Prediction ability of near infrared (NIR) spectroscopy for intramuscular fat content (IMF) determination was studied. The material comprised 126 muscle samples; 46 pig longissimus dorsi and semitendinosus and 34 beef longissimus dorsi muscle samples. The IMF content was chemically determined in duplicate using two different chemical methods; fat extraction according to Folch et al. and Soxhlet extraction with hydrolysis according to SIST ISO 1443. Folch extraction underestimated IMF content compared to Soxhlet extraction with hydrolysis (-0.32%, P < 0.0001). Similar repeatability was obtained for Folch and Soxhlet extraction with hydrolysis (0.17% and 0.18%, respectively, P < 0.0001). Sample spectra were scanned from 400–2500 nm by the NIR Systems model 6500 spectrophotometer (Silver Spring, MD, USA) and analysed by WinISI II on minced and intact (pork only) samples. Modified partial least squares regression was used to develop models and to obtain calibration statistics: coefficient of determination in calibration( R2 C) and cross-validation ( R2 CV) and standard error in calibration ( SEC) and cross-validation ( SECV). We prepared different models (for a single muscle/common, by applying NIR spectrum or the whole spectrum, on intact and minced samples). Obtained models proved the remarkable prediction ability of NIR spectroscopy to determine IMF content ( R2 CV between 0.84 and 0.99; SECV between 0.14% and 0.53%) and confirms the potential of NIR spectroscopy to replace laborious chemical procedures. Regarding the factors studied, calibrations were less accurate for intact than for minced samples; the use of an NIR spectrum compared to the whole spectrum had no important effect on the prediction ability. According to calibration statistics, the prediction using a common equation for several muscles seems more reliable than the equations within the muscle, but the latter showed lower bias.

The aim of the current work was to investigate the possibility of modifying the existing mean stage by weight (MSW) system for evaluating the average development stage in alfalfa. The modification was performed with the aim of providing a simplified system that may be used to evaluate the alfalfa development stage and to predict its nutritive value for ruminants. The suggested modification consists of designating an MSW value on the basis of the fresh weight of all morphological stages in a fresh green plant, as opposed to the original method which is based on weighing all morphological stages dried at 65°C. The investigation was done on 141 samples of one alfalfa cultivar, collected from the same location during the first three growth cycles: spring growth, the first and the second regrowth. On all collected samples the following characteristics were determined: MSW, modified MSW (mean stage by fresh weight (MSFW)), crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL), crude ash (CA) and in vitro organic matter digestibility (IVOMD). For these characteristics of chemical composition (apart from CA) and nutritive value the regressions were calculated for their prediction based on MSW and MSFW. The regressions were derived for individual growth cycles and all cycles combined. A trend for an increase in the coefficient of determination (R 2 ) was identified as well as a decrease in root-mean-square error (RMSE) for all equations derived for all investigated characteristics from the spring growth to the second regrowth. A deviation from this trend was observed only in equations derived for IVOMD. A very high correlation was observed between MSW and MSFW (r = 0·999). The determined R 2 and RMSE were very similar within the same growth cycle in all regressions for prediction of chemical composition and nutritive value derived for MSW and MSFW. Based on the results of this investigation the MSFW appears to be a quick and accurate method for determining the average development stage in alfalfa which can therefore be recommended for both scientific research and practical field use, as well as for prediction of its chemical composition and nutritive value.

This study aimed at determining the efficiency of microbial protein synthesis (EMPS) in diets based on highly wilted grass silage [(GS) DMI). All the diets were made isonitrogenous by urea supplementation (14.0, 4.0 and 2.0 g kg -1 DMI in GS-MS, GS-FB and GS-M diets). In sacco determined crude protein (CP) and organic matter (OM) degradabilities were 756, 800, 778 and 814 (P<0.05) and 563, 577, 593 and 618 g kg -1 (P<0.05) in GS, GS-MS, GS-FB and GS-M diets, respectively. Synchrony indexes that describe the synchrony of CP and OM degradation in the rumen were 0.75, 0.67, 0.67 and 0.79 in GS, GS-MS, GS-FB and GS-M diets, respectively. The EMPS, assessed by means of urinary purine derivative excretion, did not differ significantly (P>0.05) among the diets (36.6, 35.1, 34.7 and 34.0 g microbial nitrogen kg -1 OM apparently digested in the rumen in GS, GS-MS, GS-FB and GS-M diets, respectively). The estimated metabolizable protein supply from GS, GS-MS, GS-FB and GS-M diets amounted to 98, 90, 93 and 87 g kg -1 DMI, respectively. Apparently, highly wilted GS containing a high concentration of WSC (91 g kg -1 DM) supports high EMPS in the rumen and this cannot be improved by the supplementation with starch or water-soluble carbohydrates (WSC) rich feeds.

