Rumen Outflow Rate Research Articles

Influence of Jet-Sploding® and Extrusion on Ruminal and Intestinal Disappearance of Canola and Soybeans

In situ rumen degradation and intestinal digestibility of DM and CP of Jet-Sploded and extruded protein sources were estimated, using two ruminally and duodenally cannulated lactating Holstein cows, in two experiments. One-gram samples of ground (1mm) whole canola seed, canola meal, extruded canola meal, Jet-Sploded whole canola seed, Protec®, soybean meal and extruded soybean meal (Experiment 1), and whole canola seed Jet-Sploded at temperatures ranging from 116 to 177°C (Experiment 2) were heat sealed into small nylon bags for incubation in the rumen and insertion into the duodenum. Extrusion had no effect on DM or CP disappearance in the rumen nor on effective degradability. Jet-Sploding of whole canola seed dramatically reduced effective degradability (%) of DM (80.5 vs. 35.9 at .08h−1 rumen outflow rate) and CP (83.5 vs. 43.2 at .08h−1). Total tract disappearance of DM and CP exceeded 90% for all protein sources, except Protec® and Jet-Sploded material. Jet-Sploding appears to have potential for decreasing ruminal degradation of canola protein or DM without markedly decreasing intestinal digestibility.

Effect of Protein Concentration and Protein Source on the Degradability of Dry Matter and Protein in Situ

Degradability of DM and CP was determined in situ for barley, canola meal, corn gluten meal, barley silage, and four concentrate mixtures. Crude protein percent of concentrate mixtures 1 to 4, respectively, were barley plus canola 1, 15.1; barley plus canola 2, 21.0; barley plus corn gluten 1, 17.1; and barley plus corn gluten 2, 19.6. Degradability of each feedstuff was measured on each of four basal diets consisting of barley silage and one of the above concentrate mixtures fed in the proportion 40:60 (DM). The resulting CP percent of diets containing concentrates 1 to 4 were 12.3, 16.1, 13.8, and 16.4. Effective degradability for DM and CP, assuming a rumen outflow rate of .08h−1, were: barley 77.7 and 79.8; canola meal 60.9 and 66.6; corn gluten meal 18.9 and 11.0; barley silage 47.0 and 81.1; barley plus canola 1, 76.4 and 77.4; barley plus canola 2, 72.5 and 71.8; barley plus corn gluten 1, 72.8 and 55.8; barley plus corn gluten 2, 70.2 and 47.4. With two exceptions (DM degradability of concentrate 4 and CP degradability of concentrate 2), basal diet had no significant effect on effective CP or effective DM degradability. Crude protein degradability of concentrate mixtures 1 to 4, respectively, as measured (77.4, 71.8, 55.8, and 47.4) was similar to degradability estimated on the basis of their ingredient content (75.7, 72.1, 49.6, and 43.0).

The response of store lambs to dietary supplements of fish meal 2. effects of level of feeding

ABSTRACTForty-eight, individually-penned lambs (mean live weight 31·4 kg) were given diets with or without fish meal (0 and 90 g intake daily) in sufficient quantities to provide energy for maintenance and either 100, 150 or 200 g daily gain. Nitrogen (N) degradability in the rumen and fractional outflow rates of protein supplements were determined and the diets formulated such that the lambs received about 2·2 and 6·7 g undegradable rumen N daily on all three feeding levels.Live-weight gains were generally greater during the first 3 weeks than during the final 4 weeks of the experiment. Lambs given fish meal had greater gains (P < 0·001) throughout the experiment, but there was a feeding level x protein interaction (P < 0·05) during the first 3 weeks, such that the difference between diets with or without fish meal was greater at the highest feeding level.Retention of N increased with feeding level (P < 0·001) and was greatest when fish meal was given (P < 0·001). There was a feeding level x protein interaction (P < 0·05) for g N retained per 100 g N digested; N retention increased with feeding level only when fish meal was given.

The response of store lambs to dietary supplements of fish meal 1. Effects of forage-to-concentrate ratio

ABSTRACTForty-eight individually-penned lambs (mean live weight 31-4 kg) were offered one of four diets, to investigate response to a supplement of fish meal (0 and 100 g dry matter (DM) per kg M) given with diets of either 60: 40 or 40: 60 forage-to-concentrate ratio. Nitrogen (N) degradability in the rumen and fractional outflow rates of protein supplements were determined. The diets were formulated such that the lambs received about 3 or 9 g undegradable rumen N per kg DM. The diets were given daily to provide sufficient metabolizable energy for maintenance and 150 g gain, and were adjusted according to live weight at weekly intervals.Fish-meal supplementation improved daily growth over a 49-day period (P < 0·001) and enhanced N retention (P < 0·001). Live-weight gain was also marginally improved on the high-forage diets. (P < 0-05), but there was no protein supplement × forage-to-concentrate ratio interaction. Apparent digestibility of acid detergent fibre was improved by the fish-meal supplement on the high-concentrate diet.The four diets were also given to rumen-fistulated sheep. The high-concentrate diet was associated with a higher molar proportion of propionate (P < 0·05) and a lower proportion of acetate (P < 0·001). Rumen concentrations of ammonia tended to be maintained at higher levels throughout the day by the fish-meal supplement.

Rumen outflow rate estimated from the decline of chromium concentration in faecal -and rumen samples after the dosage of sodium dichromate treated fish meal.

