Methane output of tortoises: its contribution to energy loss related to herbivore body mass

An increase in body mass (M) is traditionally considered advantageous for herbivores in terms of digestive efficiency. However, recently increasing methane losses with increasing M were described in mammals. To test this pattern in non-mammal herbivores, we conducted feeding trails with 24 tortoises of various species (M range 0.52–180 kg) fed a diet of grass hay ad libitum and salad. Mean daily dry matter and gross energy intake measured over 30 consecutive days scaled to M^{0.75 (95%CI 0.64–0.87)} and M^{0.77 (95%CI 0.66–0.88)}, respectively. Methane production was measured over two consecutive days in respiration chambers and scaled to M^{1.03 (95%CI 0.84–1.22)}. When expressed as energy loss per gross energy intake, methane losses scaled to 0.70 (95%CI 0.47–1.05) M^{0.29 (95%CI 0.14–0.45)}. This scaling overlaps in its confidence intervals to that calculated for nonruminant mammals 0.79 (95%CI 0.63–0.99) M^{0.15 (95%CI 0.09–0.20)}, but is lower than that for ruminants. The similarity between nonruminant mammals and tortoises suggest a common evolution of the gut fauna in ectotherms and endotherms, and that the increase in energetic losses due to methane production with increasing body mass is a general allometric principle in herbivores. These findings add evidence to the view that large body size itself does not necessarily convey a digestive advantage.

Enrichment withn-3 fatty acid by tuna oil feeding of pigs: changes in composition and properties of bacon and different sausages as affected by the supplementation period

Khiaosa-ard R., Chungsiriwat P., Chommanart N., Kreuzer M. and Jaturasitha S. 2011. Enrichment with n-3 fatty acid by tuna oil feeding of pigs: changes in composition and properties of bacon and different sausages as affected by the supplementation period. Can. J. Anim. Sci. 91: 87–95. Belly, lean from the shoulder and backfat obtained from 80 pigs, fed either no or 1.6 kg tuna oil during fattening (35–90 kg body weight), were used to prepare bacon, Chinese-style sausage and Vienna-style sausage. The tuna oil had been supplemented either initially, at the end, or continuously during fattening. In all meat products, tuna oil supplementation clearly increased contents of n-3 fatty acids (FA), especially of the long-chain n-3 FA. Differences among supplementation periods were pronounced only in the n-3 FA proportion of total FA being lower with early tuna oil feeding. Thiobarbituric acid value, which was high in dry Chinese-style sausage, was mostly enhanced by tuna oil, whereas the period of tuna oil supplementation had no systematic influence. In conclusion, any mode of tuna oil supplementation investigated was efficient in enriching n-3 FA, but care should be taken in producing dry sausages due to their susceptibility to rancidity during storage time.

Flowering catch crops used as forage plants for dairy cows: influence on fatty acids and tocopherols in milk

The effect of several flowering dicotyledonous catch crop plants (dicots) on milk fat quality in cows was investigated to test the hypothesis that their phenolic compounds may inhibit ruminal biohydrogenation and thus enhance the transfer to milk of intact, plant-derived polyunsaturated fatty acids. Berseem clover (Trifolium alexandrinum), buckwheat (Fagopyrum esculentum), and phacelia (Phacelia tanacetifolia) were sown in mixture with ryegrass (Lolium multiflorum; intended biomass proportion of 0.2) on 1ha. For comparison, nonflowering chicory (Cichorium intybus, also sown in mixture with ryegrass) and pure ryegrass were cultivated. Realized biomass proportions (wet weight) were 91% for berseem clover, 69% for buckwheat, 54% for phacelia, and 51% for chicory. At the start of flowering (or from d 47 after sowing onward), cultures were harvested daily and fed for 20 d ad libitum to groups of 6 midlactation cows each. Additionally, 1 kg each of energy and protein concentrate and pure ryegrass hay were fed. Individual intake and milk yield of the cows were measured daily. Milk samples were obtained twice daily 5 d before and from 11 to 20 d after the start of treatment feeding. Feed samples were drawn twice a week from the fresh feeds. Apart from standard traits, feeds and milk were analyzed for fatty acids, tocopherols, and phenolic fractions. Only a few substantial treatment effects on intake and performance were observed. All diets based on dicots increased α-linolenic acid (ALA) concentrations in milk fat compared with the ryegrass diet even though the corresponding swards were not generally richer in ALA. The highest ALA concentration in milk fat (1.3 g/100g of fatty acids) occurred with the berseem clover diet. Transfer rate of ALA from feed to milk was highest with the buckwheat diet (0.09) and lowest with ryegrass (0.05). This was congruent with the differences in total extractable phenols, being high in the buckwheat sward (2.6% of dry matter) and low in the ryegrass sward (1.2% of dry matter). Intermediates of ALA biohydrogenation were lowest in the milk fat of the buckwheat group, indicating an inhibitory effect of this treatment, which provided the highest dietary levels of phenols. The α-tocopherol concentration in milk was higher with the buckwheat diet than with berseem clover and phacelia diets. The study provides evidence that the ALA concentration in milk fat could be enhanced by feeding flowering dicots; however, this was due to different modes of action.

