Asian-Australasian Journal of Animal Sciences最新文献

Objective: This study assessed the effects of probiotics on cecal microbiota, gene expression of intestinal tight junction proteins, and immune response in the cecal tonsil of broiler chickens challenged with Salmonella enterica subsp. enterica.

Methods: One-day-old broiler chickens (n = 240) were randomly allocated to four treatments: negative control (Cont), multi-strain probiotic-treated group (Pro), Salmonella-infected group (Sal), and multi-strain probiotic-treated and Salmonella-infected group (ProSal). All chickens except those in the Cont and Pro groups were gavaged with 1×108 cfu/mL of S. enterica subsp. enterica 4 days after hatching.

Results: Our results indicated that body weight, weight gain, and feed conversion ratio of birds were significantly reduced (p<0.05) by Salmonella challenge. Chickens challenged with Salmonella decreased cecal microbial diversity. Chickens in the Sal group exhibited abundant Proteobacteria than those in the Cont, Pro, and ProSal groups. Salmonella infection downregulated gene expression of Occludin, zonula occludens-1 (ZO1), and Mucin 2 in the jejunum and Occludin and Claudin in the ileum. Moreover, the Sal group increased gene expression of interferon-γ (IFN-γ), interleukin-6 (IL-6), IL-1β, and lipopolysaccharide-induced tumor necrosis factor-alpha factor (LITAF) and reduced levels of transforming growth factor-β4 and IL-10 compared with the other groups (p<0.05). However, chickens receiving probiotic diets increased Lactobacillaceae abundance and reduced Enterobacteriaceae abundance in the ceca. Moreover, supplementation with probiotics increased the mRNA expression of Occludin, ZO1, and Mucin 2 in the ileum (p<0.05). In addition, probiotic supplementation downregulated the mRNA levels of IFN-γ (p<0.05) and LITAF (p = 0.075) and upregulated IL-10 (p = 0.084) expression in the cecal tonsil.

Conclusion: The administration of multi-strain probiotics modulated intestinal microbiota, gene expression of tight junction proteins, and immunomodulatory activity in broiler chickens.

Objective: This study was conducted to estimate genetic parameters for milk yield traits using daily milk yield records from parlour data generated in an intensively managed commercial dairy farm with Jersey and Jersey-Friesian cows in Sri Lanka.

Methods: Genetic parameters were estimated for first and second lactation predicted and realized 305-day milk yield using univariate animal models. Genetic parameters were also estimated for total milk yield for each 30-day intervals of the first lactation using univariate animal models and for daily milk yield using random regression models fitting second-order Legendre polynomials and assuming heterogeneous residual variances. Breeding values for predicted 305-day milk yield were estimated using an animal model.

Results: For the first lactation, the heritability of predicted 305-day milk yield in Jersey cows (0.08±0.03) was higher than that of Jersey-Friesian cows (0.02±0.01). The second lactation heritability estimates were similar to that of first lactation. The repeatability of the daily milk records was 0.28±0.01 and the heritability ranged from 0.002±0.05 to 0.19±0.02 depending on day of milk. Pearson product-moment correlations between the bull estimated breeding values (EBVs) in Australia and bull EBVs in Sri Lanka for 305-day milk yield were 0.39 in Jersey cows and -0.35 in Jersey-Friesian cows.

Conclusion: The heritabilities estimated for milk yield in Jersey and Jersey-Friesian cows in Sri Lanka were low, and were associated with low additive genetic variances for the traits. Sire differences in Australia were not expressed in the tropical low-country of Sri Lanka. Therefore, genetic progress achieved by importing genetic material from Australia can be expected to be slow. This emphasizes the need for a within-country evaluation of bulls to produce locally adapted dairy cows.

Ahead of Print article withdrawn by publisher.

Objective: Milk fatty acid (FA) is a main nutritional component that markedly effects human health. Intentional modification of the FA profile has the potential to improve milk quality. This study aimed at the factors affecting elevated FA levels and the estimation of the genetic parameters for milk FAs in the Korean Holstein population.

Methods: Total 885,249 repeated test-day milk records including, milk yield, saturated fatty acids (SFA), polyunsaturated fatty acids (PUFA), monounsaturated fatty acids (MUFA), total unsaturated fatty acids (TUFA), fat and protein percentages were analyzed using CombiFoss FT+ system (Foss Analytical A/S, Denmark). Genetic parameters were estimated by the restricted maximum likelihood procedure based on the repeatability model using the Wombat program.

Results: The FA profile varies along with the lactation and the energy balance (EB). With the negative EB in early lactation, mobilization of body fat reserves elevates the desirable FA levels. As a result of that, milk quality is increased by means of nutritionally and usability aspects during the early lactation. Moreover, heritability estimates for SFA, MUFA, PUFA, TUFA were 0.33, 0.42, 0.37, 0.41 respectively. According to the parity wise heritability analysis, first parity cows had relatively lower heritability for SFAs (0.19) than later parities (0.28).

