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1.
Animal ; 13(11): 2621-2629, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31062681

RESUMEN

Failed transfer of passive immunity (FTPI) in dairy calves - which is often due to the low amount of colostrum provided within a few hours after birth - remains a crucial issue. Enabling dairy calves to nurse colostrum from their dams could be useful in increasing intake and thus avoiding FTPI, but further potential effects on the health and welfare of both calves and dams should also be considered. In this study, 107 calf-dam pairs from two Italian dairy farms were alternately assigned to one of the following colostrum provision methods (CPMs): 'hand-fed method' (HFM) - the calf was separated from the dam immediately after birth and colostrum was provided by nipple-bottle (n = 50); 'nursing method' (NM) - the calf nursed colostrum from the dam for the first 12 h of life without farmer assistance (n = 30); and 'mixed method' (MM) - the nursing calf received a supplementary colostrum meal by nipple-bottle (n = 27). Serum of calves (1 to 5 days of age) and samples of their first colostrum meal were analysed by electrophoresis to assess immunoglobulin (Ig) concentration. Additionally, behavioural indicators of separation distress (calf and dam vocalisations; calf refusal of the first meal after separation; undesirable dam behaviour at milking) in the following 24 h were recorded as binary variables (Yes/No), and the health status of calves (disease occurrence and mortality) and dams (postpartum disorders and mastitis occurrence) were monitored for the first 3 months of life and 7 days after parturition, respectively. The lowest FTPI occurrence (calf serum Ig concentration <10.0 g/l) was found in the MM (11.1%) and the HFM (22.0%) compared with the NM (60.0%) (P<0.05), and the highest percentage of calves with optimal transfer of passive immunity (serum Ig concentration ≥16.0 g/l) was observed in the MM (55.6%). The lowest calf-dam separation distress was observed in the HFM (P<0.05). The highest calf disease occurrence was recorded in the HFM (64.0%) and the lowest in the NM (33.3%), with an intermediate value for the MM (44.4%) (P<0.05). No effect of the CPM was observed on dam health or calf mortality (P>0.05). The results of this study indicated that providing calves with a supplementary colostrum meal in addition to nursing from the dam (MM) is truly effective in maximizing passive immunity transfer. Anyway, specific strategies should be studied to minimise calf-dam separation distress.


Asunto(s)
Enfermedades de los Bovinos/mortalidad , Bovinos/inmunología , Calostro/inmunología , Inmunización Pasiva/veterinaria , Inmunoglobulinas/inmunología , Mastitis Bovina/epidemiología , Animales , Animales Recién Nacidos , Bovinos/fisiología , Enfermedades de los Bovinos/epidemiología , Femenino , Estado de Salud , Italia , Parto , Embarazo
2.
Animal ; 12(5): 1041-1049, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29039299

RESUMEN

Despite the well-known importance of an adequate colostral immunoglobulin (Ig) transfer to calf health and survival, failed transfer of passive immunity (FTPI) remains a widespread problem in dairy farming. The aim of this study was to investigate the management factors associated with FTPI in newborn calves, evaluating particularly the combined effect of delivery time, amount and quality of the first colostrum meal. The study was conducted from March to August 2014 on 21 Italian dairy farms. Farmers were asked as first to answer a farm-level questionnaire on calf management. Blood sampling was then performed on overall 244 calves (1 to 5 days of age) born from Holstein cows, and a sample of the first colostrum meal of each calf was collected. Individual information on calves and the respective colostrum management were recorded. Serum and colostrum Ig concentrations were assessed by electrophoresis. A mixed effects multivariable logistic regression model was used to investigate the association of the variables obtained from both the management questionnaire and the individual calf data with FTPI (calf serum Ig concentration 87.6 g/l) within 1.0 h from birth. Considerable improvements are still needed about colostrum management for newborn calves in dairy farms. The results of this study will help in developing farm-specific programs for reducing the occurrence of FTPI.


Asunto(s)
Bovinos/inmunología , Calostro/inmunología , Inmunización Pasiva/veterinaria , Animales , Granjas , Femenino , Inmunoglobulina G/sangre , Modelos Logísticos , Embarazo
3.
Ecotoxicology ; 20(4): 927-35, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21298340

RESUMEN

Although the Allium cepa test has been widely used to identify potentially cytotoxic and genotoxic pollutants in aquatic environments, variable non-standardized choices have been made regarding the number of plant bulbs and roots analyzed. We propose numbers for bulbs and roots per bulb when comparing the frequencies of micronuclei, mitotic anomalies and mitotic index with this test. Roots that had been treated with aqueous solutions, such as water samples collected in August 2007 from the Paraíba do Sul River at the Brazilian cities of Tremembé and Aparecida; negative and positive controls were used for bioassays. The presence of pollutants in the river water had been presumed based on our previous cytological data and an official report by the São Paulo State Environmental Agency (Brazil) on presence of fecal contaminants (Tremembé and Aparecida) and elevated dissolved aluminium (Aparecida) in the water under study. The sampling of ten bulbs and five roots per bulb was found adequate for comparative studies to evaluate with the A. cepa test the potential damage inflicted by pollutants in aquatic environments. Furthermore, even one bulb and one root per bulb was sufficient in discerning this damage, thereby shortening the time required to attain a statistically confident comparative evaluation. However, to allow for the use of statistical programs based on the evaluation of average values, and to avoid criticism based on genetic variability, we propose that three bulbs and three roots per bulb be considered as standard sample sizes for the A. cepa test.


Asunto(s)
Contaminantes Ambientales/toxicidad , Cebollas/efectos de los fármacos , Raíces de Plantas/efectos de los fármacos , Pruebas de Toxicidad/normas , Pruebas de Micronúcleos/normas , Mitosis/efectos de los fármacos , Mutágenos/toxicidad , Cebollas/anatomía & histología , Cebollas/crecimiento & desarrollo , Raíces de Plantas/anatomía & histología , Raíces de Plantas/crecimiento & desarrollo , Tamaño de la Muestra
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