Corrigendum to: Experimental validation of the Intergovernmental Panel on Climate Change default values for ruminant-derived methane and its carbon-isotope signature

Two aspects regarding the ruminant's contribution to global methane (CH4) emissions were investigated: (i) testing the accuracy of the Intergovernmental Panel on Climate Change default values for dairy cows fed different diet types and differing slurry storage temperatures; and (ii) providing carbon-isotope (C-isotope) signature data to contribute information on the characteristics of ruminant-derived CH4 as global source. The experimental diets, fed to 18 dairy cows, were separated into forage-only (hay, C3 plant) and forage-concentrate diets (barley, C3 plant; maize, C4 plant). Accumulated slurry was stored at either 14 or 27�C. The hay diet had the highest CH4 conversion rate (Ym 7.9%). Negligible amounts of CH4 were emitted from slurries stored at low temperature. No diet effect was found at 27�C (~33 L/kg volatile solids). The isotope ratios of enteric CH4 averaged -67.7‰ (C3 plants) and -57.4‰ (C4; maize). High temperature slurry storage resulted in different enrichment factors εCO2-CH4 for maize (33.2‰) and hay (35.9‰). Compared with the Intergovernmental Panel on Climate Change default values for Ym and slurry CH4 emission the results gained in the present experiment were higher and lower, respectively. Slurry-derived CH4 was less depleted in 13C than enteric CH4, which decreases the usefulness of this signature for global ruminant-derived CH4.

Significance of phenolic compounds in tropical forages for the ruminal bypass of polyunsaturated fatty acids and the appearance of biohydrogenation intermediates as examined in vitro

The purpose of the present study was to assess the influence of phenol-rich tropical ruminant feeds on the extent of ruminal biohydrogenation (BH) of polyunsaturated fatty acids (PUFA). Samples of 27 tropical forages (mainly tree and shrub leaves), characterised by different phenolic profiles, were incubated in vitro (n = 4 replicates) with buffered rumen fluid for 24 h using the Hohenheim gas test method. Linseed oil was added as a rich source of PUFA. In the plants, total extractable phenols (TEP), non-tannin phenols, condensed tannins, and fatty acids were determined. After terminating incubation, the fatty acid profile present in fermentation fluid (total syringe content) was analysed by gas chromatography. The relationship between TEP and the disappearance of α-linolenic acid from the incubation fluid was negative (R2 = 0.48, P < 0.001), indicating that TEP reduced the ruminal BH of this PUFA. Similarly, TEP were negatively related with the disappearances of linoleic acid (R2 = 0.52, P < 0.001) and oleic acid (R2 = 0.58, P < 0.001). The appearance of rumenic acid, an important conjugated linoleic acid isomer, was positively correlated with TEP (R2 = 0.30, P < 0.01), while the opposite result was seen with stearic acid (R2 = 0.22, P < 0.05). Leaves of avocado (Persea americana) were particularly interesting, because they changed the BH pattern at a moderate TEP content of 73 g/kg DM. It is concluded that, in the tropical feedstuffs investigated, TEP have an impact on ruminal fatty acid BH and are associated with an increased bypass of PUFA and the generation of conjugated linoleic acid.