Conclusion: Genetic parameters indicated that FAs were under stronger genetic control. Therefore, we suggest implementing animal breeding programs towards improving the milk FA profile.

Objective: This study aimed to determine the effects of stress during slaughter of beef cattle on physiological parameters, carcass, and meat quality at a Federal Inspection Type slaughterhouse located in the southeast of Mexico.

Methods: A total of 448 carcasses of male Zebu×European steers with an average age of 36 months were included. Carcass assessment of presence of bruises and bruise characteristics was carried out on each half-carcass. Blood variable indicators of stress (packed cell volume, neutrophil to lymphocyte ratio, glucose, cortisol concentration) and meat quality parameters (pH, color, shear force, drip loss) were evaluated.

Results: Of the 448 carcasses evaluated, 81% of the carcasses showed at least one bruise; one bruise was detected in 36.6% and two bruises in 27.0% of animals. Of the 775 bruises found, 69.2% of the bruises were grade 1 in region 3. Of the 448 carcasses studied, 69.6% showed hyperglycemia (6.91 mmol/L); 44.3% and 22.7% showed high (74.7 ng/mL) and extremely high (108.8 ng/mL) cortisol levels, respectively, indicative of inadequate handling of animals during preslaughter and slaughter. Of the carcasses evaluated, 90.4% had a pH ≥5.8 with an average of pH 6.3. In both pH groups, meat samples showed L* values >37.0 (81.6%) and a shear force >54.3 N; meat pH≥5.8 group showed a drip loss of 2.5%. These findings were indicative of dark, firm, and dry (DFD) meat. According to principal component analysis, grades 1 and 2 bruises in region 3 and grade 1 bruises in region 5 were highly associated with cortisol, drip loss, and color parameters b* and h* and were negatively associated with L*, a*, and C*.

Conclusion: The bruises probably caused by stress-inducing situations triggered DFD meat. Appropriate changes in handling routines in operating conditions should be made to minimize stress to animals during the slaughter process to improve animal welfare and meat quality.

Objective: A total of three hundred unsexed ducks were utilized to estimate net energy requirements of maintenance (NEm) and weight gain (NEg) for 2 to 3-week-old Cherry Valley ducks and to establish a model equation to predict NE requirements using the factorial method.

Methods: To determine the apparent metabolizable energy (AME) of the diet, fifty 7-day-old ducks at approximately equal body weights (BWs) were randomly assigned into five groups that were fed at different levels (ad libitum, 85%, 75%, 65%, and 55% of ad libitum intake), and the endogenous acid-insoluble ash as indigestible marker. The two hundred and fifty 7-day-old ducks were used for a comparative slaughter experiment. At the beginning of the experiment, ten ducks were sacrificed to determine the initial body composition and energy content. The remaining ducks were randomly assigned into five groups (same as metabolic experiment). Ducks of the ad libitum group were slaughtered at 14 and 21-dayold. At the end of the experiment, two ducks were selected from each replicate and slaughtered to determine the body composition and energy content.

Results: The results of the metabolizable experiment showed AME values of 13.43 to 13.77 MJ/kg for ducks at different feed intakes. The results of the comparative slaughter experiment showed the NEm value for 2 to 3-week-old Cherry Valley ducks was 549.54 kJ/kg of BW0.75/d, and the NEg value was 10.41 kJ/g. The deposition efficiency values of fat (Kf) and crude protein (Kp) were 0.96 and 0.60, respectively, and the values of efficiency of energy utilization (Kg) and maintenance efficiency (Km) were 0.75 and 0.88, respectively.

Conclusion: The equation for the prediction of NE requirements for 2 to 3-week-old Cherry Valley ducks was the following: NE = 549.54 BW0.75+10.41 ΔW, where ΔW is the weight gain (g).

Objective: This study was designed to determine how feeding diets differing in crude protein (CP) and undegraded intake protein (UIP) levels affected productivity, blood metabolites, carcass characteristics, and the production economics of Hanwoo steers.

Methods: Thirty-six Hanwoo steers (age = 8.2±0.5 mo; body weight = 254±16.1 kg) were assigned at random to one of three treatments (4 steers/pen; 3 pens/treatment): i) a low-CP diet (LP; control) containing 12.1% CP with 35.1% UIP, 12.0% CP with 36.8% UIP, and 12.9% CP with 48.8% UIP, in the growing, fattening, and finishing periods, respectively; ii) a high-CP, low-UIP diet (HPLU) containing 15.0% CP with 33.7% UIP, 14.0% CP with 35.7% UIP, and 13.1% CP with 46.7% UIP, respectively; and iii) a high-CP, high-UIP diet (HPHU) containing 15.0% CP with 45.8% UIP, 14.0% CP with 44.6% UIP, and 13.0% CP with 51.1% UIP, respectively.

