Browsing by Subject "dairy cow"

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  • Salomaa, Sini (Helsingin yliopisto, 2014)
    The aim of this study was to investigate the effects of graded amounts of camelina oil on milk fatty acid composition in lactating cows fed diets based on a mixture of grass and red clover silages. The experiment was carried out at the University of Helsinki research farm in Viikki 30th January 2009 – 23th April 2009. Eight multiparous Finnish Ayrshire cows participated in this experiment and four of them were rumen fistulated. Experimental design used was 4 x 4 Latin square. Treatments consisted of concentrate supplements containing various levels of camelina oil (0%, 2%, 4% and 6% on air-dry basis). All concentrates contained camelina expeller (20% on air-dry basis). The cows were offered daily 12 kg of experimental concentrate and silage ad libitum. The experimental periods lasted for 21 days. The first 14 days were adaptation period and the last 7 days formed sampling period. Increase of camelina oil level in the diet linearly decreased forage and whole diet dry matter intake (P?0,002). Camelina oil level did not affect organic matter, NDF and nitrogen whole-tract digestibility (P>0,10). Milk yield and milk protein- and lactose content linearly decreased when camelina oil level increased (P<0,001). Camelina oil level did not affect milk fat yield (P>0,100). Milk fat content (P=0,014) linearly increased and protein content (P=0,032) and urea content (P<0,001) linearly decreased when camelina oil level increased. Camelina oil level did not affect milk lactose content (P>0,100). Increase of camelina oil level linearly worsened milk taste panel scores (P=0,018). Camelina oil level did not affect plasma metabolite concentrations except that of total free fatty acids that linearly increased with camelina oil supplementation (P<0,001). Effects of camelina oil supplementation on rumen pH and rumen fermentation pattern were numerically negligible. Increase of camelina oil level linearly decreased the concentration of saturated fatty acids in milk fat (P<0,001) and linearly increased those of monounsaturated (P<0,001) and polyunsaturated (P<0,002) fatty acids. Increase of camelina oil level linearly decreased the content of mammary de novo synthesised short- and medium-chain 6-14-carbon fatty acid in milk fat (P?0,028). Camelina oil level had no effect on alphalinolenic acid content in milk fat (P>0.100). Increase of camelina oil level linearly increased trans fatty acids and CLA content in milk fat (P?0,008). Camelina oil supplementation did not affect neither the milk fat content of the final product of ruminal biohydrogenation of 18-carbon unsaturates stearic acid nor that of oleic acid (P>0,10). This is possibly due to biohydrogenation not proceeding to the end, ceasing to the last step before stearic acid. Milk fat trans-11 18:1 and cis-9, trans-11 CLA contents linearly increased at remarkably high levels when camelina oil level in the diet increased (P?0,008). This is possibly due to incomplete ruminal biohydrogenation of 18-carbon unsaturated fatty acids. Camelina oil supplement improved milk fat composition by decreasing saturated and increasing the trans-11 18:1 and cis-9,trans-11 CLA content in milk. However, giving camelina oil at high levels decreased silage and whole diet dry matter intake and affected milk production negatively.
  • Martins, L. F.; Oh, J.; Harper, M.; Melgar, A.; Räisänen, S. E.; Chen, X.; Nedelkov, K.; Karnezos, T. P.; Hristov, A. N. (2022)
    The objective of this study was to investigate the effects of an exogenous enzyme preparation from As-pergillus oryzae and Aspergillus niger on lactational performance of dairy cows. Forty-eight Holstein cows (32 primiparous and 16 multiparous) averaging (+/- SD) 36.3 +/- 8.7 kg/d milk yield and 141 +/- 52 d in milk were enrolled in a 10-wk randomized complete block design experiment (total of 24 blocks) and assigned to 1 of 2 treatments: basal diet, no enzyme supplementation (CON) or the basal diet supplemented with 4.2 g/kg dry matter intake (DMI) of an exogenous enzyme prep-aration containing amylolytic and fibrolytic activities (ENZ). After a 2-wk covariate period, premixes with the enzyme preparation or control were top-dressed daily by mixing with approximately 500 g of total mixed ra-tion. Production data were collected daily and averaged by week. Milk samples were collected every other week, and milk composition was averaged by week. Blood, fe-cal, and urine samples were collected over 2 consecutive days at 0, 4, 8, 12, and 36 h after feeding during the last week of the experiment. Compared with CON, cows fed ENZ tended to increase DMI and had increased milk concentrations of true protein, lactose, and other solids. Milk fat content tended to be higher in CON cows. A treatment x parity interaction was found for some of the production variables. Primiparous cows receiv-ing ENZ had greater yields of milk, energy-corrected milk, milk true protein, and lactose compared with CON primiparous cows; these production variables did not differ between treatments for multiparous cows. Intake and total-tract digestibility of nutrients did not differ between treatments. Concentrations of blood glucose and total fatty acids were not affected by ENZ supplementation, but 0-hydroxybutyrate concentration tended to be greater in ENZ cows. Overall, the exog-enous enzyme preparation used in this study increased milk protein and lactose concentrations in all cows, and milk production in primiparous but not multiparous cows. The differential production response between pri-miparous and multiparous cows was likely a result of a greater increase in DMI with ENZ supplementation in the younger animals.
