Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 19.213
Filtrar
1.
BMC Vet Res ; 18(1): 102, 2022 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-35300681

RESUMO

BACKGROUND: Prenatal and postnatal conditions are crucial for the development of calves. Primiparous cows are still maturing during pregnancy, thus competing with the nutritional needs of their offspring. Therefore, mature cows might provide a superior intrauterine condition. Furthermore, weaning calves at an older age might affect them positively as well by reducing stress and offering time for various organs and their functions to develop. We aimed to evaluate effects of mothers' parity and calves' weaning age on gastrointestinal development and corresponding acid-base balance. Fifty-nine female German Holstein calves (about 8 days old) were investigated in a 2 × 2 factorial experiment with factors weaning age (7 vs. 17 weeks) and parity of mother (primiparous vs. multiparous). Calves were randomly assigned to one of these four groups. Animal behavior that was observed included resting, chewing and active behavior. RESULTS: Behavioral patterns were interactively affected by time and weaning age. Rumen sounds per 2 min increased in early-weaned calves during their weaning period. In late-weaned calves a consistently increase in rumen sounds was already recorded before their weaning period. Urinary N-containing compounds (creatinine, hippuric acid, uric acid, urea, allantoin) were interactively affected by time and weaning age. Concentrations of all measured compounds except urea increased during early weaning. All except hippuric acid concentration decreased in early-weaned calves after weaning. In late-weaned calves allantoin and uric acid increased before weaning and did not change during weaning. CONCLUSION: These results suggest that late-weaned calves developed adequate rumen functions and acid-base balance, whereas early-weaned calves might have suffered from ruminal acidosis and catabolism. Weaning calves at 7 weeks of age might be too early for an adequate rumen development.


Assuntos
Bovinos/fisiologia , Rúmen/fisiologia , Equilíbrio Ácido-Base , Fatores Etários , Ração Animal/análise , Animais , Peso Corporal , Bovinos/crescimento & desenvolvimento , Dieta/veterinária , Ingestão de Alimentos , Feminino , Paridade , Gravidez , Rúmen/crescimento & desenvolvimento , Rúmen/metabolismo , Desmame
2.
Molecules ; 27(3)2022 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-35164407

RESUMO

It is important to inhibit oxidative stress to maintain sperm motility during cryopreservation. The present study was performed to investigate the effects of supplementing oligomeric proanthocyanidins (OPC) and bamboo leaf flavonoids (BLF) or their combination as an extender for Simmental bull semen freezing. OPC, BLF, or their combination were added to the frozen diluent of bovine semen. Afterwards, computer-assisted semen analysis (CASA), detection of membrane functionality, acrosome integrity, mitochondrial integrity, CAT, SOD, GSH-PX, MDA, and ROS were conducted. The results showed that adding 50 mg/L OPC or 4 mg/L BLF could improve the quality of frozen sperm. Compared with 50 mg/L OPC alone, the combination of 50mg/L OPC and 2 mg/L BLF significantly increased the kinematic parameters of sperm, and sperm CAT, GSH-PX and SOD levels (p < 0.05), whereas the MDA of sperm was decreased (p < 0.05). These results indicated that compared to the addition of 50 mg/L OPC alone, a combination of 50 mg/L OPC and 2 mg/L BLF could further improve the quality of frozen semen. The results could provide theoretical data support for the development of a new protective agent and are significant for the cryopreservation of bovine semen in the future.


Assuntos
Bovinos , Crioprotetores/metabolismo , Proantocianidinas/metabolismo , Preservação do Sêmen/veterinária , Sêmen , Animais , Bovinos/fisiologia , Criopreservação/veterinária , Masculino , Compostos Fitoquímicos/metabolismo , Sasa/metabolismo , Sêmen/efeitos dos fármacos , Sêmen/fisiologia , Motilidade Espermática/efeitos dos fármacos
3.
J Dairy Sci ; 105(1): 609-622, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34763912

