Comparación del volumen aparente de la ubre, frente a la cantidad de leche producida por Vacas Holstein Mestizas, en el cantón Chambo.

Introduction. The udder (mammary system) of the cow is the most important physical asset. A large, well attached, well cared for and quality udder is very important to generate the highest milk production over a long period of time. Target. Study the relationship of the apparent volume of the udder, versus the amount of milk produced by Holstein cows. Methodology. The present study used a type of experimental research and a longitudinal method by collecting data in a given time and to determine the changes in the variables. In the present investigation, 24 crossbred Holstein females were used, 12 second and 12 third lactation. All cows were selected taking into consideration that they did not show symptoms of mastitis and their four quarters were in full production capacity. Student's t test and correlation analysis by Pearson's method using SPSS version 21 were used for data tabulation. Results. The volume of the udder of the second calving Holstein cattle was 8068.6 cm, a value that differs significantly (P 0.0001), due to the effect of the number of calvings, obtaining the highest value in third calving cows with 28.31 liters / milk / day and the lowest production was recorded in the second calving group with 24.03 liters / milk / day, so it is considered that increasing the number of deliveries presents a progressive increase in volume and milk production. Regarding the correlation between volume and milk production, they presented a high correlation of (0.69). Conclusion. Larger udders have a greater amount of secretory tissue and therefore a greater milk production.