Advancement in Assessment and the Reassessment of the Nutritive Value of Forages

Abstract

Forages, primary producers of carbon compounds, provide energy and nutrients when consumed by herbivores, resulting in “value‐added” animal products as meat, milk, and fiber and, in some cases, recreation. How a forage supports value‐added products of interest has been a concern since the mid 1800s. The characteristic of a forage that composes its nutritive value (NVAL) and its consumption and conversion by the animal determines the quality of the nutrient entity and provides an estimate of its forage quality. The first system to address forage NVAL emerged in the mid 1880s and was termed the Weende proximate analysis. Forages were separated into crude protein (CP), crude fiber (CF), ether extract (EE), nitrogen‐free extract (NFE), ash, and water. The concept of nutrient entity followed in the 1950s. By the mid 1960s, the neutral detergent fiber (NDF) system partially replaced proximate analysis and the two, along with innovations in solubility, serve as methodologies for estimating NVAL. An assessment of NVAL from the microbial view point was introduced in the early 1960s by the two‐stage in vitro dry matter disappearance (IVDMD) method, followed in the 1970s by continuous cultures. Innovation in spectral technology introduced near infrared spectrophotometry in the mid 1980s providing a rapid analysis of the NVAL fractions. A reassessment of the approach to estimating forage quality, based on the microflora's view of “particle value,” using near infrared spectral scans of the “as fed” forage has been proposed.

Nutritive values of the drought tolerant food and fodder crop enset

“…At Institute of Animal Science and Technology, Rostock University, Germany, samples were again dried at 105°C, grounded and sieved through 1 mm mesh size before further analyses. The Weende system (Burns, 2011) was used to separate samples into general fractions. Ash was defined as the residue after combustion of known amounts of DM at 600°C and organic matter (OM) as DM−ash.…”

Variations of Forage Yield and Nutritive Value in Winter Rye Germplasm

“…However, one weakness of rye as a winter forage crop is its early maturity, resulting in a significant decrease in forage production after April (Denman and Arnold, 1970). Burns (2011) defined forage quality as nutritive value × voluntary forage intake, where nutritive value was defined as the in vitro disappearance and chemical composition of forage (Mott and Moore, 1985). Nutritive value is dependent on nutrient and chemical composition of the forage, which varies according to several factors including species, cultivar, growth stages, management practices, and climate conditions.…”

A safety analysis of food waste-derived animal feeds from three typical conversion techniques in China

“…Next, the dried precipitates were turned into particles by a solid shredder and further sieved through a #50 stainless steel mesh. The nutritional indices for food waste, including crude protein (CP), ether extraction (EE), crude fiber (CF), dry matter (DM), ash (Ash), and nitrogen-free extract (NFE), were then examined according to the Weende proximate analysis method (EU, 2009;AOAC, 2012;Burns, 2011).…”

“…To systematically characterize and compare different food waste-derived animal feeds, the present research focused on the nutrient content (organoleptic properties and general nutritional indices); the presence of bovine-and sheep-derived materials; microbiological indices for Salmonella, total coliform (TC), total aerobic plate counts (TAC), molds and yeast (MY), Staphylococcus Aureus (SA), and Listeria; chemical contaminant indices for hazardous trace elements, such as chromium (Cr), cadmium (Cd), arsenic (As), lead (Pb), and mercury (Hg); and the inorganic contaminant nitrite (NIT) and organic contaminants such as aflatoxin B1 (AFB1), hexachlorocyclohexane (HCH) and dichlorodi phenyltrichloroethane (DDT). Among them, nutritional indices were chosen by the nutritive value analysis convention for feed (EU, 2009;Burns, 2011;Westendorf, 2000), and the other indices were determined according to the characteristics of the food waste, relevant food, and feed standards (AQSIQ, 2001; MOH, 2010; EU: Regulation (EC) No. 1069US Congress, 1980).…”