RESUMO

Milking stall dimensions have not been adapted to the increase in cow body size caused by selection for better milking performance over the past decades. Improper milking stall dimensions might limit cow comfort, could lead to stress responses during milking and thus could negatively affect cow welfare. A crossover study was conducted in an experimental milking parlor that was converted from a herringbone (HB) to a side-by-side (SBS) parlor. The milking stall dimensions were modified in length and width and for HB also in depth (perpendicular distance between rump rail and breast rail). The stall dimensions applied during the experiments ranged from much smaller than common in European dairy farming to much larger. Treatments were applied for 2 wk per milking parlor type. In each milking parlor type, a total of 30 cows, kept in 2 groups were observed during milking for behavioral and physiological stress responses and for milking performance. In addition, milk cortisol levels and somatic cell counts were measured at the end of the 2-wk period. Outcome variables were selected based on a principal component analysis and analyzed using mixed effects models reflecting the experimental design. The results showed that the first cow per milking batch required more time (on average >40 s) to enter very small HB stalls than to enter small, large and very large stalls (<30 s). Also, cows yielded more milk per milking in very small and very large HB stalls than in the small and large milking stall dimensions [very small: 15.8 kg; 95% confidence interval (CI), 14.2-17.4 kg); small: 14.3 kg (95% CI, 12.8-15.9 kg); large: 14.6 kg (95% CI, 13.1-16.1 kg); very large: 16.1 kg (95% CI, 14.6-17.6 kg)]. The other behavioral, physiological and milk flow parameters as well as udder health were not affected by stall dimensions. For the SBS parlor, effects of milking stall dimensions were not detectable in any of the parameters. Despite the strong avoidance behavior to enter the milking parlor (measured as latency), no acute stress responses were found during milking. However, the study cannot exclude long-term effects of narrow stall dimensions on stress levels and possibly udder health, which should be investigated in future studies.


Assuntos
Bovinos , Indústria de Laticínios , Leite , Animais , Bovinos/fisiologia , Contagem de Células/veterinária , Estudos Cross-Over , Feminino , Lactação , Glândulas Mamárias Animais
4.
Anim Genet ; 53(1): 49-57, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34807998

RESUMO

miRNAs are a class of hairpin-derived RNAs, 21-24 nucleotides in length, which are involved in a range of biological processes. The bta-miR-2285 family has over 40 members spanning the entire bovine genome. We previously found that bta-miR-2285o-3p was highly expressed in yak heart and lung when compared with cattle, which prompted us to investigate its potential function in high-altitude adaptation of yaks. In this study, we detected wide-spread high expression of bta-miR-2285o-3p in yak tissues. Further experiments revealed that the protein tyrosine phosphatase receptor type M (PTPRM) gene was the host gene of bta-miR-2285o-3p and that two linked SNPs in bta-mir-2285o precursor affected the biogenesis of mature miRNA (bta-miR-2285o-3p). Functional analysis in vitro indicated that bta-miR-2285o-3p attenuated hypoxia-induced apoptosis by targeting very low-density lipoprotein receptor (VLDLR), phosphatase and tensin homolog (PTEN) and caspase-3. Expression level analysis in vivo revealed the high negative Pearson's correlation between bta-miR-2285o-3p and caspase3 in yak, highlighting the potential important roles of bta-miR-2285o-3p in yak high-altitude adaptation. Our study provides a typical model for deciphering the function of miRNAs in environmental adaptation.


Assuntos
Apoptose/genética , Caspase 3/genética , Bovinos/fisiologia , Hipóxia/fisiopatologia , Animais , Caspase 3/metabolismo , Bovinos/genética , MicroRNAs
5.
Mol Cell Endocrinol ; 540: 111508, 2022 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-34800604

RESUMO

The uterine environment must provide sufficient endocrine conditions and nutrients for pregnancy maintenance and conceptus survival. The objective of this study was to determine the effects of preovulatory estradiol and conceptus presence on uterine transcripts and uterine luminal fluid (ULF) proteins. Beef cows/heifers were synchronized and artificially inseminated (d 0). Uteri were flushed (d 16); conceptuses and endometrial biopsies were collected. Total cellular RNA was extracted from endometrium for RNA sequencing and RT-PCR validation. There were two independent ULF pools made for each of the following groups: highE2/conceptus, highE2/noconceptus, lowE2/conceptus, and lowE2/noconceptus that were analyzed using the 2D LC-MS/MS based iTRAQ method. There were 64 differentially expressed genes (DEGs) and 77 differentially expressed proteins (DEPs) in common among the highE2/conceptus vs highE2/noconceptus and lowE2/conceptus vs lowE2/noconceptus groups. In summary, the interaction between preovulatory estradiol and the conceptus induces the expression of genes, proteins, and pathways necessary for pregnancy.


Assuntos
Bovinos , Embrião de Mamíferos/fisiologia , Percepção/fisiologia , Prenhez , Útero/metabolismo , Animais , Bovinos/genética , Bovinos/fisiologia , Embrião de Mamíferos/diagnóstico por imagem , Desenvolvimento Embrionário/fisiologia , Endométrio/metabolismo , Estradiol/farmacologia , Feminino , Fase Folicular/efeitos dos fármacos , Fase Folicular/fisiologia , Regulação da Expressão Gênica , Gravidez , Proteínas da Gravidez/genética , Proteínas da Gravidez/metabolismo , Prenhez/genética , Prenhez/psicologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ultrassonografia Pré-Natal/veterinária , Útero/diagnóstico por imagem
6.
Anim Reprod Sci ; 236: 106908, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34920187

