RESUMEN
Understanding of the social environment has the potential to benefit dairy cow welfare and production. Our aim was to evaluate the associations of stocking density, calving density, days spent in a pre-partum group before calving (days spent in close-up, DCU) and the number of days from a pen filling event (addition of new cows to the pre-partum pen) on early-lactation health, production, pregnancy and culling outcomes in dairy cows. Data were gathered from 2780 cows in 2 herds. Herd management and reproductive records were analyzed for cows receiving treatment in the first 30 d of lactation (days in milk, DIM) for clinical mastitis, reproductive tract disease, ketosis, milk fever and displaced abomasum. Principal component analysis was used to account for the relationship between gestation length (GL) and DCU and their association with early lactation disease, milk production, pregnancy and culling outcomes. The effect of stocking density, the number of days from a pen filling event to calving and the calving density experienced by a cow in her week of calving was also evaluated. Causal inference was used to correct for confounding bias due to farm identity. The odds of disease in the first 30 DIM increased with stocking density before calving. A quadratic association was found between the first principal component (PC1), representing the combined effect of GL and DCU, and the odds of disease in multiparous cows only. Early lactation milk production and 305 d milk production in multiparous cows increased with PC1 score. Quadratic relationships were found between stocking density at d 8 to 2 before calving with both early lactation and 305 d milk production in multiparous cows but no associations were found in primiparous cows. Calving density showed a quadratic association with 305 d milk production in primiparous cows. The number of days from the last pen filling event to calving was not associated with changes in milk production. Disease occurrence was negatively associated with both early lactation and 305 d milk yield in multiparous cows but only with early lactation milk production in primiparous cows. The occurrence of disease was associated with a delayed time to pregnancy only in primiparous cows while both disease and being in lactation group ≥ 3 were negatively associated with time to pregnancy in multiparous cows. Week 4 milk (W4MK) was positively associated with reduced time to pregnancy in multiparous cows. For primiparous cows, increasing age at calving was associated with increased culling risk, while being in lactation group ≥ 3 was associated with increased culling risk in multiparous cows. Culling risk decreased with increasing W4MK in all cows. These results suggest that gestation length, time spent in close-up and stocking density are important factors influencing disease incidence in early lactation and subsequent lactation performance but had differing effects on primiparous versus multiparous cows. A better understanding of how pre-partum management factors influence postpartum health and milk production can help farms to plan facilities and organize the day-to-day management of cows and will assist in improving cow welfare and productivity.
RESUMEN
The purpose of this study was to evaluate the effect of rumination times and days spent in a close-up group before calving (DCU) on early-lactation health and reproductive outcomes in dairy cows. Data were gathered for 719 cows located in a single herd. Herd management and reproductive records were analyzed for cows receiving treatment in the first 30 d of lactation (days in milk; DIM) for clinical mastitis, reproductive tract disease, ketosis, milk fever, and displaced abomasum. Rumination times for each cow were downloaded daily from the herd's automated collar system used to generate heat and health alerts for each cow beginning at 21 d precalving until 14 d postcalving. During the first 30 DIM, 121 cows (18%) developed at least 1 disease-any combination of ketosis (40 cows, 5.9% of total), mastitis (17 cows, 2.5%), metritis (75 cows, 11%), milk fever (17 cows, 2.5%), or displaced abomasum (28 cows, 4.1%); 305 cows (45%) were pregnant again at 100 DIM, and an additional 139 cows (20%) were pregnant at 150 DIM. Principal component analysis was used to determine the relationship between gestation length and DCU and their association with the odds of developing disease in early lactation. We did not find any significant association between precalving rumination time and disease within the first 30 DIM. Higher rumination time in the week before calving was shown to be strongly linked to a shorter time to subsequent pregnancy, whereas rumination times postcalving were not associated with changes in the time to pregnancy. Principal component analysis showed that a curvilinear combination of gestation length and DCU (principal component 1) was significantly associated with changes in disease incidence in the first 30 DIM. Gestation length and time spent in close up are important management factors in reducing the incidence of disease in early lactation, and rumination times around calving may help predict future reproductive outcomes.
