Modelling a quantitative ensilability index adapted to forages from wet temperate areas

Abstract

IntroductionIn some countries, the small land surface available on farms, and the seasonality of forage production are some of the structural factors limiting the profitability of the agricultural and livestock sector. Moreover, the increased size of herds involves the need for more quantity of food stored to meet the nutritional needs of animals during winter and drought periods.Forage quality influences the economic efficiency of the milk and meat production. Nowadays, the technology of using green food from f ields during vegetation growth has been abandoned and replaced by inside feeding using diets of similar composition throughout the year, which includes large amounts of high quality silage (Dinic et al., 2010a).The weather, season, management, grazing intensity, chemical and botanical composition of forages to be ensiled and the phenological stage, etc., are factors affecting the epiphytic microflora of forage and their ensilability characteristics (Woolford, 1984;McDonald et al., 1991). For a successful conservation of forages, it is necessary to know the content of water soluble carbohydrates (WSC) and buffer capacity (BC), because the amount of WSC is related with the potential to resist changes in pH also called BC. Haigh (1990) demonstrated that sunshine and rainfall data might be used to predict WSC of herbage cut for ensiling and subsequent silage dry matter. In addition, researches conducted by Martínez Fernández (2003), have confirmed previous results related by Muck et al. (1991) AbstractForage ensilability mainly depends on dry matter (DM), water soluble carbohydrates (WSC) and buffer capacity (BC) values at harvest time. According to these parameters, and based on a collection of 208 forages of known ensilability characteristics including short and long term meadows for grazing, italian ryegrass, maize, triticale, soybean, faba bean crops, and samples coming from cereal-legume associations, the objective of this study has been to define a quantitative ensilability index (EI) based on a relationship between DM, WSC and BC contents at harvest date, adapted to the characteristics of fodder from wet temperate areas. For this purpose, a discriminant procedure was used to define this EI based on a linear combination of DM, WSC and BC of forages at harvest time. The quantitative calculated indexes distinguish five successive ranges of ensilability: high ensilability (EI > +28), medium high ensilability (+9 < EI ≤ +28), medium ensilability (-28 < EI ≤ +9), medium low ensilability (-47 ≤ EI ≤ -28) and low ensilability (EI < -47). This quantitative index was externally evaluated and 100% of samples were successfully classified.Additional key words: buffer capacity; dry matter; silage; water soluble carbohydrates.* Corresponding author. admartinez@serida.org Received: 15-06-12. Accepted: 24-04-13Abbreviations used: BC (buffer capacity); DISCRIM (discriminant analysis); DM (dry matter); EI (ensilability index); FC (fermentability coefficient); HE (high ensilability); HEI (high ensilability index); LAB (...

Ensiling characteristics, in vitro rumen fermentation, microbial communities and aerobic stability of low‐dry matter silages produced with sweet sorghum and alfalfa mixtures

“…The chemical composition of SS and AF used in the present study was similar to that reported for SS and AF harvested at the dough stage and the early bloom stage, respectively, in Southern China . The ensilability of forage is mainly affected by the DM, WSC and BC when the epiphytic LAB are sufficient . In the present study, the EI of the pre‐ensiled mixtures used can be classified into five levels: high ensilability (> +28) with an EI of +29.6 (Control); moderate high ensilability (+9 < EI ≤ +28) with an EI of 14.8 (SA25); moderate ensilability (−28 < EI ≤ +9) with an EI of −8.36 (SA50); moderate low ensilability (−47 ≤ EI ≤ −28) with an EI of −39.6 (SA75); and low ensilability (EI < −47) with an EI of −58.2 (SA100).…”

“…Lactic acid, SCFA (acetic, propionic, butyric and valeric acids) and ethanol were measured in water extract using high‐performance liquid chromatography (model 1260; Agilent Technologies, Inc., Waldbronn, Germany) equipped with a refractive index detector, and the column was Carbomix® H‐NP5 column (Sepax Technologies, Inc., Newark, DE, USA) with 2.5 mmol L −1 H 2 SO 4 as mobile phase and 0.5 mL min −1 flow rate at 55 °C. The ensilability index (EI) used to predict the ensilage process, was calculated with the equation: EI = 152.29 – 0.197 DM + 0.085 WSC – 0.375 BC, where DM is in g kg −1 FM; WSC is in g kg −1 DM; and BC is in mEq NaOH kg −1 DM . Silage quality was evaluated with the fermentation end‐products as described by Conaghan et al .…”

Effect of Wilting Intensity, Dry Matter Content and Sugar Addition on Nitrogen Fractions in Lucerne Silages

“…The plant material was wilted to DM levels (DML) of 250 and 350 g kg −1 , respectively, and ensiled either without or with sucrose addition (SU) of 125 g kg −1 DM. The amount of added sucrose was chosen as it constitutes the difference between the average WSC content of lucerne with 65 g kg −1 DM and perennial ryegrass (Lolium perenne L.) with 190 g kg −1 DM [12], which is good to ensile [13]. The compaction of the lucerne at ensiling was calculated according to the recommendations of the Federal Working Group for Forage Preservation (Bundesarbeitskreis Futterkonservierung; [12]) in Germany with 190.4 (±2.3) kg DM m −3 for low-DM LS and 215.8 (±4.6) kg DM m −3 for high-DM LS.…”

A novel feedstuff: ensiling of cowpea (Vigna unguiculata L.) stover and apple (Malus domestica Borkh.) mixtures. Evaluation of the nutritive value, fermentation quality and aerobic stability

“…Forage ensilability is known to be mainly influenced by its DM and WSC contents and BC . Based on the ensilability index (EI) developed by Martinez‐Fernandez et al ., the pre‐ensiled mixture used in our study can be classified as having high ensilability (> +28) with an EI of +81.7.…”

“…Forage ensilability is known to be mainly influenced by its DM and WSC contents and BC . Based on the ensilability index (EI) developed by Martinez‐Fernandez et al ., the pre‐ensiled mixture used in our study can be classified as having high ensilability (> +28) with an EI of +81.7. Although its DM content falls within the reference range for medium ensilability category (between 200 and 250 g kg −1 DM), the WSC content and BC are well within the high ensilability category (higher than 150 g kg −1 DM and lower than 250 mmol NaOH kg −1 DM respectively).…”