جستجوی مقالات مرتبط با کلیدواژه « kefir » در نشریات گروه « دامپزشکی »

The stability of the gut ecosystem, especially the rumen, is an important area of ​​research that has an impact on the use of feed additives and is associated with a number of diseases. The current study aimed to survey the effect of concentrate: roughage (C: R) ratio and the addition of kefir on the production characteristics of in vitro ruminant fermentation. In a 5x6 factorial order, six ratios of C: R (100:0, 80:20, 60:40, 40:60, 20:80 and 0:100) and five doses of kefir (0, 0.8, 1.6, 2.4, and 3.2 ml) were used, respectively. Gas production during incubation was estimated at 0- 96 h. During inoculation, the rumen fluid was obtained at 0, 4, 8, 12, and 24 h of incubation. Cumulative gas production, GPDM, GPOM, and GPNDF at 24 h was highest at the C: R ratio of 100:0 (67.82 mL, 75.92 mL/ 200 mg, 1979.15 mL/200 mg, and 11.11 mL/ 200 mg, respectively). The kefir addition improved the kinetics and gas production significantly. The highest in vitro dry matter and organic matter digestibility (IVDMD and IVOMD) were obtained at the C: R ratio of 100:0 (9.26% and 182.2% higher than those in C: R ratio of 0:100, respectively). The increase of concentrate diet ratio improved the overall volatile fatty acids (TVFA). No interaction effect on the gas production was detected between the C: R ratio and kefir. The microorganism populations were influenced neither by the level of concentrate nor by the level of kefir. Consequently, the high concentrate-to-roughage ratio and the addition of 1.6 mL kefir to the overall dietary substrate could promote rumen fermentation and feed digestibility without affecting microbe counts.

Kefir is a fermented milk product containing some anticarcinogenic organic compounds with nutritional benefits, which made it one of the natural dairy beverages extensively consumed.

The present study was conducted to assess the effect of two selective probiotics on the values of acidic criteria and probiotic survival in the kefir produced in this study.

In the first step, the cow milk, preheated at 90oC for 5 min, was inoculated with the commercial starter and divided into two groups. They were complemented with L. acidophilus LA-5 and L. paracasei 431 and incu-bated at 30oC for 6 h. They were then preserved at refrigerated temperature up to 14 days and then sampling was carried out to evaluate the changes of values of organic acids (lactic acid and acetic acid), pH, titratable acidity and survival of probiotic complemented bacteria on the 1st, 7th, and 14th days.

The pH values of L. acidophilus LA-5 and L. paracasei 431 were 4.34 and 4.36 at the beginning of the cold storage and reached 4.27 and 4.31 at day 14. The acidity of L. acidophilus LA-5-complemented kefir on the 1st day was 0.80 gr/100 gr higher than L. paracasei 431-complemented kefir which showed 0.72 gr/100 gr. Lactic acid was ranging from 1.57 to 2.40 gr/100 mL or 2.17 to 2.42 gr/100 mL (from the 1st to the 14th day) in the kefirs complemented with L. acidophilus LA-5 and L. paracasei 431, respectively. In the kefirs complemented with L. acidophilus LA-5 and L. paracasei 431, the acetic acid was stable (from 0.11 to 0.13 gr/100 mL) during 14 days but increased in the later (from 0.11 to 0.23 gr/100 mL) .The survival of both bacteria was higher than 7 logs CFU/gr in the kefir.

Adding L. acidophilus LA-5 and L. paracacei 431 can moderate the acidity of the kefir and extend the survival of complementary probiotics at a standard level during two weeks of cold preservation.