The declining rate of Cr concentration in faeces after the dosage of a Sodium dichromate treated protein supplement can be used as an estimate of the protein outflow; rate. The experiment reported was planned to show wheter the variation in the rate of decline of Cr concentration in faeces induced by level of feeding and processing of the diet reflect the variation in rumen outflow determined by the rumen dilution rate of the marker.In a duplicate 3x3 square latin design, 6 mature ewes cannulated in rumen were fed a ground pelleted diet of ‘0.6 alfalfa hay and 0.4 barley grain at 1 or 2 x maintenance energy level (P1,P2) or the same proportions of chopped hay and -cracked barley offered in a loose mix at twice maintenance (Ch2). 50 g. of fish meal treated withsodium dichromate were given as a single dose after 15 days of adaptation period to the diet and faecal grab samples taken at 6,12,18,24,32,36,42,48,60, 72,96 and 120 h. A second dosage was given 7 days later and rumen samples withdraw-ned at 1,3,6,9,12,15,18,22,28,36,48,60 and 72 h.

Estimation of the degradability of dietary protein in the sheep rumen by in vivo and in vitro procedures.

Estimates of degradability of nitrogen in the sheep rumen for a basal hay diet and for soya-bean meal (SBM), groundnut meal (GNM) and fish meal (FM), when given together with the hay, were determined from measurements of duodenal N flow, ammonia kinetics and rumen N disappearance from polyester bags and rumen outflow rate. The ability of various in vitro procedures to predict in vivo N degradability was also examined. Four sheep were given a basal hay diet (800 g dry matter (DM) and 19 g N/d) either alone or supplemented with isonitrogenous amounts (15 g N/d) of SBM, GNM or FM. Duodenal non-ammonia-N flow (g/d) was increased more by FM (8.0) than by GNM (5.9) and SBM (5.8), whilst microbial N flow (g/d) was increased more by SBM (3.9) than by GNM (2.3) and FM (1.6). N degradability values calculated from these results were 0.88, 0.76 and 0.57 for the SBM, GNM and FM respectively. The corresponding value for hay was calculated to be 0.76. The irreversible loss of ammonia in the forestomachs (g N/d) was increased more by SBM (11.9) than by GNM (7.2) and FM (5.8), whilst ammonia outflow from the rumen (g N/d) was increased to a similar extent by all supplements (1.1, 0.9 and 0.8 respectively), as was the amount of microbial N (g/d) synthesized from sources other than rumen ammonia (1.8, 2.0 and 1.9 respectively). N degradability values calculated from these results were 0.84, 0.54 and 0.45 for the SBM, GNM and FM respectively. The fractional rate of N disappearance (/h) when the feedstuffs were incubated in polyester bags in the rumen of sheep receiving the basal hay diet (800 g DM/d) was the highest for SBM (0.145) and lowest for FM (0.037), with the hay (0.082) and GNM (0.071) intermediate, whilst the fractional outflow rates from the rumen (/h) of the three supplements were similar (0.034, 0.038 and 0.030 for SBM, GNM and FM respectively). N degradability values calculated from these results were 0.82, 0.67 and 0.60 for the SBM, GNM and FM respectively; the value for the hay was 0.73. Of a number of in vitro procedures tested, only N solubility in sodium hydroxide and ammonia or total non-protein-N (NPN) production during incubation with rumen fluid in the absence of hydrazine sulphate ranked the supplements, although not the hay, in the same order as in the vivo degradability procedures.(ABSTRACT TRUNCATED AT 400 WORDS)

Retention time of chromium-labelled feed particles and of water in the gut of sheep given hay and concentrate at maintenance.

Sheep were given a diet of 400 g chopped grass hay/d and 500 g crushed barley/d in three equal meals. The mean retention time in the whole gut (MRT) and the rumen retention time (RRT) of chromium-labelled feed particles and of water were estimated from marker concentrations in faecal samples. MRT of Cr-labelled hay (Cr-H), barley hulls (Cr-Bh), crushed peas (Pisum sativum) (Cr-CP) and rapeseed meal (Cr-RSM) were 53.5, 52.3, 44.3 and 37.0 h respectively when estimated from total faecal collections. The estimates obtained from spot samples of faeces were almost identical. RRT of Cr-H, Cr-Bh, Cr-CP, Cr-RSM (Expts 1, 2 and 3) and Cr-labelled cottonseed meal (Cr-CSM) was 35.9, 36.7, 25.3, 18.8, 19.8, 22.8 and 25.3 h respectively. The Cr-labelled feed particles showed marked variations in density in water (Dw). However, both MRT and RRT were closely related to Dw (r -0.88 and -0.95 respectively). Rumen outflow rates of Cr-RSM in individual animals were related to the rumen outflow rates of water (r 0.76).

The effects of protein degradability and food intake on milk yield and composition in cows in early lactation.

1. In two experiments measurements were made of food intake, live-weight change, milk yield and milk composition in early lactation when dairy cows were given diets containing varying proportions of protein as fish meal (low rumen degradability) or as groundnut meal (high rumen degradability). In a preliminary trial measurements were also made with cows given supplements of either fish meal or barley and fed at a restricted level of feeding. 2. When metabolizable energy (ME) intake exceeded 160 MJ/d there was no evidence of responses to changes in protein degradability, ut at ME intakes below 135 MJ/d increases in the supply of undegradable protein led to increases in fat-corrected milk yield, protein content and live-weight loss. 3. The interaction between energy intake and protein degradability is unexpected because net protein:net energy requirement increases as milk yield increases, but may be explained in terms of differential effects of changing rumen outflow rates on degradabilities.