Juha Nousiainen

Recent developments in forage evaluation with special reference to practical applications

Systemaattisesti keratyn sailorehuaineiston perusteella tehty yhteenveto osoittaa selvasti ns. virallisen rehuanalyysineli Weenden analyysin biologiset puutteet rehujen ravitsemuksellisen laadun kuvaajana. Analyysi ei kuvaa rehun kemiallisen koostumuksen ja sulavuuden valisia syy-seuraussuhteita. Lisaksi tilastolliset yhteydet vaihtelevat huomattavasti eri kasvimateriaaleilla ja ymparistoolosuhteissa. Weenden analyysin kayttoa ei siis voi suositella karkea- eika vakirehujen laadun kuvaamiseen. In vitro pepsiini-sellulaasiliukoisuus (OMS) ja sulamattoman kuidun (iNDF) pitoisuus sen sijaan ennustivat karkearehujen orgaanisen aineen sulavuuden riittavan tarkasti kaytannon ruokinnansuunnittelua varten, edellyttaen etta analyysitulokset muunnettiin sulavuudeksi rehutyyppikohtaisia korjausyhtaloita kayttaen eli erikseen ensimmaisesta sadosta ja jalkikasvusta tehdyille nurmisailorehuille, palkokasvisailorehuille ja kokoviljasailorehuille. Detergenttikuituanalyysi, joka jakaa rehun kuiva-aineen liukoiseen ja lahes taysin kayttokelpoiseen solunsisallykseen (NDS) seka liukenemattomaan kuituun (NDF), on Weenden analyysia huomattavasti kehityskelpoisempi vaihtoehto. Kun kuituanalyysiin yhdistetaan pitka in situ potsi-inkubaatio, rehun kuiva-aine saadaan jaettua kolmeen biologisesti mielekkaaseen osaan: NDS, potentiaalisesti sulava kuitu (pdNDF) ja iNDF. Rehun D-arvo eli sulavan orgaanisen aineen pitoisuus kuiva-aineessa voidaan ennustaa ns. summatiivisella yhtalolla. Yhtalossa lasketaan yhteen sulanut NDS, joka voidaan maarittaa Lucasin yhtalolla, ja sulanut kuitu (pdNDF-pitoisuus × pdNDF:n sulavuus tai vaihtoehtoisesti NDF-pitoisuus × NDF:n sulavuus). Rehutyyppikohtaiset summatiiviset yhtalot ennustivat karkearehujen D-arvon lahes yhta hyvin kuin OMS ja iNDF. Kun koko aineistoa tarkasteltiin yhdessa, summatiiviset yhtalot olivat parempia kuin iNDF ja erityisesti OMS. Jos D-arvon ennustevirhe halutaan saada pienemmaksi kuin 15 g/kg kuiva-ainetta, on kaytettava rehutyyppikohtaisia yhtaloita riippumatta siita, onko laskennan perusteena OMS, iNDF tai summatiivinen yhtalo. Toinen vaihtoehto tulevaisuudessa on dynaamisten mallien kaytto. Ne pystyvat samanaikaisesti huomioimaan kaksi tarkeaa dynaamista prosessia, jotka rajoittavat rehun sulatusta potsissa eli kuidun virtaus- ja sulatusnopeuden. Dynaamisten mallien kaytto edellyttaa kuitenkin sita, etta rehuista voidaan helposti ja luotettavasti maarittaa iNDF-pitoisuus ja kuidun sulatusnopeus. Maatilarehujen iNDF-maaritys NIRS-menetelmalla toteutuu Suomessa lahiaikoina, mutta kuidun sulatusnopeuden maaritys vaatii viela lisatyota.

