Animal Science Journal最新文献

Early pregnancy detection in alpacas, whose breeding season is limited to the rainy season and has a long gestation period, is important for reproductive management. Conventional detection methods such as ultrasonography cannot be used to detect pregnancy before 30 days after mating. In this study, we examined the feasibility of using fecal steroid hormones as an early detection method in pregnant and non-pregnant alpacas. Fecal and blood samples were collected from pregnant and non-pregnant alpacas after mating. Progesterone (P4) and estradiol 17-β were extracted and quantified from blood and fecal samples. A positive correlation exists between the steroid hormones in serum and feces, indicating that serum steroid hormone concentrations can be estimated from fecal steroid hormones. Within 10 days after mating, both pregnant and non-pregnant alpacas had fecal P4 concentrations greater than 1.0 ng/mg dry matter (DM), but by 15 days after mating, fecal P4 concentrations decreased to the pre-mating concentration in non-pregnant alpacas. From 15 days after mating, non-pregnant alpacas had a low fecal P4 concentration (< 1 ng/mg DM), whereas a high fecal P4 concentration indicated the possibility of pregnancy, suggesting that this test is clinically beneficial as a supportive test for pregnancy detection.

In this study, the effects of cage type and the light–dark cycle on the behavior of hens before, during, and after forced molting were determined. For this purpose, 73-week-old hens were placed in the two different cage types used in the experiment. The barley method was used to induce molting at 75 weeks of age. The molting period lasted 35 days in total. The frequencies of walking, feeding, comforting, and preening behaviors were affected by the forced molting period. The addition of enrichment materials to the cage did not cause any changes in hen behavior. The light–dark cycle was important for the frequency of all examined behaviors except fighting behavior. No interaction was found among forced molting period, cage type, and light–dark cycle regarding behaviors. It is thought that there is a decrease in welfare-related behaviors at the end of the laying period and this decrease does not increase with forced molting using barley; on the contrary, appropriate forced molting applied to hens during this period will increase welfare. It was observed that cage type did not cause a significant difference in hen behavior during the forced molting period.

Gestation length (GL) in cattle is associated with neonatal health and the subsequent reproductive performance of dams. We performed a genome-wide association study (GWAS) using 25,144 single nucleotide polymorphisms (SNPs) in 4373 animals to detect genetic variants associated with GL as a fetal trait in Japanese Black cattle in Gifu Prefecture. We identified four significant SNPs on chromosome 21 in moderate linkage disequilibrium (LD). The minor allele of the most significant SNP has the effect on −2.47 days GL with a 0.019 allele frequency. Of the 4373 animals, 140 heterozygotes and one homozygote with the minor allele were traced back to a heterozygous sire. The 7.2 Mb LD region harbors three genes: gamma-aminobutyric acid type A receptor subunit beta3 (GABRB3), arrestin domain containing 4 (ARRDC4), and nuclear receptor subfamily 2 group F member 2 (NR2F2, also known as COUP-TFII). RNA expression analysis and its functions suggest that GABRB3, ARRDC4, and NR2F2 (COUP-TFII) are involved in glucose production via the hypothalamic–pituitary–adrenal axis during the fetal stress response at gestation period termination. These results suggest that an increase in the allele frequency of the associated SNPs has an impact on genetic improvement by shortening the GL in the population.

