Journal of Animal Science and Technology最新文献

The objective of this study was to evaluate the effects of age on growth and fecal parameters, nutrient digestibility, hematology, and serum biochemistry of Beagle dogs. A total of 18 healthy Beagles were allotted into three groups according to age (puppy, under 1 year old; adult, 1-7 years old; senior, over 7 years old). The study lasted for 17 days, with a 7-day adaptation period and 10-day evaluation period. During the evaluation period, individual body weight, length, and food intake were estimated and recorded to calculate growth parameters. Fecal samples were collected from all beagles to evaluate fecal score and nutrient digestibility by visual observation and chemical analyses, respectively. Blood samples were collected from each dog to evaluate hematological and biochemical parameters using an automated hematology analyzer and clinical autoanalyzer, respectively. Puppy group had increased (p < 0.05) body weight change during the study compared with adult and senior groups. At the end of the food trial, body condition score of all age groups were ideal. Puppies had higher (p < 0.05) fecal moisture content and diarrhea frequency than adult and senior dogs. Senior group had lower (p < 0.05) apparent total tract digestibility (ATTD) of crude protein than puppy and adult groups. Puppy group had lower (p < 0.05) ATTD of ether extract, crude fiber, and nitrogen-free extract than adult and senior groups. Puppies had higher number of white blood cells and neutrophils at the initial (p < 0.05) and final (p = 0.062) day of the evaluation period than senior dogs. Senior dogs had lower (p < 0.05) levels of serum albumin, glucose, and creatinine during the evaluation than puppies. Puppy group had higher (p < 0.05) serum alkaline phosphate level at the initial and final day of the evaluation than adult and senior groups. In conclusion, our study determined the effect of age on growth and fecal parameters, nutrient digestibility, hematology, and serum biochemistry of Beagle dogs.

This study was conducted to examine the negative impact of heat stress on broiler chickens and laying hens and to explore the potential of dietary functional nutrients in mitigating these effects. Heat stress in poultry was found to negatively influence productivity and immune response while simultaneously increasing mortality, internal nutrient requirements, and stress-related hormones levels. These physiological changes led to increase of blood glucose levels, respiration, muscle tension, and neural sensitivity. To address these heat stress-induced challenges, the inclusion of functional nutrients in poultry diets may offer several benefits, including: (i) attenuation of heat stress responses, (ii) enhancement of immune function, (iii) improvement of antioxidant capacity, (iv) maintenance of productivity, and (v) promotion of intestinal health. These functional effects are expected to enhance disease resistance and overall productivity. However, the effectiveness of dietary functional nutrients may differ based on the specific type of additive, the method of administration, and physiological and environmental conditions. Therefore, it is crucial to optimize the selection and application of functional nutrients to the particular needs and context of each poultry farming operation. In conclusion, this study provides foundational insight and strategic recommendations for practical use of dietary functional nutrients to reduce the impact of heat stress in broiler chickens and laying hens.

The protein content of pet food affects its metabolizable energy content and palatability. Although pork is a high-quality protein source, it is not commonly used in pet food due to the lack of verification of its potential as a primary protein source. Hence, in this study, the potential of pork as a protein source in pet food was verified through digestibility testing involving beagle dogs. A pork-based diet made from pork hind legs and a chicken-based diet were provided to 12 beagle dogs. The palatability and digestibility of nutrients of the pork-based diet were compared with those of the chicken-based diet. The results showed that the palatability and apparent total tract digestibility of nutrients (dry matters, crude fat, crude ash, nitrogen-free extract, and amino acids) of the pork-based diet were similar to those of the chicken-based diet. This study suggests that pork hind legs can be used as a protein source in dog food.

Avian influenza (AI) is a serious global threat to poultry and public safety, although some native chicken varieties show resilience, such as the Ri chicken in Vietnam. Major histocompatibility complex B (MHC-B), a critical component of the chicken immune system, has been shown to influence disease resistance. This study examined the MHC-B haplotype diversity in a Ri chicken population that is sensitive to AI. Ri chickens were genotyped for MHC-B single nucleotide polymorphisms (SNPs) using the Kompetitive Allele Specific Polymerase Chain Reaction (KASP). Statistical tests revealed no significant differences in allele frequencies of the SNPs between resistant (R) and susceptible (S) groups. Haplotype analysis identified 32 unique haplotypes, with only one shared haplotype between the R and S groups. However, a phylogenetic analysis did not find distinct clustering of MHC-B alleles of the Ri chicken groups. Further research with a larger sample size is recommended to establish representative group-specific haplotypes and enhance our comprehension of the intricate genetic mechanisms underlying disease resistance in poultry. The implications of this research extend to improving disease resistance strategies and guiding selective breeding practices in the poultry industry.

