Journal of Poultry Science最新文献

Farm biosecurity is valuable for reducing the indiscriminate use of antimicrobials. However, its relationship with antimicrobial usage can be difficult to assess because of multiple factors. This study evaluated the impact of biosecurity practices on productivity, frequency of antimicrobial use, and development of antimicrobial resistance. Among factors related to biosecurity, mortality rate <2% within one week of age, survival rate >98%, and production index >350 in farms in which: bedding was not reused or only reused once, regular advice and biosecurity training was provided by poultry veterinarians, distinctions between clean and dirty areas were strictly enforced at all times, workers used farm biosecurity manuals, or disinfection guidelines were fully implemented, including cleaning before introducing new flocks and daily disinfection throughout growth, were significantly higher than those in farms without these measures (p < 0.05). The absence of biosecurity practices increased antimicrobial use to one (25.7%), two (39.2%), and three (25.7%) times (p < 0.05). In farms that implemented biosecurity practices, the antimicrobial administration was significantly increased to two times (44.2%) (p < 0.05), with only 17.4% of farms using antimicrobials three times. The prevalence of environmental Escherichia coli resistant to multiple cephalosporins and chloramphenicol, which are not used on broiler farms, was significantly reduced by biosecurity practices (p < 0.05). Our findings indicate that improved biosecurity practices decrease antimicrobial use, decrease the incidence of antimicrobial-resistant bacteria, and help to eliminate resistant bacteria in farm environments.

Unmethylated cytosine-phosphate-guanine (CpG) motifs are often found in bacteria and viruses, but are rare in mammals. In mammals, CpG oligodeoxynucleotides (CpG ODN) stimulate the innate immune system via toll-like receptor 9 (TLR9). However, TLR9 is absent in birds; instead, TLR21 serves as the receptor for CpG ODN. While CpG ODN induce behavioral and physiological changes in mammals, there is limited research on their effects on behavioral and physiological parameters in birds. The aim of the present study was to determine whether intraperitoneal injection of K3, a synthetic class B CpG ODN, affected food intake, voluntary activity, cloacal temperature, blood constituents, and feed passage from the crop in chicks (Gallus gallus). Additionally, the effects of K3 (GC), which contains GpC motifs instead of CpG motifs, were investigated to determine the importance of these CpG motifs. Intraperitoneal injection of K3 significantly increased the mRNA expression of interleukin-1β, interleukin-6, interleukin-8, and interferon-γ in the spleen. These changes were not observed with K3 (GC) administration. Intraperitoneal injection of K3 significantly decreased food intake but did not affect voluntary activity. K3 also significantly increased cloacal temperature, tended to increase plasma glucose and corticosterone concentrations and significantly decreased feed passage from the crop. In contrast, K3 (GC) showed no effects on these parameters. These results demonstrate that class B CpG ODN is associated with anorexia, hyperthermia, and reduced feed passage through the digestive tract in chicks during bacterial and viral infections.

In the present study, the effects of dietary supplementation with a mixed fermented loquat leaf tea residue (MFL) were evaluated on muscle α-tocopherol concentration and drip loss of Tsushima-Jidori crossbred chicken. MFL contained significantly less β-carotene, α-tocopherol, and total catechin than that of residues of green tea leaf infusion, although total polyphenol was significantly higher and 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity tended to be higher, indicating increased antioxidant properties. A total of 120 male Tsushima-Jidori crossbred chickens were divided into two groups at 62 days of age. The control group was fed a basal diet (commercial finisher diet containing 16.5% crude protein and 12.77 MJ/kg metabolizable energy) and the test group was fed a basal diet supplemented with MFL at a concentration of 1.0% until 90 days of age. Body mass, body mass gain, feed intake, and tissue mass did not significantly differ between the two groups. Dietary supplementation with MFL significantly increased breast muscle α-tocopherol concentration and reduced muscle drip loss. This was accompanied by a lower muscle K-value, which indicated the freshness of the meat. These results suggested that dietary supplementation with MFL improved the shelf life and water-holding capacity of breast muscles of Tsushima-Jidori crossbred chickens.

