Time Spent in a Maternity Pen during Winter Influences Cow and Calf Behavior in Pasture-Based Dairy Systems.

Our study compared the behavior of prepartum dairy cows that either remained in an outdoor paddock until calving (OP) during winter or were moved to an indoor maternity pen either early (EM) or late (LM) relative to calving. Forty-two multiparous Holstein cows were divided into three treatments (OP, EM, or LM) and monitored from 3 weeks before to 1.5 h after calving. Cows in EM and LM were moved to a maternity pen starting at week three and week one before the expected calving date, respectively. We assessed the cleanliness of the cows at calving, immunoglobulin G concentration in colostrum, and the behavior and vitality of calves across treatments. Cows spent more time lying in EM compared to OP and LM during the weeks -3 and -2 relative to calving, but lying time was increased in LM cows compared with OP cows during the week -1 relative to calving. Prepartum rumination time was lowest in OP cows but not different between EM or LM. Calves from OP cows spent more time lying and had lower vitality after calving than those from LM and EM cows, respectively; calves from EM and LM cows were intermediate for lying and vitality, respectively, but did not differ from either group. The cleanliness was greatest in cows that calved indoors (EM or LM); nevertheless, precalving management did not affect the IgG concentration in colostrum. Our study demonstrates that, in comparison with OP, EM and LM have positive implications for the welfare of the dam and its newborn calf during winter.

Measuring Calves' Usage of Multiple Environmental Enrichment Objects Provided Simultaneously.

This study aims to assess calf usage of five potential enrichment devices provided simultaneously. We used 25 weaned Holstein-Friesian calves housed in groups of five (five replicates), and their behavior was recorded continuously with video cameras. This longitudinal observational study used a pen equipped with a mechanical and fixed brush, cowhide, and horizontal and vertical ropes. Data collected included how many visits each object received per day, the type of object usage, and the duration of the visits. Calves used all five objects at least once, and they used items more during the daytime than at night. Brushes were used mainly for grooming (e.g., rubbing or scratching), while ropes and cowhide for oral interactions (e.g., licking, chewing, and biting), most likely to lack oral stimulations that would naturally be satisfied by suckling and grazing at this age. The objects most frequently used were the mechanical brush and the horizontal rope, and they received the highest number of visits (214.9 and 154.9 bouts/day, respectively). The least chosen object was the stationary brush, which had the lowest number of visits (62.9 bouts/day). The provision of multiple enrichment objects for weaned calves should be considered as they may add complexity and novelty to barren environments.

Responses of Outdoor Housed Dairy Cows to Shade Access during the Prepartum Period under Temperate Summer Conditions.

Cows are affected by environmental factors associated with warm weather conditions; however, little is known about the effect of shade access especially during the prepartum period of dairy cows in temperate regions. This study assessed the effect of shade on the behavior (lying, rumination, feeding, and drinking), body fat mobilization, and health status of outdoor-housed dairy cows during the prepartum period under temperate summer conditions. During the 3 weeks prior to calving, 24 multiparous Holstein cows were grouped (4 cows/group) and assigned to either an open corral without shade or with access to shade until calving. We daily measured shade use, lying, rumination, feeding, and drinking behavior. Weekly, prepartum non-esterified fatty acids (NEFA) and postpartum b-hydroxybutyrate (BHB) concentrations were measured. Clinical examination was periodically performed individually until 21 postpartum days. Shade use averaged 45.6, 46.0, and 19.8% during the hottest hours of the day (11-18 h) in weeks 3, 2, and 1 prior to calving, respectively. Shaded cows had higher values for rumination time and feeding time during the morning but spent less time drinking during the warmest hours than unshaded cows. NEFA and BHB concentrations and clinical diseases were similar between both treatments. These findings suggest that under temperate summer conditions the access to an artificial shade is an important resource, observing beneficial effects mainly on behavioral variables.

Prepartum factors associated with postpartum diseases in pasture-based dairy cows.

