Growth is an economically important trait for farm animals and can be defined as any change in body size such as body weight or length per time unit (Narinç et al. 2017). This trait is influenced by genetic factors, environmental factors such as feeding condition, and the interaction between them. The knowledge of animal growth is important for the improvement of management and feeding practices in order to maximize the profit of livestock industry (Narinç et al. 2017; Do & Miar 2020). Mathematical models have been successfully characterized growth patterns and visualized the shape of growth over time. Among these models, non-linear models are the most applied models as they allow the interpretation and understanding of growth patterns underlying growth periods (Schnute 1981). Several non-linear models such as the Gompertz (Gompertz 1825), Logistic (Pearl 1977), Bridges (Bridges et al. 1992), and Richards (Richards & Kavanagh 1945) are widely used to describe the growth curve (Kaplan & Gürcan 2018). The growth parameters derived from mathematical models have shown that these parameters are heritable and are responsive to the selection programs (Mignon-Grasteau et al. 2000; Manjula et al. 2018).In Vietnam, chicken is one of the most common farm animals.The species is not only important for the food resources for people but also for the cultures of the country. Vietnam owns about

The aim of this study was to evaluate the effects of diets containing rice distillers’ by‐product (RDP) on growth performance, carcass characteristics, meat quality, and gut microbiota of fattening pigs. Twenty‐four crossbred finishing pigs (Duroc × Landrace × Yorkshire), 56.9 ± 3.1 kg initial body weight, were randomly allocated to three groups. For 56 days, pigs were fed one of three diets including RDP0 (control), RDP15 (15% RDP in DM), and RDP30 (30% RDP in DM). With RDP level in diet, average daily gain and backfat thickness linearly increased (p < 0.05), and drip loss tended to increase (p ≤ 0.08). In addition, 16S ribosomal RNA gene amplicon profiling showed that RDP was associated with modulation of colonic microbiota composition, especially at family and genus levels. Relative abundance of Porphyromonadaceae and Erysipelotrichaceae families in colonic digesta increased with inclusion of RDP, while that of Enterobacteriaceae decreased. The proportion of genera unclassified Erysipelotrichaceae, and Butyrivibrio increased as inclusion of RDP. These results indicate that up to 30% inclusion in diet of finishing pigs, RDP can modulate colonic microbiota composition, and induces an improvement of animal growth and fat deposition.

The aim of the present study was to improve the penetration during in vitro fertilization (IVF) of a frozen lot of epididymal sperm with a notoriously low fertilization ability of a Ban boar which is a native Vietnamese breed by optimizing different parameters of the IVF system. In Experiment 1, we determined that Pig-fertilization medium was superior medium to Tyrode's albumin lactate pyruvate-polyvinyl alcohol medium for IVF and defined the optimum the sperm concentration (1 × 10 sperm/ml). In Experiment 2, we clarified that partial removal of cumulus cells from cumulus-oocyte complexes by hyaluronidase treatment before IVF enhances sperm penetration, whereas complete cumulus removal reduces penetration. Finally, in Experiment 3 the elevation of concentration of caffeine in Pig-fertilization medium from 2 to 5 mmol/L and the prolongation of the co-culture of gametes from 3 to 5 hr significantly increased the total penetration rate from 15.2% to over 50%. In conclusion, the combination of partial oocyte denudation, an elevated caffeine concentration in Pig-fertilization medium and an extended interval of IVF with using an optimized sperm concentration was a potent way to improve the fertilization results for a frozen epididymal Ban sperm lot with low fertility.

This study was conducted in Mia chicken breed to evaluate the association between four single nucleotide polymorphisms (SNPs), in insulin (INS) and growth hormone (GH) genes, with growth traits. Three genotypes for the SNP A3971G of INS gene and the SNP G662A and C423T of GH gene were present in the population while only two genotypes were found in the Mia chicken breed for SNP T3737C of INS gene (TT and TC). The SNP T3737C INS gene and G662A GH gene had significant association with growth traits (P < 0.05). A significant association of T3737C INS gene with body weight (BW) was observed at 10 to 12 weeks of age and average daily gain (ADG) at 6-8 weeks of age. The SNP G662A of the GH gene was significantly associated (P < 0.05) with BW of Mia chicken at ages from 7 to 14 weeks and with ADG (4-6; 6-8; 8-10; 10-12 and 2-16 weeks). Chicken with the GG genotype had greater BW and ADG compared to the other genotypes. The results demonstrated that this SNP G662A GH gene may be used as a candidate marker gene for genetic improvement of growth traits in Mia chicken breed.

Vietnam is an agricultural country, with 70% of the human population living in rural areas (Desvaux, Vu Dinh, Phan Dang, & Pham Thi, 2008). In these areas, nearly 50%-90% of households own livestock (Burgos, Hong Hanh, Roland-Holst, & Burgos, 2007). Moreover, according to Ngoc (2020), approximately 7,864,700 households raised poultry in 2019. Local chickens in Vietnam account for over 70% of the national poultry population (Lan Phuong, Dong Xuan, & Szalay, 2015). There are 21 local chicken breeds, of which Ri, Tau Vang, Mia, Dong Tao and Ho are the most popular and historical breeds in specific regions (Pham Cong, 2016). Although these breeds are abundant, their productivity is low. Moreover, to meet consumer demand, livestock