  • Taponen, S.; Liski, E.; Heikkilä, A. -M.; Pyörälä, S. (2017)
    The aim of this study was to determine risk factors for bovine intramammary infection (IMI) associated with the most common bacterial species in Finland. Large databases of the Finnish milk-recording system and results of microbiological analyses of mastitic milk samples from Valio Ltd. (Helsinki, Finland) were analyzed. The study group comprised 29,969 cows with IMI from 4,173 dairy herds. A cow with a quarter milk sample in which DNA of target species was detected in the PathoProof Mastitis PCR Assay (Thermo Fisher Scientific, Waltham, MA) was determined to have IMI. Only cows with IMI caused by the 6 most common pathogens or groups of pathogens, coagulase-negative staphylococci (CNS), Staphylococcus aureus, Streptococcus uberis, Streptococcus dysgalactiae, Corynebacterium bovis, and Escherichia coli, were included. The control group comprised 160,176 IMI-free cows from the same herds as the study group. A multilevel logistic regression model was used to study herd- and cow-specific risk factors for incidence of IMI. Pathogen-specific results confirmed those of earlier studies, specifically that increasing parity increases prevalence of IMI regardless of causative pathogen. Holsteins were more susceptible to IMI than Nordic Reds except when the causative pathogen was CNS. Occurrence of IMI caused by C. bovis was not related to milk yield, in contrast to IMI caused by all other pathogens investigated. Organic milk production was associated with IMI only when the causative pathogen of IMI was Staph. aureus; Staph. aureus IMI was more likely to occur in conventional than in organic production. Cows in older freestall barns with parlor milking had an increased probability of contracting an IMI compared with cows in tiestall barns or in new freestall barns with automatic milking. This was the case for all IMI, except those caused by CNS, the prevalence of which was not associated with the milking system, and IMI caused by Staph. aureus, which was most common in cows housed in tiestall barns. A better breeding index for milk somatic cell count was associated with decreased occurrence of IMI, indicating that breeding for improved udder health has been successful in reducing the incidence of IMI caused by the most common pathogens in Finland. In the Finnish dairy sector, the importance of other measures to control IMI will increase as the Holstein breed progressively takes the place of the Nordic Red breed. Attention should be paid to hygiene and cleanliness, especially in old freestall barns. Based on our results, the increasing prevalence of automatic milking is not a reason for special concern.
  • Ewaoche, Anne (Helsingin yliopisto, 2017)
    In dairy cattle, milk flow is an important functional trait which impacts production. Milk flow can be measured accurately by electronic milking meters (EMM) and robots. It is necessary to understand the implications of the transition from the use of subjective scores (milkability, from very slow - 1 to very fast - 5) to objective measurements (milk flow, kg/min), as well as the genetic (co)variation of the traits and with production and health traits. Records from Finnish Ayrshire primiparous cows were analysed for milkability, milk flow, annual milk yield and somatic cell count (SCC). Milk flow was recorded by Tru-Test (EMM) and the Lely robot milking systems. A total of 64 696 cows were analysed for milkability, 1618 cows for Tru-Test and 2232 cows for Lely. To estimate variance components, heritability, genetic and phenotypic correlations, both single and two-trait animal models were fitted and analysed under REML using the DMU software. Heritability of milkability was 0.25 (standard error 0.01). For milk flow, heritability was 0.41 (0.08) and 0.52 (0.08) for Tru-Test and Lely, respectively. The genetic correlations with milk yield were 0.10 (0.04), 0.43 (0.14) and 0.37 (0.14), and with SCC, 0.50 (0.04), 0.42 (0.17) and 0.35 (0.17) for milkability, Tru-Test and Lely, respectively. Common sires provided a way to find the correlation between milkability and milk flow in the absence of common records; the results were positive but low. In conclusion, selection for milk flow is more efficacious than for milkability demonstrating the influence of quality and volume of recording on estimating heritability and genetic correlation.
  • Sahra, Mia (Helsingin yliopisto, 2019)
    Kivennäis- ja hivenaineet ovat lypsylehmälle välttämättömiä elintoimintojen ja tuotannon ylläpitoon. Härkäpavun siementä voidaan käyttää valkuaisen lähteenä ja koko kasvustoa säilörehuna, mutta niiden hivenainekoostumusta ei tunneta yhtä hyvin kuin rypsirouheen ja nurmisäilörehun. Tutkimuksessa verrattiin lypsylehmän kivennäis- ja hivenaineiden saantia ja sulavuutta härkäpapusäilörehusta ja härkäpavun siemenestä nurmisäilörehuun ja rypsirouheeseen. Tutkielmassa tarkasteltiin kahta koetta, jotka oli tehty Viikin opetus- ja tutkimustilalla vuosina 2014 ja 2015. Molemmissa kokeissa oli 8 Ayrshire-rotuista lypsylehmää. Kokeet toteutettiin kaksinkertaisina 4x4 latinalaisina neliöinä, joissa oli neljä ruokintaa neljänä kolmen viikon jaksona. Koeasetelmat olivat 2x2 faktoriaalisia. Ensimmäisessä kokeessa faktoreina olivat säilörehun kasvilaji (nurmi tai 1:1 nurmi+härkäpapu-kevätvehnä) ja väkirehun raakavalkuaispitoisuus (175 tai 200 g/kg ka). Toisessa kokeessa faktoreina olivat valkuaistäydennys eri lähteistä (rypsirouhe tai härkäpapu), sekä näiden osittainen korvaaminen Spirulina platensis mikrolevällä. Kokeen 2 koeruokinnat olivat isonitrogeenisiä valkuaisrehujen suhteen. Kokeessa 2 kaikissa koeruokinnoissa oli sama pitoisuus kaupallista kivennäisrehua ja kokeessa 1 kivennäislisä oli täysrehuissa. Härkäpapusäilörehuseos sisälsi enemmän kivennäisaineita, mutta vähemmän hivenaineita kuin nurmisäilörehu. Härkäpavun siemen sisälsi 70 % enemmän kuparia kuin rypsirouhe. Härkäpapusäilörehuseos lisäsi eri kivennäisaineiden saantia 1-6 %, mutta vähensi hivenaineiden, kuten raudan ja mangaanin saantia 5-7 % verrattuna nurmisäilörehuun. Härkäpavun siemen lisäsi kuparin saantia 9 %, mutta pienensi magnesiumin, rikin, raudan, mangaanin ja seleenin saanteja 2-14 % verrattuna rypsirouheeseen. Härkäpavun lisääminen ruokintaan kokoviljasäilörehuna tai kokonaisena siemenenä ei vaikuttanut kivennäis- tai hivenaineiden sulavuuteen. Härkäpapusäilörehu tai härkäpavun siemen eivät eronneet merkittävästi nurmirehusta tai rypsistä hivenaineiden lähteinä. Härkäpapu ei sisältänyt mitään kivennäis- tai hivenainetta haitallisen suurta tai hälyttävän pientä määrää.
