Piena lopkopības raksturojums bioloģiskās lauksaimniecības sistēmā SEG emisiju kontekstā | Characteristics of dairy livestock in organic farming system in the context of ghg emissions
2021
Kreismane, D., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia). Faculty of Agriculture. Inst. of Animal Sciences | Aplocina, E., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia). Faculty of Agriculture. Inst. of Animal Sciences | Naglis-Liepa, K., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia). Faculty of Economics and Social Development | Berzina, L., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia). Faculty of Information Technologies | Frolova, O., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia). Faculty of Environment and Civil Engineering | Lenerts, A., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia). Faculty of Economics and Social Development
Certified organic dairy farms are one of the most effective measures in terms of climate policy to reduce GHG and ammonia emissions due to the fact that animals are grazed in the summer, manure is composted and the animals are fed mainly with self-produced fodder. However, to achieve the economic and climate goals of farms, it is necessary to improve both animal nutrition and welfare. Nitrogen excretion in faeces and urine can be reduced by feeding the animals with a balanced diet with a differentiated crude protein content depending on the lactation phase. The increase of the content of non-starch polysaccharides in the feed improves the utilization of feed in the animal, and, as a result, nitrogen is excreted more in faeces than in the urine. Using the feeding program NorFor to optimize feed rations, it is estimated that with increased protein intake in organic farms with an average lactation milk yield of 6,000 kg, at the beginning of lactation N in faeces and urine is by 27 g dE−1 more than in dairy cows with 5,880 kg of milk yield. In mid-lactation, reducing the crude protein content of the ration by an average of 10 g kgE−1 dry matter, the difference is 20.8 g dE−1. By reducing the crude protein content in the dry matter by further 20–25 g at the end of lactation and during the dry period, N excretion in faeces and urine is significantly reduced, regardless of the milk yield. By increasing the number of lactations per cow on average to 4.5 in all types of farms, it is possible to reduce the number of heifers per dairy cow. With the planned longevity of the cow in 2030, by reducing the number of heifers required for the renewal of the herd by 12.54 thousand, ammonia emissions can be reduced by 0.051 kt.
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