Effects of sunflower seed supplementation and different dietary protein concentrations on the ciliate protozoa population dynamics in the rumen of sheep

Abstract

. 2003. Effects of sunflower seed supplementation and different dietary protein concentrations on the ciliate protozoa population dynamics in the rumen of sheep. Can. J. Anim. Sci. 83: 809-817. The effects of feeding a linoleic acid-rich sunflower seed supplement and different levels of dietary protein on protozoal numbers and fermentation parameters in rumen fluid were determined in an 84-d experiment with rumen-cannulated sheep. The experiment comprised four treatments, two with low crude protein diets [12% of dietary dry matter (DM)] and two with high protein diets (16% of DM). On both low and high protein diets, one treatment was without (Control) and one with the sunflower seed (high linoleic acid variety 6150) supplement (14% of dietary DM). The four diets used were based on corn silage and corn grain, and soybean meal was used to achieve the desired concentration of dietary protein. The sheep were fully fed each morning and rumen fluid samples were taken 2 h later on various days of the experiment (daily during the first 14 d for enumeration of protozoa). In addition, rumen fluid was sampled at different hours after feeding on day 43 of the experiment. Results showed a protozoa-decreasing effect (P < 0.001) of sunflower seeds causing a decline in protozoa numbers after 2 d of supplementation. The effect of protein on protozoa numbers was dependent on the presence of sunflower seed supplement. Measurements on day 43 showed increased protozoa numbers (P < 0.05) and ammonia nitrogen concentrations (P < 0.001) due to higher dietary protein, and decreased protozoal numbers (P < 0.05) and ammonia nitrogen (P < 0.001) due to the sunflower seed supplement, without significant effects (P > 0.05) on volatile fatty acid concentrations. The linoleic acid-rich sunflower seed supplement was highly effective in reducing both protozoa numbers and ammonia nitrogen concentrations in rumen fluid. Pour chaque régime, un traitement consistait aussi en une ration enrichie (14 % de la MS) de graines de tournesol (variété 6150, riche en acide linoléique) et une autre sans ce supplément (témoin). Les quatre régimes étaient à base de maïs d'ensilage et de maïs-grain, le tourteau de soja servant à atteindre la concentration de protéines souhaitée. Les animaux étaient nourris le matin et les échantillons de liquide du rumen prélevés deux heures plus tard, à des jours variables (quotidiennement au cours des 14 premiers jours, pour l'énuméra-tion des protozoaires). Les prélèvements ont aussi été effectués à divers moments après l'alimentation, le 43 e jour. Les résultats indiquent que les graines de tournesol réduisent (P < 0,001) le nombre de protozoaires au bout de deux jours. L'incidence des protéines sur la population de protozoaires dépend des graines de tournesol. Les mesures prises le 43 e jour indiquent qu'une concentration plus élevée de protéines alimentaires accroît le nombre de protozoaires (P < 0,05) et la concentration d'azote ammoniacal (P < 0,001), mais que le supplément de graines de tournesol réduit la population de ...

Interaction of sunflower oil with monensin on milk composition, milk fatty acid profile, digestion, and ruminal fermentation in dairy cows

“…Similar increases in milk fat total trans11-18:1 proportion has been reported with the combination of safflower oil and monensin (Bell et al, 2006). Besides its high concentration in linolenic acid, sunflower oil is highly effective in reducing both protozoa numbers and ammonia N concentrations in rumen fluid (Ivan et al, 2003), which would improve N utilization by cows. Therefore, a combination of sunflower oil and monensin would be interesting to increase beneficial FA in milk fat and improve N utilization.…”

“…One objective of feeding sunflower oil was to enhance N utilization through a reduction in ammonia N concentration in the rumen, which would likely be achieved by lower protozoa counts (Ivan et al, 2003). However, sunflower oil had no effect on ammonia N concentration, which could result of the length of the feeding periods of 28 d being too short to affect significantly protozoa counts.…”

Fatty acid profiles of rumen fluid from sheep fed diets supplemented with various oils and effect on the rumen ciliate population

“…Contrary to findings of Ivan et al (2001) no significant effect of SO supplementation on the protozoan concentration was observed. It is well known that oils high in C18 fatty acids are toxic to protozoa (Newbold and Chamberlain, 1988;Ivan et al, 2003Ivan et al, , 2004Hristov et al, 2004). On the other hand, the Eremoplastron dilobum 54* 33** 38** 83 9 SO -sunflower oil; RO -rapeseed oil; LO -linseed oil; CO -control; *P < 0.05; **P < 0.01; ***P < 0.001 differences from control rumen ciliates could play an important role in the rumen content of TVA and CLA (Devillard et al, 2006;Yánez-Ruiz et al, 2006;Or-Rashid et al, 2007).…”

Effects of dietary sunflower seeds on lactation performance and conjugated linoleic acid content of milk

“…Because feeding sunflower oil to dairy cows and beef steers (Mir et al 2002) increased the CLA concentration in milk and meat, respectively, it was hypothesized that provision of whole sunflower seed (SS) would not only increase milk CLA concentration but maintain milk and component yield. The dietary inclusion of SS has been shown to decrease the protein requirement in lambs because of reduction of protozoal numbers in the rumen leading to more efficient use of the dietary protein (Ivan et al 2003). Therefore it was of interest to determine the effect of dietary SS on milk CLA concentration and yield of CLA and milk components, when dietary protein was provided at a level lower than required to support the expected milk protein yield.…”