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In this newsletter we briefly present current activities concerning the NorFor feed table, including an example of cooperation between NorFor and the academic world.

At NorFor, we take reliable and correct feed table data very seriously, since this is of fundamental significance to the quality of the output from our feed model. We are involved in many kinds of activities to ensure correct and well-documented input values, the sample study below being just one example.

NorFor also frequently offers support to university students and encourages them to take part in enhancement of the model and gain knowledge in the field of nutrition. This is made possible through NorFor’s development strategy, which includes a fully documented and transparent model as well as a willingness to share information and knowledge openly.

Patrik Nordgren, NorFor.

Nutrient and energy values for compound feeds in the NorFor FST are generally correct

A sample study has been conducted to determine the accuracy of nutrient and energy values in commercially available feeds that are included in NorFor’s Feed Stuff Table (FST), as a means of further improving the accuracy of NorFor’s feed model.

The purpose of the study was to detect any possible discrepancies between guideline values and delivered quality, including how low-cost feed can exhibit surprisingly high energy values. 

46 compound feeds from 20 feed manufacturers (out of more than 2000 feeds in the FST) were randomly selected for testing, which was done by collecting samples on farms in Denmark, Norway, Sweden and Iceland in 2015.

Only a few deviations

 The results show a generally good correlation between declared values and measured content, with only a small number of observations outside EU-regulated specifications, mostly of minor importance. As an example, only one feed supplier out of 20 stated too high energy values.

Other results from the study include new guidelines for feed companies on how to update compound feeds to the NorFor FST, as well as the need to develop a precise lab method to determine NEL20 content, which in this study had to be estimated, when the composition of ingredients is unknown (NEL 20 = the net energy value to lactation for every 20 kilograms of dry feed). 

The samples were analyzed using NIR (Near Infra Red) screening by two different laboratories, BLGG in the Netherlands and KF Lab in Denmark. The data from the two labs were quite similar for most nutrients, which indicates similar quality standards and efficient analysis methods being used. The following nutrients were analyzed: crude protein, soluble crude protein, crude fat, NDF, starch, ash and crude fiber.

The study was carried out by Camilla Engell Sørensen, Niels Bastian Kristensen and Nikolaj Hansen from SEGES, Berglind Osk Ó∂insdóttir from RML, Ingunn Schei from TINE and Hans Lindberg from Växa Sverige.

The full results can be found at norfor.info.

Comparative study of feed intake in relation to age and stage of lactation

Trials conducted with Danish Jersey and Holstein herds show how the cow’s stage of lactation and age affect feed intake – variations that are of great significance to farm economics.

 A recent study from Aarhus University comparing the results from two different trials produced the following findings: 

  • In one of the trials, older Jersey cows showed 23% higher feed utilization than first calvers, while the equivalent figure in the other trial was 9%.

  • The differences were particularly noticeable at the start of lactation, but after week 31 the first calvers overtook the older Jersey cows in feed utilization. 

  • NorFor’s feed intake model was evaluated in conjunction with the trials. Some over-prediction was noted, particularly in one trial.

There are a number of forecasting models for the cows’ feed utilization that take account of a varying number of parameters. No model is exactly right all of the time, but the deviations shown by the NorFor model are among the lower ones.

NorFor’s feed evaluation program, which takes account of each individual animal’s characteristics as well as each individual feedstuff has been in use since 2007. It provides information on both the distribution between compound feed and roughage and the total cost of the feed. In the trials concerned, the deviation between forecast and outcome was ‑2% for Holstein cows and +6% for Jersey cows.

Cooperation with universities

The study concerned was conducted as a thesis paper by Martin Øvli Kristensen at Aarhus University, supervised by Nicolaj Ingemann Nielsen from SEGES/NorFor. It is based on trials performed by Bossen et al (2009) and Alstrup et al (2015), both of which contain sufficient quantities of raw data to enable comparisons between the trials.

For further information contact Patrick Nordgreen +46 10 471 06 50.

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