RESUMO

There have been increased effects of silver nanoparticle (Ag-NPs) on livestock during the past decade, but data related to adverse effects of Ag-NPs on reproductive tissues are limited. In the present study, the possible cytotoxic effects of Ag-NPs on oxidant/antioxidant balance, apoptosis and steroid hormone production in ovarian granulosa cells of cattle were studied.Cultured granulosa cells were treated with 10 nm Ag-NPs at various concentrations (1-100 µg/ml) for 24 h, and cell toxicity, oxidant/antioxidant markers, reactive oxygen species (ROS) production, abundances of apoptotic/antiapoptotic and steroidogenesis related mRNA transcripts were determined. The amount of DNA fragmentation was also determined using the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Results indicated treatment of granulosa cells with Ag-NPs induced an increase of reactive oxygen species production concomitant with increased malondialdehyde concentrations and decreased antioxidant enzyme activities. There was a maximal percentage of TUNEL+ cells (46.6%) after treatment with 50 and 100 µg/ml of Ag-NPs. The Ag-NPs could induce apoptosis in granulosa cells as indicated by the increase in caspase-3 activity, and larger abundance of BCL2 associated X (BAX) and lesser abundance of B-cell lymphoma 2 (BCL2) mRNA transcripts. The abundance of steroidogenic enzyme mRNA transcripts decreased concomitant with suppression of steroid hormone synthesis from Ag-NP-treated cells. Findings indicate silver nanoparticles (SNP) induce apoptosis and oxidative stress and change the pattern of steroid hormone synthesis in granulosa cells of cattle. The results indicate Ag-NPs may inhibit the function and viability of ovarian cells.


Assuntos
Apoptose , Bovinos/fisiologia , Hormônios Esteroides Gonadais/biossíntese , Células da Granulosa/metabolismo , Nanopartículas Metálicas , Estresse Oxidativo , Prata/efeitos adversos , Animais , Feminino , Células da Granulosa/efeitos dos fármacos
7.
Sci Rep ; 11(1): 23201, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34853357

RESUMO

Although there are many studies on the importance of fatty acids (FA) in our diet and on the influence of dairy diets on FA metabolism, only a few investigate their predictive capacity to discriminate the type, amount and conservation method of farm forages. This research quantifies differences in milk FA concentrations and, using a supervised factorial discriminant analysis, assesses potential biomarkers when replacing maize with other silages, grass/lucerne hays or fresh grass. The statistical modelling identified three main clusters of milk FA profiles associated with silages, hays and fresh grass as dominant roughages. The main implication of a dairy cow feeding system based on poliphytic forages from permanent meadows is enhancing milk's nutritional quality due to an increase in beneficial omega-3 polyunsaturated FA, conjugated linoleic acids and odd chain FA, compared to feeding maize silage. The study also identified a small but powerful and reliable pool of milk FA that can act as biomarkers to authenticate feeding systems: C16:1 c-9, C17:0, C18:0, C18:3 c-9, c-12, c-15, C18:1 c-9, C18:1 t-11 and C20:0.


Assuntos
Ração Animal , Bovinos/fisiologia , Ácidos Graxos/análise , Leite/química , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Indústria de Laticínios , Dieta/veterinária , Análise Discriminante , Ácidos Graxos/metabolismo , Feminino , Lactação , Leite/metabolismo , Análise Multivariada , Valor Nutritivo , Poaceae/química , Silagem/análise , Zea mays/química
8.
J Therm Biol ; 102: 103118, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34863481

RESUMO

The objective of this study was to evaluate the influence of the increasing temperature-humidity index (THI) on the body temperature of cows from different breed groups. Vaginal temperature was monitored in cows from two breed groups: a) British breeds (Hereford, Angus and their crosses, n=4); and b) their crosses with Bonsmara (BO, n=6). Vaginal temperature in cows of British breeds was always higher (P < 0.05), and the higher temperature picks coincide with afternoon hours. British cows maintained stable their vaginal temperature if THI was lower than 72.8, but for higher values, they showed linear increases. Moreover, the threshold THI associated to increase in vaginal temperature in British breeds was 72.8. However, vaginal temperature remained unchanged in Bonsmara crosses. The present work suggests that THI greater than 72.8 could affect the body temperature in grazing cattle of British breeds but not its crosses with Bonsmara.