Ochratoxin A (OTA) widely exists in raw food and feed materials and can induce liver damage and toxicity. However, the mechanisms of OTA-induced hepatotoxicity were largely unknown. Thus, our study aimed to uncover the vital genes relevant to OTA-induced hepatotoxicity in broiler chickens. Gene expression data of chicken embryo primary hepatocytes (CEPHs) in OTA-treated and control groups were obtained from the GEO database. Totally 1407 differentially expressed genes (DEGs) were selected, of which 850 and 557 genes were up- and downregulated in OTA-treated CEPHs. Gene ontology (GO) enrichment revealed that the DEGs were in connection with various biological processes, such as signal transduction, extracellular matrix organization, axon guidance, cell division, cholesterol homeostasis, proteolysis, microtubule cytoskeleton organization, and chromosome segregation. Pathway enrichment showed that the DEGs were related to metabolic pathways, ferroptosis, calcium, FoxO, Wnt, cell cycle, apoptosis, calcium, and cell adhesion molecules signaling pathways. Furthermore, the hub genes, including CDK1, DLGAP5, KIF2C, VCL, ITGB3, and ZYX, were identified as hub genes potentially contributing to OTA-induced hepatotoxicity. Taken together, this study provides valuable insights into the mechanisms underlying OTA-induced hepatotoxicity in broiler chickens.

The aims of this study were to determine adaptation mechanism of sheep to salinity in drinking water. A group of 10 male sheep were used in a 6-week of experiment, with 1 week for pre-treatment period (Week 1), 4 weeks for during treatment period (Week 2 to Week 5), and 1 week for posttreatment period (Week 6). During the pre- and posttreatment periods, sheep consumed with fresh water. However, during treatment period, they were given with diluted seawater (DSW) at concentrations of 0.5%, 1.0%, 1.5%, and 2% for Weeks 2, 3, 4, and 5, respectively. Animal was offered 300 g concentrate and corn stover silage for ab libitum. Dry matter intake decreased as DSW increased, whereas sheep drinking DSW showed an increase in water intake and urine volume (p < 0.05). Body weight change decreased in 2% DSW. Sheep consuming 2% DSW exhibited higher plasma electrolyte levels compared to other groups. But plasma levels of AST, ALT, and creatinine were unaffected by DSW (p > 0.05). The elevated levels and excretions of urinary electrolytes were found in DSW groups (p < 0.05). Water balance was unaffected by DSW, except during the recovery period. It concluded that adapted sheep can consume DSW up to 1.5% without harmful effects.

Pork primal weight and primal yield are important indicators for pig breeding, feeding management, commercial distribution systems, and meat processing. Here, we aimed to determine whether primal weight and primal yield could be predicted through non-destructive measurements of pork carcass traits. A total of 4397 carcasses (1958 gilts and 2439 barrows) from eight major meat processing centers were used, and the mean primal weight and primal yield were 56.0 kg and 73.9%, respectively. Significant sex differences were observed for all primal and carcass traits (P < 0.001), except for carcass weight. A maximum of 12 variables were examined, and primal weight was predicted with very high accuracy (R = 0.95, RMSE = 1.7, RPD = 3.0) using four variables. Primal yield was predicted with relatively good accuracy (R = 0.71, RMSE = 2.3, RPD = 1.4) using three variables, and these same variables were also effective for predicting primal weight. These prediction formulas were sufficiently accurate without accounting for the effect of sex. Overall, our results demonstrate that primal weight and primal yield can be accurately predicted using four variables, “carcass weight,” “backfat thickness above M. gluteus medius,” “spinous process length of 13th thoracic vertebra,” and “length from 1st thoracic vertebra to backfat,” without accounting for the effect of sex.

The aim of this experiment was to evaluate the effect of different levels of zinc supplements on egg quality and quantity traits as well as egg enrichment with zinc in laying hens from 40 to 50 weeks of age. A total of 240 Hy-line laying hens were distributed among eight treatments and five replications (six birds per replication). The control group received no zinc diet, while the other treatments were supplemented with varying levels of zinc sulfate (80, 120, and 160 mg/kg) or zinc hydroxy chloride (50, 75, and 100 mg/kg). An additional group of zinc-methionine supplement at 124 mg/kg was also included. Results showed that different levels of zinc supplementation caused a significant improvement in eggshell resistance, eggshell percentage, feed conversion ratio, and Haugh unit compared to the control group. Adding organic and hydroxy sources of zinc significantly increased zinc contents in egg yolk, tibia bone, and blood. In addition, the treatments containing zinc supplements caused an increase in the antibody level against the Newcastle disease compared to the control (P < 0.05). Different levels and sources of zinc had no significant effect on eggshell thickness, specific gravity, and egg mass. Results showed that adding zinc in hydroxy chloride form at 100 mg/kg could improve performance indices, safety, and egg enrichment with zinc.