This cross-sectional observational study aimed to identify prepartum management, environmental, and animal factors associated with clinical -lameness, metritis, mastitis- and subclinical -calcium imbalance, magnesium imbalance- diseases in pasture-based dairy cows. A total of 565 cows from 25 commercial dairy farms in southern Chile were enrolled over four months. Data on prepartum management and environmental conditions were obtained through a survey and inspections of prepartum paddocks. Cows were evaluated two times. In the first evaluation, between 30 to 3 days before calving, cows were assessed for lameness, body condition score, and blood samples were collected to measure nonesterified fatty acid (NEFA), calcium (Ca), and magnesium (Mg). In the second evaluation, between 3 to 21 DIM, cows were assessed for metritis, lameness, and blood samples were collected and analyzed for total Ca and Mg concentration. Cows were considered as having Ca imbalance if Ca < 2.0 mmol/L, and Mg imbalance if Mg < 0.65 mmol/L. Postpartum clinical mastitis was diagnosed based on the foremilk's daily condition and udder assessed by the milker at each milking during the postpartum transition period. Multivariable logistic regression models, controlling for the farm as a random effect, were built to identify prepartum factors for each postpartum disease. The odds of postpartum lameness were higher for cows that were lame during the prepartum period, had elevated prepartum NEFA concentrations, had greater parity, and for cows that were kept in paddocks with no grass cover. The odds of metritis were higher in cows with lower parity, with increased prepartum NEFA, in cows that had dystocia, and farms with predominantly Holstein breed, and that did not have calving records. The odds of clinical mastitis were higher for cows lame during the prepartum period. The odds of Ca imbalance were higher in cows with a long dry period, dystocic calving, and in farms without prepartum anionic salts supplementation. The odds of Mg imbalance were higher in cows with lower prepartum Mg concentrations, higher prepartum Ca concentration, and higher parity. Our findings indicate that farmers could benefit from refining these areas to improve their cows' health and welfare.

Effect of dietary inclusion of winter brassica crops on milk production, feeding behavior, rumen fermentation, and plasma fatty acid profile in dairy cows.

This study determined feeding behavior, dry matter (DM) intake (DMI), rumen fermentation, and milk production responses of lactating dairy cows fed with kale (Brassica oleracea) or swede (Brassica napus ssp. napobrassica). Twelve multiparous lactating dairy cows (560 ± 22 kg of body weight, 30 ± 4 kg of milk/d, and 60 ± 11 d in milk at the beginning of the experiment; mean ± standard deviation) were randomly allocated to 3 dietary treatments in a replicated 3 × 3 Latin square design. The control diet comprised 10 kg of grass silage DM/d, 4 kg of ryegrass herbage DM/d, and 8.8 kg of concentrate DM/d. Then, 25% of herbage, silage, and concentrate (DM basis) was replaced with either kale or swede. Cows offered kale had decreased total DMI compared with cows fed the control and swede diets, whereas inclusion of swede increased eating time. Milk production, composition, and energy-corrected milk:DMI ratio were not affected. Cows fed with kale had a greater rumen acetate:propionate ratio, whereas swede inclusion increased the relative percentage of butyrate. Estimated microbial N was not affected by dietary treatments, but N excretion was reduced with inclusion of kale, improving N utilization. Cows fed kale tended to have increased nonesterified fatty acids and showed presence of Heinz-Ehrlich bodies, whereas hepatic enzymes such as aspartate aminotransferase, γ-glutamyl transferase, and glutamate dehydrogenase were not affected by dietary treatments. In plasma, compared with the control, swede and kale reduced total saturated fatty acids and increased total polyunsaturated fatty acids and total n-3 fatty acids. Overall, feeding cows with winter brassicas had no negative effect on production responses. However, mechanisms to maintain milk production were different. Inclusion of swede increased the time spent eating and maintained DMI with a greater relative rumen percentage of butyrate and propionate, whereas kale reduced DMI but increased triacylglycerides mobilization, which can negatively affect reproductive performance. Thus, the inclusion of swede may be more suitable for feeding early-lactating dairy cows during winter.

Transition diseases in grazing dairy cows are related to serum cholesterol and other analytes.

The objectives of this study were to describe the incidence of postpartum disease and to evaluate the association with serum cholesterol concentrations during the first 3 weeks after calving in grazing dairy cows. The association between non-esterified fatty acids (NEFA), ß-hydroxybutyrate (BHBA), calcium and postpartum diseases was also evaluated. A total of 307 Holstein dairy cows from 6 commercial grazing herds in Osorno, Chile, were monitored from calving until 21 days in milk. Cases of retained placenta, clinical hypocalcemia and clinical mastitis were recorded by the farmer using established definitions. Twice weekly, cows were evaluated for metritis by the same veterinarian based on vaginal discharge and body temperature. Postpartum blood samples were collected weekly and analyzed for serum concentrations of cholesterol, NEFA, BHBA and calcium. Cows were considered as having subclinical ketosis if BHBA >1.2 mmol/L, and subclinical hypocalcemia if calcium <2.0 mmol/L in any of the 3 weekly samples. Overall, 56% of the cows studied developed at least one clinical or subclinical disease after calving. Incidence of individual diseases was 8.8% for retained placenta, 4.2% for clinical hypocalcemia, 11.7% for clinical mastitis, 41.1% for metritis, 19.9% for subclinical hypocalcemia and 16.6% for subclinical ketosis. Lower postpartum cholesterol in cows was associated with developing severe metritis or having more than one clinical disease after calving. For every 0.4 mmol/L decrease in serum cholesterol cows were nearly twice as likely to be diagnosed with multiple clinical diseases after calving. Higher BHBA concentrations and lower calcium concentrations during week 1 were associated with severe cases of metritis. Low serum calcium concentration during week 1 was also associated with developing more than one clinical disorder after calving. In conclusion, the incidence of postpartum diseases can be high even in grazing herds and lower serum cholesterol concentrations were associated with occurrence of clinical postpatum disorders.