Assuntos
Regulação da Temperatura Corporal , Temperatura Corporal , Bovinos/fisiologia , Termotolerância , Animais , Feminino , Especificidade da Espécie
9.
Sci Rep ; 11(1): 23877, 2021 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-34903778

RESUMO

Bovine respiratory disease (BRD) remains the leading infectious disease in post-weaned beef cattle. The objective of this investigation was to contrast the at-arrival blood transcriptomes from cattle derived from two distinct populations that developed BRD in the 28 days following arrival versus cattle that did not. Forty-eight blood samples from two populations were selected for mRNA sequencing based on even distribution of development (n = 24) or lack of (n = 24) clinical BRD within 28 days following arrival; cattle which developed BRD were further stratified into BRD severity cohorts based on frequency of antimicrobial treatment: treated once (treated_1) or treated twice or more and/or died (treated_2+). Sequenced reads (~ 50 M/sample, 150 bp paired-end) were aligned to the ARS-UCD1.2 bovine genome assembly. One hundred and thirty-two unique differentially expressed genes (DEGs) were identified between groups stratified by disease severity (healthy, n = 24; treated_1, n = 13; treated_2+, n = 11) with edgeR (FDR ≤ 0.05). Differentially expressed genes in treated_1 relative to both healthy and treated_2+ were predicted to increase neutrophil activation, cellular cornification/keratinization, and antimicrobial peptide production. Differentially expressed genes in treated_2+ relative to both healthy and treated_1 were predicted to increase alternative complement activation, decrease leukocyte activity, and increase nitric oxide production. Receiver operating characteristic (ROC) curves generated from expression data for six DEGs identified in our current and previous studies (MARCO, CFB, MCF2L, ALOX15, LOC100335828 (aka CD200R1), and SLC18A2) demonstrated good-to-excellent (AUC: 0.800-0.899; ≥ 0.900) predictability for classifying disease occurrence and severity. This investigation identifies candidate biomarkers and functional mechanisms in at arrival blood that predicted development and severity of BRD.


Assuntos
Doenças dos Bovinos/genética , Bovinos/genética , Infecções Respiratórias/genética , Transcriptoma , Animais , Biomarcadores/metabolismo , Bovinos/fisiologia , Infecções Respiratórias/veterinária
10.
Genes (Basel) ; 12(11)2021 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-34828436

RESUMO

Lactation persistency and milk production are among the most economically important traits in the dairy industry. In this study, we explored the association of over 6.1 million imputed whole-genome sequence variants with lactation persistency (LP), milk yield (MILK), fat yield (FAT), fat percentage (FAT%), protein yield (PROT), and protein percentage (PROT%) in North American Holstein cattle. We identified 49, 3991, 2607, 4459, 805, and 5519 SNPs significantly associated with LP, MILK, FAT, FAT%, PROT, and PROT%, respectively. Various known associations were confirmed while several novel candidate genes were also revealed, including ARHGAP35, NPAS1, TMEM160, ZC3H4, SAE1, ZMIZ1, PPIF, LDB2, ABI3, SERPINB6, and SERPINB9 for LP; NIM1K, ZNF131, GABRG1, GABRA2, DCHS1, and SPIDR for MILK; NR6A1, OLFML2A, EXT2, POLD1, GOT1, and ETV6 for FAT; DPP6, LRRC26, and the KCN gene family for FAT%; CDC14A, RTCA, HSTN, and ODAM for PROT; and HERC3, HERC5, LALBA, CCL28, and NEURL1 for PROT%. Most of these genes are involved in relevant gene ontology (GO) terms such as fatty acid homeostasis, transporter regulator activity, response to progesterone and estradiol, response to steroid hormones, and lactation. The significant genomic regions found contribute to a better understanding of the molecular mechanisms related to LP and milk production in North American Holstein cattle.


Assuntos
Bovinos/genética , Lactação/genética , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Animais , Bovinos/fisiologia , Feminino , Estudo de Associação Genômica Ampla/veterinária
11.
PLoS One ; 16(11): e0260510, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34843562

RESUMO

In actual farms, individual livestock identification technology relies on large models with slow recognition speeds, which seriously restricts its practical application. In this study, we use deep learning to recognize the features of individual cows. Alexnet is used as a skeleton network for a lightweight convolutional neural network that can recognise individual cows in images with complex backgrounds. The model is improved for multiple multiscale convolutions of Alexnet using the short-circuit connected BasicBlock to fit the desired values and avoid gradient disappearance or explosion. An improved inception module and attention mechanism are added to extract features at multiple scales to enhance the detection of feature points. In experiments, side-view images of 13 cows were collected. The proposed method achieved 97.95% accuracy in cow identification with a single training time of only 6 s, which is one-sixth that of the original Alexnet. To verify the validity of the model, the dataset and experimental parameters were kept constant and compared with the results of Vgg16, Resnet50, Mobilnet V2 and GoogLenet. The proposed model ensured high accuracy while having the smallest parameter size of 6.51 MB, which is 1.3 times less than that of the Mobilnet V2 network, which is famous for its light weight. This method overcomes the defects of traditional methods, which require artificial extraction of features, are often not robust enough, have slow recognition speeds, and require large numbers of parameters in the recognition model. The proposed method works with images with complex backgrounds, making it suitable for actual farming environments. It also provides a reference for the identification of individual cows in images with complex backgrounds.


