AlkaNor: WP2-The effects of different formulations of alkaline grain diets on feed intake, ruminal fermentation parameters, animal performance and nutrient use efficiency with early lactating NRF dairy cows (copy)
1 Formål
The objective of the AlkaNor project (RCN 302341) is to assess the effects of increased share of Norwegian ingredients in dairy cow diets on animal performance, health, nutrient use efficency and greenhouse gas emission. This specific objective of experiment assessing the effects of different formulations of alkaline grain diets, relative to a commonly used commercial dairy cow diet with high proportion of imported ingredients, on feed intake, nutrient digestibility, rumen physiology, methane emission, nutrient excretion, and milk yield and milk composition.
2 Skadevirkninger
-The planned feeding experiment is not expected to have any distress on the animals. Animals will be fed normal diary cow diets composed of grass/clover silage and 4 types of concentrate feeds to their demand calculated according to the Nordic Feed Evaluation method. However, subacute rumen acidosis (SARA), a physiological condition characterized by a drop in pH of the rumen and production might occur. This often goes unnoticed at farm level becuase of lack of good indicators. We use new technologies (Smaxtec and RumiWatch Units) to detect this and develop proxies for future use in dairy production system.
-Rumen fluid sampling through cannula is not expected to create any distress as these cows have prior exposure to such samplings. These cows have gone through comparable experiments.
-Blood samples for plasma metabolites will be taken at 13 time points during the experimental period of >140d. This is expected to have mild short-lived distress for the cows at time of sampling. The blood volume sampled per sampling day (2-vacutainer tubes of 10mL each) will be way below in the safe volume for single bleed from dairy cows weighing ~660 kg BW.
3 Forventet nytteverdi
The hypothesis that the we can increase the share of local ingredients in dairy cow diets through chemical and physical treament without adverse effects on production, health and GHG will have multitude of benefits. If achieved, this will:
-Reduce the level of imported protein ingredients in dairy cows with reduced carbon-foot-print of dairy prodcuts, and increased feed self-sufficiency.
-Aggregate data on enteric methane emission for updating the national greenhouse gas emission inventory based on the diverse dietary treatments.
-Produce an in-depth knowledge on the mechanisms of the sub-acute rumen acidosis, develop proxies to detect this.
-Provide opprutnities for strategic allocation of imported protein ingredients based on critical need (i.e., monogastric animals).
4 Antall dyr og art
Eight rumen-cannulated cows
5 Hvordan etterleve 3R
-The project contains 3 experimental work-packages (WP1,WP2,WP3) of which WP1 in the first project year characterized and screened the current experimental feeds using lab, in vitro and in sacco methods. This has saved resources, and replaced a potentially large animal experiment.
-The planned experimental design (4x4 Latin square) uses each cow as its control over the treatments and largely reduces the number of animals required without comprimising data collected.
- Furthermore, the re-use of the already existing cannulated cows for this experiment by avoiding new cannulations, is part the REFINEMENT attribute of the 3R.
The objective of the AlkaNor project (RCN 302341) is to assess the effects of increased share of Norwegian ingredients in dairy cow diets on animal performance, health, nutrient use efficency and greenhouse gas emission. This specific objective of experiment assessing the effects of different formulations of alkaline grain diets, relative to a commonly used commercial dairy cow diet with high proportion of imported ingredients, on feed intake, nutrient digestibility, rumen physiology, methane emission, nutrient excretion, and milk yield and milk composition.
2 Skadevirkninger
-The planned feeding experiment is not expected to have any distress on the animals. Animals will be fed normal diary cow diets composed of grass/clover silage and 4 types of concentrate feeds to their demand calculated according to the Nordic Feed Evaluation method. However, subacute rumen acidosis (SARA), a physiological condition characterized by a drop in pH of the rumen and production might occur. This often goes unnoticed at farm level becuase of lack of good indicators. We use new technologies (Smaxtec and RumiWatch Units) to detect this and develop proxies for future use in dairy production system.
-Rumen fluid sampling through cannula is not expected to create any distress as these cows have prior exposure to such samplings. These cows have gone through comparable experiments.
-Blood samples for plasma metabolites will be taken at 13 time points during the experimental period of >140d. This is expected to have mild short-lived distress for the cows at time of sampling. The blood volume sampled per sampling day (2-vacutainer tubes of 10mL each) will be way below in the safe volume for single bleed from dairy cows weighing ~660 kg BW.
3 Forventet nytteverdi
The hypothesis that the we can increase the share of local ingredients in dairy cow diets through chemical and physical treament without adverse effects on production, health and GHG will have multitude of benefits. If achieved, this will:
-Reduce the level of imported protein ingredients in dairy cows with reduced carbon-foot-print of dairy prodcuts, and increased feed self-sufficiency.
-Aggregate data on enteric methane emission for updating the national greenhouse gas emission inventory based on the diverse dietary treatments.
-Produce an in-depth knowledge on the mechanisms of the sub-acute rumen acidosis, develop proxies to detect this.
-Provide opprutnities for strategic allocation of imported protein ingredients based on critical need (i.e., monogastric animals).
4 Antall dyr og art
Eight rumen-cannulated cows
5 Hvordan etterleve 3R
-The project contains 3 experimental work-packages (WP1,WP2,WP3) of which WP1 in the first project year characterized and screened the current experimental feeds using lab, in vitro and in sacco methods. This has saved resources, and replaced a potentially large animal experiment.
-The planned experimental design (4x4 Latin square) uses each cow as its control over the treatments and largely reduces the number of animals required without comprimising data collected.
- Furthermore, the re-use of the already existing cannulated cows for this experiment by avoiding new cannulations, is part the REFINEMENT attribute of the 3R.