  • Tauriainen, Vappu (Helsingin yliopisto, 2020)
    Faba bean (Vicia faba) has potential as a domestic supplemental protein feed, as its seeds are rich in crude protein and starch. However, faba bean protein is low in methionine and highly degradable in the rumen, which reduces its nutritional value. The rate of protein degradation can potentially be decreased by industrial heat and steam treatment. The aim of the study was to investigate how feed industrial processing and methionine supplementation can affect the milk yield and milk composition of dairy cows. The study was conducted at the research farm of the University of Helsinki in Viikki from 6.1.2018 to 21.4.2018. Five multiparous Finnish Ayrshire cows with ruminal fistulas participated in the study, which utilized a 5x5 Latin square study design with three-week trial periods. The five experimental treatments consisted of the following isonitrogenous protein feeds: rapeseed meal (RR), milled faba bean (HJ), roasted (industrial heat treatment) faba bean (HR) and methionine-supplemented (15 g/day omasal infusion) faba bean feeds HJM and HRM. The cows were fed TMR (total mixed ratio) ad libitum. TMR was based on first cut timothy and meadow fescue grass silage (D-value 706 g/kg dry matter), including a mixture of barley-oats, sugar beet pulp and a mineral supplement. The share of concentrate in the dry matter of TMR was 38 %. Faba bean feedings (HJ, HJM, HR, HRM) increased dry matter intake by an average of 1.6 kg/day compared to rapeseed feeding, but this had no effect on milk yield, which averaged 27.7 kg/day in the experiment. Crude protein and starch intakes were higher in faba bean feedings compared to rapeseed feeding. Rapeseed meal contained more fat than milled and roasted faba beans, which increased total fat intake in rapeseed feeding. Faba bean feedings increased the digestibility of crude protein and the protein content of milk compared to rapeseed feeding. Roasting of faba beans tended to increase milk and lactose yields (HJ, HJM vs. HR, HRM). However, methionine supplementation had no effect on milk or protein yield (HJ, HR vs. HJM, HRM). Faba bean feedings increased the content of saturated de novo fatty acids in milk fat and decreased the content of long-chain mono- and polyunsaturated fatty acids compared to rapeseed feeding. Feeding had little effect on rumen fermentation or plasma energy metabolites. According to this study, faba beans were palatable as a supplementary protein feed and it was possible to replace rapeseed meal by milled or roasted faba beans without a decrease in total dry matter intake or milk yield. Roasting of faba bean tended to increase milk yield compared to milled faba bean. Faba bean feeds increased the content of saturated de novo fatty acids and reduced the content of unsaturated fatty acids. Methionine supplementation had no effect on milk production in this study.
  • Anttila, Anne (Helsingfors universitet, 2014)
    The aim of this study was to investigate dairy cow performance on faba bean compared to rapeseed meal on silage based diets. Increasing use of grain legumes may improve selfsufficiency of feed protein. The study was conducted at the research farm of University of Helsinki. In the experiment, eight multiparous Finnish Ayrshire cows were used. Four of them were fitted with rumen fistula. In the beginning of the experiment, cows were 100 (± 51) days in milk. Replicated 4x4 Latin square design was used: the other square consisted of cows with rumen fistulas and the other of intact cows. Treatments of the study were concentrate feeds as follows: control (no protein supplement), rapeseed meal, faba bean and mixture of rapeseed meal and faba bean. Concentrates were fed at a rate of 14 kg/d and silage was given ad libitum. Concentrate feeds including protein supplement were isonitrogenous crude protein content being approximately 200 g/kg DM. Protein supplementation increased silage intake (2,4 kg/d) and milk production (1,6 – 4,9 kg/d). Protein supplementation decreased milk fat content (41,2 vs. 45,3 g/kg DM) but increased milk protein content (35,5 vs. 34,3 g/kg). Feed nitrogen utilization to milk, AAT and ME utilizations and ECM yield to feed intake -ratio were decreased on protein supplementation. In this experiment however rapeseed meal did not give responses of same level as was expected according to results of earlier experiments. Diets including faba bean increased silage intake and milk production compared to rapeseed meal diet. Rapeseed meal diet decreased silage intake 2,7 kg and milk yield 2,5 kg compared with faba bean diet. Mixture of rapeseed and faba bean resulted in the highest milk production being 2 kg more than on average on rapeseed meal and faba bean diets. Utilization of ME and ECM yield to feed intake –ratio were increased with rapeseed meal diet. According to this study rapeseed meal as a protein supplement can be substituted by faba bean in dairy cow diets on silage based diets.
