Mikko Tuori

Comparison of the protein evaluation systems of feeds for dairy cows

Abstract Four different feed protein evaluation systems were compared on the basis of 157 treatment means obtained from 25 productions trials. Comparisons were made between the British metabolizable protein ( ARC, 1984 , AFRC, 1992 ), the French PDI ( Verite et al., 1979 , Verite and Peyraud, 1989 ) and the Nordic AAT–PBV systems ( Madsen, 1985 ). Protein values for feedstuffs were calculated using effective protein degradability (EPD) estimated by the nylon bag method and to estimate energy supply for rumen microbial protein synthesis either feed table values or determined diet digestibilities were used. Protein supply (S), requirement (R), S/R ratio and utilization of absorbed amino acids available for milk protein production were calculated using treatment means. The accuracy of the systems to predict differences in dietary protein value was studied by one-way analysis of variance using trial as a factor. Coefficient of variation (C.V.) in S/R ratio and utilization of amino acids for milk protein production were smallest with the AAT–PBV system indicating that this system was the most accurate in predicting differences in dietary protein value. Accuracy of the AAT–PBV system was further improved by reducing the original passage rate of 0.05 h−1 to 0.02 h−1 for forages, 0.03 h−1 for energy supplement and 0.04 h−1 for protein supplements in calculating EPD values. Estimating microbial protein synthesis from digestible carbohydrates (DCHOs) and rumen degradable protein (RDP) rather than from DCHO alone also improved accuracy. A value of 179 g per kg DCHO+RDP was used to estimate microbial protein synthesis. Since 1995, a modified AAT–PBV system has replaced digestible crude protein for feed evaluation in Finland. Regression analyses showed that the utilization of AAT for milk protein production improved with increasing production level. In feeding recommendations this was taken into account by reducing AAT requirement per kg of corrected milk with increasing production level.

Equol in milk of dairy cows is derived from forage legumes such as red clover

The intake of isoflavones and the resulting equol contents of both plasma and milk of the same red clover-fed cows are reported for the first time in cyclic change-over design study. Cows were fed four different red clover silages and two timothy-meadow fescue silages as controls. The red clover silages contained daidzein, formononetin, biochanin A and genistein, whereas the timothy-meadow fescue silages contained no isoflavones. We found a strong association (y = 0.071x+2.75, R 2 0.71) between the formononetin intake (x) and equol concentration (y) in the plasma, while the formononetin intake and milk equol concentration were weakly associated (y = 0.0035x+0.358, R 2 0.20). This means that a small part of the total formononetin in the silage is secreted into milk as equol. The mean equol contents in plasma and milk of cows fed red clover silage diets were in the range of 4.6-8.4 mg/l and 458-643 microg/l, respectively, while the respective values for the control diets were in the range of 0.8-1.5 mg/l and 171-287 microg/l. We showed that shorter growing periods of red clover resulted in higher silage formononetin contents and plasma and milk equol contents, suggesting that the equol content of milk can be manipulated by varying the harvesting strategy of red clover. We conclude that milk equol is derived from the formononetin of red clover silage and that milk from red clover-fed cows can be considered as a source of equol in human nutrition.

Phytoestrogen Content of Birdsfoot Trefoil and Red Clover: Effects of Growth Stage and Ensiling Method

The phytoestrogen content of birdsfoot trefoil (Lotus corniculatus L.) and red clover (Trifolium pratense L.) was determined. In addition, the effects of growth stage, wilting and ensiling additives on content were studied. Birdsfoot trefoil raw material and silage contained only traces of phytoestrogens. In red clover raw material and silage, the phytoestrogen content varied from 0.8% to 1.1% of dry matter. Content was affected by growth stage of the plant and wilting. Formononetin concentration decreased as the plant matured from budding to flowering stage, and wilting from 25% to 40% of dry matter content decreased genistein and biochanin A content. The phytoestrogen content of red clover silage was 18% higher than that of raw material. Silage additives also affected the content. Silage ensiled with an additive containing Lactobacillus plantarum bacterial inoculate had higher concentrations of genistein and biochanin A than silage made with formic acid.

Effects of supplementary concentrate composition on milk yield, milk composition and pasture utilization of rotationally grazed dairy cows

Abstract Twenty eight lactating cows were used in a randomized block design experiment to evaluate the effects of supplementary nitrogen source and heat treatment of rapessed meal containing concentrate compound on pasture utilization under a controlled rotational grazing system. The four supplemental concentrates were: 1) a cereal by-product based basic dairy concentrate (BDC); 2) BDC with 0.9% additional urea (UREA); 3) BDC with 12% rapeseed meal (RSM); and 4) expanded (heat treated) concentrate compound containing BDC and 12% rapeseed meal (EDC). The crude protein (CP, g kg−1 DM) content in the supplement was 124 (BDC), 150 (UREA), 154 (RSM) and 156 (EDC) respectively. The supplementary concentrate was fed at a fixed rate of 0.30 kg−1 of milk. Daily milk yield and concentrate consumption were recorded. No differences existed among four concentrate supplements for energy corrected milk yield (27.4, 26.9, 27.1, 27.7 kg d−1) and fat content, (39.9, 38.2, 38.1, 39.8 g kg−1). Milk protein content tended to decrease (P 4 cm) available (HOMA) was 13.8, 24.5, 17.2 and 18.2 for the months of May, June, July and August-September, respectively. The mean in vitro organic matter digestibility (IVOMD, g kg−1) was 788 and 770 for the periods of May and June and then dropped to 696 and 686 in the second half of the experimental period.

