农林科学最新文献

This study evaluates the effects of dietary Chinese herb ultrafine powder (CHUP) supplementation in late-phase laying hens on the quality and nutritional values of eggs. A total of 576 Xinyang black-feather laying hens (300-day-old) were randomly allocated into eight groups for a 120-day feeding trial. Each group contained eight replicates with nine hens per replicate. The experimental groups included the control (basal diet) and different levels of CHUP groups (details in 'Materials and methods'). The results showed that the eggshell strength was increased (p < 0.05) in the L, LF, L-LF, L-T, and LF-T groups on day 60 of the trial. In addition, the plasma estradiol level in the L-LF, LF-T, and L-LF-T groups and unsaturated fatty acids concentrations in egg yolk of the CHUP groups (except LF-T group) were increased, whereas total cholesterol (T, L-LF, L-T, and L-LF-T groups) in egg yolk and the atherogenicity (T, L-T, and L-LF-T groups) and thrombogenicity (T, L-LF, L-T, and L-LF-T groups) indexes were decreased (p < 0.05) on day 60 of the trial compared with the control group. Moreover, bitter amino acids in egg albumen were decreased (p < 0.05) in the L-LF group on day 60 and the L-LF-T group on day 120 of the trial. Collectively, these findings indicate that dietary CHUP supplementation could improve eggshell quality and increase plasma reproductive hormone, fatty acid and amino acid composition, and nutritional values of eggs, especially L-LF and L-LF-T.

Research on the effects of selenium nanoparticles (Se-NPs), particularly in Japanese quails, is lacking, especially regarding the potential for DNA damage. Therefore, this study aimed to investigate the impact of administering 0.2 and 0.4 mg/kg of Se-NPs on the growth performance, DNA integrity, and histopathological alterations of the liver, lung, kidney, and heart in quails. A total of 480 one-day-old Japanese quails were divided into three experimental groups as follows: Group 1 served as the control and received only basic feed, while Group 2 and 3 received 0.2 mg/kg and 0.4 mg/kg of Se-NPs via oral gavage. Our results suggested that, birds fed with Se-NPs at both levels significantly (p < .01) reduced feed intake, however, weight gain was significantly (p < .01) increased in quails supplemented with 0.2 mg/kg. Similarly, feed conversion ratio (FCR) was significantly (p < .01) reduced in group supplemented with 0.2 mg/kg Se-NPs. White blood cells increased significantly (P0.01) in 0.4 mg/kg while haemoglobin and red cell distribution width decreased (p < .01) in the same group. Both treatment regimens resulted in DNA damage and histopathological alterations; however, the adverse effects were more prominent in the group receiving the higher dose of 0.4 mg/kg. These findings indicate that the lower dose of 0.2 mg/kg may have beneficial effects on growth. However, the higher dose of 0.4 mg/kg not only negatively impacts growth but also leads to histopathological alterations in major organs of the body and DNA damage as well.

The study investigated the impact of incorporating a specific herbal blend comprising coriander, garlic, and fenugreek (CGF) at various levels on the zootechnical performance, blood metabolites and nutrient digestibility in broiler chickens. The 42-day experiment involved 360 broilers (Cobb 500), organized into four distinct treatment groups. The dietary interventions included a control group consisting of a basal diet and the same diet was supplemented with CGF at rates of 1, 2, and 3%. Broilers receiving a 1% phytogenic mixture exhibited significantly increased live weight and carcass weight. Moreover, the digestibility of crude protein and crude fat significantly improved in broilers supplemented with a 1% phytogenic mixture. On the other hand, the digestibility of calcium and phosphorus showed a notable increase in broilers fed with a 3% phytogenic mixture. Regarding serum metabolites, the 1% phytogenic mixture group displayed significantly higher levels of high density lipoprotein and triglycerides. The supplementation of the broiler diet with a herbal mixture of coriander, fenugreek, and garlic at a 1% rate resulted in improved growth performance, carcass quality, nutrient digestion, and lipid profile.