Assuntos
Bovinos/anatomia & histologia , Indústria de Laticínios/métodos , Processamento de Imagem Assistida por Computador/métodos , Redes Neurais de Computação , Algoritmos , Animais , Bovinos/fisiologia , Feminino
12.
BMC Vet Res ; 17(1): 359, 2021 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-34798894

RESUMO

BACKGROUND: This study aimed to evaluate spexin as a novel blood marker and to describe the relationship of this peptide with selected biochemical metabolites measured during the transition period in dairy cows. Additionally, mRNA expression of the spexin gene as well as spexin receptors - galanin receptor type 2 and galanin receptor type 3, was investigated in several bovine tissues. Blood samples were collected at weekly intervals starting at 21 days before the estimated parturition day until 21 days in milk to determine concentrations of spexin, nonesterified fatty acids, ß-hydroxybutyrate acid, total and active ghrelin, progesterone, glucose, insulin, IGF-I, triglycerides, cholesterol, leptin, corticosterone and 17-ß-estradiol as well as the activity of aspartate transaminase, alkaline phosphatase and gamma-glutamyl transferase. RESULTS: Spexin concentration decreased from 21 d before parturition to calving day and next it rose during the first 14 d of lactation. The lowest concentration of spexin was recorded on the calving day and it differed from the mean level of this peptide before parturition as well as postpartum. Moreover, differences were observed between mean spexin concentrations before and after calving. Spexin levels were moderately negatively correlated with NEFA (r = - 0.39) and total ghrelin contents (r = - 0.41), weakly correlated with BHBA (r = - 0.35) while they showed a moderate positive relationship with progesterone concentrations (r = 0.42). Moreover, we detected that mRNA expression of GALR2, GALR3 and SPX is present in various bovine tissues (kidney, bowel, rumen, spinal cord, lung, skeletal muscle, liver, heart, fat and spleen). CONCLUSION: A negative correlation between spexin concentration and NEFA, BHBA and total ghrelin contents as well as a positive relationship with levels of progesterone, metabolites and hormones, which are key players in the dairy cow transition period, may confirm an important function of this peptide in metabolism regulation. Thus measurement of spexin concentration could provide useful supplementary information for dairy cow herd health monitoring.


Assuntos
Bovinos/sangue , Bovinos/fisiologia , Hormônios Peptídicos/sangue , Animais , Biomarcadores/sangue , Bovinos/metabolismo , Indústria de Laticínios , Feminino , Hormônios/sangue , Lactação/metabolismo , Período Pós-Parto/sangue , Período Pós-Parto/metabolismo , Gravidez/metabolismo
13.
Sci Rep ; 11(1): 21152, 2021 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-34707145

RESUMO

In this study we present systematic framework to analyse the impact of farm profiles as combinations of environmental conditions and management practices on common diseases in dairy cattle. The data used for this secondary data analysis includes observational data from 166 farms with a total of 5828 dairy cows. Each farm is characterised by features from five categories: husbandry, feeding, environmental conditions, housing, and milking systems. We combine dimension reduction with clustering techniques to identify groups of similar farm attributes, which we refer to as farm profiles. A statistical analysis of the farm profiles and their related disease risks is carried out to study the associations between disease risk, farm membership to a specific cluster as well as variables that characterise a given cluster by means of a multivariate regression model. The disease risks of five different farm profiles arise as the result of complex interactions between environmental conditions and farm management practices. We confirm previously documented relationships between diseases, feeding and husbandry. Furthermore, novel associations between housing and milking systems and specific disorders like lameness and ketosis have been discovered. Our approach contributes to paving a way towards a more holistic and data-driven understanding of bovine health and its risk factors.


Assuntos
Criação de Animais Domésticos/normas , Doenças dos Bovinos/epidemiologia , Bovinos/fisiologia , Animais , Feminino , Masculino
14.
Biol Reprod ; 105(6): 1458-1473, 2021 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-34647570

RESUMO

Dairy cow subfertility is a worldwide issue arising from multiple factors. It manifests in >30% early pregnancy losses in seasonal pasture-grazed herds, especially when cows are inseminated in the early post-partum period. Most losses occur before implantation, when embryo growth depends on factors present in maternal tract fluids. Here we examined the proteomic composition of early and mid-postpartum uterine luminal fluid (ULF) in crossbred lactating dairy cows to identify molecular determinants of fertility. We also explored changes in ULF from first to third estrus cycles postpartum in individual cows, linking those changes with divergent embryo development. For this, we flushed uteri of 87 cows at Day 7 of pregnancy at first and third estrus postpartum, recovering, and grading their embryos. Out of 1563 proteins detected, 472 had not been previously reported in this fluid, and 408 were predicted to be actively secreted by bioinformatic analysis. The abundance of 18 proteins with roles in immune regulation and metabolic function (e.g. cystatin B, pyruvate kinase M2) was associated with contrasting embryo quality. Matched-paired pathway analysis indicated that, from first to third estrus postpartum, upregulation of metabolic (e.g. creatine and carbohydrate) and immune (e.g. complement regulation, antiviral defense) processes were related to poorer quality embryos in the third estrus cycle postpartum. Conversely, upregulated signal transduction and protein trafficking appeared related to improved embryo quality in third estrus. These results advance the characterization of the molecular environment of bovine ULF and may aid understanding fertility issues in other mammals, including humans.


