ăn thí nghiệm gồm: lô đối chứng không bổ sung bột quế, lô 2 (CT1) bổ sung 2 gam bột quế/kg thức ăn và lô 3 (CT2) bổ sung 2,5 gam bột quế/kg thức ăn. Khả năng sinh trưởng, năng suất thịt của gà ở 2 lô bổ sung bột quế cao hơn so với lô đối chứng (P <0,01). Chỉ tiêu cholesterol toàn phần, LDL-cholesterol ở lô CT1 và lô CT2 thấp hơn so với lô đối chứng (P <0,05), trong khi HDL-cholesterol của lô CT1 và lô CT2 cao hơn so với lô đối chứng (P<0,05). Chỉ tiêu AST và ALT ở lô CT1 và lô CT2 thấp hơn so với lô đối chứng (P <0,05). Tế bào lympho và bạch cầu trong máu gà ở lô CT1 và lô CT2 thấp hơn so với lô đối chứng (P <0,05). Gà được nuôi bằng khẩu phần ăn của lô CT1 có chi phí để sản xuất 1kg gà thấp hơn so với lô đối chứng và lô CT2.

The research was conducted to improve the quality of in introbovine embryo vitrification. Bovine oocyteswere matured thenfertilizedwith frozen-thawed semen at1, 2or 5× 106sperm/ml for 6 hours to find the optimal conditions. Theblastocysts were then rapidly frozen in the medium using TCM199+BSA (Tissue culture medium-199+Bovine serum albumin) or DPBS+FBS (Dulbecco's phosphate-buffered saline+Fetal bovine serum). There was no significant difference in the maturation rateof oocytes matured in BO-IVM or TCM-199 medium. In vitrofertilized bovine oocyteswith frozen-thawed sperm atconcentration of 2 × 106sperm/ml for 6 hours gave the highest fertilization and blastocyst rate. The survival rate after thawing of bovine embryosfrozenin DPBS+FBS and TCM199 + BSA medium was92.96% and 82.71%, respectively, however, there was no significantdifference between the groups. Thehatching rate after thawing of embryos vitrified in TCM 199 + BSA medium reached 54%, significantly higher than that ofembryos vitrifiedin DPBS+FBS medium (28.8%). Inthe gene-edited embryo group, the number of survival embryos after thawing reached 96.03 % compared to 88.82 % in the IVF group. The source of oocytesalso affected the survival rate of embryos after thawing.

The study was conducted to evaluate the maturation rate and development of frozen porcine oocytes by vitrification method. After thawing, porcine oocytes were matured in Porcine Oocyte Maturation medium (POM), then fertilized with frozen-thawed semen and cultured in Porcine Zygote Medium (PZM3); non-frozen porcine oocytes were cultured in the same procedure as control. The results showed the maturation rate (64.97 ± 3.42%), fertilization rate (74.37 ± 2.08%) and blastocyst formation rate (9.61±1.81%) of frozen-thawed porcine oocytes. This appeared that for the first time in Vietnamimmature pig oocytes were frozen by vitrification and developed to blastocyst stage after thawing, although these results were lower than those of the group of eggs without cryopreservation with maturation and embryogenesis rates of 84.30 ± 1.90% and 46.68 ± 5.86% and 22.96 ± 3.53%, respectively. This study shows that vitrification had great potential in the application of immature pig oocytes.

The law of diminishing returns(LDR) has been applied in numerous fields, including livestock production, to determine the optimum level of a certain variable input. This integrated review tries to synthesize and discuss the appropriateness of LDR in describing profiles of livestock yields and grass regrowth after each cutting in response to to increased levels of a variable production input, as well as to analyse and generalize major applications of the law in determining the optimum levels for a number of important variables such as slaughtering age, feeding level, nutrient contents in the ration, grass cutting interval, herd size, stocking density, etc. in order to balance economic profit, social justice, environmental protection, and animal welfare, thus ensuring sustainable development of livestock production.

Intensification of livestock production has negatively affected animal welfare and the ecosystem. Improvement of animal welfare has been increasingly concerned and put in laws or regulations. In fact, animal welfare, which is directly associated and interacted with human well-being and the environment, has led to the new concept of one health and one welfare. The aim of this paper is to help policy makers, professionals, producers and stakeholders to identify more clearly the interrelationship among animal welfare, human welfare, and environmental protection, and thus to promote the collective or joint actions to achieve sustainable development goals. Improvement of animal welfare would help improve human welfare and vice versa. Environmental protection is crucial for the welfare of human and animals and fundamental to sustainable development. One welfare should be a comprehensive aproach to ensure sustainable development of livestock production. To put this approach into practice, it is needed to develop an assessment framework and a program with standards and practical guidelines for one welfare application.