Browsing by Subject "NEFA"
Now showing items 1-3 of 3
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(2013)Tutkimus liittyi moniosaiseen, Maa- ja metsätalousministeriön ja Helsingin yliopiston eläinlääketieteellisen tiedekunnan rahoittamaan projektiin Hyvinvoinnin lisääminen sianlihantuotannossa (INWEPP). Tarkoituksena oli selvittää häkki-, karsina- ja pesäporsimisympäristöjen vaikutukset ja yhteydet alkuimetyskaudella emakon vapaiden rasvahappojen (NEFA) vapautumiseen sekä oksitosiini-, prolaktiini- ja kortisolieritykseen ja porsastuotokseen. Yorkshiren ja maatiaisen 11 risteytysensikkoa ja 22 risteytysemakkoa jaettiin kolmeen erilaiseen porsimisympäristöön noin seitsemän päivää ennen odotettua porsimista. Jokaisessa ryhmässä oli lähes yhtä monta ominaisuuksiltaan samanlaista ensikkoa ja useammin kuin kerran porsinutta emakkoa. Porsimisympäristöinä olivat häkki (2,1m x 0,8m) ja karsina (2,8m x 2,1m) vähäisillä kuivikkeilla sekä karsina runsailla kuivike- ja pesäntekomateriaaleilla (pesä). Kaikki emakot laitettiin heti porsimisen jälkeen häkkeihin. Verinäytteiden ottoa varten ensikoille ja emakoille laitettiin katetri ja verinäytteet otettiin kolmena peräkkäisenä päivänä ennen odotettua porsimispäivää ja neljänä päivänä porsimisen jälkeen. Näytteistä määritettiin NEFA, oksitosiini, kortisoli ja prolaktiini. Porsaiden kuolleisuudessa ei ollut eroja ympäristöjen välillä. Huomioitaessa myös kuolleena syntyneet porsaat, kuolleisuus oli 14,2 % häkkiympäristössä, 24,6 % karsinaympäristössä ja 12,6 % pesäympäristössä. Vapaissa porsimisympäristöissä oli parhaat porsaiden kasvutulokset, erityisesti karsinaympäristössä. Pesäympäristössä oli suurin pahnuepaino porsaiden syntymähetkellä. Häkki- ja karsinaympäristöissä emakoilla oli ensikoita suuremmat pahnueet seitsemän päivän kuluttua porsimisesta. Pahnuepainojen ja pahnuekokojen erot olivat suuntaa-antavia. Porsimisen jälkeen kortisolin tai oksitosiinin pitoisuuksissa ei ollut eroja sen suhteen oliko emakko porsinut yhden vai useamman kerran tai missä ympäristössä porsiminen tapahtui. Prolaktiinipitoisuus oli emakoilla ensikoita korkeampi, mutta pitoisuudet eivät eronneet porsimisympäristöjen välillä. Karsina- ja pesäympäristöissä ensikot mobilisoivat emakoita enemmän kudosrasvoja. Pesäympäristössä porsineilla ensikoilla oli korkeampi plasman NEFA-pitoisuus verrattuna häkki- ja karsinaympäristöissä porsineisiin. Erot olivat suuntaa-antavia. Plasman NEFA-pitoisuuksien erot ympäristöjen välillä eivät selitä karsinaympäristössä porsineiden emakoiden ja ensikoiden hyvää porsaskasvua. Pesäntekomateriaalien tarjoaminen emakoille ja ensikoille saattaa vähentää kuolleena syntyneiden porsaiden määrää ja liikkumisen mahdollistaminen porsimisen päättymiseen asti voi edesauttaa porsaiden hyvää kasvua. Pesäntekomateriaalien tarjoaminen ei tässä tutkimuksessa vaikuttanut yksiselitteisesti emakoiden emo-ominaisuuksiin tai stressiin alkuimetyskaudella.