Prediction of the relative intake potential of grass silage by dairy cows

Data based on the mean treatment values from production studies in lactating dairy cows were used to estimate relationships between silage composition and silage dry matter intake (SDMI). Data from 21 studies were used to estimate relationships between D-value (g digestible organic matter in kg dry matter (DM)) and crude protein (CP) content, and SDMI. The silages were harvested at different maturities but using the same ensiling techniques within the study. Relationships between silage fermentation characteristics and SDMI were estimated using data from 47 studies. The silages were harvested at the same time from the same sward but using various additives. When factorial designs were used, silage data within each treatment (subexperiment) were recorded separately. The data sets included 125 D-value and 234 fermentation observations. Relationships between SDMI and silage parameters were analyzed using mixed model regression analyses with experiment as a fixed factor and subexperiment within experiment as a random factor. The ranges for silage CP concentration and D-value were 111 to 238 (S.D. 25.2) and 589 to 756 (S.D. 48.5) g/kg DM, respectively. D-value was a much better predictor of SDMI than CP (R2 within experiment 0.71 vs. 0.26). The effect of D-value on SDMI diminished with increasing level of concentrate supplementation (interaction P<0.001). D-value had a greater effect on SDMI when the total DM intake was high. SDMI was negatively correlated with concentrations of ammonia N, lactic acid, individual and total volatile fatty acids and total fermentation acids and positively correlated to the concentration of residual water soluble carbohydrates. Total acid concentration was the best SDMI predictor of individual fermentation parameters (R2 within experiment 0.41) followed by lactic acid and ammonia N. Use of quadratic regressions generally increased the variation accounted for by the model. The best multiple regression accounted for 0.51 of the variation in SDMI within experiment. To facilitate interpretation of data, a theoretical model is presented. An interplay between physical load and capacity to use energy determines SDMI of well-fermented silages over the whole range of D-values. With increasing extent of fermentation SDMI is constrained by nutrient imbalance, most probably amino acid to energy ratio at the tissue level, resulting from reduced microbial protein synthesis in the rumen. Low palatability can further constrain silage DM intake. For advisory silage evaluation the following model predicting relative SDMI is proposed: SDMI index=100+0.151×(D-value−690)−0.000531×(TA2−6400)−4.7650 [Ln(Ammonia N) −Ln(50)], where D-value and total acids (TA) are expressed as g/kg DM and ammonia N as g/kg total N, respectively. Regression coefficients are scaled to a mean SDMI of 10 kg DM/day. The values of 690, 80 and 50 are used as standard D-value (g/kg DM), total acid (g/kg DM) and ammonia N (g/kg N) for high quality restrictively fermented silages. The model parameters were limited to those which are currently available for Finnish farm silage analyses, i.e., by near infra-red reflectance spectra (D-value) and electrometric titration (fermentation parameters).

The effect of harvesting strategy of grass silage on digestion and nutrient supply in dairy cows.

This study examined the effects of primary growth (PG) and regrowth (RG) timothy-meadow fescue silages harvested at 2 stages of growth on feed intake, cell wall digestion and ruminal passage kinetics in lactating dairy cows. Four dairy cows equipped with rumen cannulas were used in a study designed as a 4 x 4 Latin square with 21-d periods. The experimental silages were offered ad libitum with 8 kg/d of concentrate. Ruminal digestion and passage kinetics were assessed by the rumen evacuation technique. Silages of PG were on average more digestible than RG silages. The concentration of neutral detergent fiber (NDF) and indigestible NDF (iNDF) increased and the concentration of digestible organic matter in dry matter (DM) of silages decreased with advancing maturity in PG and RG. Cows consumed more feed DM, energy, and protein and produced more milk when fed PG diets rather than RG diets. Delaying the harvest decreased DM intake and milk production in PG and RG. There were no differences between PG and RG in rumen pH, ammonia N, or total volatile fatty acid concentrations. The intake of N, omasal canal flow of total nonammonia N and microbial N, excretion of N in feces, and ruminal true digestibility of N were higher for PG than for RG diets. The efficiency of microbial N synthesis was not different between PG and RG. Intake and omasal canal flow of organic matter, NDF, and potentially digestible NDF (pdNDF) were higher in PG than in RG. Whole-diet digestibility of organic matter, NDF, or pdNDF in the rumen or in the total tract was not different between PG and RG despite the higher digestibility of PG silages measured in sheep. Rumen pool sizes of crude protein and iNDF were lower for PG diets, whereas the pool size of pdNDF was higher for PG diets than for RG diets. The rate of passage of iNDF was higher for PG diets than for RG diets, with no difference between them in rate of digestion or passage of pdNDF. The lower milk production in cows fed regrowth grass silages compared with primary growth silages could be attributed to the lower silage DM intake potential. Chemical composition of the silages, rumen fill, digestion and passage kinetics of NDF, or the ratio of protein to energy in absorbed nutrients could not explain the differences in DM intake between silages made from primary and regrowth grass.

Comparison of in vitro and in situ methods in evaluation of forage digestibility in ruminants.

