Prediction of the nutritive value of wet whole-crop sorghum silage according to the INRA feeding system by near-infrared spectroscopy

Olive leaves obtained as a byproduct in the Mediterranean region could play an important role in the nutrition of extensive ruminant systems. However, the reported variation in their nutritive value, among other reasons due to discrepancies in mineral content, is considered an important obstacle for their common use. Near-infrared spectroscopy (NIRS) could fulfill the requirements of these productive systems, providing analytical information in a rapid and economic way. In this work, the effect of soil contamination on NIR spectra has been studied, as well as its correction with some of the most commonly used spectral pretreatments (derivatives, multiplicative scatter correction, auto scaling, detrending, and a combination of the last two transforms). Effects were evaluated by visual inspection of the transformed spectra and comparison of the calibration statistics obtained to estimate acid insoluble ash and total ash contents and in vitro pepsin cellulase digestibility of organic and dry matter. The incidence of spectral curvature effects caused by soil contamination that can be conveniently corrected with pretreatments such as derivatives was confirmed.

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Nutritional characteristics and in vitro digestibility by near-infrared spectroscopy of local and hybrid napiergrass varieties grown in rain-fed and irrigated conditions

Animal Production Science ◽

10.1071/an14289 ◽

2014 ◽

Vol 54 (10) ◽

pp. 1775

Author(s):

U. P. Tiwari ◽

B. Turano ◽

R. Jha

Keyword(s):

Infrared Spectroscopy ◽

Near Infrared Spectroscopy ◽

Nutritional Value ◽

Nutritive Value ◽

Near Infrared ◽

In Vitro Digestibility ◽

Neutral Detergent Fibre ◽

Drought Tolerant ◽

Animal Feeding

Napiergrass can produce large amounts of biomass and its nutritive value has a significant effect on its effectiveness for animal production. However, temperature and drought stress limit its productivity. Drought-tolerant pearl millet × napiergrass hybrid (PMN) varieties were developed and produce high biomass yields. The nutritional content and digestibility of PMN is not well known, which limits its use in animal feeding. It was hypothesised that PMN hybrids are more drought tolerant and have higher nutritive value than napiergrass varieties. Four napiergrass varieties (Bana grass, Mott, MB4, and N51) and four PMN (PMN2, PMN3, 5344, 4604) were tested with or without irrigation treatment in a strip-plot design, with the objective of evaluating the nutritional value and in vitro digestibility of PMN hybrids and napiergrass. The forages were harvested on Day 110 of planting. Samples were hand chopped, oven-dried, ground to pass through a 1-mm screen and analysed for their nutrient content and in vitro digestibility using near-infrared spectroscopy. Dry matter (DM) content of PMN2 (24.3%) and PMN3 (22.9%) was significantly higher (P < 0.05) than 5344, Bana grass and N51 napiergrass varieties. No differences (P > 0.05) in acid detergent fibre, neutral detergent fibre, crude protein and metabolisable energy were found among napiergrass varieties. With no effect (P > 0.05) of irrigation, lignin content was highest (P < 0.08) in 4604 (8.2%) and lowest in 5344 (5.2%). Starch was highest (P < 0.05) in irrigated MB4 than both irrigated and non-irrigated 4604. Non-fibre carbohydrate content was highest (P < 0.05) in PMN2 (12.8%) than MB4 (8.7%). The in vitro true digestibility was significantly higher (P < 0.05) in 5344 and Bana grass (70.0% and 68.0% of DM, respectively), than PMN3 (54.5%). Rate of digestion was significantly higher (P < 0.05) in 5344 (4.9%/h) than PMN2 (2.7%/h), others were in between. Neutral detergent fibre digestibility (NDFD) of 5344 and Bana grass (56.7% and 53.2% of neutral detergent fibre, respectively) was significantly higher (P < 0.05) than PMN2 (38.0%). Although no effect of irrigation was observed, there was an interaction (P < 0.05) between variety and irrigation on neutral detergent fibre digestibility of napiergrass varieties. In conclusion, among four PMN varieties tested, PMN3 and 5344 has higher nutritional value and in vitro digestibility than PMN2 and 4604 even when grown in non-irrigated condition. Thus, PMN3 and 5344 is the preferred napiergrass variety for animal feeding, even in rain-fed farming conditions.

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Prediction of chemical, nutritive and agronomic characteristics of wheat by near infrared spectroscopy

The Journal of Agricultural Science ◽

10.1017/s0021859699008382 ◽

2000 ◽

Vol 135 (4) ◽

pp. 409-417 ◽

Cited By ~ 50

Author(s):

P. C. GARNSWORTHY ◽

J. WISEMAN ◽

K. FEGEROS

Keyword(s):

Infrared Spectroscopy ◽

Chemical Composition ◽

Near Infrared Spectroscopy ◽

Broiler Chickens ◽

Nutritive Value ◽

Near Infrared ◽

Rapid Determination ◽

Chemical Constituents ◽

Metabolizable Energy ◽

Agronomic Characteristics

Near infrared spectroscopy (NIRS) is widely used in the flour milling industry for rapid determination of moisture and protein in wheat. However, these measurements give little indication of the nutritive value of wheat when fed to poultry or pigs. Accurate estimates of nutritive value require specialist facilities and are time-consuming and costly. Accordingly, prediction from chemical or NIRS measurements would be of some considerable benefit. In the current study 160 samples of wheat, representing 24 different varieties, were used to generate NIRS calibration equations for chemical, nutritive and agronomic characteristics. Predictions of chemical constituents in wheat were very accurate. Coefficients of determination (r2) were 0·94 for dry matter, 0·90 for crude protein, 0·97 for ash, 0·78 for starch and 0·98 for oil. True metabolizable energy in broiler chickens was predicted more accurately (r2 = 0·52 for adult birds, 0·74 for young birds) than apparent metabolizable energy (r2 = 0·45). Digestible energy (r2 = 0·17) and nitrogen digestibility (r = 0·22) in pigs were not predicted very accurately on a smaller subset (n = 33). Agronomic characteristics were predicted very accurately (r2 = 0·98 hardness, 0·80 bushel weight, 0·99 thousand-grain weight). Predictions of nutritive value of wheat from chemical or agronomic characteristics are very inaccurate, since coefficients of determination vary from zero to 0·25. It is concluded that NIRS can accurately estimate the chemical composition of wheat, but accurate prediction of nutritive value is reduced by animal variation. Nevertheless, NIRS is potentially more reliable for assessing nutritive value than chemical composition or agronomic characteristics.

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