Suckling piglets face the hurdle of pathogenic inversion before the full development of their gastrointestinal tract. The provision of Lactobacillus (L) salivarius guarantees resilient gut health, controls pathogens, increases microbiota, and fortifies intestinal structure. We evaluated the effect of L. salivarius LS144 probiotic given to suckling piglets through the post-weaning stage on the gut microbiota, intestinal morphology, and growth performance. A total of 120 three-day-old crossbred (Landrace × Yorkshire × Duroc) piglets were assigned to four dietary treatments on the basis of initial body weight. The NN group was not supplemented with the probiotic in both the suckling and post-weaning phases, the NP group was supplemented with the probiotic during the post-weaning phase, the PN group was supplemented with the probiotic only during the suckling phase, and the PP group was supplemented with the probiotic during both the suckling and post-weaning periods. Results revealed that the average daily gain was higher (p < 0.05) in the PN and PP groups than in the NN and NP groups in phase 1. In the overall study (1-51 d), average daily gain was greater (p < 0.05) in the PP treatment compared to all other groups. The average daily feed intake was higher (p < 0.05) in the PP group (22-51 d) than all groups. The villus height was greater in the duodenum (p < 0.05), jejunum (p < 0.05), and ileum (p < 0.05) in the PP compared with the NN. The pH of the intestinal digesta was higher (p < 0.05) in the NN treatment than in the PN and PP treatments in the duodenum. The population of total L. bacteria was greater in both the PN and PP groups compared to the NN treatment in the duodenum (p < 0.01), jejunum (p < 0.05), ileum (p < 0.01), and cecum (p < 0.01). There was no significant difference in the population of total anaerobes, Clostridium, and coliform bacteria in the duodenum, jejunum, ileum, and cecum among the groups. Based on these findings, dietary supplementation with L. salivarius in suckling piglets continued to post-weaning could establish appropriate intestinal microbiota, improve feed intake, and increase the villus height, which translates to improved growth performance during this critical period in piglet's life.

An experiment involving 720 one-day-old male broilers (Ross 308) was conducted to investigate the effects of graded levels of crude protein and standardized ileal digestible (SID) amino acids (AA) on growth performance during the pre-starter period (0 to 7 d), and to compare the subsequent growth performance of birds fed a commercial diet in the later phase (8 to 28 d). On d 1, all birds were individually weighed and allocated to six groups with eight replicate pens (15 birds/pen). Broilers were fed diets containing six different dietary SID AA levels relative to the 90 to 115% requirement for 7 d. From d 8 to 28, birds were fed a commercial diet containing nutrient levels meeting their dietary requirements. The body weight gain (BWG; p = 0.044) and gain-to-feed ratio (G:F; p = 0.005) of birds increased quadratically, and feed intake of birds linearly increased with increasing dietary AA concentration during d 0 to 7. Following the transition to a commercial diet, body weight at 14, 21, and 28 d, BWG, feed intake, and G:F linearly increased (p < 0.05). From 22 to 28 days of age, BWG (p = 0.001) and feed intake (p = 0.008) of birds linearly increased compared to the 90% SID AA treatment, whereas G:F was not affected (p = 0.088) by dietary treatment. Overall, BWG and the growth rate of broilers aged 8 to 28 d also exhibited linear increments (p < 0.01) by the dietary AA concentrations in diets during the first week. The study findings confirm the influence of dietary AA concentrations on the growth performance of broilers in the first week after hatch, demonstrating that this impact persists in the later growth stage. Therefore, ensuring sufficient dietary AA intake during the first week of life can enhance performance in later stages of development in broiler chickens.