Asunto(s)
Enfermedades de los Bovinos , Cetosis , Animales , Bovinos , Femenino , Cetosis/veterinaria , Lactancia , Leche , Periodo Posparto , Embarazo , Resultado del EmbarazoRESUMEN
The objective of this study was to compare the reproductive performance of lactating dairy cows submitted to first AI after combination of estrus detection and fixed timed AI (FTAI) and FTAI only. Cows were randomly assigned to receive AI at detected estrus between 50 and 70 d in milk (DIM), if not detected in estrus, were enrolled in either Ovsynch (ED-Ov, n = 485) or PRIDsynch (ED-PR, n = 505) protocols; or received FTAI at 80 DIM after Double-Ovsynch protocol (DO, n = 501). Cows were body condition scored (BCS) at calving and at 43 DIM; and evaluated for postpartum disorders within 7 d postpartum; clinical mastitis, lameness and bovine respiratory disease were recorded until first AI. Ovarian cyclicity was monitored at 43 and 50 DIM, and at 70 and 77 DIM. Pregnancy diagnoses (PD) were performed at 32 and 63 d after AI. Overall prevalence of postpartum anovulation was 7.8%. Pregnancy per AI (P/AI) did not differ between reproductive strategies at 32 d PD (ED-Ov = 43.2%; ED-PR = 41.7%; DO= 45.3%). Primiparous cows had greater P/AI than multiparous cows (53.7% vs 36.8%). Cows on farm 1 had lower P/AI compared with their counterparts on farm 2 (42.1% vs 45.4%). Cows with BCS > 2.5 at 43 DIM had greater P/AI compared with cows with BCS ≤ 2.5 (44.5% vs 34.7%). Similar P/AI for cow's receiving AI at detected estrus and FTAI, low prevalence of disease anovulation may have contributed to the similar performance of ED-Ov, ED-PR and DO.
RESUMEN
The work presented in this pilot study aimed to identify potential risk factors associated with bovine periodontitis development. Bovine periodontitis is a multifactorial polymicrobial infectious disease for which the aetiopathogenesis and risk factors are not fully understood. From cattle slaughtered in an abattoir in Scotland, 35 dental arcades with periodontal lesions and 40 periodontally healthy arcades were selected over seven visits for study. Multivariable logistic regression analysis was used to evaluate the association between periodontitis and the independent variables, gender, age and breed. For every increase in year of age, cattle were 1.5 times more likely to have periodontitis. A graphical analysis indicated that within the limits of this study, we could not detect any major influence of breed on the age-effect. Although logistic regression analysis demonstrated that periodontitis lesions are more prevalent with increasing age of cattle the underlying mechanisms remain unclear. It is likely that periodontitis is an important cause of oral pain in older cattle and can contribute to reduced productivity/performance. Further studies with a larger sample size are necessary to elucidate the associations between potential risk factors and periodontitis in cattle and to define its effects on animal welfare and productivity.
Asunto(s)
Enfermedades de los Bovinos , Periodontitis , Animales , Bovinos , Enfermedades de los Bovinos/epidemiología , Periodontitis/epidemiología , Periodontitis/veterinaria , Proyectos Piloto , Factores de Riesgo , Escocia/epidemiologíaRESUMEN
Mastitis, inflammation of the mammary gland, is often caused by intramammary infection with bacterial organisms. It impacts on dairy cattle welfare, production, udder health and longevity in the herd. Current detection methods for mammary inflammation and infection all have limitations, particularly for on-farm diagnosis of non-clinical mastitis after calving. Acute phase proteins have been suggested as alternative early indicators of the disease and can potentially be used as cow-side test with results in real time. In this study, milk haptoglobin concentrations were investigated over the first week postpartum to explore haptoglobin's potential as indicator of udder health in dairy heifers. Haptoglobin concentration was highest on day 3 of lactation, and was positively correlated with somatic cell count, a commonly used marker of inflammation (rs=0.68). Haptoglobin level was also associated with bacteriological culture results, a key indicator of infection status, whereby median haptoglobin concentration on days 3 and 5 was higher in quarters that were infected at calving than quarters that were non infected at calving. Sensitivity and specificity of haptoglobin concentration as indicator of infection were low, both for lenient and strict culture-based definitions of intramammary infection (57 or 60% and 61 or 63%, respectively). Although haptoglobin was a poor biomarker for intramammary infection with coagulase negative staphylococci in heifers during the first week after calving, it may have value as an indicator of major pathogen infections, particularly in large scale dairy herds where pre-partum heifers are managed off-site.
