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| 2. |
- Danielsson, Rebecca, et al.
(författare)
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Effects on enteric methane production and bacterial and archaeal communities by the addition of cashew nut shell extract or glycerol-An in vitro evaluation
- 2014
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Ingår i: Journal of Dairy Science. - : American Dairy Science Association. - 0022-0302 .- 1525-3198. ; 97, s. 5729-5741
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Tidskriftsartikel (refereegranskat)abstract
- The objective of the study was to evaluate the effect of cashew nut shell extract (CNSE) and glycerol (purity >99%) on enteric methane (CH4) production and microbial communities in an automated gas in vitro system. Microbial communities from the in vitro system were compared with samples from the donor cows, in vivo. Inoculated rumen fluid was mixed with a diet with a 60:40 forage:concentrate ratio and, in total, 5 different treatments were set up: 5 mg of CNSE (CNSE-L), 10 mg of CNSE (CNSE-H), 15 mmol of glycerol/L (glycerol-L), and 30 mmol of glycerol/L (glycerol-H), and a control without feed additive. Gas samples were taken at 2, 4, 8, 24, 32, and 48 h of incubation, and the CH4 concentration was measured. Samples of rumen fluid were taken for volatile fatty acid analysis and for microbial sequence analyses after 8, 24, and 48 h of incubation. In vivo rumen samples from the cows were taken 2 h after the morning feeding at 3 consecutive days to compare the in vitro system with in vivo conditions. The gas data and data from microbial sequence analysis (454 sequencing) were analyzed using a mixed model and principal components analysis. These analyses illustrated that CH4 production was reduced with the CNSE treatment, by 8 and 18%, respectively, for the L and H concentration. Glycerol instead increased CH4 production by 8 and 12%, respectively, for the L and H concentration. The inhibition with CNSE could be due to the observed shift in bacterial population, possibly resulting in decreased production of hydrogen or formate, the methanogenic substrates. Alternatively the response could be explained by a shift in the methanogenic community. In the glycerol treatments, no main differences in bacterial or archaeal population were detected compared with the in vivo control. Thus, the increase in CH4 production may be explained by the increase in substrate in the in vitro system. The reduced CH4 production in vitro with CNSE suggests that CNSE can be a promising inhibitor of CH4 formation in the rumen of dairy cows.
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| 3. |
- Andrée O´ Hara, Elisabeth, et al.
(författare)
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Effects of dry period length on milk production and energy balance in two cow breeds
- 2018
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Ingår i: Animal. - 1751-7311 .- 1751-732X. ; 12, s. 508-514
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Tidskriftsartikel (refereegranskat)abstract
- Shortening the dry period (DP) has been proposed as a strategy to improve energy balance (EB) in cows in early lactation. This study evaluated the effects of shortening the DP on milk yield (MY), EB and residual feed intake (RFI) in two breeds; Swedish Red (SR) and Swedish Holstein (SH). Cows were blocked by breed and parity and then randomly assigned to one of two treatments; short DP of 4 weeks (4W, n = 43) or conventional DP of 8 weeks (8W, n = 34). Cows were kept and fed under the same conditions, except for the 4 weeks when the 4W group were still lactating prepartum and thus kept with the lactating cows. Milk yield and BW were recorded and body condition score (BCS) was rated from 10 weeks prepartum to 12 weeks postpartum. Dry matter intake (DMI) was recorded for lactating cows postpartum. Milk yield was reduced by 6.75 kg/day during the first 12 weeks postpartum ( P< 0.001) for the 4W cows compared with 8W cows, but there was no significant difference in total MY (3724 kg compared with 3684 kg, P = 0.7) when the milk produced prepartum was included. Protein content was higher in 4W cows (3.42%) than in 8W cows (3.27%) ( P<0.001) postpartum. In the 8W group, cows lost more BCS after calving ( P<0.05). Cows of SR breed had higher BCS than cows of SH breed (SR = 3.7, SH = 3.2, P< 0.001), but no differences in BW were found between breed and treatment. Energy balance was improved for cows in the 4W group ( P< 0.001), while feed efficiency, expressed as RFI, was reduced for 4W cows than for 8W cows (5.91 compared with −5.39, P<0.01). Shortening the DP resulted in improved EB postpartum with no difference between the breeds and no milk losses when including the milk produced prepartum.
