LiGAPS-Beef

Submitted by marcel.lubbers on Fri, 07/08/2016 - 08:50
General
Name
LiGAPS-Beef (Livestock simulator for Generic analysis of Animal Production Systems –Beef cattle)
Program type
Livestock growth simulation model / R 2.15.3
Available since
Description

LiGAPS-Beef is a mechanistic model to assess potential and feed-limited beef production in different beef production systems across the world. The model is one of the first using concepts of production ecology to simulate livestock production. LiGAPS-Beef consists of a thermoregulation sub-model, a feed intake and digestion sub-model, and an energy and protein utilization sub-model. Energy and protein flows are included. Livestock production can be assessed for individual animals and herds. LiGAPS-Beef simulates cattle growth based on defining growth factors (genotype or breed and climate) and limiting growth factors (feed quality and feed quantity). The model can be used to assess yield gaps in beef production systems, and to explore improvement options for yield gap mitigation.

Scale of application
animal and herd (farm)
Spatial resolution
farm
Key outputs

Feed intake, average daily gain, feed efficiency, weight of edible beef, carcass weight, and the factors constraining growth (genotype, heat stress, cold stress, digestion capacity, energy deficiency, protein deficiency)

Time horizon
Life cycle of an individual animal or all animals in a herd unit. The length of the life cycle can be up to 11-12 years for cows in a herd unit.
Time step of modeling
one day
Required to run

R 2.15.3, or a more recent version of this programming language, is required to run the model. In addition, RStudio 0.98, or a more recent version of this programming language, is recommended to run the model.

Required to develop

R 2.15.3, or a more recent version of this programming language, is required to run the model. In addition, RStudio 0.98, or a more recent version of this programming language, is recommended to run the model.

Database I/O
Files with daily weather data (.csv extension). Results from LiGAPS-Beef can be written to files with various extensions (.csv, .pdf., .txt, .xls).
Examples

Description and evaluation of LiGAPS-Beef

  • A brief description and illustration of LiGAPS-Beef can be found at http://dx.doi.org/10.1017/S1751731118001726(Van der Linden et al., 2018, Animal 13 : 845-855). This paper concludes that LiGAPS-Beef has scope to be used for the assessment and analysis of yield gaps in different beef production systems across the globe. The version of the model used in this paper is freely accessible at the model portal of the Plant Production Systems group of Wageningen University and the Library of Wageningen University & Research (https://doi.org/10.18174/442973).    
  • The results of a sensitivity analyses of LiGAPS-Beef are available at http://dx.doi.org/10.1017/S1751731118001738(Van der Linden et al., 2018, Animal 13 : 856-867). In addition, this paper evaluates the performance of the thermoregulation sub-model and the feed intake and digestion sub-model.  
  • The performance of LiGAPS-Beef at the animal level has been evaluated with data from experiments in Australia, Uruguay, and the Netherlands is available at https://doi.org/10.1017/S1751731118002641(Van der Linden et al., 2018, Animal 13 : 868-878). The results of this evaluation indicate that the accuracy of LiGAPS-Beef is acceptable, and that the model provides a good basis for simulating potential and feed-limited beef production. The defining and limiting factors for growth and production of beef cattle were simulated adequately, which provides scope to use the model for yield gap analysis. 
Applications & Use

Applications of LiGAPS-Beef

  • LiGAPS-Beef has been combined with the grass growth model LINGRA (Light INterception and utilization- GRAss, available on the PPS model portal also) to simulate beef production of Charolais cattle in the Charolais area of France under climate change. The combination of LiGAPS-Beef and LINGRA allows to determine optimum stocking densities under feed-limited cattle production and water-limited grass production. Beef production per hectare was investigated under the current climate conditions, and under climate change scenarios with projections for smallest and largest climate change in the year 2050. This paper is available at https://doi.org/10.1017/S2040470016000200(Van der Linden et al., 2016, Advances in Animal Biosciences 7 : 224-226). This research was presented at the LiveM 2016 conference in Potsdam, Germany, on the 15th of June, 2016. The conference presentation can be found at http://ojs.macsur.eu/index.php/Reports/article/view/SP8-18or http://edepot.wur.nl/393445.
  • The combination of LiGAPS-Beef and the grass growth model LINGRA was used to assess and analyse yield gaps in 12 farm types with Charolais cattle in the Charolais area of France. The yield gaps of the whole feed-crop livestock systems were on average 85% of the potential production, and 47% of the resource-limited production. The main factors explaining the yield gaps were the diets, water-limitation in feed crops, and cattle management. Mitigating the yield gaps, however, may not be profitable from an economic perspective. This study is available at https://doi.org/10.1016/j.agsy.2017.09.006(Van der Linden et al., 2018 Agricultural Systems 159 : 21-31). A presentation about (a preliminary version of) this paper is available at the website of the Wageningen Centre for Agroecology and Systems Analysis (http://www.wacasa.wur.nl/sites/default/files/WaCASA%2020161214_AvdL.pdf).        
Author(s)
Aart van der Linden, Gerrie W.J. van de Ven, Simon J. Oosting, Martin K. van Ittersum, and Imke J.M. de Boer
Address
Animal Production Systems group, Wageningen University, P.O. Box 338, 6700 AH Wageningen, The Netherlands
Website

Wageningen University, Animal Production systems group, http://www.aps.wur.nl/UK/

Wageningen University, Plant Production systems group, http://www.pps.wur.nl/UK/

Global Yield Gap Atlas, www.yieldgap.org