Bovine viral diarrhea virus (BVDV), is widely spread, poses a considerable risk of infection in the majority of dairy farms, causing respiratory, gastrointestinal, and reproductive problems. The aim of this study was to determine the seroprevalence and the risk variables associated with the seroprevalence of BVDV infection in cattle in four Egyptian governorates. A total of 680 blood samples were collected from cattle and examined for the presence of antibodies against BVDV using indirect ELISA (iELISA). Reproductive and management factors were considered, and epidemiological surveys were conducted. The total seroprevalence of BVDV in cattle was 18.24% (124/680) and it was significantly higher in females 19.66% (116/590), cattle older than 8 years 22.14% (62/280), dairy animals 22.65% (94/514), introduction of new animals to herd 21.39% (89/416), breeding with artificial insemination 28.46% (74/260), animals with history of abortion 28.76% (49/357), or during lactation stage 23% (89/387). The present findings suggest that BVD is prevalent in Egyptian dairy cattle and has an impact on farm productivity and production. Therefore, older, lactating, and aborted animals should also be identified for the disease, pose a risk of infection, and be handled appropriately.

This study investigated the impact of different levels of coated cysteamine hydrochloride (CSH) supplementation on ruminal fermentation, nutrient digestibility, and blood metabolites in Charolais cross bulls. Twelve bulls were allotted to three feeding treatments in a replicated 3 × 3 Latin square design: 0% CSH (control), 0.5% CSH, and 1.0% CSH in concentrate. Animals were fed concentrate at 1.5% of body weight. Dry matter intake (DMI) and DMI as a percentage of body weight showed no significant differences among treatments (p > 0.10). Nutrient digestibility was consistent across treatments, except for a slight decrease in NDF digestibility with 1% CSH (p = 0.07). Ruminal pH, ammonia nitrogen, volatile fatty acid (VFA) proportions, and total VFA concentration were similar among treatments (p > 0.05). Total bacteria, fungal zoospores, and protozoa populations in the rumen did not vary significantly (p > 0.05). Blood glucose and triglyceride concentrations remained stable (p > 0.05), while blood urea nitrogen (BUN) levels were higher in CSH-supplemented groups (p < 0.05). In conclusion, incorporating CSH levels ranging from 0.5% to 1.0% into the diet did not adversely affect feed intake, ruminal fermentation, or microbial populations. Additionally, 1.0% CSH improved BUN concentration in growing Charolais cross bulls.

This case study evaluated the mammary infection status of dairy cows during the dry periods and explored the associated problems in their quarters with dry cow therapy (DCT). This study assessed intramammary infections, antibiotic efficacy, and antimicrobial resistance of pathogens in 464-quarter milk samples from 59 dairy cows during the dry periods after applying blanket DCT, non-DCT, and selective DCT approaches on three farms. The recovery rates of intramammary infections were 95% (19/20 quarters) with blanket DCT on farm A, 70% (14/20) with non-DCT on farm B, and 19% (4/21) with selective DCT on farm C. Analysis of mammary infections in cows with DCT revealed that mammary infections were controlled by blanket DCT, well controlled by non-DCT, and substantial problems remained in selective DCT. Lower intramammary infection prevalence in the quarters at postpartum appeared to be associated with higher recovery of mammary infections, fewer new infections, and lower uncured mammary infections within the herds. Antibacterial resistance in 14 coagulase-negative staphylococci isolated to six antimicrobial drugs was suggested to be linked to antibiotic use on the farm. Follow-up studies on the quarter-based infection status with DCT will assist in improving mastitis control in cows during the dry period.