Assuntos
Bovinos/fisiologia , Período Pós-Parto/fisiologia , Prenhez/fisiologia , Proteoma , Útero/fisiologia , Animais , Indústria de Laticínios , Estro/fisiologia , Feminino , Lactação/fisiologia , Gravidez , Proteômica
15.
PLoS One ; 16(10): e0257249, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34648524

RESUMO

OBJECTIVES: Antibiotics are important for improving animal health and production. However, the deposition of its residues in food of animal origin intended for human consumption at non-permissible levels has generated global health concern and the need to tackle this using the "One Health Approach". This study assessed the knowledge and practice of 286 cattle handlers in Kwara State, Nigeria. METHODS: A web-based cross sectional online survey using a semi-structured questionnaire was conducted from November to December, 2019. Univariate, bivariate and multivariate analyses were performed at 95% confidence interval to determine predictors of good knowledge and practices towards Antibiotic Residues in Meat and Milk among cattle handlers. RESULTS: This study revealed that majority (52.7% n = 165/286) of the cattle handlers were not aware of antibiotic residues. Knowledge and practices regarding antibiotic residues were generally poor among the study population; 36.7% and 35.5% had satisfactory knowledge and practice respectively. The age (p = 0.026), gender (p = 0.006) and business duration (p = 0.001) of participants were significantly associated with their knowledge of antimicrobial residues. The effect of education on knowledge was modified by age. The odds of having poor knowledge on antibiotic residues increased 4 times among participants who were ≤40 years old than those above 40 years (Stratum Specific OR = 3.65; CI = 1.2, 11.1; p = 0.026). Knowledge levels of participants were statistically associated with their practice levels p<0.05 (OR = 2.43; CI = 1.45. 4.06; p = 0.0006). CONCLUSION: This implies that poor knowledge is a risk factor to having poor practice among cattle handlers. Deliberate efforts towards educating cattle farmers on best farm practices in antibiotic use would prevent antibiotic residues in meat and milk. Also, an effective surveillance system for monitoring the use of veterinary drugs in Kwara State, Nigeria is crucial.


Assuntos
Criação de Animais Domésticos , Antibacterianos/análise , Bovinos , Fazendeiros , Leite/química , Carne Vermelha/análise , Adulto , Animais , Bovinos/fisiologia , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Nigéria , Drogas Veterinárias/análise
16.
BMC Vet Res ; 17(1): 311, 2021 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-34563192

RESUMO

BACKGROUND: Metabolic profile evaluation is a tool widely used in ruminant nutrition as metabolic cues that relate nutrition to physiology. Metabolic and hormonal traits change during pre-partum and lactation according to parity in dairy cows, but studies of beef cows under grazing are scarce. The present study aimed to evaluate how metabolic and hormonal traits change over time, their relationship to performance, and determine if these factors differ according to the parity order of grazing beef cows. Thirty-six pregnant Nellore cows (12 nulliparous, 12 primiparous, and 12 multiparous) were used. The study started at 60 d prepartum until 203 d of lactation. RESULTS: The initial body weight (BW) and final BW were higher for multiparous cows (P > 0.05). An interaction occurred between parity and day (P < .0001) for body condition score. Nulliparous and primiparous body condition score were reduced from - 60 prepartum to 30 postpartum, then stabilized 60 postpartum (P < 0.05), while multiparous maintained body condition score from - 60 days until 60 days postpartum (P > 0.05). Calf BW, final BW, and average daily gain did not differ between parities (P > 0.05). Effect of day (P < 0.05) was detected for non-esterified fatty acids, triglycerides, total cholesterol, LDL, VLDL, progesterone, and insulin. An interaction was observed between parity and days for glucose, HDL, ß-hydroxybutyrate, creatinine and IGF-1 (P < 0.05). Parity affected serum urea nitrogen, total proteins, albumin, and globulins (P < 0.05). Parity and day relative to calving did not impact total T3 and T4 (P > 0.05). CONCLUSIONS: Hormonal and metabolic profile is strongly influenced by the stage of lactation. Time effects (pre-partum and lactation period) were more pronounced in nulliparous since they displayed more unbalanced metabolic and hormonal traits and lowered BCS pre- and postpartum.