Estudio Ultrasonográfico de las Estructuras Nerviosas del Canal Vertebral a Nivel de la Articulación Atlantooccipital en Caninos Adultos / Ultrasonographic Study of the Nervous Structures of the Vertebral Canal at the Atlantooccipital Joint Level in Adult Dogs

Los objetivos de este estudio fueron describir y comparar, mediante el ultrasonido, las estructuras nerviosas que se encuentran en el canal vertebral a nivel de la articulación atlanto-occipital en caninos adultos de talla corporal pequeña y grande. Se utilizaron 20 caninos adultos clínicamente sanos: 10 caninos de talla corporal pequeña (peso < a 10 kg) y 10 a caninos de talla corporal grande (peso > a 20 kg). Se realizó el examen ultrasonográfico con un transductor de 7,5 MHz, utilizando para ello el espacio atlantooccipital como ventana ecográfica. Se midieron diámetros verticales y horizontales del saco dural y médula espinal, y áreas del saco dural, médula espinal y espacio subaracnoídeo. Se calcularon razones entre algunas mediciones. Las estructuras estudiadas se observaron ecográficamente de modo similar en los caninos de ambos grupos. La duramadre se observó como una línea hiperecoica continua, adherida al borde óseo del canal vertebral. La médula espinal se observó como una estructura ovalada hipoecoica, con un parénquima homogéneo. Los diámetros verticales y horizontales del saco dural, médula espinal y las áreas del saco dural, médula espinal y espacio subaracnoídeo fueron significativamente menores (p<0,05) en los caninos de talla corporal pequeña. Las diferencias entre las áreas de médula espinal entre los grupos fue menor a 0,1 cm² y entre las áreas de saco dural y espacio subaracnoídeo fue de aproximadamente 1 cm². Se concluye que el ultrasonido permite visualizar adecuadamente la médula espinal y estructuras asociadas en la región de la articulación atlanto-occipital en caninos adultos. Finalmente, existieron diferencias mínimas en los valores de áreas de médula espinal y notoriamente mayores en los valores de áreas del saco dural y espacio subaracnoídeo entre ambos grupos de animales.

The goals of this study were to describe and compare by ultrasound the nervous structures in the vertebral canal at the atlanto-occipital joint region in small and large size adult dogs. A total of 20 healthy adult dogs were selected for the study. They were 10 small dogs (< 10 kg) and 10 large dogs (> 20 kg). Ultrasonographic examination was performed with a 7,5 MHz transducer and using the atlanto-occipital space as an echographic window. In transverse images, vertical and horizontal diameters of the dural sac and spinal cord and areas of the dural sac, spinal cord and subarachnoid space were measured. Some ratios between measurements were also calculated. Analysed structures were observed in a similar way in both groups of dogs. The dura mater was observed as an echogenic continuous line and attached to the bony border. The subarachnoid space has an anechoic appearance. The pia mater was observed as a thin echogenic line covering the spinal cord surface. The spinal cord was observed as an oval hypoechogenic structure inside the vertebral canal and with a homogeneous parenchyma without differentiation between gray and white matter. Vertical and horizontal diameters of the dural sac and spinal cord and areas of the dural sac, spinal cord and subarachnoid space were significantly different (P<0,05) in both group of dogs. Differences of spinal cord areas between small and large dogs were minimal (<0,1 cm²), compared with differences between dural sac and subarachnoid space areas (around 1 cm x). In conclusion, ultrasound allows an adequate examination of spinal cord and associated structures at the atlanto-occipital joint region in adult dogs. Differences between groups are minor in areas of spinal cord and larger in areas of dural sac and subarachnoid space.