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| 4. |
- Werner Omazic, Anna
(författare)
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Glycerol supplementation in dairy cows and calves
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The production of biodiesel from rapeseed oil methyl ester leaves glycerol (synonym: glycerine, 1,2,3-propanetriol) as a valuable by-product and a promising feed supplement for farm animals. This thesis provides information about the supplemental feeding with glycerol to dairy cows in early lactation and to young calves, and describes the fate of glycerol entering the rumen and the impact of glycerol on enteric methane production and gastrointestinal microbial populations. This was achieved by investigating the effects of two glycerol products of different purity - crude glycerol (88.1%) and glycerol (>99%) - on milk production, feed intake and metabolic parameters in 42 dairy cows in early lactation. Furthermore, different routes of the disappearance of glycerol from the rumen were quantified. These were i) fermentation in the rumen, ii) absorption across the rumen epithelium and iii) rumen outflow through the omasal orifice. The effect of glycerol on enteric methane production, rumen volatile fatty acid profiles and microbial population in rumen fluid was investigated in a gas in vitro system. Finally, the effects of oral rehydration solutions (ORS) with added glycerol on metabolic parameters and intestinal microbiota were examined in young calves. Glycerol supplementation, irrespective of purity, did not significantly affect milk yield or composition, the total intake of dry matter or metabolic parameters in dairy cows in early lactation. It was estimated that approximately 70% of the glycerol was absorbed mainly from the rumen, but probably also from the small intestine. A smaller fraction disappeared from the rumen compartment by microbial digestion. These findings indicate that glycerol is an available gluconeogenic substrate which might efficiently contribute to glucose synthesis in the liver. Addition of glycerol in the gas in vitro system indicated no reduction in methane production. Furthermore, bacterial and archaeal community structures subjected to additional glycerol followed a similar pattern as the in vitro control with no feed additive. Glycerol was also shown to be a suitable component in ORS for young calves since it ameliorated the effects of dehydration on feed and fluid deprived calves. In calves, glycerol was rapidly absorbed, presumably in the small intestine, and thus most likely not available to the intestinal microbiota.
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| 5. |
- Werner Omazic, Anna, et al.
(författare)
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High- and low-purity glycerine supplementation to dairy cows in early lactation: effects on silage intake, milk production and metabolism
- 2013
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Ingår i: Animal. - 1751-7311 .- 1751-732X. ; 7, s. 1479-1485
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Tidskriftsartikel (refereegranskat)abstract
- This study evaluated the effects of supplemental low- and high-purity glycerine on silage intake, milk yield and composition, plasma metabolites and body condition score (BCS) in dairy cows. A total of 42 cows of the Swedish Red Breed, housed in individual tie stalls, were fed 0.25 kg of low- or high-purity glycerine on top of concentrate, twice daily during the first 4 weeks of lactation. One-third of the cows acted as controls, receiving no glycerine. Silage was fed for ad libitum intake and concentrate was fed at restricted level of intake, about 6 kg/day for primiparous cows and 7 kg/day for multiparous cows. Feed refusals were weighed daily Cows were milked twice daily milk yield was recorded on four occasions per week and milk samples were collected simultaneously Blood samples were drawn from the coccygeal vessel once a week. Low- and high-purity glycerine had no effect on silage or total dry matter intake (P = 0.38 and P = 0.75, respectively) or on BCS (P = 0.45). Cows fed high-purity glycerine tended to have higher milk yield than control cows (P = 0.06). Milk composition tended to differ among treatments. No main effects of treatment on concentration of glycerine (P = 0.44), glucose (P = 0.78), insulin (P = 0.33), non-esterified fatty acids (P = 0.33) and beta-hydroxybutyrate (P = 0.15) in plasma. These data indicate that high-purity glycerine has the potential to increase milk yield, as well as enhance the milk protein concentration and milk fat + protein yield.
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| 6. |
- Werner Omazic, Anna, et al.
(författare)
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Oral rehydration solution with glycerol to dairy calves: Effects on fluid balance, metabolism, and intestinal microbiota
- 2013
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Ingår i: Acta Agriculturae Scandinavica, Section A - Animal Science. - : Informa UK Limited. - 0906-4702 .- 1651-1972. ; 63, s. 47-56
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Tidskriftsartikel (refereegranskat)abstract
- Response to glycerol and glucose as an additive for oral rehydration solution (ORS) was investigated in two trials comprising of total 24 young calves. The aim was to prevent dehydration and energy deficiency and to increase the population of beneficial bacteria in the intestinal microbiota. Calves responded with a modest elevation of glucose and insulin in plasma when fed ORS with glycerol/glucose. The glycerol/glucose mixture concentration in plasma increased markedly following an oral glycerol load. There was no increase in 1,3-propanediol, and the VFA pattern was unchanged in calves receiving ORS containing glycerol/glucose mixture, indicating that glycerol was rapidly absorbed into blood. Numbers of enterobacteria and lactobacilli were not affected by treatment, and glycerol-utilizing Lactobacillus reuteri was detected in calf feces irrespective of treatment and sampling time. In conclusion, glycerol can be used as a component of ORS for young calves without negative impact on calf performance and health.
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| 7. |
- Werner Omazic, Anna, et al.
(författare)
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The fate of glycerol entering the rumen of dairy cows and sheep
- 2015
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Ingår i: Journal of Animal Physiology and Animal Nutrition. - : Wiley. - 0931-2439 .- 1439-0396. ; 99, s. 258-264
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated the fate of glycerol entering the rumen, in particular whether glycerol could be absorbed across the rumen epithelium. Three non-lactating rumen-fistulated cows were used to calculate the overall disappearance rate of glycerol in vivo and evaluate the rate of ruminal glycerol absorption. Rumen epithelial tissues isolated from sheep were used to characterise glycerol transport properties. The rate of rumen microbial degradation of glycerol was then studied in an in vitro system under anaerobic and thermo-regulated conditions. The results showed that glycerol can be absorbed from the rumen in significant amounts. The fractional rate of absorption of glycerol was not affected by variations in glycerol concentration in the buffer solution in the in vivo study. The glycerol absorption apparently occurred largely by passive diffusion and was probably not facilitated by carriers. Glycerol also disappeared via microbial digestion and outflow from the rumen through the omasal orifice.
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