For all crop species, an accurate, quick, and simple method for determination of mean development stage of plants has a key role for scientific and practical use. The investigation was performed to validate a modified methodology for determination of mean stage of development in alfalfa (Medicago sativa L.). The modified methodology, mean stage by fresh weight (MSFW), assumes that mean stage by weight (MSW) could be determined by fresh, and not only by dry weight, as was required by the original methodology. A total of 198 alfalfa samples were collected in 2010 and 2011. Sampling completely covered three growth cycles: spring growth and first and second regrowths. The correlation (r) between MSW and MSFW was >0.99. In 92% of samples, absolute deviation between MSW and MSFW was <0.15 on a scale between 0 and 9. The equation for prediction of MSFW based on measured MSW, MSFWpredicted = 0.9808 × MSW, was developed with the data from the first year (n = 141) and tested with second‐year samples (n = 57). Prediction error, expressed by root mean squared deviation (RMSD), was 0.045, while components of mean squared deviation (MSD), such as squared bias (SB), nonunity slope (NU), and lack of correlation (LC), were 8.12 × 10−4, 5.45 × 10−4, and 6.67 × 10−4, respectively. Values close to zero in all three MSD components show that validation line had a ≈ 0, b ≈ 1, and r2 ≈ 1. As a simpler methodology, MSFW gives an opportunity to be more applicable in practice with all of the benefits of the MSW methodology.

IZVLEČEKČas košnje je zelo pomemben dejavnik količine in kakovosti pridelka krme enovrstnih koševin. Zato smo želeli analizirati časovne poteke pridelka zelinja, morfološkega razvoja in parametrov kakovosti lucerne med rastno sezono ter jih povezati s časom košnje. Poljski poskus v split-plot zasnovi z dvema blokoma smo izvedli v Ljubljani leta 2016. Glavne parcele so predstavljale 4 rastne cikluse (C1-C4), podparcele pa 9 tedenskih terminov za merjenje pridelka in vzorčenje zelinja. Rast lucerne je bila v prvi polovici rastne sezone boljša kot v drugi. Pridelek zelinja je v zadnjih dveh ciklusih hitro dosegel maksimum in se nato zmanjševal. Statistična analiza je pokazala, da so linearni regresijski modeli primerni za opisovanje časovnih potekov naslednjih spremenljivk: morfološkega razvoja (PRF), surovih beljakovin (SB), vlaken, netopnih v nevtralnem detergentu (NDV) in neto energije za laktacijo (NEL). Morfološki razvoj lucerne je bil hitrejši poleti kot pomladi ali jeseni, vendar je po tej lastnosti med ciklusi izrazito odstopal samo prvi. Kakovost lucerne je bila predvsem zaradi počasnejšega razvoja v celoti najboljša v C1, kar se je bolj odrazilo pri NDV in NEL kot pri SB. C1 je bil po kakovosti lucerne enakovreden samo C4 na začetku rasti. Upoštevajoč pridelek in vsebnost NEL je bila optimalna starost lucerne ob košnji od 28 do 35 dni spomladi in poleti ter od 35 do 42 dni jeseni.Ključne besede: lucerna; pridelek; morfološki razvoj; hranilna vrednost; časovni potek ABSTRACT HERBAGE YIELD, MORPHOLOGICAL DEVELOPMENT AND NUTRITIVE VALUE OF LUCERNE DURING GROWTH SEASON IN CENTRAL SLOVENIA: ANALYSIS OF TIME PATTERNSCutting time is a pivotal factor affecting herbage yield and nutritive value of forage crop monocultures. Therefore, our objectives in this lucerne study were to analyse temporal patterns of herbage yield, morphological development and quality parameters over growth season, and to relate these patterns to the time of cutting. A field experiment in split-plot design with two block replications was conducted in Ljubljana in 2016. Four growth cycles (C1-C4) were assigned to the main plots, and nine weekly intervals at which herbage yield was measured and herbage samples taken were assigned to the sub-plots. Dry-matter herbage yield accumulated faster during the first half of the season than during the second one. It peaked early in each of the last two growth cycles and after that started to decrease. Statistical analysis showed that linear regression models are acceptable to describe time patterns of morphological development stages (MSW) and contents of crude protein (CP), neutral detergent fibre (NDF) and net energy for lactation (NEL). MSW increased faster during the summer than during the spring or autumn, but only C1 was distinct in this pattern. Lucerne forage quality was generally the highest in C1 mainly due to slower morphological development. This high quality reflected more in NDF and NEL than in CP. In respect of the quality, only C4 at the beginning of the growth was equivalent to C1. Cons...