Protocol biopsy-driven interventions after pediatric renal transplantation

The therapeutic value of protocol biopsies (PBs) in renal transplant recipients remains unclear. We performed protocol biopsies in 57 children six months after transplantation. We increased the CNI dose in patients with borderline findings. In cases of Banff grade Ia, six prednisolone IV-pulses were given and the CNI dose was increased. CNI toxicity and polyomavirus nephropathy led to a reduction in the CNI dose. GFR was compared with a control group of 51 children with no PBs transplanted in the same period. Forty-two percent of PBs had no pathological changes, 24% IF/TA. Borderline findings were detected in 11%, Banff grade Ia in 15% (CNI), toxicity in 8%, and one case showed polyomavirus nephropathy. GFR after 1.5 and 2.5 yr was similar in both groups. GFR 3.5 yr after transplantation was significantly higher in the intervention group (57 ± 17 vs. 46 ± 20). Patients treated with low-dose CNI and everolimus had a significantly lower number of pathological findings in PBs. The performance of protocol biopsies followed by a standardized treatment algorithm led to better graft function 3.5 yr after transplantation. Prospective randomized studies to confirm our findings are needed.

Feed, N and P utilisation of Brown Swiss heifers in comparison with Angus and Simmental suckler cows with their progeny grazing mountain pastures

Abstract. The aim of the present study was to compare intake and nutrient turnover in two major production systems on mountainous pastures, suckler beef production and rearing of heifers. Data from 4 × 6 Angus or Simmental suckler beef cows with Angus sired calves were opposed to those measured in six growing Brown Swiss heifers applying a contrast model. In each of two vegetative seasons (years A and B) animals were kept together on three mountainous pastures, P1 (1 000 m a.s.l.), P2 and P3 (both 2 000 m a.s.l.), providing either first growth (P1, P2) or re-growth herbage (P3). Intake and herbage digestibility were estimated by the double alkane indicator technique. On average of the two years, the cows together with their progeny weighed 741 kg and the heifers 374 kg. The average daily body weight gain in beef calves (1 044 g) was twice of that measured in the heifers (546 g). Body weight of the cows remained quite constant on average. Dry matter intakes were 17.0 and 8.2 kg/d, and 118 and 96 g/kg0.75 body weight in suckler cows with progeny and heifers, respectively. On all pastures, cattle of both categories selected herbage of similar energy and protein content. Digestibilities of organic matter (73–74 %) and fibre (NDF, 69 %) were similar between categories, though differing among pastures. Nitrogen utilisation was equal in both categories (8 % of intake), but varied among pastures (11 %, 8 % and 5 % on P1, P2 and P3, respectively) and years (11 % and 6 % in years A and B) due to different herbage N contents and intakes. When related to intake, also excretion of faecal and urinary N was equal in both categories. Faecal P losses relative to weight gain were similar in both categories but differed between pastures and years. The results demonstrated unexpectedly similar nutrient use efficiencies and relative N and P losses of the two livestock system options currently common in utilising of mountainous pasture.

De novo therapy with everolimus, low-dose ciclosporine A, basiliximab and steroid elimination in pediatric kidney transplantation

The number of acute rejections and infections after pediatric kidney transplantation (KTX) could not be reduced in the last years. To reduce these events, we investigated a new immunosuppressive protocol in a prospective trial. After KTX, 20 children (median age 12 years, range 1-17) were initially treated with Basiliximab, ciclosporine A (CsA) (trough-level = C0 200-250 ng/mL) and prednisolone. After 2 weeks, CsA dose was reduced to 50% (C0 75-100 ng/mL, after 6 months: 50-75 ng/mL) and everolimus (1.6 mg/m²) /day) was started (C0 3-6 ng/mL). Six months after KTX prednisolone was set to alternate dose and stopped 3 months later. All 20 protocol biopsies 6 months after KTX showed no acute rejection or borderline findings. Indication biopsies resulted in no acute rejections and two borderline findings. Mean glomerular filtration rate (GFR) 1 year after KTX was 71 ± 25 mL/min/1.73 m². Without cytomegalovirus (CMV)-prophylaxis, only two primary CMV infections were seen despite a donor/recipient-CMV-constellation pos./neg. in 10/20 children. In pediatric KTX, de novo immunosuppression with low-dose CsA, everolimus and steroid withdrawal after 9 months led to promising results according to numbers of acute rejections and infections. Further follow up is needed. Future larger trials will have to confirm our findings.