Assuntos
Bovinos/sangue , Bovinos/fisiologia , Metabolismo Energético/fisiologia , Hormônios/sangue , Paridade/fisiologia , Animais , Peso Corporal/fisiologia , Feminino , Lactação , Gravidez
17.
J Therm Biol ; 100: 103033, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34503778

RESUMO

The objective of this study was to explore the responses of beef calves to long-term heat stress (HS) exposure at various levels in comparison with the animals under thermoneutral conditions by evaluating growth performance, physiological, blood, and behavioural parameters. Data were collected from sixteen beef calves (BW: 136.9 ± 6.23 kg; age: 169.6 ± 4.60 d) kept at four stress levels of designated temperature humidity index (THI): threshold (22-24 °C, 60%; THI = 70 to 73), mild (26-28 °C, 60%; THI = 74 to 76), moderate (29-31 °C, 80%; THI = 81 to 83), and severe (32-34 °C, 80%; THI = 89 to 91) stress levels in climatic controlled chambers. Feed and water intake were recorded daily, and body weight was measured once a week. Blood was sampled every three days to analyse metabolite parameters. Dry matter intake (DMI) (p = 0.069, tendency) and blood glucose levels (p = 0.028) were decreased after sudden exposure to HS conditions (severe THI levels). Also, blood cortisol (p = 0.002), glutamic-oxaloacetic transaminase (GOT) (p = 0.009), blood urea nitrogen (BUN) (p = 0.004) and standing time (p = 0.009) were increased in moderate and severe THI levels compared with threshold after exposure to HS conditions. However, in the severe THI group, blood cortisol (p < 0.05), glucose (p < 0.05), GOT (p < 0.05) and BUN (p < 0.05) levels were returned to normal range after 6-13 days of continuous HS exposure. In conclusion, DMI, blood cortisol, GOT, glucose, BUN, and standing time were closely associated with long-term HS condition in beef calves. In addition, calves exposed to HS modulated their physiological responses that resulted in the regulation of the pertinent blood metabolites in the blood to maintain homeostasis during the long-term HS.


Assuntos
Bovinos/fisiologia , Termotolerância , Animais , Aspartato Aminotransferases/sangue , Comportamento Animal , Glicemia/metabolismo , Nitrogênio da Ureia Sanguínea , Peso Corporal , Bovinos/sangue , Bovinos/crescimento & desenvolvimento , Ingestão de Alimentos , Hidrocortisona/sangue
18.
J Therm Biol ; 100: 103041, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34503788

RESUMO

The objectives of this study were to investigate the effects of the cow-related factors on rectal temperature (RT) and respiration rate (RR) of lactating dairy cows under different heat stress (HS) conditions and establish the temperature-humidity index (THI) thresholds at which RT and RR begin to increase for cows in China. Cow-related factors included body posture (standing and lying), milk yield (<26 kg/d, ≥ 26-39 kg/d, and ≥39 kg/d), days in milk (≤60 d, > 60 and ≤ 150 d, and >150 d), and parity (1, 2, and ≥3). Records of RT, RR, and individual characteristics were collected from July to October 2020 on a commercial dairy farm in Northern China, where 826 Holstein lactating cows were measured. Using the broken-stick regression models and the entire dataset, the THI thresholds for RT and RR were 69.8 and 67.1, respectively. Therefore, the heat stress conditions during this study were classified according to the THI levels as thermoneutrality (TN, 60 < THI ≤ 67), mild (67 < THI ≤ 72), moderate (72 < THI ≤ 80), and severe (80 < THI ≤ 86). Results showed that lying cows exhibited the higher RT and RR but the lower THI threshold for RT (68.8 vs. 70.7) and RR (65.6 vs. 68.4) than standing cows; milk yield is positively associated with the values of RT and RR under TN or HS conditions, and the THI thresholds for RT (70.2 vs. 70.0 vs. 68.0) and RR (68.1 vs. 64.7 vs. 64.7) were progressively lower for low-yielding, middle-yielding, and high-yielding cows; there was a significant increase in RT and RR in early-lactation cows compared to late-lactation cows under TN or HS conditions (P < 0.001), and the lowest THI threshold (67.8 for RT and 64.7 for RR) was observed in early-lactation cows, followed by mid-lactation cows (68.2 for RT and 65.3 for RR) and late-lactation cows (70.0 for RT and 67.3 for RR); the effects of parity were not significant on RT (P > 0.05), but significant on RR (P < 0.001). The THI thresholds for RT (69.2) and RR (66.0) were lowest for cows in 3rd-parity and higher, followed by cows in 2nd-parity (70.0 for RT and 68.9 for RR) and 1st-parity (70.7 for RT and 66.6 for RR). This study highlighted the great significance of considering the cow-related factors in heat stress responses and THI threshold assessment. For dairy cows in China, we suggest that cooling should be initiated when THI reaches 65 to 66.