The objective of this study was to compare the application of different in vitro and in situ methods in empirical and mechanistic predictions of in vivo OM digestibility (OMD) and their associations to near-infrared reflectance spectroscopy spectra for a variety of forages. Apparent in vivo OMD of silages made from alfalfa (n = 2), corn (n = 9), corn stover (n = 2), grass (n = 11), whole crops of wheat and barley (n = 8) and red clover (n = 7), and fresh alfalfa (n = 1), grass hays (n = 5), and wheat straws (n = 5) had previously been determined in sheep. Concentrations of indigestible NDF (iNDF) in all forage samples were determined by a 288-h ruminal in situ incubation. Gas production of isolated forage NDF was measured by in vitro incubations for 72 h. In vitro pepsin-cellulase OM solubility (OMS) of the forages was determined by a 2-step gravimetric digestion method. Samples were also subjected to a 2-step determination of in vitro OMD based on buffered rumen fluid and pepsin. Further, rumen fluid digestible OM was determined from a single 96-h incubation at 38°C. Digestibility of OM from the in situ and the in vitro incubations was calculated according to published empirical equations, which were either forage specific or general (1 equation for all forages) within method. Indigestible NDF was also used in a mechanistic model to predict OMD. Predictions of OMD were evaluated by residual analysis using the GLM procedure in SAS. In vitro OMS in a general prediction equation of OMD did not display a significant forage-type effect on the residuals (observed - predicted OMD; P = 0.10). Predictions of OMD within forage types were consistent between iNDF and the 2-step in vitro method based on rumen fluid. Root mean square error of OMD was least (0.032) when the prediction was based on a general forage equation of OMS. However, regenerating a simple regression for iNDF by omitting alfalfa and wheat straw reduced the root mean square error of OMD to 0.025. Indigestible NDF in a general forage equation predicted OMD without any bias (P ≥ 0.16), and root mean square error of prediction was smallest among all methods when alfalfa and wheat straw samples were excluded. Our study suggests that compared with the in vitro laboratory methods, iNDF used in forage-specific equations will improve overall predictions of forage in vivo OMD. The in vitro and in situ methods performed equally well in calibrations of iNDF or OMD by near-infrared reflectance spectroscopy.

Nitrogen and phosphorus balances on Finnish dairy farms

The calculation of whole-farm nutrient balance is an effective and simple method for estimating the potential nutrient loading from dairy farming into the environment. In Finland, however, the published results based on larger number of farms are still lacking. In this study whole-farm nitrogen (N) and phosphorus (P) balances on Finnish dairy farms were studied based on short-cut data for the year 2002. The survey was targeted to 1260 dairy farms, located all over Finland. Of the 386 replies received, 319 were used for subsequent statistical analyses. The association between selected farm variables and nutrient balance was studied using regression analysis and a sensitivity coefficient was calculated for each regression slope. The average (± standard deviation) whole-farm nutrient balance for N and P was 109 (±41.3) and 12 (±7.2) kg ha -1 , respectively. The most responsive factors affecting the nutrient balances were total nutrient and fertilizer import per ha, followed by animal density, milk export per ha and concentrate import per ha. The results suggested that nutrient surpluses could be controlled more easily in combined crop and milk than in specialised milk production. It is concluded that nutrient surplus on Finnish dairy farms is markedly lower than that on areas with intensive production in central European countries. However, when nutrient balances were extrapolated to comparable production intensity as in central Europe, the level of the surpluses was equal.

The effect of constant or variable forage to concentrate ratio in total mixed ration on performance of primiparous dairy cows

Abstract The performance of 45 primiparous Ayrshire cows fed total mixed ration (TMR) with constant (TMR1) or variable (TMR3) proportion of concentrate in dry matter was studied. On TMR1 treatment the forage to concentrate ratio of TMR was 53:47 in dry matter (DM) throughout the lactation. On TMR3 the forage to concentrate ratio increased during the lactation being 43:57, 53:47 and 63:37 on 0–100, 101–200 and 201–305 days post partum, respectively. The experimental period was 305 days of the first lactation. The feeding strategy had no significant effect on average milk yield. The energy corrected milk yield was 24.4 kg/day on TMR1 and 24.3 kg/day on TMR3 treatment. Also milk protein content was not affected by the treatment, but the milk fat content tended (P

The effect of concentrate crude protein content and feeding strategy of total mixed ration on performance of primiparous dairy cows

The effect of total mixed ration (TMR) with constant (TMR1) or decreasing (TMR3) proportion of concentrate in dry matter (DM) and with different crude protein (CP) content of concentrate (170 or 200 g/kg DM) on the performance of 51 first parity Ayrshire cows was studied. On TMR1 diet the forage to concentrate ratio in DM was 55:45 throughout the lactation. On TMR3 the forage to concentrate ratio was 45:55, 55:45 and 65:35 during the lactation days 0–100, 101–200 and 201–305, respectively. There was no significant interaction between feeding strategy (TMR1 or TMR3) and CP content of the concentrate on the performance parameters studied. Feeding strategy had no effect on energy corrected milk (ECM) production (26.6 vs. 27.1 kg/day), milk composition, DM intake (18.0 vs. 18.2 kg/day) or post partum development of the body condition score of the cows. The higher CP content of the concentrate increased (P<0.05) the milk (24.8 vs. 26.2 kg/day) and milk protein yield (871 vs. 922 g/day) and tended to increase (P=0.13) the ECM yield (26.3 vs. 27.4 kg/day). Milk composition was not affected by the CP content. DM intake was higher in early and mid lactation but not in late lactation when CP content of the concentrate was 200 g/kg DM compared to 170 g/kg DM. Increase in CP content of the concentrate decreased the protein conversion efficiency (milk protein/CP intake) in early and mid lactation but not in late lactation. It can be concluded that there is no advantage to primiparous cows of adjusting the forage to concentrate ratio in TMR with progressing lactation. Results also showed that the primiparous cows benefited from the protein content of the concentrate higher than 170 g/kg DM.

