Showing papers by "P.J. Van Soest published in 2004"
TL;DR: In this article, the CNCPS for sheep was used to predict energy and protein requirements of sheep, with a special emphasis on dairy sheep, whose specific needs are not considered by most sheep-feeding systems.
Abstract: The Cornell Net Carbohydrate and Protein System (CNCPS), a mechanistic model that predicts nutrient requirements and biological values of feeds for cattle, was modified for use with sheep. Published equations were added for predicting the energy and protein requirements of sheep, with a special emphasis on dairy sheep, whose specific needs are not considered by most sheep-feeding systems. The CNCPS for cattle equations that are used to predict the supply of nutrients from each feed were modified to include new solid and liquid ruminal passage rates for sheep, and revised equations were inserted to predict metabolic fecal N. Equations were added to predict fluxes in body energy and protein reserves from BW and condition score. When evaluated with data from seven published studies (19 treatments), for which the CNCPS for sheep predicted positive ruminal N balance, the CNCPS for sheep predicted OM digestibility, which is used to predict feed ME values, with no mean bias (1.1 g/100 g of OM; P > 0.10) and a low root mean squared prediction error (RMSPE; 3.6 g/100 g of OM). Crude protein digestibility, which is used to predict N excretion, was evaluated with eight published studies (23 treatments). The model predicted CP digestibility with no mean bias (-1.9 g/100 g of CP; P > 0.10) but with a large RMSPE (7.2 g/100 g of CP). Evaluation with a data set of published studies in which the CNCPS for sheep predicted negative ruminal N balance indicated that the model tended to underpredict OM digestibility (mean bias of -3.3 g/100 g of OM, P > 0.10; RMSPE = 6.5 g/100 g of OM; n = 12) and to overpredict CP digestibility (mean bias of 2.7 g/100 g of CP, P > 0.10; RMSPE = 12.8 g/100 g of CP; n = 7). The ability of the CNCPS for sheep to predict gains and losses in shrunk BW was evaluated using data from six studies with adult sheep (13 treatments with lactating ewes and 16 with dry ewes). It accurately predicted variations in shrunk BW when diets had positive N balance (mean bias of 5.8 g/d; P > 0.10; RMSPE of 30.0 g/d; n = 15), whereas it markedly overpredicted the variations in shrunk BW when ruminal balance was negative (mean bias of 53.4 g/d, P < 0.05; RMSPE = 84.1 g/d; n = 14). These evaluations indicated that the Cornell Net Carbohydrate and Protein System for Sheep can be used to predict energy and protein requirements, feed biological values, and BW gains and losses in adult sheep.
281 citations
TL;DR: It is demonstrated clearly that some unique odor-active compounds found in pasture plants can be transferred to the cheese.
121 citations
TL;DR: Panelists were able to detect significant differences in the sensory characteristics of cheeses produced from milk of cows consuming native pastures versus TMR even when the color difference was masked, a unique approach in sensory analysis was developed using sunglasses with lenses designed to block light at the specific wavelengths at which panelists would detect differences in color.
88 citations
TL;DR: In this article, a study on the influence of diet upon cheese flavour was carried out on Hyblean pastures, where over 100 plant species belonging to over 25 families occur, although not all of these may occur in single pasture.
Abstract: The Hyblean pastures are characterized by a great variety of native forages, and offering opportunity for selective feeding by animals. Over 100 plant species belonging to over 25 families occur, although not all of these may occur in single pasture.1 The occurrence of pasture species and the selective forage behaviour of dairy cattle in very complex pastures was part of a larger study on the influence of diet upon cheese flavour. The plant diversity may contribute to cheese flavour.2 The animals were individually followed on the pasture and the kind of species and plant parts selected were recorded.3 The volatile constituents of the above-ground (aerial) parts of the most commonly occurring and selected plant species in the Hyblean pasture were extracted by steam distillation and analysed by GC–olfactometry (GC–O) and GC–MS. The number of odour-active compounds identified in the plants ranged from 12 in Sinapis to 26 in Erodium. Copyright © 2004 John Wiley & Sons, Ltd.
10 citations