Results: The treatments did not affect feed intake and growth performance, except for average daily gain during the fattening period that tended to be the lowest (p = 0.08) in the HPLUfed steers. The feed CP conversion ratio over the entire feeding period was higher with high-CP diets. The treatments did not affect most blood metabolites; however, blood cholesterol and low-density lipoprotein concentrations during the fattening and finishing periods were the lowest in steers fed a HPLU diet. The treatments had negligible effects on cold carcass weight, yield traits including longissimus muscle area, backfat thickness, yield index, and yield grade, plus quality traits including meat color, fat color, texture, and maturity. However, marbling score and frequency of carcass quality grade 1++ were greater in HPHU-fed steers.

Conclusion: Feeding diets with higher CP and UIP levels did not affect growth performance but tended to improve the carcass quality of Hanwoo steers, resulting in greater economic return.

Plant-based meat analogues, edible insects, and cultured meat are promising major meat alternatives that can be used as protein sources in the future. It is also believed that the importance of meat alternatives will continue to increase because of concerns on limited sustainability of the traditional meat production system. The meat alternatives are expected to have different roles based on their different benefits and limitations. Plant-based meat analogues and edible insects can replace traditional meat as a good protein source from the perspective of nutritional value. Furthermore, plant-based meat can be made available to a wide range of consumers (e.g., as vegetarian or halal food products). However, despite ongoing technical developments, their palatability, including appearance, flavor, and texture, is still different from the consumers' standard established from livestock-based traditional meat. Meanwhile, cultured meat is the only method to produce actual animal muscle-based meat; therefore, the final product is more meat-like compared to other meat analogues. However, technical difficulties, especially in mass production and cost, remain before it can be commercialized. Nevertheless, these meat alternatives can be a part of our future protein sources while maintaining a complementary relationship with traditional meat.

Objective: The rapid and reliable detection of the African swine fever virus (ASFV) plays an important role in emergency control and preventive measures of ASF. Some methods have been recommended by FAO/OIE to detect ASFV in clinical samples, including realtime polymerase chain reaction (PCR). However, mismatches in primer and probe binding regions may cause a false-negative result. Here, a slight modification in probe sequence has been conducted to improve the qualification of real-time PCR based on World Organization for Animal Health (OIE) protocol for accurate detection of ASFV in field samples in Vietnam.

Methods: Seven positive confirmed samples (four samples have no mismatch, and three samples contained one mutation in probe binding sites) were used to establish novel real-time PCR with slightly modified probe (Y = C or T) in comparison with original probe recommended by OIE.

Results: Both real-time PCRs using the OIE-recommended probe and novel modified probe can detect ASFV in clinical samples without mismatch in probe binding site. A high correlation of cycle quantification (Cq) values was observed in which Cq values obtained from both probes arranged from 22 to 25, suggesting that modified probe sequence does not impede the qualification of real-time PCR to detect ASFV in clinical samples. However, the samples with one mutation in probe binding sites were ASFV negative with OIE recommended probe but positive with our modified probe (Cq value ranked between 33.12-35.78).

Conclusion: We demonstrated for the first time that a mismatch in probe binding regions caused a false negative result by OIE recommended real-time PCR, and a slightly modified probe is required to enhance the sensitivity and obtain an ASF accurate diagnosis in field samples in Vietnam.

Objective: This study aimed to elucidate the effect of miR-140 on the proliferation of porcine fetal fibroblasts (PFFs) and identify the target genes of miR-140 in PFFs.

Methods: In this study, bioinformatics software was used to predict and verify target genes of miR-140. Quantitative polymerase chain reaction and western blot were used to detect the relationship between miR-140 and its target genes in PFFs. Dual luciferase reporter gene assays were performed to assess the interactions among miR-140, type 1 insulinlike growth factor receptor (IGF1R), and SRY-box 4 (SOX4). The effect of miR-140 on the proliferation of PFFs was measured by CCK-8 when PFFs were transfected with a miR-140 mimic or inhibitor. The transcription factor SOX4 binding to promoter of IGF1R was detected by chromatin immunoprecipitation assay (ChIP).

Results: miR-140 directly targeted IGF1R and inhibited proliferation of PFFs. Meanwhile, miR-140 targeted transcription factor SOX4 that binds to promoter of porcine IGF1R to indirectly inhibit the expression of IGF1R. In addition, miR-140 inhibitor promoted PFFs proliferation, which is abrogated by SOX4 or IGF1R knockdown.

Conclusion: miR-140 inhibited PFFs proliferation by directly targeting IGF1R and indirectly inhibiting IGF1R expression via SOX4, which play an important role in the development of porcine fetal.