  • McCubbin, Kayley D.; de Jong, Ellen; Lam, Theo J. G. M.; Kelton, David F.; Middleton, John R.; McDougall, Scott; De Vliegher, Sarne; Godden, Sandra; Rajala-Schultz, Paivi J.; Rowe, Sam; Speksnijder, David C.; Kastelic, John P.; Barkema, Herman W. (2022)
    Administering intramammary antimicrobials to all mammary quarters of dairy cows at drying-off [i.e., blanket dry cow therapy (BDCT)] has been a mainstay of mastitis prevention and control. However, as udder health has considerably improved over recent decades with reductions in intramammary infection prevalence at drying-off and the introduction of teat sealants, BDCT may no longer be necessary on all dairy farms, thereby supporting antimicrobial stewardship efforts. This narrative review summarizes available literature regarding current dry cow therapy practices and associ-ated impacts of selective dry cow therapy (SDCT) on udder health, milk production, economics, antimicro-bial use, and antimicrobial resistance. Various methods to identify infections at drying-off that could benefit from antimicrobial treatment are described for select-ing cows or mammary quarters for treatment, includ-ing utilizing somatic cell count thresholds, pathogen identification, previous clinical mastitis history, or a combination of criteria. Selection methods may be enacted at the herd, cow, or quarter levels. Producers' and veterinarians' motivations for antimicrobial use are discussed. Based on review findings, SDCT can be ad-opted without negative consequences for udder health and milk production, and concurrent teat sealant use is recommended, especially in udder quarters receiving no intramammary antimicrobials. Furthermore, herd selection should be considered for SDCT implementa-tion in addition to cow or quarter selection, as BDCT may still be temporarily necessary in some herds for optimal mastitis control. Costs and benefits of SDCT vary among herds, whereas impacts on antimicrobial resistance remain unclear. In summary, SDCT is a vi-able management option for maintaining udder health and milk production while improving antimicrobial stewardship in the dairy industry.
  • Tucker, Cassandra; Jensen, Margit Bak; de Passille, Anne Marie; Hänninen, Laura; Rushen, Jeff (2021)
    Adequate time lying down is often considered an important aspect of dairy cow welfare. We examine what is known about cows’ motivation to lie down and the consequences for health and other indicators of biological function when this behavior is thwarted. We review the environmental and animal-based factors that affect lying time in the context of animal welfare. Cows can be highly motivated to lie down. They show rebound lying behavior after periods of forced standing and will sacrifice other activities, such as feeding, to lie down for an adequate amount of time. They will work, by pushing levers or weighted gates, to lie down and show possible indicators of frustration when lying behavior is thwarted. Some evidence suggests that risk of lameness is increased in environments that provide unfavorable conditions for cows to lie down and cows are forced to stand. Lameness itself can result in longer lying times, whereas mastitis reduces it. Cow-based factors such as reproductive status, age, and milk production influence lying time, but the welfare implications of these differences are unknown. Lower lying times are reported in pasture-based systems, dry lots, and bedded packs (9 h/d) compared with tiestalls and freestalls (10 to 12 h/d) in cross-farm research. Unfavorable conditions, including too few lying stalls for the number of cows, hard or wet lying surfaces, inadequate bedding, stalls that are too small or poorly designed, heat, and rain all reduce lying time. Time constraints, such as feeding or milking, can influence lying time. However, more information is needed about the implications of mediating factors such as the effect of the standing surface (concrete, pasture, or other surfaces) and cow behavior while standing (e.g., being restrained, walking, grazing) to understand the effect of low lying times on animal welfare. Many factors contribute to the difficulty of finding a valid threshold for daily lying time to use in the assessment of animal welfare. Although higher lying times often correspond with cow comfort, and lower lying times are seen in unfavorable conditions, exceptions occur, namely when cows lie down for longer because of disease or when they spend more time standing because of estrus or parturition, or to engage in other behaviors. In conclusion, lying behavior is important to dairy cattle, but caution and a full understanding of the context and the character of the animals in question is needed before drawing firm conclusions about animal welfare from measures of lying time.
  • Niemelä, Kirsi (Helsingfors universitet, 2011)
    The aim of this study was to develop mathematical energy balance models for early and middle lactation period of dairy cows. The traits for predicting were information of diet, feed, milk production, milk composition, body weight and body condition score. This study was a part of development work of KarjaKompassi-project. The data used in this study was based on 12 feeding experiments performed in Finland. The complete data from the studies included 2647 weekly records from multiparous dairy cows and 1070 weekly records from primiparous dairy cows. The data was collected from calving to 8-28 weeks of lactation. Three-fourths of the totals of 344 dairy cows were Finnish Ayshire cows and the rest of the cows were Friesian Cattle. The cows were fed by the Finnish feeding standards. The data was handled by the Mixed-procedure of the SAS-programme. The outliers were removed with Tukey´s method. The relationship between energy balance and predictor traits was studied with correlation analysis. The regression analysis was used to predicting energy balance. To quantify the relationship of lactation day to energy balance, 5 functions were fitted. The random factor was a cow in the experiment. The model fit was assessed by residual mean square error, coefficient of determination and Bayesian information criterion. The best models were validated in the independent data. Ali-Schaeffer achieved the highest fit functions. It was used by the basal model. The error in every model grew after the 12th lactation week, because the number of records decreased and energy balance turned positive. The proportion of concentrate in the diets and concentrate dry matter intake index were the best predictors of energy balance from traits of diet. Milk yield, ECM, milk fat and milk fat-protein ratio were good predictors during lactation period. The RMSE was lower when ECM was standardized. The body weight and body condition score didn’t improve the predictive value of the basal model. The models can be used to predict energy balance in the herd level, but they are not applicable for predicting individual cow energy balance.
