Effect of lipid supply on in vivo digestion in cows: Comparison of hay and corn silage diets

The effect of rape seed oil supplementation on efficiency of microbial protein synthesis was estimated on three rams fitted with rumen cannulae in 3x3 Latin square design consisting of three experimental diets differing in the percentage of rape seed oil supplement. The basic diet for all animals was composed of 60% concentrate and 40% meadow hay which was supplied with 0. 3 or 6% of rape seed oil. Supplementation of the diet with 3 or 6% of rape seed oil did not have a significant effect on rumen pH and total volatile fatty acid concentrations (P<0.05). There was a statistically significant difference in the level of valeric acid among groups. Also the level of ammonia-N was altered significantly. Daily output of microbial protein-N, determined from allantoin content in the urine, decreased with the amount of fat added to the ration from 15 to 13 and 12 g, respectively, but these differences were not statistically significant.

Section: Discussionsupporting

confidence: 55%

A note on the effect of rape seed oil in concentrate/hay ration on microbial protein synthesis in sheep

Szumacher-Strabel

Potkański²

1997

“…Ruminal VFA patterns of sheep were not altered when 10% canola fatty acids were added to a diet containing ground lucerne hay (Tackett et al, 1996). Volatile fatty acid concentrations in the rumen were similar for diets consisting of 60% meadow hay as for diets composed of 65% maize silage supplemented with 7% RSO on a DM basis (Ben Salem, 1993).…”

Section: Resultsmentioning

confidence: 92%

Microbial protein net synthesis in sheep fed hay-concentrate diets supplemented with different source and level of fat

Szumacher-Strabel¹

1998

Three experiments in a 4 x 4 Latin square design were carried out on four rams fitted with rumen cannulas to investigate the effect of varying sources and levels of fat addition on microbial protein net synthesis (MN) in sheep fed a concentrate-based diet (60% of concentrate and 40% of meadow hay). In the 1 st experiment addition of rape seed oil (RSO) was tested, linseed oil (LSO) was added in the 2 nd , and tallow (TAL) in the in 3 rd experiment. Treatments in all experiments were similar: a control group without fat addition and experimental groups with 4, 8 and 10% of fat in DM of the diet. Microbial production in the rumen, purine derivatives in urine, ruminal ammonia, pH, fatty acids in the rumen were measured. In all cases fat addition resulted in decreased MN, however, 8% fat supplementation had the least deleterious effect on MN production. Fat addition significantly affected purine derivatives excretion. LSO as the supplemental fat led to a decrease in N ammonia concentration from 7.8 mmol/L in the control group to 6.39 mmol/L in the group that received 8% LSO, whereas a significant increase to 9.00 mmol/L was observed when 10% LSO in DM was fed. Ruminal fluid pH was not altered by treatments. In all of the experiments, the increased fat content in the diets decreased the molar percentage of acetic acid. Supplementation of the diet with LSO and TAL resulted in an increase of the propionic acid level (P<0.05).

“…These effects may be attributed to the type of added fat and diet composition. In the experiments of Ben Salem et al (1993) the negative effects of lipids on rumen parameters were less important when fibre intake was high. Some other authors did not find a negative effect of fat on rumen parameters of ruminants fed concentrate rations.…”

Section: Introductionmentioning

confidence: 89%

Microbial protein net synthesis in sheep fed meadow hay supplemented with different source and level of fat

Szumacher-Strabel¹

1998

Three experiments were carried out on four rams fitted with rumen cannulas in a 4 x 4 Latin square design to investigate the effect of varying source and level of fat addition on microbial protein net synthesis (MN) in sheep fed meadow hay. The addition of rape seed oil (RSO) was tested in the 1 st experiment, the addition of linseed oil (LSO) in the 2 nd , and tallow (TAL) in the 3 rd experiment. Treatments in all experiments were similar: a control group without added fat and experimental groups with 4, 8 and 10% of fat in DM of diet. The fat source did not affect microbial protein net synthesis, but addition of 8% of fat tended to increase MN. The highest level of all purine derivatives was observed when RSO was added to meadow hay, whereas tallow addition decreased level of all purine derivatives. The effect of fat was well demonstrated in the variation in pH, and the levels of NH3-N and volatile fatty acids.