Diurnal Variation in the Composition of Ileal Digesta and the Ileal Digestibilities of Nutrients in Growing Pigs

Abstract

Diurnal variation in the chemical composition of digesta and its effect on nutrient digestibilities of diets varying in dietary fibre content was examined in pigs fitted with a PVTC‐cannula at the terminal ileum. The pigs were fed three times a day (08:00, 16:00 and 24:00 h). A barley control diet and four barley‐based diets containing two levels (100 or 200 g kg‐1 diet) of alfalfa meal or white clover meal and Cr2O3 as an indigestible marker were fed according to a 5×5 Latin square design. In each experimental period, digesta were collected for 1 h every third hour on each of two separate sampling days, covering in total a 24 h period. The concentration of dry matter (DM), crude protein (CP), ash and chromium (Cr) in the ileal digesta varied in relation to time of feeding. However, the patterns were similar after all three meals (08:00, 16:00 and 24:00 h) and independent of diet. The maximum DM, CP and ash contents were reached 4–5 h post‐feeding. The highest (P < 0·05) DM concentration was found in the ileal digesta of pigs fed the barley control diet. The DM concentration decreased (P < 0·05) as the inclusion level of alfalfa meal and white clover meal was increased. The lowest DM concentration was found for the highest inclusion level of alfalfa meal. The ileal digestibilities of both organic matter and CP were lower 1–2 h post‐feeding compared with those recorded 3–5 h later, indicating that the less digestible components of a diet have shorter transit times. The pooled ileal digestibilities of organic matter and CP from the three 8 h periods (08:00–16:00 h, 16:00–24:00 h, 24:00–08:00 h) did not differ (P < 0·05) from each other. Therefore, the estimate of digestibility can be based on digesta samples collected from any interval between two consecutive meals. However, care must be taken to obtain representative samples of digesta between meals. © 1997 SCI.

The effect of dietary level of soybean oil and palm oil on apparent ileal amino acid digestibility and postprandial flow patterns of chromic oxide and amino acids in pigs

“…Day of collection did not affect (P > 0.05) any of the digestibility coefficients. This is in agreement with the findings of Jørgensen et al (1997). For increased accuracy, the means of the two separate days of collection, and not individual days, were used when comparing period and diet means.…”

“…For example the apparent ileal lysine digestibility coefficients from the first to last sampling blocks were as follows: 85.5, 82.4, 83.7, 83.9, 85.9, and 84.4%, respectively. However, in order to reduce variation in measured amino acid digestibility coefficients, it is ideal to collect ileal digesta continuously between feedings, or in another manner that accounts for the diurnal pattern of digesta flow, as discussed by Jørgensen et al (1997).…”

Factors affecting digestibility of barley-based diets for growing pigs

“…The 5-day pre-feed period was followed by a 7-day faecal collection period and by 2-day  12-h collections of ileal digesta. Ileal digesta was collected during daytime only as work by Jorgensen et al (1997) concluded that ileal flow and composition of digesta followed similar patterns after feeding and that a representative sample could be collected during the day provided feeding was at regular intervals.…”

Digestibility of carbohydrates in growing pigs: a comparison between the t-cannula and the steered ileo-caecal valve cannula

“…Prerequisites for this method are that the animals are in a balanced physiological state and that the sampling of ileal chyme is representative. Jørgensen et al (1997) studied the diurnal variation in the composition of ileal digesta and the ileal digestibilities of nutrients and concluded that the estimate of digestibility can be based on digesta samples collected from any interval between two consecutive meals provided that all periods between meals are represented in the pooled ileal sample. This is the case in the present study where the pooled ileal sample is based on two 8 h periods.…”