  • Kuiri, Sini (Helsingin yliopisto, 2019)
    Siirtyminen ummessaolokaudelta tuotoskaudelle on lypsylehmälle haastava ajanjakso, jolloin tapahtuu monia aineenvaihdunnallisia muutoksia. Tunnutusruokinnassa dieetin väkirehun osuutta lisätään muutamia viikkoja ennen poikimista, jotta lehmä ja sen pötsi sopeutuisivat poikimisen jälkeiseen, runsaasti energiaa sisältävään ruokintaan. Tutkimuksen tavoitteena oli selvittää tunnutusruokinnan vaikutusta tuotoskauden alun maito-tuotokseen, maidon koostumukseen, kuiva-aineen syöntiin ja eläimen energiatasetta kuvaaviin veriparametreihin hyödyntäen aikaisemmin julkaistuja tieteellisiä tutkimuksia. Meta-analyysin aineistona käytettiin 20 vertaisarvioitua tutkimusta, joissa ummessaolokauden ruokinnan solunsisällyshiilihydraattien (SSHH) pitoisuutta muutettiin aikaisintaan 30 päivää ennen odotettua poikimista. Tunnutusdieetin SSHH- ja NDF-pitoisuuksien yhteyttä maitotuotokseen, maidon koostumukseen, kuiva-aineen syöntiin sekä veren NEFA (vapaat rasvahapot)- ja BHBA (β-hydroksivoihappo)-pitoisuuksiin tarkasteltiin käyttämällä regressioanalyysiä sekä lineaarista ja toisen asteen sekamallia. Aineiston luokittelevina tekijöinä käytettiin tunnutusdieetin pääasiallisen karkearehun tyyppiä (maissisäilörehu, nurmisäilörehu) ja kontrollidieetin SSHH-pitoisuutta (alle 250 g/kg ka, yli 250 g/kg ka). Väkirehun lisäämisen vaikutusta verrattuna pelkästään nurmisäilörehua sisältävään tunnutuskauden ruokintaan tutkittiin Mix 2.0 PRO ohjelman Random-mallilla. Tunnutusdieetin SSHH-pitoisuuden lisääminen ja NDF-pitoisuuden vähentäminen pienensi veren NEFA-pitoisuutta ennen poikimista sekä suurensi hieman maidon valkuaispitoisuutta ja valkuaistuotosta. NDF-pitoisuuden lisääminen pienensi suuntaa antavasti EKM- ja valkuaistuotoksia. Toisen asteen mallissa SSHH-pitoisuuden vaikutus poikimisen jälkeiseen kuiva-aineen syöntiin oli käyräviivainen ja vaihteli dieetin SSHH-pitoisuuden mukaan. Dieetin SSHH-pitoisuuden ja karkearehutyypin välillä ei havaittu tilastollisesti merkitseviä yhdysvaikutuksia maitotuotokseen, maidon koostumukseen, kuiva-aineen syöntiin tai veriparametreihin. Kun tunnutusdieetin SSHH-pitoisuuden lähtötaso oli vähintään 250 g/kg ka, SSHH-pitoisuuden lisääminen paransi hieman maitotuotosta ja poikimisen jälkeistä kuiva-aineen syöntiä. Väkirehun lisääminen pelkästään nurmisäilörehua sisältäneeseen tunnutuskauden dieettiin suurensi maidon rasvapitoisuutta ja rasvatuotosta. Tunnutusruokinnan vaikutukset maitotuotokseen, maidon koostumukseen ja kuiva-aineen syöntiin olivat pieniä, mutta veren NEFA-pitoisuuden pienentymisellä ennen poikimista voi olla positiivisia vaikutuksia lehmän terveyteen.
  • Tapola, Tuire (Helsingin yliopisto, 2020)
    Milk fat contains a lot of (70–75 %) saturated fat, which is connected to Finnish public heart and coronary diseases. However, it is possible to alter the fatty acid composition of milk fat by giving cows lipid supplements such as crushed rapeseeds. The aim of this pilot study was to investigate how the lipids of crushed rapeseeds affect dairy cow’s milk fatty acid composition. The effects of rapeseed lipids on saturated and unsaturated fatty acid concentrations in milk fat were studied in particular. Additionally, it was investigated how dietary lipids affect cows’ dry matter (DM) intake and milk production as it is known that high amounts of lipids can reduce DM intake and fiber digestion in the rumen. The study consisted of two successive three week long periods of which the first one was control period and the second one test period. There were six ayrshire cows which had been on average 181 days in milk at the beginning of the study. The cows were given partial total mixed ratio (pTMR) containing grass silage as forage (60 % of diet DM) during the whole study. Concentrates comprised cereals, rapeseed meal, molassed sugar beet pulp and mineral supplements. Control diet’s barley was replaced by oats and most of the rapeseed meal was replaced by crushed rapeseed in the test diet. Crushed rapeseed was added 160 g/kg pTMR DM. Cows were also given complete feed 3kg/day at milkings. Lipids of crushed rapeseeds reduced the concentration of saturated fatty acids by 20 % in milk fat. Of all the saturated fatty acids, palmitic acid (C16:0) was decreased by 38 % and stearic acid (C18:0) was increased by 94 %. Of these two saturated fatty acids, C16:0 is linked to higher total plasma cholesterol levels whereas C18:0 is considered to have a neutral effect in humans. The concentration of monounsaturated oleic acid (cis-9 C18:1), which is known to be hypocholesteremic, increased by 78 % in milk fat. Test diet caused decline in DM intake and milk production. It is likely that the milk production decreased partly because the cows were in declining milk production phase. Test feed decreased the apparent digestibility of neutral detergent fiber (NDF), because the amount of rapeseed lipids in the diet was high (48 g/kg diet DM). Crushed rapeseeds suit excellently to alter dairy cow’s milk fatty acid composition. The amount of lipid supplementation should not be too high in order to avoid decreases in DM intake and NDF digestibility as occurred in this study.