Assuntos
Regulação da Temperatura Corporal , Bovinos/fisiologia , Resposta ao Choque Térmico , Lactação/fisiologia , Taxa Respiratória , Criação de Animais Domésticos/métodos , Animais , Feminino
19.
J Therm Biol ; 100: 103052, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34503799

RESUMO

Thermal microchip sensors can automate body temperature measurements. The best site of implantation is still unknown, and the accuracy and precision of body temperature predictions based on microchip data need to be investigated. The aim of this study was to investigate the best site for microchip implant for monitoring body temperature in dairy calves. Seventeen calves were used (32.2 ± 5.2 kg of body weight) and the microchips were implanted four days after birth. The microchips were implanted at navel, ear and tail base (subcutaneous), neck (cleidocephalicus) and internal face of leg (gracilis) (intramuscular). Rectal temperature (RT, °C), obtained with a clinical thermometer, was considered as core temperature. Air temperature (AT), relative humidity (RH) and the temperature and humidity index (THI) were evaluated at the same time of rectal and microchip temperature measurements over 56 days. The range of AT, RH and THI was 7.6-34.4 °C, 17.5-99.0% and 50.6 to 91.5. The average for rectum, ear, neck, tail, leg, and navel were 38.7; 36.9; 38.0; 37.0, 37.8 and 37.0 °C. The intramuscular implantations had closest values to RT. The correlations between RT and ear, neck, tail, leg, and navel temperatures were 0.56, 0.60, 0.60, 0.53 e 0.48. The RT prediction based on microchip data had precision (rc) ranged between 0.49 and 0.60 and accuracy (Cb) between 0.79 and 0.88. The inclusion of AT, RH and THI as predictive variables in models decrease the mean absolute error (23%) and increase the precision (21.3%) and accuracy (10.2%). The Concordance Correlation Coefficient and root-mean-square error for equations using tail or neck microchips were 0.68 and 0.67, and 0.29 and 0.28 °C, respectively. The tail base is a promising site for microchip implantation to predict rectal temperature. The inclusion of air temperature as a predictive variable in the models is recommended.


Assuntos
Temperatura Corporal , Bovinos/fisiologia , Termometria/instrumentação , Animais , Bovinos/crescimento & desenvolvimento , Dispositivos Lab-On-A-Chip/veterinária , Termômetros/veterinária , Termometria/métodos , Termometria/veterinária , Dispositivos Eletrônicos Vestíveis/veterinária
20.
J Therm Biol ; 100: 103064, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34503804

RESUMO

Ruminant testes are ~2-6 °C below body temperature; increased testicular temperature reduces sperm motility and morphology. Our objective was to serially monitor scrotal subcutaneous temperatures during testicular heat stress and relate those to sperm quality. Two experiments were conducted, with temperature sensors surgically implanted in scrotal subcutaneous tissues recording temperatures every 15 min and semen collected and evaluated weekly. After an initial control interval, testicular temperature was increased. In Experiment 1, in two Angus bulls, whole-scrotum insulation for 96 h increased scrotal subcutaneous temperatures by ~2.0-2.5 °C (P < 0.05). Total and progressive motility decreased (P < 0.05) and reached a nadir at Week 3 (~20 and 10%, respectively). Furthermore, morphologically normal sperm and acrosome integrity also decreased significantly, reaching nadirs at Weeks 3 (15%) and 4 (34%). In Experiment 2, 10 Dorset rams were allocated randomly into two equal groups and either: 1) exposed to 28 °C ambient temperature and 30-34% RH for 8 h/d for 4 d; or 2) subjected to scrotal neck insulation that was applied and removed at the same time as the start and completion, respectively, of heat exposures in the other rams. Scrotal subcutaneous temperatures (monitored in three rams per group) were increased in response to whole-body heating (~0.8 °C, P < 0.05), but not significantly changed by scrotal neck insulation. Decreases in sperm quality were generally similar between treatments, with the most profound changes evident 4 wk after heat stress, with ~10 percentage point reductions in both total and progressive motility and ~10 and 20 percentage point decreases in morphologically normal sperm in rams with whole-body heating versus scrotal neck insulation, respectively. In conclusion, scrotal subcutaneous temperature was significantly increased by scrotal insulation or whole-body heating, but not by scrotal neck insulation; however, all three heat-stress models decreased sperm motility and morphology in bulls and rams.


Assuntos
Bovinos/fisiologia , Transtornos de Estresse por Calor/prevenção & controle , Escroto/fisiologia , Ovinos/fisiologia , Temperatura Cutânea , Acrossomo/fisiologia , Animais , Regulação da Temperatura Corporal , Transtornos de Estresse por Calor/fisiopatologia , Transtornos de Estresse por Calor/veterinária , Masculino , Escroto/citologia , Análise do Sêmen/veterinária
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...