Nutrient accounting at the herd, field, and whole-farm levels on two Pennsylvania dairy farms

Authors

  • Kaitlyn A. Lutz Center for Animal Health and Productivity, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA 19348
  • Darren W. Ramsburg Center for Animal Health and Productivity, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA 19348
  • Zhengxia Dou Center for Animal Health and Productivity, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA 19348

DOI:

https://doi.org/10.21423/bovine-vol45no2p165-175

Keywords:

dairy, nitrogen, phosphorus, nutrient utilization efficiency, cattle dung, cattle feeding, cattle manure, cows, crop management, crop production, cycling, dairy cattle, dairy cows, dairy farming, dairy farms, dairy herds, farm surveys, fertilizers, fodder crops, milk, milk production, nutrient balance, nutrients, waste management

Abstract

The objective of this study was to evaluate nitrogen (N) and phosphorus (P) utilization efficiencies and environmental implications on two dairy farms and identify areas where veterinarians can make an impact. The study surveyed two commercial dairy farms in southeastern Pennsylvania, Farm A and Farm B. Each farm owner provided information regarding the management of animals, crops and animal waste. This information was used to calculate a nutrient flow for N and P at the herd, crop, and farm level. The herd-level evaluation accounted for nutrients directly entering the animals in the form of feed, captured in the body during growth, and exiting the animals as manure and milk. The crop-level nutrient balance accounted for manure and imported fertilizer spread on the fields, compared with the nutrient uptake rates of the crops grown. The whole-farm evaluation describes the nutrient flow across the farm boundaries. Based on the information collected during this survey, both farms were net importers of N and P. However, efficiency of N and P were calculated as higher than previously reported in the literature. The milk nitrogen efficiencies on Farm A and Farm B were calculated to be 25% and 23%, respectively. The herd phosphorus utilization efficiency was calculated to be 46% and 39% on Farm A and B, respectively. Despite excellent nutrient utilization, the study identified management practice changes that would yield positive environmental and economic outcomes.

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Published

2011-06-01

How to Cite

Lutz, K. A., Ramsburg, D. W., & Dou, Z. (2011). Nutrient accounting at the herd, field, and whole-farm levels on two Pennsylvania dairy farms. The Bovine Practitioner, 45(2), 165–175. https://doi.org/10.21423/bovine-vol45no2p165-175

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