  • Sarjokari, K.; Hovinen, M.; Seppä-Lassila, L.; Norring, M.; Hurme, T.; Peltoniemi, O.A.T.; Soveri, T.; Rajala-Schultz, P.J. (2018)
    ABSTRACT On-farm death (OFD) of a dairy cow is always a financial loss for a farmer, and potentially a welfare issue that has to be addressed within the dairy industry. The aim of this study was to explore the associations between OFD of dairy cows, housing, and herd management in freestall barns. To achieve the goal, we followed 10,837 cows calving in 2011 in 82 herds. Data were gathered with observations and a structured interview during farm visits and from a national dairy herd improvement database. The hazard of OFD was modeled with a shared frailty survival model, with SAS 9.3 PHREG procedure (SAS Institute Inc., Cary, NC). The study population was 58% Ayrshire and 42% Holstein cows. The median herd size and mean milk yield in the study herds were 116 cows and 9,151 kg of milk per cow per year. The overall probability of OFD was 6.0%; 1.8% of the cows died unassisted and 4.2% were euthanized. Variation in OFD percentage between individual herds was large, from 0 to 16%, accounting for 0 to 58% of all removals in the herds. Keeping close-up dry cows in an own group was associated with higher hazard of OFD [hazard ratio (HR) = 1.37] compared with keeping them in the same pen with far-off dry cows. Higher hazard on OFD was observed when barns had only one kind of calving pens; single (HR = 2.09) or group pens (HR = 1.72), compared with having both of those types. The hazard of OFD was lower if the whole herd was housed in barns or pens that had only 1 type of feed barrier at the feed bunk, namely post-and-rail (HR = 0.51) or a type with barriers between the cow's heads (HR = 0.49), compared with having 2 types. Lower OFD hazard was observed with wider than 340 cm of walking alley next to the feeding table (HR = 0.75), and with housing a whole herd in pens with only 1 type of walking alley surface, specifically slatted (HR = 0.53) or solid (HR = 0.48), compared with having both types. The hazard of OFD was higher with stalls wider than 120 cm (HR = 1.38) compared with narrower stalls. The hazard of OFD was also associated with breed, parity, and calving season. This study identified many factors that contribute to the incidence of OFD of dairy cows. The solutions for reducing on-farm mortality include housing, management, and breeding choices that are most probably herd specific.
  • Bougouin, A.; Hristov, A.; Dijkstra, J.; Aguerre, M. J.; Ahvenjarvi, S.; Arndt, C.; Bannink, A.; Bayat, A. R.; Benchaar, C.; Boland, T.; Brown, W. E.; Crompton, L. A.; Dehareng, F.; Dufrasne, I.; Eugene, M.; Froidmont, E.; van Gastelen, S.; Garnsworthy, P. C.; Halmemies-Beauchet-Filleau, A.; Herremans, S.; Huhtanen, P.; Johansen, M.; Kidane, A.; Kreuzer, M.; Kuhla, B.; Lessire, F.; Lund, P.; Minnee, E. M. K.; Munoz, C.; Niu, M.; Noziere, P.; Pacheco, D.; Prestlokken, E.; Reynolds, C. K.; Schwarm, A.; Spek, J. W.; Terranova, M.; Vanhatalo, A.; Wattiaux, M. A.; Weisbjerg, M. R.; Yanez-Ruiz, D. R.; Yu, Z.; Kebreab, E. (2022)
    Manure nitrogen (N) from cattle contributes to nitrous oxide and ammonia emissions and nitrate leaching. Measurement of manure N outputs on dairy farms is laborious, expensive, and impractical at large scales; therefore, models are needed to predict N excreted in urine and feces. Building robust prediction models requires extensive data from animals under different management systems worldwide. Thus, the study objectives were (1) to collate an international database of N excretion in feces and urine based on individual lactating dairy cow data from different continents; (2) to determine the suitability of key variables for predicting fecal, urinary, and total manure N excretion; and (3) to develop robust and reliable N excretion prediction models based on individual data from lactating dairy cows consuming various diets. A raw data set was created based on 5,483 individual cow observations, with 5,420 fecal N excretion and 3,621 urine N excretion measurements collected from 162 in vivo experiments conducted by 22 research institutes mostly located in Europe (n = 14) and North America (n = 5). A sequential approach was taken in developing models with increasing complexity by incrementally adding variables that had a significant individual effect on fecal, urinary, or total 2manure N excretion. Nitrogen excretion was predicted by fitting linear mixed models including experiment as a random effect. Simple models requiring dry matter intake (DMI) or N intake performed better for predicting fecal N excretion than simple models using diet nutrient composition or milk performance parameters. Simple models based on N intake performed better for urinary and total manure N excretion than those based on DMI, but simple models using milk urea N (MUN) and N intake performed even better for urinary N excretion. The full model predicting fecal N excretion had similar performance to simple models based on DMI but included several independent variables (DMI, diet crude protein content, diet neutral detergent fiber content, milk protein), depending on the location, and had root mean square prediction errors as a fraction of the observed mean values of 19.1% for intercontinental, 19.8% for European, and 17.7% for North American data sets. Complex total manure N excretion models based on N intake and MUN led to prediction errors of about 13.0% to 14.0%, which were comparable to models based on N intake alone. Intercepts and slopes of variables in optimal prediction equations developed on intercontinental, European, and North American bases differed from each other, and therefore region-specific models are preferred to predict N excretion. In conclusion, region-specific models that include information on DMI or N intake and MUN are required for good prediction of fecal, urinary, and total manure N excretion. In absence of intake data, region-specific complex equations using easily and routinely measured variables to predict fecal, urinary, or total manure N excretion may be used, but these equations have lower performance than equations based on intake.