Bovine and ovine papillomaviruses (BPVs - OaPVs) are infectious agents that have an important role in bladder carcinogenesis of cattle. In an attempt to better understand territorial prevalence of papillomavirus genotypes and gain insights into their molecular pathway(s), a virological assessment of papillomavirus infection was performed on 52 bladder tumors in cattle using droplet digital polymerase chain reaction (ddPCR), an improved version of conventional PCR. ddPCR detected and quantified BPV DNA and mRNAs in all tumor samples, showing that these viruses play a determinant role in bovine bladder carcinogenesis. OaPV DNA and mRNA were detected and quantified in 45 bladder tumors. BPV14, BPV13, BPV2, OaPV2, OaPV1, and OaPV3 were the genotypes most closely related to bladder tumors. ddPCR quantified BPV1 and OaPV4 DNA and their transcripts less frequently. Western blot analysis revealed a significant overexpression of the phosphorylated platelet derived growth factor β receptor (PDGFβR) as well as the transcription factor E₂F₃, which modulate cell cycle progression in urothelial neoplasia. Furthermore, significant overexpression of calpain1, a Cys protease, was observed in bladder tumors related to BPVs alone and in BPV and OaPV coinfection. Calpain1 has been shown to play a role in producing free transcription factors of the E₂F family, and molecular findings suggest that calpain family members work cooperatively to mutually regulate their protease activities in cattle bladder tumors. Altogether, these results showed territorial prevalence of BPV and OaPV genotypes and suggested that PDGFβR and the calpain system appeared to be molecular partners of both BPVs and OaPVs.

Background: Sebaceous adenitis (SA) is an immune-mediated disease targeting the sebaceous glands. Meibomian gland dysfunction is a disease affecting meibomian glands with inflammatory features. Sebaceous and meibomian glands share anatomical, physiological and embryological similarities. The involvement of meibomian glands in dogs with SA is currently unknown.

Objectives: To evaluate meibomian glands in dogs affected by SA and compare them with healthy dogs.

Animals: Eighteen dogs were enrolled. Nine dogs with SA were retrospectively identified from clinical records and represented the case group. Nine healthy, breed- and age-matched dogs were prospectively enrolled in the control group.

Materials and methods: Both groups underwent dermatological examination, Schirmer tear test-1 (STT-1), tear meniscus height (TMH), slit-lamp biomicroscopy, interferometry (INT) and noncontact infrared meibography (NIM).

Results: One third of SA dogs presented subepithelial crystalline opacities. No significant difference between groups was observed in TMH (p = 0.944) and STT-1 values (p = 0.066). INT (p = 0.016) and NIM grades (p = 0.010) were significantly higher and lower in the SA group compared to the control group, respectively. INT values decreased with age (η = 0.930), while NIM scores (η = 0.935) increased.

Conclusions: Clinical Relevance: Subepithelial crystalline opacities in SA dogs might reflect a reduced tear film quality. In the absence of standardised methods, INT and NIM proved to be noninvasive and useful methods to examine meibomian glands. Dogs with SA showed a thinner lacrimal lipid layer and more severe meibomian gland abnormalities than control dogs, which seemed to progress with age.

A reliable phylogeny is crucial for understanding the evolution and radiation of animal taxa. Phylogenies based on morphological data may be misleading due to frequent convergent evolution of traits-a problem from which molecular phylogenies suffer less. This may be particularly relevant in oribatid mites, an ancient soil animal taxon with more than 11,000 species, where the classification of species into high-ranking taxa such as superfamilies is equivocal. Here, we present a molecular phylogeny of 317 oribatid, 4 astigmatid and 17 endeostigmatid mite species/taxa based on 18S rDNA sequences. We aimed at testing the validity of the 41 superfamilies of oribatid mites recognized by Norton and Behan-Pelletier (in Krantz and Walter, A manual of Acarology, 3rd ed., Texas Technical University Press, Lubbock, 2009). The results indicate that 17 of the 41 oribatid mite superfamilies are monophyletic but that 18 superfamilies are paraphyletic or polyphyletic (5 superfamilies were only included with one species and Microzetoidea were not included). Our findings point to the importance of convergent evolution in polyphyletic oribatid mite taxa. Convergent evolution and the old age of mites likely resulted in a mosaic-like distribution of morphological characters impeding phylogenetic reconstructions based on morphology, calling for molecular approaches to improve oribatid mite systematics.

