Hector A Delgado

McGill University | McGill

Stall base and stall surface (i.e., with or without bedding) are key risk factors in cow comfort in dairy herds. In Canada, rubber mats, concrete floors, and mattresses are the most common stall bases used in tie-stall systems. Straw, wood shavings, and sand, at variable depths, are the most commonly used type of bedding. The Clegg hammer (Clegg Im...

Health disorders, such as milk fever, displaced abomasum, or retained placenta, as well as poor reproductive performance, are known risk factors for culling in dairy cows. Clinical mastitis (CM) is one of the most influential culling risk factors. However the culling decision could be based either on the disease status or on the current milk yield,...

The relationship between cows’ health, reproductive performance or disorders and their longevity is well demonstrated in the literature. However these associations at the cow level might not hold true at the herd level, and herd-level variables can modify cow-level outcomes independently of the cows’ characteristics. The interaction between cow-lev...

A retrospective cohort study was conducted using production and health records from Québec dairy herds which were integrated with the objectives of calculating different lifetime profitability measures and developing analyses of the impact of selected reproduction and health variables on profitability. The dataset for the study consisted of lifetim...

Several health disorders, such as milk fever, displaced abomasum, and mastitis, as well as impaired reproductive performance, are known risk factors for the removal of affected cows from a dairy herd. While cow-level risk factors are well documented in the literature, herd-level associations have been less frequently investigated. The objective of...

The objectives of this study were to: 1) quantify culling rates of Quebec dairy herds, and 2) investigate if Quebec dairy farms could be differentiated based on herd-level factors such as management, reproduction, production and health indices, and explore their relationship with herd culling rate.

Abstract Text: Economic values were estimated by regressing profit, adjusted for opportunity cost, up to the end of the 4th lactation on EBVs, using random regressions within herd-year cohort of first calving. Kilograms Fat, kg Protein, milking speed, temperament, rump and conformation all had positive economic values, whereas herd life, angularity...

Abstract Text: In Quebec, management of dairy herds is affected by various combinations of milking systems (Milk Line, Milking Parlor or Milking Robot), housing systems (Tie-Stall or Free-Stall), and feeding systems (Traditional Feeding, Automatic Forage Distribution, Automatic Concentrate Distribution, Computerized Automatic Concentrate Distribu...