Effect of silage dry matter content and rapeseed meal supplementation on dairy cows: 2. Rumen fermentation and digesta passage rate

The effects of direct-cut and wilted silage with or without rapeseed meal (RSM) supplementation on rumen fermentation and digesta passage rates were studied in a 44 balanced Latin square experiment with four multiparous cows. The dry matter (DM) and crude protein (CP) degradabilities of silages were determined in sacco. RSM supplementation replaced 16% of the oat‐barley concentrate mixture. The daily concentrate amount was 10 kg. Silages were given ad libitum. The effective degradabilities of dry matter and protein (EPD) were higher (p<0.001) in direct-cut silage but wilted silage had higher (p<0.001) content of rapidly degradable protein. Rumen ammonia concentration was higher with direct-cut silage (10.16 versus 8.47 mmol/l, p<0.01), reflecting higher CP content and EPD. Rumen pH and total volatile fatty acid (VFA) concentration in rumen were not affected by silage type, and the differences in molar proportions of rumen VFA’s were small. The proportion of propionate tended to be higher (p<0.10) with wilted silage, whereas the proportion of butyrate was higher (133 versus 128 mmol/mol, p<0.01) with direct-cut silage. The retention time of the digesta particle phase in alimentary tract was shorter (p<0.05 or better) with wilted silage. Pool mean retention time (PMRT), which illustrates the retention time of particles in rumen, was shorter (34.0 versus 28.3 h, p<0.05) with wilted silage. Similarly, retention time of particles in the rumen pool of particles small enough to leave the rumen tended to be shorter (p<0.10) with wilted silage. RSM supplementation tended to increase (p<0.10) rumen ammonia concentration and decreased the molar proportion of rumen butyrate (132 versus 127 mmol/l, p<0.05). The retention time of particles in pool, which illustrates the rate of particle break down in the rumen, was shorter (p<0.10) with RSM. In conclusion, the ruminal retention time

Effect of Concentrate Crude Protein Level on Grass Silage Intake, Milk Yield and Nutrient Utilisation by Dairy Cows in Early Lactation

Twenty-one multiparous dairy cows were fed concentrates containing three levels (119, 154 and 191g/kg DM) of crude protein (CP) during the first ten weeks of lactation. Part of the grain and molassed sugar beat pulp was substituted with 0% (RSM0), 15% (RSM15) or 30% (RSM30) rapeseed meal. Wilted grass silage was fed ad libitum after calving. The average response between RSM0 and RSM15 was +1.66kg milk/d per percentage unit change in concentrate CP content. No further response occurred between RSM15 and RSM30. The positive effect of RSM inclusion was seen throughout the experimental period and was associated with increased plasma non esterified fatty acids (NEFA) and decreased plasma insulin concentration one week after calving, and higher efficiency of metabolisable energy utilisation for milk production. Digestibility of the diet remained unaffected. Milk and plasma urea tended to increase with RSM30 indicating excessive supply of rumen degradable protein. Because of the limited potential of cows to compensate for a deficit in feed protein supply by mobilising tissue protein, a substantial milk yield response can be achieved with a moderate level of protein supplementation during early lactation.

Comparison of energy evaluation systems for dairy cow feeds

Abstract Nine energy evaluation systems were compared on the basis of results from 51 milk production trials and 261 diets. The nine systems evaluated were the fattening feed unit used in Finland (FU F ), the feed unit used in Denmark (FU D ), the metabolizable energies used in the UK (ME MAFF , ME ARC ) and Sweden (ME SW ), the net energy in lactation used in the Netherlands and Norway (NEL NL ), France (NEL FR ) and the USA (NEL US ) and the net energy in fattening from Rostock (NEF RO ). Energy values for feedstuffs were calculated using the same digestibility coefficients in each system. Energy supply ( S ), requirements ( R ) and the S / R ratio were calculated using the treatment means. The accuracy of the systems was studied through the one-way analysis of variance with the trial as a classifier. Small residual variance (MSE) in the S / R ratio indicated that a system accurately predicted the differences in the productive values of the diets within the trial. The relation between estimated and observed milk yield was studied through regression analysis. The MSE of the S / R ratio was smallest in ME MAFF and NEL NL . The regression coefficient between the estimated and observed milk yields was closest to one and the intercept closest to zero in ME MAFF and in NEL NL . It is concluded that with Finnish dairy cow diets, ME MAFF is the most accurate of the feed evaluation systems examined; the next best are NEL NL and NEL US .

