Comparison of a Plantain-Chicory Mixture with a Grass Permanent Sward on the Live Weight Gain and Meat Quality of Lambs.

Under the predicted conditions of climate change, the productivity of temperate grasslands may be affected by drought stress, especially in spring and summer. In this scenario, water-deficit-tolerant species such as plantain and chicory are interesting alternatives for use in sheep production systems. In this study, we compared a mixture of plantain and chicory herbage (PCH) with a grass-based permanent sward (GBS) on the weight gain and meat quality of lambs finished on these grasslands. Fifteen weaned lambs (31.3 kg and 4 months of age) were assigned to each treatment for seven weeks in late spring and live weight gain (LWG), carcass and meat quality were evaluated. There was a tendency (p = 0.09) in final weight (40.3 ± 0.8 kg) and live weight gain (173 ± 10 g/d) to be higher in PCH compared to GBS. Carcass weight, dressing percentage and meat quality in terms of pH, color and tenderness did not differ (p > 0.05) and were considered to be of good quality. We concluded that both swards result in comparable lamb performance and good meat quality.

Prediction efficiency by near-infrared spectroscopy of immunoglobulin G in liquid and dried bovine colostrum samples.

The objective of this study was to compare the prediction efficiency of IgG concentration in bovine colostrum by NIRS, using liquid and dried (Dry-Extract Spectroscopy for Infrared Reflectance, DESIR) samples by transflectance and reflectance modes, respectively. Colostrum samples (157), obtained from 2 commercial Holstein dairy farms, were collected within the first hour after calving and kept at -20 °C until analysis. After thawing and homogenisation, a subsample of 500 mg of liquid colostrum was placed in an aluminium mirror transflectance cell (0·1 mm path length), in duplicate, to collect the spectrum. A glass fiber filter disc was infused with another subsample of 500 mg of colostrum, in duplicate, and dried in a forced-air oven at 60 °C for 20 min. The samples were placed in cells for dry samples to collect the spectra. The spectra in the VIS-NIR region (400-2500 nm) were obtained with a NIRSystems 6500 monochromator. Mathematical treatments, scatter correction treatments and number of cross-validation groups were tested to obtain prediction equations for both techniques. Reference analysis for IgG content was performed by radial immunodiffusion. The DESIR technique showed a higher variation in the spectral regions associated with water absorption bands, compared with liquid samples. The best equation for transflectance method (liquid samples) obtained a higher coefficient of determination for calibration (0·95 vs. 0·94, respectively) and cross validation (0·94 vs. 0·91, respectively), and a lower error of cross validation (9·03 vs. 11·5, respectively) than the best equation for reflectance method (DESIR samples). In final, both methods showed excellent capacity for quantitative analysis, with residual predictive deviations above 3. It is concluded that, regarding accuracy of prediction and time for obtaining results of IgG from bovine colostrum, NIRS analysis of liquid samples (transflectance) is recommended over dried samples (DESIR technique by reflectance).

Potencial uso de espectroscopia de reflectancia en el infrarrojo cercano (NIRS) para identificación de charqui de bovino, llama y caballo / Potential use of near infrared reflectance spectroscopy (NIRS) for the identification of beef, llama and horse jerky

Visible and near infrared reflectance spectroscopy (VIS/NIRS) was evaluated as a tool to discrimínate jerky from different species. Spectra were taken by reflectance in a NIRSystems 6500 monochromator and the software NIRS 3.0 and WinIsi II Version 1.02A were used. Twenty samples of jerky corresponding to beef, llama and horses, respectively, were ground, homogenized and analyzed spectrally. The regression equations (PLS) were developed testing different mathematical treatments. The results for jerky show that NIRS can successfully discriminate 100% of llama, 95% of horses and 80% of beef samples, probably as a consequence of differences in intramuscular fat, protein and water contents of the different species. Thus, NIRS is a fast, inexpensive and non-destructive method that can be used to discriminate jerky from these species.

Se usó espectroscopía visible y de reflectancia en el infrarrojo cercano (VIS/NIRS) como herramienta para discriminar charqui de diferentes especies. Los espectros se tomaron por reflectancia en un equipo monocromador NIRSystems modelo 6500, con un software NIRS 3.0, y WinIsi II Versión 1.02 A. Se molieron, homogenizaron y analizaron espectralmente 20 muestras de charqui correspondientes a bovino, llama y caballo. Se desarrollaron ecuaciones de regresión (PLS) probando diferentes tratamientos matemáticos. Los resultados para charqui muestran que NIRS puede discriminar satisfactoriamente 100% de las muestras de llama, 95% de caballos y 80% de bovino, probablemente como consecuencia de diferencias en el contenido de grasa intramuscular, proteína y agua de las diferentes especies. Así, la técnica NIRS muestra ser un método rápido, económico y no destructivo que puede usarse para discriminar charqui de diferentes especies.