Production of high quality goat milk through increased use of Norwegian feed resources and improved feed utilization

Norwegian goat milk production has an important role in Norwegian agriculture by producing high quality milk and dairy products based on the utilization of local feed resources and as helping preserve the agricultural landscape. In recent years, TINE has invested considerable resources in developing Norwegian goat milk products. However, this requires high quality goat milk and it is therefore important to acquire new knowledge that can ensure a further improvement in goat milk quality while focusing on the use of Norwegian feed resources. During the last ten years, the genetic profile of the Norwegian dairy goat population has changed and the health status has improved considerable. In order to respond to these changes, better nutrition is needed during the lactation period. Revision of feeding standards and improved feeding strategies is therefore needed. The main objective of the project: Generate new knowledge needed to strengthen the capacity of the goat milk industry to deliver profitable products with high nutritive value based on Norwegian feed resources in effective and sustainable production systems. Sub-goals: - Develop new feeding strategies for dairy goats allowing for an optimal utilization of Norwegian vegetable fat with a high inclusion of Norwegian cereals. - Develop feeding strategies ensuring a high herbage intake in combination with adequate amounts of concentrates during the pasture season. - Revise the requirements for energy and protein in Norwegian goat milk production, taking into account the genetic changes and improved health status during the last ten years. - Develop the use of bioindicators as a tool for monitoring energy and protein balance in high yielding dairy goats, and possibly establish intervention levels for prevention of metabolic diseases. Being browsers, goats utilize trees and herbs in natural pastures in an extraordinary way. This is favorable for the reputation of the goat milk industry, and for maintaining open landscapes. A field experiment was conducted in 18 herds with reduced concentrate levels on pasture. GPS maps showed that the goats go further and exploit larger areas when they get less concentrate. In other words, there is potential for better utilization of natural pastures at a lower level of concentrate. A strategy of rapid or slow concentrate escalation postpartum was tested in a field experiment including 8 herds. Rapid increase of concentrates did not have a significant effect on total milk yield in the first 90 days of lactation, daily milk yield (ECM) or the shape of the lactation curve. The milk of goats on a slow increase of concentrates tended to have higher fat content. The goats on slow treatment probably compensated for the lower ration of concentrates by eating more roughage. Slow concentrate escalation is probably preferable as it is more efficient in terms of feed conversion ratio. An adequate supply of dietary fat is crucial in ensuring production of goat milk with high dry matter content and good sensory properties. An experiment conducted showed that it is possible to increase the proportion of unsaturated fat in goat's milk using rapeseed instead of palm oil-based fat, without reducing milk yield, fat content or total fat production. Rapeseed also improved the sensory quality of the milk compared to the palm oil-based fat. This is a promising result for further use of Norwegian rapeseed in concentrates for dairy goats. For the further development of efficient and sustainable goat milk production, increased use of Norwegian cereals is of great interest. However, a high proportion of rapidly degradable carbohydrates in the diet and low concentration of cell wall carbohydrates, are likely to decrease the milk fat content, affect rumen conditions and even initiate rumen acidosis. To find the limits for optimal intake of starch from barley ensuring a good nutrient utilization and maintaining healthy animals, an experiment with rumen cannulated goats was conducted The results indicate that goats tolerate a higher amount of starch in their diet than first expected, provided that the ration is divided into several meals during the day. Alkaline treatment of the barley resulted in higher milk yield on less feed. This is most likely due to a better match between the supply of ammonia (nitrogen) and energy for the microbes resulting in improved microbial growth in the rumen and thus a better utilization of the fiber fraction of the feed. An extensive sampling and analysis programme of biomarkers (urea, etc.) in blood and milk has been carried out during the project period. Results from the experiments will provide important data for the revision of feeding standards and the development of new feeding strategies for high yielding Norwegian goats. The project has been carried out in close collaboration with leading goat research teams in France (INRA) and TINE SA, Norgesfôr AS and Fiskå Mølle AS.

Prosjektet har vist at det er mulig å opprettholde en effektiv produksjon av geitemjølk med minst like god kvalitet med økt andel norske fôrressurser. Mindre behov for importerte fôrmidler vil gjøre geitemjølksproduksjonen mindre sårbar og mere bærekraftig, samtidig som omdømmet til næringa vil forbedres.

During the last ten years, the genetic profile of the Norwegian dairy goat population has changed and the health status has improved drastically. In order to respond to these developments, better nutrition is needed during the lactation period. Revision o f feeding standards and improved feeding strategies is therefore an important goal for the project, which will deal with three major aspects: Roughage intake, dietary fat sources and feeding of concentrates during the grazing season. Being browsers, goats utilize trees and herbs in natural pastures in an extraordinary way. This is favorable for the reputation of the goat milk industry, and for maintaining open landscapes. The project will examine strategies for concentrate supplementation during the grazi ng season, with the aim to identify ways of optimizing the use of natural pastures, without restricting milk yield and impairing milk quality. An adequate supply of dietary fat is crucial in ensuring production of goat milk with high dry matter content a nd good sensory properties. Norwegian plant fat sources, such as rape seed oils, are promising as feed supplements. Increased use of Norwegian cereals (barley, oat and wheat) is requested by farmers who wish to increase their production. More knowledge i s however required about the tolerance to higher intakes of cereals while maintaining high roughage intakes, efficient nutrient utilization and healthy animals. The research questions will be addressed in feeding experiments, in dose-response trials with highly degradable starches from Norwegian cereals fed to fistulated lactating animals, and in field experiments testing strategies for concentrate use during grazing. Expected results from the trials will provide essential data for revision of feeding standards and development of new feeding strategies for high yielding Norwegian dairy goats, which will be done in close collaboration with international partners from leading centers for goat research (INRA).