Journal Article

Effects of dry period length on production, cash flows and greenhouse gas emissions of the dairy herd: A dynamic stochastic simulation model

van Middelaar, Corina E., Mostert, Pim F., de Boer, Imke J. M., Hogeveen, Henk, Kemp, Bas, van Knegsel, Ariëtte T. M., Kok, Akke

2017

Overview

Shortening or omitting the dry period of dairy cows improves metabolic health in early lactation and reduces management transitions for dairy cows. The success of implementation of these strategies depends on their impact on milk yield and farm profitability. Insight in these impacts is valuable for informed decision-making by farmers. The aim of this study was to investigate how shortening or omitting the dry period of dairy cows affects production and cash flows at the herd level, and greenhouse gas emissions per unit of milk, using a dynamic stochastic simulation model. The effects of dry period length on milk yield and calving interval assumed in this model were derived from actual performance of commercial dairy cows over multiple lactations. The model simulated lactations, and calving and culling events of individual cows for herds of 100 cows. Herds were simulated for 5 years with a dry period of 56 (conventional), 28 or 0 days (n = 50 herds each). Partial cash flows were computed from revenues from sold milk, calves, and culled cows, and costs from feed and rearing youngstock. Greenhouse gas emissions were computed using a life cycle approach. A dry period of 28 days reduced milk production of the herd by 3.0% in years 2 through 5, compared with a dry period of 56 days. A dry period of 0 days reduced milk production by 3.5% in years 3 through 5, after a dip in milk production of 6.9% in year 2. On average, dry periods of 28 and 0 days reduced partial cash flows by €1,249 and €1,632 per herd per year, and increased greenhouse gas emissions by 0.7% and 0.5%, respectively. Considering the potential for enhancing cow welfare, these negative impacts of shortening or omitting the dry period seem justifiable, and they might even be offset by improved health.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Adaptatiefysiologie / Adaptation Physiology / Agrarische bedrijfseconomie / Agricultural production / Air pollution / Analysis / Animal lactation / Animal Production Systems / Animals / Bedrijfseconomie / Biology and Life Sciences / Business Economics / Calves / Cattle / Causes of / Climate change / Computation / Computer simulation / Cow's milk / Culling / Dairy cattle / Dairy farming / Dairying / Decision making / Dierlijke Productiesystemen / Dry periods / Earth Sciences / Ecology and Environmental Sciences / Economics / Emissions / Environmental aspects / Farms / Feeds / Fertility / Greenhouse effect / Greenhouse gas emissions / Greenhouse Gases / Growth / Internet / Lactation / Leerstoelgroep Adaptatiefysiologie / Leerstoelgroep Dierlijke productiesystemen / Life cycle analysis / Life cycle engineering / Life cycles / Livestock / Medicine and Health Sciences / Metabolism / Milk / Milk production / Models, Theoretical / Physical Sciences / Physiology / Profitability / Research and Analysis Methods / Simulation / Simulation models / Social Sciences / Stochastic Processes / Stochasticity / Studies / WASS / WIAS