[This corrects the article DOI: 10.2141/jpsa.2024021.].

Stress in day-old chickens from commercial hatcheries is associated with problematic behavior in adult animals. Recently, we developed a new behavioral handling test for day-old chickens and demonstrated that it assessed temperament differences between seven breeds of native Japanese and Western chickens. In this study, we used 2-day-old male chicks from five of the above breeds to investigate the relationship between temperament and mRNA levels of three stress-related genes (nuclear receptor subfamily 3 group C member 1 (NR3C1), cytochrome P450 family 11 subfamily A member 1, and hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase 1) involved in the hypothalamic-pituitary-adrenal axis. Principal component analysis of 10 behavioral traits for the handling test revealed that the Fayoumi breed and Hiroshima line of the Chabo breed, both of which exhibited boisterous temperament, clustered separately from the other breeds. Only NR3C1 expression showed a significant positive correlation with two behavioral traits (general vocalization and approaching the wall), and a negative correlation with movement. These results suggest that the complex temperament of day-old chickens is regulated, in part, by stress-related genes along the hypothalamic-pituitary-adrenal axis.

This study evaluated the effects of whole flaxseed (WFS), fish oil (FO), and different sources of Se, Zn, and Fe (inorganic, organic, and nano-source) on egg production, quality, sensory attributes, and serum protein metabolites in laying hens. A total of 144 hens were divided into six groups with six replicates of four hens each. Hens were fed six diets as follows: 1) control diet; 2) 7.5%WFS+1.5%FO; 3) 7.5%WFS+1.5%FO+175 mg/kg vitamin E (VE); 4) 7.5%WFS+1.5%FO+175 mg/kg VE + inorganic sources of Se, Zn, and Fe (ISeZnFe); 5) 7.5%WFS+1.5%FO+175 mg/kg VE + organic sources of Se, Zn, and Fe (OSeZnFe); 6) 7.5%WFS+1.5%FO+175 mg/kg VE + nano-source of Se, Zn, and Fe (NSeZnFe) from 40-50 weeks of age. Laying hens fed 7.5% WFS, 1.5% FO, and different sources of trace elements in their diets had no negative effects on laying rate, egg weight, egg mass, feed intake, feed conversion ratio, body weight change, or survival rate compared to that of hens fed the control diet. Dietary treatments did not negatively affect the external and internal egg characteristics or egg sensory attributes. Feeding 7.5%WFS+1.5%FO+VE+ISeZnFe positively influenced yolk color in fresh eggs. Dietary treatments had a significant impact on egg nutritional composition, with the highest levels of macronutrients found in eggs from hens fed the 7.5%WFS+1.5%FO+VE+NSeZnFe treatment. The highest plasma globulin concentrations were observed in hens fed organic and nano-source trace elements. The same diets reduced plasma uric acid levels. Based on these findings, the inclusion of organic or nano-source trace minerals in diets containing WFS and FO positively affected egg quality and hen protein metabolites.

Helmeted guinea fowl are social animals and only males form a hierarchy in the wild. Non-cage husbandry systems benefit the reproductive health of guinea fowl; however, there are concerns that the feeding duration of subordinate individuals is insufficient. Here, the pecking orders formed during small-scale floor feeding were investigated. There were three experimental categories: male-only (four males), female-only (four females), and mixed category (two males, two females). Each experimental category was set up three times and included different individuals. Behaviors were recorded for 130 h 52 min, 89 h 11 min, and 98 h 46 min in the male, female, and mixed categories, respectively. Male helmeted guinea fowls pecked other males, whereas females exhibited little pecking behavior. Male pecking behavior was not homogeneous within each experimental group. It has been suggested that males form a pecking order, whereas females have no hierarchy under small-scale floor-feeding conditions, as observed in the wild. In most cases, on the first day the number of pecking behaviors was low 20 min after the start of the experiment. The three subordinate individuals in the mixed category had little time to feed, whereas the other birds in the mixed category and all helmeted guinea fowl in the male- and female-only categories had longer feeding durations. We suggest that helmeted guinea fowl may be reared under small-scale floor feeding, and that the health of males should be managed. However, rearing females and males under small-scale floor feeding conditions should be avoided. This study contributes to improving the welfare of helmeted guinea fowl reared under small-scale floor feeding.