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(2020)In the beginning of lactation, dairy cows experience a negative energy balance that can lead to ketosis. Ketosis is a metabolic condition that affects production and health, and can occur clinically or subclinically. The aim of this thesis was to investigate the association of ketosis and the cow’s breed and parity to milk production and composition. Also the association of predicted NEFA, dry period, rest period and days open with ketosis, breed and parity was investigated. The data was acquired from ProAgria’s Maidosta Maitoon (MaMa) project, where 12 dairy farms had during two test periods tested milk’s BHB (β-hydroxybutyrate) concentration during the first seven weeks after calving. On each period, 20 animals per farm were participating and each animal’s production information came from Mtech Digital Solutions. NEFA values were predicted by using the milk fatty acid composition determined with mid-infrared (MIR) spectrometry. The animals were divided into four different groups based on the milk BHB concentration (≤ 50, ≤ 100, ≤ 200 and ≥ 500 µmol/L). The most common breeds on the farms, Ayrshire and Holstein, were included in the analysis. Parity was investigated by first comparing heifers with cows and then by dividing the animals into four different parity groups (1., 2., 3. and ≥ 4.). The milk production and composition were analyzed with repeated measures for the periods of 60 and 305 days in milk. The dry period, rest period and days open were analyzed with Friedman’s non-parametric variance analysis. The ketosis group did not affect daily milk yield during 60 or 305 days. Milk fat concentration was higher and protein concentration lower in groups with higher milk ketone concentration. Holstein cows had higher milk production than Ayrshire cows, and older cows had higher production than heifers. Milk production and ECM up to 60 days tended to increase by parity, peaking in the third parity group and decreasing in the fourth or higher lactation. Milk protein yield increased in Ayrshire cows in association with higher milk BHBA concentration, whereas the opposite was observed in Holstein cows (interaction breed x ketosis group, P = 0,045). The interaction between breed and parity tended to affect protein content, Ayrshire heifers had lower protein content than Holstein heifers but Ayrshire cows had higher protein content than Holstein cows. The predicted NEFA concentration increased by ketosis group. Holstein cows tended to have greater predicted NEFA concentrations than Ayrshire cows and heifers had significantly greater predicted NEFA concentrations than cows. Ketosis group affected the length of the dry period; the dry period was the longest in the third ketosis group. In addition, the length of the dry period was increased by parity. Ayrshire had shorter rest period and less days open than Holstein. Based on the results from this study, there was a difference between breeds on how ketosis affects milk production and milk composition. Further research is needed to understand the basis of the difference between breeds.
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(2018)Energy requirement of dairy cows can be higher than energy intake during early lactation. When energy balance is negative cows mobilize energy from body tissue. This increases the concentration of non-esterified fatty acids (NEFA) in the plasma. NEFA uptake to mammary gland is directly related to the plasma NEFA concentration. Therefore, negative energy balance and the plasma NEFA concentration may be predicted from fatty acid concentration of the milk determined from mid-infrared (MIR) spectral data. The objective of this study was to analyze the relationship between milk fatty acid profile, single fatty acid concentrations and plasma NEFA concentration. In addition, the aim was to test, if the MIR spectrum results can be used in predicting plasma NEFA concentration and subsequently negative energy balance in dairy cows. This study was a part of the Nordic Feed Efficiency -project. Data were collected in three research farms from primiparous Nordic Red dairy cows between September 2013 and August 2016. Second lactation data were collected from the same cows when possible. There were 610 records from 143 primiparous cows, and 199 records from 49 cows in second lactation. Data were analyzed with Mixed- procedure of the SAS software. The association between the plasma NEFA concentration and predictor traits were studied with correlation analysis. Plasma NEFA concentration was predicted by using regression analysis. Regression models were examined separately for both parities. Among milk fatty acids C18:1c9 had the strongest correlation to plasma NEFA concentration in both lactations. Plasma NEFA concentration predicted based on the model including C18:1c9 concentration and days in milk (DIM) had a strong correlation with observed plasma NEFA concentration being 0.84 in first lactation and 0.89 in second lactation. Models including concentrations of two milk fatty acids and DIM had higher coefficients of determination than models including one fatty acid concentration and DIM. Best two fatty acid models included concentrations of C14:0 and C18:1c9 and DIM as predictor variables. The coefficients of determination for these models were 0.54 in first lactation and 0.69 in second lactation. Prediction error was smaller in second lactation models models (RMSE 0.08 mmol/L) than in first lactation models (RMSE 0.16 mmol/L). Adding more prediction variables did not improve the models. Prediction models in this research underestimated the highest plasma NEFA concentrations, because in some cases plasma NEFA concentration can reflect stress in addition to negative energy balance. These models are useful and reliable in predicting existence and severity of negative energy balance of dairy cows with similar feeding as in this study.
Now showing items 1-3 of 3