  • Ternman, Emma; Nilsson, Emma; Nielsen, Per Peetz; Pastell, Matti; Hänninen, Laura; Agenäs, Sigrid (2019)
    ABSTRACT The importance of rest and sleep is well established; we know, for example, that lack of sleep impairs immune function in rats and increases pain sensitivity in humans. However, little is known about sleep in dairy cows, but a lack of rest and sleep is discussed as a possible welfare problem in cattle. A first step toward a better understanding of sleep in dairy cows is to quantify the time cows spend awake and asleep in different stages of lactation. Using electrophysiological recordings on 7 occasions in wk −2, 2, 7, 13, 22, 37, and 45 in relation to calving, we investigated changes in rapid eye movement (REM) sleep time as well as non-rapid eye movement (NREM) sleep, drowsing, awake, and rumination in 19 dairy cows of the Swedish Red breed kept in single pens with ad libitum access to feed and water. The recordings on wk −2 and 45 were conducted during the dry period, and all others during lactation. The PROC MIXED procedure in SAS (SAS Institute Inc., Cary, NC) was used to test for significant differences in REM, NREM, drowsing, awake, and rumination between the different stages of lactation cycle. Pairwise comparisons between all recording occasions showed that total REM sleep duration was shorter for cows in wk 2 relative to calving compared with wk −2, and the number of REM sleep bouts were fewer in wk 2 compared with wk −2. The REM sleep was recorded during both the day (0500–2100 h) and night (2100–0500 h), but predominantly performed at night compared with daytime, and the bout duration was longer during nighttime compared with daytime. A tendency was observed for time spent in NREM sleep to be shorter in wk 2 relative to calving compared with wk −2. The duration spent drowsing was shorter for cows in wk 2 and 13 relative to calving compared with wk −2. We found no effect of stage of lactation cycle on the duration of awake or ruminating. Our study is the first to assess sleep distribution during a lactation cycle, and our results show that stage of lactation is important to consider when moving forward with sleep investigations in dairy cows. The shortest REM sleep duration was found for cows 2 wk after calving and longest 2 wk before calving, and the difference was due a higher number of REM sleep bouts in the recording 2 wk before calving. The REM sleep and rumination predominantly occurred at night but were recorded during both day and night.
  • Vainio, Laura (Helsingin yliopisto, 2019)
    Sulavuustutkimuksen avulla pyritään arvioimaan eläinten ravintoaineiden tarvetta, kehittämään rehujen koostumuksia ja minimoimaan eläintuotannon ympäristövaikutukset. Eläimen rehunsyönnin ja sonnan kokonaiskeruun avulla laskettua sulavuutta käytetään laajasti, mutta menetelmään liittyy virhelähteitä ja ongelmia. Merkkiaineen käyttö sulavuuden tutkimisessa poistaa kokonaiskeruun tarpeen, mutta se ei ole myöskään ongelmaton. Sisäiset merkkiaineet ovat aineita, joita on luontaisesti rehussa, kuten piioksidi, ligniini, happoon liukenematon tuhka (AIA) ja sulamaton neutraalidetergenttikuitu (iNDF). Ulkoiset merkkiaineet ovat rehuun lisättäviä reagoimattomia valmisteita, kuten liukenemattomia metallioksideja, muovia, kumia tai väriaineita. Tämän tutkimuksen tavoitteena on verrata lypsylehmillä iNDF:n ja AIA:n avulla laskettuja sulavuuksia käyttäen aineistona aiemmin AIA:lla tehtyjä sulavuustutkimuksia. Tutkimusaineistona oli viisi Viikin opetus- ja tutkimustilan navetassa vuosina 2013–2015 tehtyä ruokintatutkimusta. Lehmien poikimisesta oli 100–212 päivää. Koeasetelmat olivat pääasiassa kahden neliön latinalaisia neliöitä. Ruokintakeskiarvoja aineistossa oli 21. Rehu- ja sontanäytteistä määritettiin iNDF nailonpussimenetelmällä uittamalla näytepusseja 12 vrk kahden fistelöidyn lehmän pötsissä. Ravintoaineiden sulavuudet laskettiin iNDF-merkkiaineella ja orgaanisen aineen sulavuuksille laskettiin suhdeluku iNDF-sulavuus/AIA-sulavuus. Lisäksi laskettiin sonnan määrä ja sonnassa erittyneen iNDF:n osuus syödystä iNDF:stä (recovery). Aineistosta laskettiin koeruokintojen minimi ja maksimi, keskiarvo sekä keskihajonta. AIA- ja iNDF-merkkiaineella saatujen sulavuusarvojen välistä yhteyttä testattiin yksinkertaisella regressioanalyysillä. Lisäksi analysoitiin sekamallin regressioanalyysillä mitkä rehuannosta kuvaavat laatuparametrit selittivät parhaiten AIA- ja iNDF-sulavuuksien eroa. Tutkimusaineiston rehujen iNDF-pitoisuudet vaihtelivat 58–146 g/kg ka ja iNDF:n osuus NDF:stä 136–318 g/kg NDF. Koeruokintojen AIA-pitoisuudet vaihtelivat 8,6–14,9 g/kg ka ja iNDF-pitoisuudet 50,8–132 g/kg ka. Aineiston ruokintakeskiarvojen AIA:lla määritetty orgaanisen aineen sulavuus vaihteli 0,646–0,760, kuiva-aineen syönti 18,2–25,8 kg ka/pv, energiakorjattu maitotuotos 24,9–38,4 kg/pv ja väkirehun osuus 42,1–53,0 % kuiva-aineesta. Ravintoaineiden iNDF:llä määritetyt sulavuudet olivat keskimäärin pienempiä kuin AIA-sulavuudet. Orgaanisen aineen iNDF- ja AIA-sulavuuksien keskimääräinen suhdeluku oli 0,959 ja keskimääräinen erotus 0,028. Keskimäärin sonnassa erittyneen iNDF:n osuus syödystä iNDF:stä oli 0,922. Regressioanalyysin mukaan eri merkkiaineilla määritetyissä sulavuuksissa oli suurin ero rehuannoksen sulavuuden ollessa matala, mutta ero pieneni sulavuuden parantuessa. Parhaiten iNDF- ja AIA-sulavuuksien suhdelukua selitti dieetin iNDF-pitoisuus. Mitä suurempi dieetin iNDF-pitoisuus oli, sitä pienempi oli orgaanisen aineen sulavuus iNDF:llä määritettynä verrattuna AIA:lla määritettyyn. Tutkimuksen perusteella iNDF:llä ja AIA:lla saatujen sulavuustulosten välinen suhde vaihtelee riippuen rehuannoksen ominaisuuksista. Tutkielman aineistossa iNDF:n käyttö sisäisenä merkkiaineena vastasi AIA:lla saatuja sulavuustuloksia sitä paremmin mitä pienempi rehuannoksen iNDF-pitoisuus oli ja mitä parempi rehuannoksen sulavuus oli.
