Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Optimal dairy feed input selection under alternative feeds availability and relative prices
    Alqaisi, Othman ; Moraes, Luis Eduardo ; Ndambi, Oghaiki Asaah ; Williams, Ryan Blake - \ 2019
    Information Processing in Agriculture 6 (2019)4. - ISSN 2214-3173 - p. 438 - 453.
    Diet formulation - Feed availability - Feed prices - Feed switch - LP modelling

    Feed formulation is essential in the dairy production chain from economic, nutritional, and environmental perspectives. Optimizing the feed formulation across those three domains – given uncertainty of input prices, input availability, and regional climatic conditions – is a challenge for those in the industry. The diet formulation method that is widely used by trading firms and feed production facilities employs a static linear programming (LP) approach. This approach does not allow for intertemporal feed formulations and switches between dietary feed commodities under feed availability conditions, which result in foregone economic gains for feed producers. The current study develops a multi-period LP feed model that uses historical data to capture ration switch opportunities between available feed resources for dairy cows and demonstrates the potential use of the method in different commodity feed availability situations. We apply 14 diet formulations, each covering 150 months, representing a total of 2100 diets. The diet formulation considers a specific milk production level for a “model cow”, alternative feed formulations available, and volatility in feed prices. The results demonstrate that there is an opportunity for efficiency gains in the dairy industry with respect to feed formulation. Based on dietary feed inclusion and price spreads, barley can be an important dairy feed grain which completely replaces wheat, corn, and sorghum at price spreads of less than 94%, less than 78%, and less than 67%, respectively. Grain-based feed scenarios represent the lowest nutrient variation while multiple meal feeds had the lowest costs. Furthermore, and on average, multiple meal feed scenarios provided 10% higher dietary crude protein contents compared to grain based feed scenarios (i.e. 163 vs 179 g/kg DM formulated feed). Meanwhile, multiple meal feeding cost was 11% lower than that in the grain based feeding scenarios. Additionally, the use of multiple meals reduces alfalfa dietary inclusion by 7% on dry matter basis. Our analysis shows a strong reduction in feed cost associated with dietary crude protein reduction equivalent to 7.6 USD/tonne per 1% reduction in dietary crude protein level. The modeling approach allows for the interaction between feed components over time taking into consideration volatile global feed prices, thereby improving feed availability and feed formulation. Overall, the model provides a decision making tool to improve the use of feed resources in the dairy sector.

    Effects of pre and post-calving feed supplementation on milk yield, reproductive performance and farm profitability of Ethiopian dairy cows
    Ndambi, O.A. ; Wassink, G. ; Abebe, Kiros ; Alqaisi, Othman - \ 2018
    Wageningen : Wageningen University & Research (DairyBISS Research Brief 001) - 3 p.
    Time series livestock diet optimization : cost-effective broiler feed substitution using the commodity price spread approach
    Alqaisi, Othman ; Ndambi, Oghaiki Asaah ; Williams, Ryan Blake - \ 2017
    Agricultural and Food Economics 5 (2017)1. - ISSN 2193-7532
    Broiler diet - Byproducts - Feed industry - Multi-stage linear-programming - Price spread - Trading
    Sustainable feed formulation (defined here as nutritional and economic feed optimization) is substantial in feed chain production from crop farmers to livestock producers. Diet formulation employing a static linear programming (LP) approach, which is widely used in trading firms and feed production facilities, does not allow for intertemporal flexibility. Our approach allows the interaction between feed components over time, considering the volatile global feed prices, thereby improving sustainability in feed formulation and feed availability. The objectives of this study were to (1) develop a multi-stage LP feed model, (2) demonstrate its potential use in broiler feeding, and (3) illustrate the impact of feed input price spread (variation) on the composition of broiler diets. Modeling resulted in reciprocal relationships between conventional feeds and byproducts at different rates. Based on the price spreads expressed as a percentage of DDGS (distiller’s dried grains with solubles) price compared to corn price, three positions of dietary switch were identified; corn-DDGS price spreads of higher than 94%, between 76 and 94%, and lower than 76% corresponding to limited/no inclusion, partial inclusion, and maximum replacement of corn by DDGS, respectively. Rapeseed meal inclusion was 4, 5, and 6% in the corn-based starter, grower, and finisher diets, respectively, and its potential to replace soybean meal was limited by its higher fiber content. Based on the simulated compound feed prices, the global broiler feed industry could gain 1.7 billion USD through improved resources planning.
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