No abstract

No abstract

Background: Ultrasound allows the udder evaluation of lactating cattle, through parameters such as the area of the cistern of the mammary gland and teat, and can reveal structures with different echogenicity, indicating injuries as mastitis, edema, hematoma, abscess, atrophy and fibrosis in the mammary gland parenchyma. The aim of this study was to observe the clinical, morphometric and sonographic assessment of the mammary gland of Jersey cows, evaluating the correlation of this exam and the production of milk. Materials, Methods & Results:Nine Jersey breed cows, aged 3 to 9 years, in a variable order of first to seventh lactation were evaluated. Animals were submitted to general and specific clinical examination of the mammary gland. For the evaluation, inspection and palpation of the gland cistern and teat cistern, measuring with tape measure the udder circumference and width and height of each mammary quarter was held, and length measurements of the four teats individually using a caliper. By palpation the mammary gland parenchyma was classified as nothing worthy of note and fibrosis. After this evaluation, the mammary glands were evaluated using ultrasound, analyzing biometrics and echotexture in order to detect and/or confirm possible changes identified in prior palpation. The diameter of the gland and teat cistern were measured, and the echogenicity of each region and each mammary quarter, checking the homogeneity of the parenchyma, evaluating the possible presence of nodules, scarring or acute injuries. The average milk production was 15.57 ± 5.4 L. There was no correlation between milk production, measured biometric data of the mammary gland and clinical and ultrasonographic changes (P > 0.05). On palpation exam, a few number of animals had soft to normal consistency in mammary glands (2/9), the occurrence of fibrosis was observed, but could only be detected by ultrasonography (4/9). Discussion: Using the ultrasound examination is possible to access more accurately the morphology of the udder of lactating animals, examining and measuring the area of the cistern of the mammary gland and teat, the thickness of the wall and ceiling interface. Several studies correlate the morphology of these parameters with resistance to mastitis. The imaging aids to differentiate the teats according to animal age, milk production, lactation number, size, as well as a predisposition to mastitis. In healthy animals, the boundary between the gland cistern and teat cistern is marked by the presence of large anechoic structures. Changes in the teats of a gland with mastitis are mild inflammation, proliferation of tissues and mucosal lesions. No significant correlation between the morphology, physical examination and ultrasound changes of the mammary gland and milk production was observed. Possibly this was due to the limited number of experimental animals, and there is a wide variation in age and clinical profiles, as already observed in other studies that cows with high and wide rear udders tend to have higher milk production....

The objectives of this study were 1) to monitor corpus luteum (CL) dynamics after two different protocols of ovulation induction in prepubertal Nellore heifers, and 2) to determine differences in luteal function. Fifty-seven heifers (weight 289.61 ± 32.28 kg, BCS 5.66 ± 0.65, age 17.47 ± 0.81 months) were divided into two groups: GP4+GnRH received a progesterone (P4) device of 3rd use for 10 days, followed by the administration of 0.02 mg buserelin acetate (GnRH) 48 h after removal of the device, and GGnRH received only GnRH. The CLs formed were monitored by ultrasonography every 2 days until their functional regression (decrease in the color Doppler signal and serum P4 concentration < 1 ng/mL), determining their diameter and area, numerical pixel value (NPV), pixel heterogeneity, and vascularization percentage. The peak systolic velocity, end diastolic velocity, resistivity index and pulsatility index (PI) of the ovarian artery and serum P4 concentration were also measured. A lifespan of the CL of more than 16 days was classified as normal-function and of less than 16 days as premature regression. The variables were compared between treatments, CL categories (normal-functional, prematurely regressed or non-functional), days of evaluation, and their interactions using the MIXED procedure of the SAS program (p ≤ 0.05). Three animals of each group (6/57 = 11%) did not respond to treatment, corresponding to an ovulation rate of 89%. There was a higher percentage of normal-function CLs in GP4+GnRH (81%) and a higher percentage of non-functional CLs in GGnRH (52%; P4 concentration < 1 ng/mL in all assessments). Normal-function CLs exhibited a greater area, vascularization percentage and P4 concentration than prematurely regressed and non-functional CLs. Lower diameter, area, NPV and P4 concentration were observed for non-functional CLs, but there was no difference in vascularization percentage compared to prematurely regressed CLs. Progesterone concentration was efficient in diagnosing CL function and was positively correlated with CL area (r = 0.62; p < 0.001) and vascularization percentage (r = 0.38; p < 0.001). Diameter and PI were important for the early diagnosis of non-functional and prematurely regressed CLs, respectively. In conclusion, luteal function differed for the first CL that develops after ovulation induction in prepubertal heifers. Ultrasonographic parameters (diameter, area, NPV, vascularization percentage, and PI) can be used to predict CL function.