9.4 Voluntary Intake in Ruminants Affected by Silage Extracts and Amines in Particular

1982 ◽  
Vol 6 ◽  
pp. 180-182
Author(s):  
J. G. Buchanan-Smith
Keyword(s):  
Food Intake ◽  
Butyric Acid ◽  
Feed Intake ◽  
Dry Matter ◽  
Gamma Amino Butyric Acid ◽  
Maize Silage ◽  
Short Term ◽  
Amino Butyric Acid ◽  
Voluntary Intake

Gamma amino butyric acid (GABA) is a food intake depressant (Morley, 1980) and is quantitatively a significant nitrogenous constituent in silage (Oshima and McDonald, 1978). When maize silage extracts were infused into the rumen of sheep, it was shown that short-term feed intake could be depressed but this effect was attributed to high rumen osmolality (Phillip, Buchanan-Smith and Grovum, 1981) The purpose of the present experiments was to determine whether GABA and low dry matter lucerne silage extracts could depress food intake in sheep.

Food intake and ruminal osmolality in sheep: differentiation of the effect of osmolality from that of the products of maize silage fermentation

1981 ◽  
Vol 96 (2) ◽  
pp. 439-445 ◽  
Author(s):  
L. E. Phillip ◽  
J. G. Buchanan-Smith ◽  
W. L. Grovum
Keyword(s):  
Food Intake ◽  
Dry Matter ◽  
Latin Square ◽  
Linear Increase ◽  
Maize Silage ◽  
Specific Effects ◽  
Silage Fermentation ◽  
Significant Difference ◽  
Voluntary Intake ◽  
Ruminal Contractions

SUMMARYFive rumen-cannulated Cheviot lambs were used in two successive experiments to differentiate the effect of osmolality from the specific effects of the soluble compounds in maize silage on voluntary intake and ruminal motility. In Expt 1, extracts from fresh (FCE) and ensiled (CSE) maize were adjusted to pH 6·5 andtonicities of 200, 400, 800, and 1600 m-osmol/kg with NaCl, then infused into the rumen according to a 5×5 repeated latin-square design. Water was infused as the control. In Expt 2 solutions of NaCl, with tonicities similar to those in Expt 1, were also infused into the rumen. The lambs were fed ad libitum a diet of pelleted lucerne, but on the morning of infusion they were deprived of food for 4 h and infused continuously for 4 h commencing after 1 h of food deprivation. The infusion of FCE and CSE resulted in no significant difference in cumulative dry matter (D.M.) intake. However, increasing the tonicities of the infusates caused a linear increase (P < 0·05) in ruminal osmolality and a corresponding linear reduction in food intake during the first 30 min of feeding. Infusion of NaCl alone produced a similar effect on intake. The linear regression coefficients of food intake (Y) (g D.M./kg W0·75) against rumen osmolality (X) (m-osmol/kg) were –0·077±0·0085 (r2 = 0·78), –0·082±0·0095 (r2 = 0·76) and –0·073±0·0065 (r2 = 0·84) for FCE, CSE and NaCl, respectively, with no significant differences among the infusates. The frequencies of ruminal contractions during the infusion of FCE and CSE were similar (P > 0·05) and were unaffected (P > 0·05) by ruminal osmolality up to 550 m-osmol.

Food intake in sheep following intraruminal infusion of extracts from lucerne silage with particular reference to organic acids and products of protein degradation

1986 ◽  
Vol 106 (3) ◽  
pp. 611-617 ◽  
Author(s):  
J. G. Buchanan-Smith ◽  
L. E. Phillip
Keyword(s):  
Food Intake ◽  
Organic Acids ◽  
Protein Degradation ◽  
Food Consumption ◽  
Butyric Acid ◽  
Dry Matter ◽  
Amino Butyric Acid ◽  
High Dry Matter ◽  
Discernible Effect ◽  
Cumulative Intake

SummarySheep were infused intraruminally with iso-osmotic solutions of saline, organic acids or lucerne silage extracts with or without additional acids and products of protein degradation found in silage. The post-ingestive effects of silage constituents on food intake were assessed by measuring the voluntary consumption of high dry matter silage over a 20 h period following feeding. In Expt 1, three different silage extracts each depressed food intake up to 4 h following feeding. In Expt 2, one of these extracts, to which 40 g of γ-amino butyric acid (GABA) was added, depressed intake up to 4 h following feeding; with the further addition cf 10 g α-amino butyric acid (AABA) and 28 g amines to this extract, intake was enhanced within 0·5 h but depressed from 4 to 8 h following feeding. In Expt 3, infusion of organic acids alone did not significantly depress food intake relative to saline, nor was there a discernible effect on food intake when graded levels of nitrogenous constituents from silage were added to the infusates. In Expt 4, infusion of an extract, to which only AABA and four other amines were added, depressed cumulative intake up to 8 h following feeding and had a more pronounced effect on food consumption than infusion of the extract with these constituents together with GABA. It was concluded that soluble constituents in silage can inhibit intake but no single constituent is primarily responsible.

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