Omasal sampling technique in estimation of the site and extent of mineral absorption in dairy cows fed rapeseed and soybean expellers

Fysiologisessa kokeessa selvitettiin rypsi- ja soijapuristeruokinnanvaikutusta lypsylehmien kivennaisaineiden eli natriumin, kaliumin, magnesiumin, fosforin ja rikin sulatukseen. Lehmien paivittainen vakirehuannos oli 9 kg, ja se koostui ohran ja kauran seoksesta, jota korvattiin rypsi- tai soijapuristeella kahdella kayttomaaralla siten, etta vakirehujen valkuaispitoisuudet olivat 130, 180 ja 230 g/kg kuiva-ainetta. Koeruokintoja oli yhteensa viisi. Lehmat soivat vapaasti sailorehua, joka sisalsi puolet puna-apilaa ja puolet timotei-nurminataa. Lisaksi lehmille annettiin suolaa ja hivenainelisa, mutta ei muita kivennaislisia. Potsisulavuus maaritettiin satakertanaytteenottomenetelmalla, ja kokonaissulavuus sonnan kokonaiskeruun avulla. Muiden kivennaisten paitsi natriumin saanti lisaantyi valkuaislisan myota, ja rypsipuristetta saaneiden lehyliopistomien kivennaisten saanti oli yleensa suurempi kuin soijapuristetta saaneiden. Magnesiumin imeytyminen tapahtui paaasiassa potsi-verkkomahasta, mutta kalsium, fosfori, natrium ja kalium imeytyivat paaasiassa potsi-verkkomahan jalkeen. Rikkia imeytyi seka potsi-verkkomahasta etta sen jalkeen. Rikin nettoimeytyminen potsi- verkkomahasta osoittaa sailorehusta ja viljasta koostuvien ruokintojen sisaltaneen riittavasti rikkia potsimikrobien tarpeeseen. Suuri satakertaan virtaava natriumin ja fosforin maara kertovat naiden kivennaisten runsaasta erityksesta syljen mukana. Satakerta on tarkea kivennaisten, erityisesti natriumin ja fosforin imeytymispaikka. Tulokset osoittavat myos, etta lisafosforin ja -magnesiumin tarvetta ei ollut kokeessa kaytetyilla vilja-sailorehuruokinnoilla kaytettaessa rypsirehuja valkuaislahteena.

Replacing grass silage with pea-barley intercrop silage in the feeding of the dairy cow

The effect of replacing wilted grass silage (GS) with pea-barley intercrop silage (PBS) on feed intake, diet digestibility and milk production was studied with 8 multiparous Ayrshire-cows in a replicated 4 × 4 Latin square experiment. Proportion of PBS was 0 (PBS0), 33 (PBS33), 67 (PBS67) or 100 (PBS100) % of silage dry matter (DM). The DM content was 559 and 255 g kg-1 for GS and PBS. Crude protein content was 131 and 170 g kg-1 DM, respectively. Pea-barley silage was more extensively fermented than GS with total fermentation acid content of 120 vs. 12 g kg-1 DM. Silage was fed for ad libitum intake and supplemented with on the average 13 kg concentrate per day. Silage DM intake was 9.2 (PBS0), 9.7 (PBS33), 9.0 (PBS67) and 7.1 (PBS100) kg per day (P quadr. < 0.05). The energy corrected milk yield [30.3 (PBS0), 29.8 (PBS33), 30.3 (PBS67), 31.3 (PBS100) kg per day] was not significantly affected by the treatment. Milk protein concentration decreased linearly (P < 0.05) in response to feeding PBS. It is concluded that PBS can replace up to two thirds of wilted, moderate quality GS in the feeding of dairy cows because in this experiment pure pea-barley silage reduced silage intake.

Variety, time of harvest and conditions during growing season have impact on red clover isoflavone content

Red clover (Trifolium pratense L.) is the predominant legume used in northern European agriculture. Official red clover variety trials are conducted by Natural Resources Institute Finland (Luke) to determine the value of field crop varieties. The trials used for the current analysis were conducted in Luke units in southern Finland (Mikkeli) and northern Finland (Ruukki) in two consecutive years. Plant samples for isoflavone analyses were collected from four varieties grown as four replicates and harvested twice during both growing seasons. The four main isoflavones biochanin A, genistein, daidzein and formononetin were analysed using high performance liquid chromatography. Total phytoestrogen content in the varieties varied in the range of 11.2−14.8 mg g-1 dry matter (DM). The variety and the time of harvest had most effect on the isoflavone, especially formononetin, contents of red clover. A more northern growing area and challenging weather conditions were associated with increased isoflavone concentrations.