A new protein evaluation system for horse feed from literature data

Few data on apparent pre-caecal digestibility (APCD) of crude protein (CP) and particularly amino acids (AA) are available from studies with horses. Protein bound in cell walls (i.e. neutral detergent insoluble CP (NDICP)) is unlikely to be decomposed by digestive enzymes in the small intestine. In contrast the corresponding analytical fraction of neutral detergent soluble CP (NDSCP) (NDSCP = CP-NDICP) is likely to be available for auto-enzymatic digestion. A literature analysis on the relationship between NDICP/NDSCP and pre-caecal indigestible/digestible CP was carried out. There was a strong positive relationship between NDICP and pre-caecal indigestible CP, which suggests that NDICP can be used to estimate the part of protein that is not available for digestion in the small intestine. There was also a correlation between NDSCP and pre-caecal digestible protein. The slope of the linear regression line between NDICP and pre-caecal digestible CP was 0.9, suggesting an APCD of NDSCP of 90 %. Thus pre-caecal digestible CP may be predicted by multiplying NDSCP by 0.9. Because the literature identifies a similar AA profile in NDICP and NDSCP within a given feed the presented concept may preliminarily be transferred to AA. The proposed system can at any time be adapted to the scientific progress without altering its structure. Such adaptations would be necessary particularly when new knowledge exist on the distribution of AA onto NDICP/NDSCP, the APCD of individual AA from NDSCP, and the impact of feed processing and chewing on particle sizes and protein digestibility

A new protein evaluation system for horse feed from literature data

Few data on apparent pre-caecal digestibility (APCD) of crude protein (CP) and particularly amino acids (AA) are available from studies with horses. Protein bound in cell walls (i.e. neutral detergent insoluble CP (NDICP)) is unlikely to be decomposed by digestive enzymes in the small intestine. In contrast the corresponding analytical fraction of neutral detergent soluble CP (NDSCP) (NDSCP = CP-NDICP) is likely to be available for auto-enzymatic digestion. A literature analysis on the relationship between NDICP/NDSCP and pre-caecal indigestible/digestible CP was carried out. There was a strong positive relationship between NDICP and pre-caecal indigestible CP, which suggests that NDICP can be used to estimate the part of protein that is not available for digestion in the small intestine. There was also a correlation between NDSCP and pre-caecal digestible protein. The slope of the linear regression line between NDICP and pre-caecal digestible CP was 0.9, suggesting an APCD of NDSCP of 90 %. Thus pre-caecal digestible CP may be predicted by multiplying NDSCP by 0.9. Because the literature identifies a similar AA profile in NDICP and NDSCP within a given feed the presented concept may preliminarily be transferred to AA. The proposed system can at any time be adapted to the scientific progress without altering its structure. Such adaptations would be necessary particularly when new knowledge exist on the distribution of AA onto NDICP/NDSCP, the APCD of individual AA from NDSCP, and the impact of feed processing and chewing on particle sizes and protein digestibility

Limits of an easy system to simulate in vitro gastric and small intestine digestion of horses

extended abstrac

Measurement of immunoglobulin concentration in goat colostrum

Failure of transfer of passive immunity is a major cause of increased susceptibility to infectious agents in newborn kids. Feeding of high quality colostrum is the most effective way to obtain sufficient immunoglobulin. The aims of the present study are (1) to evaluate the density measurement using a hydrometer to estimate the immunoglobulin concentration in caprine colostrum and (2) to measure the effect of colostrum temperature on density and subsequently on immunoglobulin estimations. First colostrum of 30 multiparous goats has been studied. Colostrum had a dry matter of 29.0 ± 6.3%. The fat concentration was 94.5 ± 39.9 g/L and protein concentration was 148.4 ± 28.9 g/L. Mean total immunoglobulin concentration was 54.4 ± 26.4 g/L measured by ELISA as reference method. Total immunoglobulin was subdivided into subclasses: immunoglobulin G (1 and 2) 49.1 ± 25.7 g/L (90.3%), immunoglobulin M 3.19 ± 1.66 g/L (6.0%) and immunoglobulin A 2.00 ± 1.03 g/L (3.7%). Density measurements (1044.3 ± 7.3 g/L) using a hydrometer devised for cow colostrum were compared to density measured by a pycnometer (1044.6 ± 8.3 g/L) which is the reference method. Colostrum density measured with the hydrometer showed a correlation with results obtained using the reference method (r = 0.99, P < 0.01). As in colostrum of several other species the density is temperature dependent. Therefore, a correction to the temperature for which the hydrometer is designed is necessary. Regression analysis between density and immunoglobulin concentration revealed only a moderate R2 value (0.44). Therefore, the value of density to predict immunoglobulin concentration is limited