  • Lamminen, M.; Halmemies-Beauchet-Filleau, A.; Kokkonen, T.; Vanhatalo, A.; Jaakkola, S. (2019)
    Alternative protein sources such as microalgae and faba beans may have environmental benefits over rapeseed. We studied the effects of rapeseed meal (RSM) or faba beans (FB) as a sole protein feed or as protein feeds partially substituted with Spirulina platensis (spirulina) microalgae on milk production, N utilization, and AA metabolism of dairy cows. Eight multiparous Finnish Ayrshire cows (113 +/- 36.3 d in milk; mean +/- SD) were used in a balanced, replicated 4 x 4 Latin square with 2 x 2 factorial arrangement of treatments and 21-d periods. Four cows in one Latin square were rumen cannulated. Treatments were 2 isonitrogenously fed protein sources, RSM or rolled FB, or one of these sources with half of its crude protein substituted by spirulina (RSM-SPI and FB-SPI). Cows had ad libitum access to total mixed rations consisting of grass silage, barley, sugar beet pulp, minerals, and experimental protein feed. The substitution of RSM with FB did not affect dry matter intake (DMI) but decreased neutral detergent fiber intake and increased the digestibility of other nutrients. Spirulina in the diet decreased DMI and His intake. Spirulina had no effect on Met intake in cows on RSM diets but increased it in those on FB diets. Energy-corrected milk (ECM) and protein yields were decreased when RSM was substituted by FB. Milk and lactose yields were decreased in cows on the RSM-SPI diet compared with the RSM diet but increased in those on FB-SPI compared with FB. The opposite was true for milk fat and protein concentrations; thus, spirulina in the diet did not affect ECM. Feed conversion efficiency (ECM: DMI) increased in cows on FB diets with spirulina, whereas little effect was observed for those on RSM diets. The substitution of RSM by FB decreased arterial concentration of Met and essential AA. Spirulina in the diet increased milk urea N and ruminal NH4-N and decreased the efficiency of N utilization in cows on RSM diets, whereas those on FB diets showed opposite results. Met likely limited milk production in cows on the FB diet as evidenced by the decrease in arterial Met concentration and milk protein yield when RSM was substituted by FB. The results suggest the potential to improve milk production response to faba beans with supplementation of Met-rich feeds such as spirulina. This study also confirmed spirulina had poorer palatability than RSM and FB despite total mixed ration feeding and lower milk production when spirulina partially replaced RSM.
  • Mäntysaari, Päivi; Juga, Jarmo; Lidauer, M.H.; Häggman, J.; Mehtiö, T.; Christensen, J.M.; Mäntysaari, E.A. (2022)
    The relationships between dairy cow milk-based energy status (ES) indicators and fertility traits were studied during periods 8 to 21, 22 to 35, 36 to 49, and 50 to 63 d in milk. Commencement of luteal activity (C -LA) and interval from calving to the first heat (CFH), based on frequent measurements of progesterone by the management tool Herd Navigator (DeLaval), were used as fertility traits. Energy status indicator traits were milk beta-hydroxybutyrate (BHB) concentration provided by Herd Navigator and milk fat: protein ratio, concen-tration of C18:1 cis-9, the ratio of fatty acids (FA) C18:1 cis-9 and C10:0 in test-day milk samples, and predicted plasma concentration of nonesterified fatty acids (NEFA) on test days. Plasma NEFA predictions were based either directly on milk mid-infrared spectra (MIR) or on milk fatty acids based on MIR spectra (NEFAmir and NEFAfa, respectively). The average (standard deviation) C-LA was 39.3 (+/- 16.6) days, and the average CFH was 50.7 (+/- 17.2) days. The correlations between fertility traits and ES indicators tended to be higher for multiparous (r < 0.28) than for primiparous (r < 0.16) cows. All correlations were lower in the last period than in the other periods. In period 1, correlations of C-LA with NEFAfa and BHB, respectively, were 0.15 and 0.14 for primiparous and 0.26 and 0.22 for multiparous cows. The associations between fertility traits and ES indicators indicated that negative ES during the first weeks postpartum may delay the onset of luteal activity. Milk FPR was not as good an indicator for cow ES as other indicators. According to these findings, predictions of plasma NEFA and milk FA based on milk MIR spectra of routine test-day samples and the frequent measurement of milk BHB by Herd Navigator gave equally good predictions of cow ES during the first weeks of lactation. Our results indicate that routinely measured milk traits can be used for ES evaluation in early lactation.