Milk quality in Norwegian goats - presentation of the project Quality Goat Milk for Cheese Production

Janne Karin Brodin

The pattern of consumption of goat milk in Norway is currently changing, and consumers are more inclined to cheese than whey products (brown cheese). This calls for an improvement of overall quality and especially of flavor and rennet coagulation properties of the milk. The milk quality of Norwegian goats is variable and often does not meet the requirement of the industry for cheese production.

Photo: Janne Brodin

Representatives from the industry

TINE – The Norwegian Dairy Association
Norsk Sau og Geit, NSG - Norwegian Association of Sheep and Goat Breeders

Foreign co-workers
Yves Chilliard, INRA, France
Laurence Bernard, INRA, France
Christine Leroux, INRA, France
Edouardo Manfredi, INRA, France
Donata Marletta, University of Catalania, Italy
Mette Olaf Nielsen, LIFE, Denmark

Objectives
The main project objective is to establish breeding and feeding strategies that ensure optimal and stable goat milk quality for consumer preferred cheese products. The quality can be improved by feeding strategies on short term basis and through breeding on long term basis.

The main areas of the research
The main activities are within three areas; milk quality determination, modern breeding methods and nutrition.

Milk quality
Rennet coagulation properties of the goat milk are correlated to the content and quality of casein and whey proteins, calcium and lipids in the milk. A central part of the project is to identify parameters that can describe the rennet coagulation properties of the Norwegian goat milk.

The Department of Chemistry, Biotechnology and Food Science (IKBM) is responsible for the research on milk quality and rennet coagulation. Ragnhild Aabøe Inglingstad is PhD student on this part of the project and Gerd Vegarud, Tove Guldbrandsen Devold, Siv Skeie and Elling Olav Rukke are her supervisors.

Milk from the feeding experiments in the project is analyzed for

Photo: Ingjerd Dønnem

Rennet coagulation
Size of the casein micelle
Quantity of proteins and individual caseins
Ion activity of calcium and pH
Total content of calcium, potassium and phosphorus
Lipid profile of triglycerides and free fatty acids
Size of milk fat globules
Characterization of lipids in fat globule membrane

Presentations/publications:

Breeding
Different variants of casein genes give variable cheese yield. The project will try to establish the relationship between casein gene variants and rennet coagulation and sensory quality of the milk. One objective is to check the applicability of FTIR spectra from TINE for these specific quality parameters, and use this information in the breeding program.

PhD student Binyam Dagnachew at the Department of Animal and Aquacultural Sciences (IHA) works with casein gene variants, and the use of multivariate analysis in the breeding program. Researchers Achim Kohler at Nofima Food and Theo Meuwissen at IHA are his supervisors together with the project leader Tormod Ådnøy from IHA.

Presentations/publications:

Nutrition

Photo: Janne Brodin

The nutrition experiments attempts to give fundamental knowledge about how different feeding strategies affects the quality of goat milk through the lactation cycle. Two extensive nutrition experiments are carried out during the project period.

At Bioforsk, by researcher Håvard Steinshamn, there has been carried out an experiment on the research station Gibostad in Troms. The research tasks were to study the effect of natural pasture on milk production and quality in early and late grazing season, where natural pasture was compared with cultivated pasture and hay by using goats in the same stage of lactation. Consequently, the effect of pasture quality and stage of lactation was not confounded. A part of the experiment consisted of measuring the feed intake by alkane marker and to look at the goats’ feed preferences. A closer presentation of the experiment and results exists on Bioforsk home page.

At IHA, by post doc Margrete Eknæs, there has been carried out an experiment on nutrition and physiology at different stages of lactation. The objective of the experiment is to study the effect of concentrate containing glucogenic compounds versus fat on energy status, fat metabolism, gene expression and milk quality in different stages of lactation. Read more about the experiment here.

Presentations/publications:

Seminars
"Milk quality and lactation physiology in goats" – Ås, 31 of May 2010
The project arranged a seminar at Ås 31 of May 2010. The topic was goat milk quality with focus on lipolysis and milk FFA in relation to fat metabolism and nutrient supply to the mammary gland.

Presentations:

Tormod Ådnøy:
”Quality goat milk for cheese production”

Yves Chilliard:
”Fat metabolism in mammary gland and body, milk lipolysis and FFA. How to use gene expression as a tool to describe how different diets influence mammary gland lipid metabolism”.

Mette Olaf Nielsen:
”Partitioning of nutrients to the mammary gland. Regulation of nutrient uptake (hormones, metabolites etc.) and effect of stage of lactation”.

Funding

Photo: Janne Brodin

The project is financed by the Research Council of Norway (9 168 000 NOK), TINE (1 500 000 NOK), own efforts from UMB (1 350 000 NOK) and Nofima Food (800 000 NOK). The project has a total funding on 12 818 000 NOK. The end of the project is 30 of June 2013.

Updated: 12.11.12
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