Our study aimed to evaluate the effect of different treatments for BRD on health and welfare in fattening bulls. A total of 264 bulls were enrolled. Welfare was assessed on day 2 (T0) and day 15 (T1) after arrival. A decrease in the welfare level was observed from T0 to T1. All bulls were inspected clinically at T0 and T1 revealing an increase of skin lesions and lameness in T1. In both periods, a high incidence of respiratory disease was observed. A prevalence of 79.55% and 95.45% of Mycoplasma bovis using RT-PCR and culture at T0 and T1 respectively was observed. Blood samples were collected for haematology at T0 and T1. At T0, 36 animals were individually treated for BRD with an antimicrobial (IT), 54 received a metaphylactic treatment with tulathromycin (M), 150 received a metaphylactic treatment with tulathromycin plus a second antimicrobial (M + IT) whereas 24 were considered healthy and therefore not treated (NT). Additionally, 128 were treated with a non-steroid anti-inflammatory (NSAID). Neutrophils of M + IT were significantly higher than groups NT and M and the lymphocytes of M + IT were significantly lower than that of IT. White blood cells, neutrophils and N/L ratio of animals treated with an NSAID was significantly higher than that not treated. Lung inspection of 172 bulls at the abattoir indicated that 92.43% presented at least one lung lesion. A statistically significant effect of the NSAID treatment on the lung lesions was observed. Our findings indicate that BRD was a major welfare and health concern and evidence the difficulties of antimicrobial treatment of M. bovis.

The gut microbiota (GM) is essential for mammalian health. Although the association between infant GM and breast milk (BM) composition has been well established in humans, such a relationship has not been investigated in horses. Hence, this study was conducted to analyze the GM formation of foals during lactation and determine the presence of low-molecular-weight metabolites in mares' BM and their role in shaping foals' GM. The fecal and BM samples from six pairs of foals and mares were subjected to 16S ribosomal RNA metagenomic and metabolomic analyses, respectively. The composition of foal GM changed during lactation time; hierarchical cluster analysis divided the fetal GM into three groups corresponding to different time points in foal development. The level of most metabolites in milk decreased over time with increasing milk yield, while threonic acid and ascorbic acid increased. Further analyses revealed gut bacteria that correlated with changes in milk metabolites; for instance, there was a positive correlation between Bacteroidaceae in the foal's gut microbiota and serine/glycine in the mother's milk. These findings help improve the rearing environment of lactating horses and establish artificial feeding methods for foals.

Phlebotomus perniciosus is a major vector of Leishmania infantum in the Mediterranean. While the seroprevalence of leishmaniosis in Spanish dogs and cats has been studied, data on the exposure of cats to P. perniciosus bites under natural conditions without repellents is limited. Stray cats could serve as sentinels for L. infantum and P. perniciosus exposure. This study analyzed sera from 204 apparently healthy stray cats, collected from January 2021 to January 2022, for antibodies against P. perniciosus saliva and L. infantum parasites. Anti-sand fly antibodies were detected in 40.69% of cats using an ELISA with the recombinant salivary protein SP03B of P. perniciosus. Seroprevalence of L. infantum infection was 23.52% by Western blot and 27.41% by ELISA, with an overall seroprevalence of 40.69% (95% CI 34.18-47.54%). This is the first assessment of antibody response to P. perniciosus saliva and L. infantum in naturally exposed stray cats in Spain. Further research is needed to examine the salivary antigens recognized by cats and to explore the relationship between P. perniciosus exposure and L. infantum infection severity in cats.

Background: Protection from solar ultraviolet radiation (UVR) is paramount in light-skinned pig breeds such as Yorkshire or Landrace to avoid sunburn.

Objectives: Determination of the UVR exposure of a pig and the sun protection abilities of shade cloths with different shade rates.

Animals: Life-sized plastic model of a Landrace pig.

Materials and methods: The model was equipped with 20 UVR meters at various anatomical positions that recorded the erythemal effective solar irradiance. A turntable enabled irradiation from different directions. Solar irradiance was measured in direct sunlight as well as under three shade cloths with different shade rates (50%, 75% and 90%) and a camouflage net. The sun protection factors (SPF) were determined as the ratio of unshaded-to-shaded measurements at the same solar elevation. The exposure ratio to ambient (ERTA) was calculated for each body site with respect to ambient irradiance. It allows determination of when pigs are at risk of sunburn and protection is needed.

Results: The calculated ERTA values show that some body parts may receive higher values than ambient UVR. Measurements showed that the SPF of shade cloths depends on textile denseness. Selected shade cloths reached values of 3.5 (shade rate 50%), 4.2 (75%) and 5.8 (90%). Protection by the camouflage net was poor. The highest SPF was gained on body sides where ERTA was highest.

Conclusions and clinical relevance: Shade cloths can protect all body sites effectively and vulnerable sites in particular. The results of our study enable an estimation of when pigs are at risk of sunburn and provide quantitative metrics for sun protection. This allows effective prevention of UVR-caused skin damage and secondary disorders.