Prediction of silage composition and organic matter digestibility from herbage composition and pepsin-cellulase solubility

Tassa tutkimuksessa selvitettiin mahdollisuuksia ennustaanurmisailorehun koostumus ja sulavuus sailorehun raaka-aineena kaytetyn ruohon koostumus- ja in vitro #NIMI? ja nurminadan seoskasvustoista tehdyista sailorehuista, joista 27 oli ensimmaisesta sadosta ja 25 jalkikasvusta. Sailorehujen ja raaka-aineiden koostumus maaritettiin standardimenetelmin ja sulavuutta arvioitiin pepsiini-sellulaasiliukoisuudella. Sailorehujen in vivo sulavuus maaritettiin passeilla sonnan kokonaiskeruumenetelmalla. Raaka-aineen ja vastaavan sailorehun ominaisuuksien yhteyksia tarkasteltiin regressioanalyysilla. Kaikki sailorehut olivat hyvin sailyneita. Sailorehun kuiva-aine-, raakavalkuais- ja solunseinakuitupitoisuus pystyttiin arvioimaan suhteellisen tarkasti raaka-aineen perusteella, silla ennustevirheet olivat melko pienia. Ruohojen pepsiini-sellulaasiliukoisuus oli merkitsevasti korkeampi kuin sailorehujen [779 vs. 756 g (kg kuivaainetta)- 1], mika johtuu paaasiassa sailonnan aikana tapahtuvan sulavan orgaanisen aineen havikista hengitys-, kaymis- ja puristenestetappioiden takia. Sailorehun sulavuus pystyttiin kuitenkin arvioimaan yhta hyvin ruohon ja sailorehun pepsiini-sellulaasiliukoisuuden perusteella. Ensi- ja jalkikasvusta tehdyille rehuille pitaisi kayttaa eri korjausyhtaloita pepsiini-sellulaasiliukoisuuden muuntamisessa sulavuudeksi, silla regressioyhtaloiden vakiot ja kulmakertoimet poikkesivat lukuarvoiltaan selvasti toisistaan. Sailorehun koostumus ja sulavuus voitiin arvioida luotettavasti raaka-aineena kaytetyn ruohon perusteella, kun aineistona kaytettiin hyvin sailyneita sailorehuja.

Colostral whey concentrate supplement increases complement activity in the sera of neonatal calves

We evaluated the effect of a commercial bovine colostral whey on the complement-mediated immune responses of calves. Two groups of neonatal calves were fed, in addition to whole milk (WM) and pooled colostrum (PC), different amounts of a commercial immunoglobulin concentrate made from pooled colostral whey (Ig-C) for the first two feedings post natum. The control group was fed WM and PC only. Serum samples were obtained at the ages of 2, 7, 14 and 30 d. Bacteriolytic activity against complement-sensitive Escherichia coli JM103 and opsonic activity against complement-lysis-resistant E. coli IH3080 strains were studied, as well as the levels of C3 complement component and E. coli JM103 specific antibodies in the sera. Groups fed Ig-C had 2-3 times higher bacteriolytic activity than the control group of both the classic (P < 0.005) and alternative pathways (P < 0.0001) at days 2 and 7 post natum. This effect is obviously not caused solely by the antibodies ingested but also involves other unknown colostral factors, possibly lectins. The opsonisation capacities of the sera correlated well with the amounts of immunoglobulins ingested (P < 0.05) at days 2-14. The levels of C3 component in sera did not differ between the groups. In the group fed the largest amount of immunoglobulins levels of E. coli JM103-specific antibodies were highest (P < 0.0001). It can thus be concluded that the antibody independent complement activities of serum can be increased substantially by feeding colostral whey concentrate to calves during their first days of life.

Chitin as an indigestible marker could be used to measure fecal output in dairy cows by NIRS

Trabajo presentado al: 10th International Symposium on the Nutrition of Herbivores (ISNH), p. 659. 2-6 de septiembre de 2018. Clermont-Ferrand (Francia).--Tambien aparece en: Advances in Animal Biosciences 9 (3).Interest and limits of two methods to characterize the individual variability in feeding behaviour of barn-dried hay measured continuously in dairy goats. 10th International Symposium on the Nutrition of HerbivoresComunicacion oral presentada al: 10th International Symposium on the Nutrition of Herbivores (ISNH), p. 658. 2-6 de septiembre de 2018. Clermont-Ferrand (Francia).--Tambien ha sido publicada en: Advances in Animal Biosciences 9 (3)