In swine breeding programs, it has now become critically important to emphasize selection for resilience to external environmental stress factors that have negatively impacted the productivity of pigs, such as those due to climate change induced temperature increases, or the intensification of housing environments. Secretion of cortisol, a neurophysiological change mediated by the hypothalamic-pituitary-adrenal axis, is a central mechanism in the biological stress response. This hormone is closely related to pig robustness and health and can serve as an informative indicator of stress resistance and robustness in pigs. To identify positional candidate genes and their genetic variants influencing blood cortisol levels, we conducted genome-wide association study (GWAS), joint linkage and linkage disequilibrium (LALD) mapping and Bayesian fine-mapping analysis in an F₂ resource population generated by crossing Duroc pigs with Korean native pigs. The data used in the study included 243 F₂ animals. We utilized imputed whole-genome sequencing data for our analyses. GWAS results revealed a genome-wide significant quantitative trait locus (q-value < 0.05) located within a ~2.46 Mb region between single nucleotide polymorphisms 7:114031215 and 7:116497417 on pig chromosome 7, which accounted for 12.65% of the phenotypic variation. LALD mapping analysis was performed to narrow down the confidence interval (CI) of the quantitative trait locus which resulted in a CI of 2.39 Mb (7:114409266~116803751). Further, to identify candidate causal genes within the 2.39 Mb region, fine-mapping analysis was performed within the region. The fine-mapping analysis identified SERPINA1, ITPK1, CLMN, SERPINA12, and PRIMA1, in addition to SERPINA6, which was previously shown to be associated with blood cortisol levels. Our results identified positional candidate genes and genetic variants associated with serum cortisol concentrations that can be included in marker panels for genomic prediction to improve selection for robustness in pigs.

[This corrects the article DOI: 10.5187/jast.2024.e7.].

This study explored the correlation between anti-Müllerian hormone (AMH) levels and reproductive efficiency in native Korean cattle (Hanwoo) as potential oocyte donors in ovum pick-up (OPU) programs. In an effort to enhance the efficiency of oocyte collection, this research explored the correlation between AMH levels and various factors, including the quantity of follicles, retrieved oocytes, and the proportion of transferable embryos. A total of 42 Hanwoo cows were included in this study with AMH levels ranging from 276.5 to 2,212.5 pg/mL. These cows were categorized into three groups based on AMH concentration: high (H), medium (M), and low (L), along with the control group. To monitor the quantity of antral follicles in each group during OPU, Ultrasound scanner was used, and the retrieved oocytes were duly recorded. The implantable embryos produced from the retrieved oocytes were quantified. The results show a significant positive correlation between AMH levels and the numbers of antral follicles (R² = 0.5785, p < 0.0001), retrieved oocytes (R² = 0.6857, p < 0.0001) and transferable embryos (R² = 0.4049, p < 0.0001), indicating that higher AMH levels correspond to increased numbers of antral follicles and retrieved oocytes. However, the correlation between AMH levels and the proportion of transferable embryos was not statistically significant (R² = 0.1476, p = 0.5225). In conclusion, AMH levels were significantly correlated with the number of antral follicles and retrieved oocytes, demonstrating their potential as indicators for selecting oocyte donors for Hanwoo cattle. Although the relationship with the proportion of transferable embryos was not statistically significant, this study offers valuable insights for the improvement of the efficiency of oocyte donation plans in Hanwoo cattle by considering the AMH levels.

This study aimed to investigate lactic acid bacteria with antimicrobial activities against infectious diarrheal pathogens in pigs and their genetic characteristics. Acid-resistant lactic acid bacteria were examined for bile resistance, pancreatic enzyme resistance, gelatinase and urease activities, and antibiotic resistance. Subsequently, selected isolates were examined for antimicrobial activities against Campylobacter coli, Clostridium perfringens, Escherichia coli, and Salmonella Typhimurium, and their effects on paracellular permeability and the expression of tight junction protein-encoding genes in HT-29 cells were assessed. Whole genome sequencing was performed to identify the genes related to safety and antibacterial activity. Of the 51 isolates examined, 12 were resistant to bile and pancreatin and did not produce gelatinase and urease. Of these 12, isolates 19, 20, 30, 36, and 67 showed tetracycline resistance and isolates 15, 19, and 38W showed antimicrobial activity against infectious diarrheal bacteria. Treatment with isolate 38W significantly reduced the paracellular permeability induced by E. coli in HT-29 cells and alleviated the expression of tight junction protein-encoding genes (claudin-1, occludin, and ZO-1) induced by E. coli inoculation. Isolates 15, 19, and 38W were named as Pediococcus pentosaceus SMFM2016-NK1, SMFM2016-YK1, and SMFM2016-WK1, respectively. Bacteriocin-related genes were YheH, ytrF, BceA, BceB, and MccF in SMFM2016-NK1; YheH, ytrF, BceA, BceB, entK, lcnA, MccF, and skgD in SMFM2016-YK1; and YheH, ytrF, BceA, BceB, and MccF in SMFM2016-WK1. SMFM2016-YK1 harbored the tetM gene. These results indicate that P. pentosaceus SMFM2016-WK1 might control diarrheal pathogens isolated from pigs. However, a further study is necessary because the results were obtained only from in vitro experiment.