Asunto(s)
Haptoglobinas/metabolismo , Glándulas Mamarias Animales/microbiología , Mastitis Bovina/diagnóstico , Leche/química , Animales , Bacterias , Bovinos , Recuento de Células/veterinaria , Femenino , Haptoglobinas/química , Lactancia , Mastitis Bovina/microbiología , Leche/microbiología , Proyectos Piloto , Periodo PospartoRESUMEN
Thermosensitive polymer networks were synthesized from poly(ethylene glycol), hexamethylene diisocyanate and 1,2,6-hexanetriol in stoichiometric proportions. By varying the amount of 1,2,6-hexanetriol and the molar mass of the poly(ethylene glycol), a wide range of networks with different crosslinking densities was prepared. The networks obtained were characterized by the temperature dependence of their degree of equilibrium swelling in water and by their Young's moduli. For each network, the molecular weight between crosslinks was estimated. The structure of the hydrogels was analysed with respect to scaling laws, and it was found that the results obtained with PEG 1500 and PEG 6000 hydrogels are in agreement with theoretical predictions, whereas those obtained with PEG 400 hydrogels are in disagreement. The release properties of PEG hydrogels were studied by the determination of the diffusion coefficient for acebutolol chlorhydrate and by an analysis of the effect of temperature on these coefficients. Finally, these release properties were correlated with the swelling and structural properties of the hydrogels.
Asunto(s)
Polietilenglicoles/química , Acebutolol/administración & dosificación , Difusión , Hidrogel de Polietilenoglicol-Dimetacrilato , Peso Molecular , Polietilenglicoles/administración & dosificación , TemperaturaRESUMEN
Cervical lymphnodes metastatization by the squamous cell carcinoma of the head and neck is well known as a prognostic negative factor as far as survival is concerned. Multivariate analysis has been used on 207 cases of head and neck squamous cell carcinomas (HNSCC) in order to identify the possible prognostic significance of a group of clinical and histopathological characteristics, aiming to find a correlation with the possible occurrence of cervical lymphnodes. Two hundred and seven patients (168 males and 39 females, mean age: 62 years) with SCCHN were studied. They underwent surgery alone and radiotherapeutic associated treatment. Variables regarding the patient, carcinoma and histology were analysed: age, sex, smoking and alcohol consumption, performance status, concomitant internal pathologies (cardiopathies, hepatopathies, broncho-pneumopathies, metabolic disorders), site and size of primary tumor (T stage), number and size of laterocervical lymph node localization (clinical N stage), grading, vascular permeation, perineural infiltration. Multivariate analysis of prognostic factors was performed using BMDP's PLR programme. Some variables showed a great risk of lymphnode metastasis; among sites: supraglottic larynx (p = 0.05), base of the tongue (p = 0.04), hypopharynx (p = 0.05); some histological parameters as lower degree of histological differentiation (p = 0.02), the presence of vascular permeation (p = 0.06) and perineural invasion (p = 0.07) appear to represent predisposing factors for the onset of adenopathies. By considering prognostic factors as shown, it is possible to better identify metastasis risk cases, that leads to improved therapeutical strategies.
Asunto(s)
Carcinoma de Células Escamosas/patología , Neoplasias de Cabeza y Cuello/patología , Metástasis Linfática , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Carcinoma de Células Escamosas/diagnóstico por imagen , Carcinoma de Células Escamosas/mortalidad , Carcinoma de Células Escamosas/cirugía , Terapia Combinada , Femenino , Neoplasias de Cabeza y Cuello/diagnóstico por imagen , Neoplasias de Cabeza y Cuello/mortalidad , Neoplasias de Cabeza y Cuello/cirugía , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Estadificación de Neoplasias , Probabilidad , Pronóstico , Radiografía , Estudios Retrospectivos , Tasa de Supervivencia , Factores de TiempoRESUMEN
Accurate identification of mastitis-causing bacteria supports effective management and can be used to implement selective use of antimicrobials for treatment. The objectives of this study were to compare the results from a culture-based mastitis pathogen detection test kit ('VetoRapid', Vétoquinol) with standard laboratory culture and to evaluate the potential suitability of the test kit to inform a selective treatment programme. Overall 231 quarter milk samples from five UK dairy farms were collected. The sensitivity and specificity of the test kit for the identification of Escherichia coli, Staphylococcus aureus, coagulase-negative staphylococci, Streptococcus uberis and Enterococcus spp. ranged from 17 per cent to 84 per cent and 92 per cent to 98 per cent, respectively. In total, 23 of 68 clinical samples were assigned as meeting the requirement for antimicrobial treatment (Gram-positive organism cultured) according to standard culture results, with the test kit results having sensitivity and specificity of 91 per cent and 78 per cent, respectively. Several occurrences of misidentification are reported, including S. aureus being misidentified as coagulase-negative staphylococci and vice versa. The test kit provides rapid preliminary identification of five common causes of bovine mastitis under UK field conditions and is likely to be suitable for informing selective treatment of clinical mastitis caused by Gram-positive organisms.