Effects of phenolic compounds in propolis on digestive and ruminal parameters in dairy cows

Abstract

-Four rumen-cannulated primiparous lactating cows were studied in a 4 × 4 Latin square design experiment to evaluate the effects of propolis-based products (PBP) with different concentrations of propolis and alcohol levels on total digestibility, (TD), ruminal digestibility (RD), intestinal digestibility (ID), pH, ruminal ammonia-nitrogen production (NH 3 -N), rumen microbial synthesis, and blood parameters. The feed consisted of 591.9 g/kg corn silage and 408.1 g/kg concentrate (dry matter [DM] basis), and treatments differed with regard to the inclusion (via ruminal cannula) or exclusion of PBP as follows: control (without the PBP), PBP B1 (3.81 mg of phenolic compounds/kg of ingested DM), PBP C1 (3.27 mg of phenolic compounds/kg of ingested DM), and PBP C3 (1.93 mg of phenolic compounds/kg of ingested DM). Inclusion of PBP reduced the RD of dietary crude protein (CP). Treatment PBP C1 reduced ruminal NH 3 -N production, while PBP B1 increased the ID of CP relative to that in the control. These findings indicate that propolis had a positive effect on rumen nitrogen metabolism. Rumen pH, efficiency of microbial protein synthesis, and blood parameters were not affected by addition of PBP, but there were significant effects on the other parameters when the treatments containing propolis were contrasted.

Ruminal pH and N-NH3 behavior: a Bayesian approach

“…The average ruminal pH was not affected (p > 0.05) by treatments applied, unlike the average concentration of N-NH 3 (p < 0.05, Table 1) (AGUIAR et al, 2014). Means followed by the same letter, into the row, do not differ at 5% of significance, according to the test of Tukey.…”

“…SE = Standard error. Source: Aguiar et al (2014). Aguiar et al (2014), on evaluating rumen pH as a function of time after feeding, found quadratic behavior (pH = 6.86944 -0.42107h + 0.042898h 2 ; R 2 = 73.6%) and estimated a minimum pH value of 5.83 at 4 h 54 min after feeding.…”

“…Source: Aguiar et al (2014). Aguiar et al (2014), on evaluating rumen pH as a function of time after feeding, found quadratic behavior (pH = 6.86944 -0.42107h + 0.042898h 2 ; R 2 = 73.6%) and estimated a minimum pH value of 5.83 at 4 h 54 min after feeding. Furthermore, N-NH 3 behavior as function of time after feeding was found to be quadratic (N-NH 3 = 16.4810 + 7.96253h -0.871208h 2 ; R 2 = 95.1%) and maximum value of N-NH 3 was estimated as 34.67 mg dL -1 of ruminal fluid at 4 h 36 min after feeding.…”

“…It is known that ruminal pH directly affects the microbial growth rate, because ruminal microorganisms grow better in specific pH ranges. A diet with high grain content favors the growth of amylolytic bacteria and production of lactic acid, which leads to a drop in pH and consequently inhibits the growth of certain bacteria that grow better at higher pH (AGUIAR et al, 2014). …”

“…The data analyzed here was obtained from Aguiar et al (2014), who studied the effect of diets with 59.19% corn silage and 40.81% concentrate on ruminal pH and N-NH 3 levels. Four treatments with different inclusion doses of LLOS 5 products were used: T1, control (no additive); T2, LLOS B1 (3.81 g phenolic compounds/kg ingested dry matter); T3, LLOS C1 (3.27 g phenolic compounds/kg ingested dry matter); and T4, LLOS C3 (1.93 g phenolic compounds/kg ingested dry matter).…”