The implementation of more animal welfare-centric livestock production systems holds considerable potential for achieving sustainable production in Japan. However, such systems generally reduce productivity per unit area, impose financial burdens on farmers that adversely affect their physical and mental health, and require increased consumer awareness. In particular, declines in productivity per unit area substantially affect the farming economy, giving rise to concerns about the sufficient egg production for the population, which consequently exacerbates Japan's food security concerns. In this study, our goal was to predict temporal trends in the Japanese transition to welfare-centric facilities by analyzing desired egg consumption. We formulated five scenarios, ending in 2050, to assess the future impact of changing the proportions of types of egg production on total production, numbers of hens, total farm area, production costs, and retail prices. Multiple issues were identified in our analysis. First, Japanese production uses conventional caging, which provides high efficiency, maximum output, and decreased prices. Our simulations suggest that ensuring optimal production is likely to present challenges as animal welfare is addressed. They also suggest that the poultry industry or the Japanese government will likely need to plan changes in production methods will likely be necessary to prevent egg surpluses and/or shortages. Additional issues were identified, including price increases, numbers of hens, total farm area, and production costs. This study offers valuable insights for policymakers in their decision-making processes to help optimize production methods while considering food security, animal welfare, and farmers' welfare.

Broodiness in egg-laying hens (EHs) leads to ovarian atrophy, resulting in reduced egg-laying performance. However, the ovarian regulatory mechanisms in broody hens (BCs) remain elusive. Therefore, ovaries were removed from 300-day-old BCs and EHs for RNA sequencing. Ovarian morphology and histological characteristics of the BC and EH groups were compared and analyzed. The EH group had significantly more hierarchical follicles (HFs) and small yellow follicles (SYFs) than that of the BC group. Although several secondary follicles (SFs) and primary follicles were observed in the ovaries of the EH group, only a few SFs were observed in the ovaries of the BC group. Subsequently, RNA-sequencing analysis was conducted to determine the ovarian expression profiles of the two groups. Transcriptome sequencing identified 259 differentially expressed genes (DEGs) between the BC and EH groups. Of the 259 DEGs, 136 were upregulated and 123 were downregulated. The DEGs were mapped to 22 gene ontology terms and 4 Kyoto Encyclopedia of Genes and Genomes pathways for ovarian tissue. The analysis showed that matrix metalloproteinases 11/13 (MMP11/MMP13) were enriched in the extracellular matrix. The extracellular matrix mediated by MMP13 is affected by follicle-stimulating hormone, prolactin, and estrogen, which are critical signaling pathways that may affect ovarian follicle development to regulate the large yellow follicle reserve process and the ovulation cycle of broody Chahua chickens. These findings indicate that understanding differences in gene expression between the ovarian tissues of BCs and EHs could serve as a valuable reference point for enhancing egg-laying performance in Chahua chickens.

Cadaverine is a bioactive substance derived from lysine degradation by lysine decarboxylase and has gained attention for its physiological effects. Studies in rodents have revealed its role as a cell growth regulator, particularly intestinal bacterial-produced cadaverine. However, the nutritional and physiological roles of cadaverine during the embryonic period remain unclear, especially considering the immature state of the gut microbiota and digestive functions during this stage. This study explored the potential functions of cadaverine as a nutritional and metabolic signal during chicken embryonic development. Experiments were conducted using an in ovo administration method to evaluate the effects of nutritional bioactive substances on developing chicken embryos. Although there were no observable changes in body or organ weights of newly hatched chicks following in ovo cadaverine administration to day 18 chick embryos, plasma tryptophan, N^τ-methylhistidine, and N^π-methylhistidine concentrations decreased and the gene expression of insulin/insulin-like growth factor 1 signaling in skeletal muscle was upregulated. These findings imply that cadaverine influences tryptophan metabolism and skeletal muscle catabolism during the embryonic period, suggesting its role as a bioactive factor contributing to energy metabolism signaling in skeletal muscle.