In large litters birth weight and gender is decisive for growth performance but less for carcass and pork quality traits

This study aimed to examine whether growth performance, carcass and meat quality traits differed among high (H), medium (M) and low (L) birth weight (BtW) gilts and barrows born from large litters (>16 piglets born alive). Regardless of gender, H pigs grew faster (P<0.05) during the suckler period than L and M pigs. From weaning to slaughter at 113 kg catch-up growth was observed in M barrows. In gilts and barrows percentage ham was greater (P<0.05) and percentage total subcutaneous fat was lower (P<0.10) in H compared to M and L pigs. Compared to L and M pigs, H pigs displayed in general better quality in the longissimus muscle whereas the opposite was observed in the semitendinosus muscle. The superiority of H compared to M and L BtW littermates regarding carcass and meat quality appears to be less evident when pigs originate from large litters.

Characterization of rapeseed (Brassica napus) oils by bulk C, O, H, and fatty acid C stable isotope analyses

Rapeseed ( Brassica napus ) oils differing in cultivar, sites of growth, and harvest year were characterized by fatty acid concentrations and carbon, hydrogen, and oxygen stable isotope analyses of bulk oils (delta(13)C(bulk), delta(2)H(bulk), delta(18)O(bulk) values) and individual fatty acids (delta(13)C(FA)). The delta(13)C(bulk), delta(2)H(bulk), and delta(18)O(bulk) values were determined by continuous flow combustion and high-temperature conversion elemental analyzer-isotope ratio mass spectrometry (EA/IRMS, TC-EA/IRMS). The delta(13)C(FA) values were determined using gas chromatography--combustion-isotope ratio mass spectrometry (GC/C/IRMS). For comparison, other C(3) vegetable oils rich in linolenic acid (flax and false flax oils) and rich in linoleic acid (poppy, sunflower, and safflower oils) were submitted to the same chemical and isotopic analyses. The bulk and molecular delta(13)C values were typical for C(3) plants. The delta(13)C value of palmitic acid (delta(13)C(16:0)) and n-3 alpha-linolenic acid (delta(13)C(18:3n-3)) differed (p < 0.001) between rape, flax, and poppy oils. Also within species, significant differences of delta(13)C(FA) were observed (p < 0.01). The hydrogen and oxygen isotope compositions of rape oil differed between cultivars (p < 0.05). Major differences in the individual delta(13)C(FA) values were found. A plant-specific carbon isotope fractionation occurs during the biosynthesis of the fatty acids and particularly during desaturation of C(18) acids in rape and flax. Bulk oil and specific fatty acid stable isotope analysis might be useful in tracing dietary lipids differing in their origin.

Influence of colour type and previous cultivation on secondary metabolites in hypocotyls and leaves of maca (Lepidium meyenii Walpers)

BACKGROUND

Maca is an Andean crop of the Brassicaceae family which is mainly known for its fertility-enhancing properties following consumption. The hypocotyls display various colours ranging from white to black. Each colour has different biological effects. The aim of this study was to analyse the concentrations of major secondary metabolites in hypocotyls and leaves of maca in a controlled planting experiment in the Peruvian Andes at 4130 m above sea level. The effects of colour type and of previous cultivation of the field were examined.

RESULTS

In the hypocotyls, the colour type effect was significant for most secondary metabolites; exceptions were beta-sitosterol and campesterol. The lead-coloured, yellow and violet maca hypocotyls were rich in glucosinolates, macaene and macamides, respectively. Previous cultivation affected macaene, campesterol and indole glucosinolate concentrations. Effects on metabolite concentrations in the leaves were minor. Hypocotyls were richer in macaene, macamides and glucosinolates than were leaves, and were poorer in beta-sitosterol and total phenols.

CONCLUSION

Colour type has to be considered in maca production, as colour associates with variations in concentrations of distinct bioactive metabolites. Leaves may be interesting for animal nutrition purposes as they contain essentially the same secondary metabolites as the hypocotyls but in clearly lower concentrations.

Experimental validation of the Intergovernmental Panel on Climate Change default values for ruminant-derived methane and its carbon-isotope signature

Two aspects regarding the ruminant’s contribution to global methane (CH4) emissions were investigated: (i) testing the accuracy of the Intergovernmental Panel on Climate Change default values for dairy cows fed different diet types and differing slurry storage temperatures; and (ii) providing carbon-isotope (C-isotope) signature data to contribute information on the characteristics of ruminant-derived CH4 as global source. The experimental diets, fed to 18 dairy cows, were separated into forage-only (hay, C3 plant) and forage-concentrate diets (barley, C3 plant; maize, C4 plant). Accumulated slurry was stored at either 14 or 27°C. The hay diet had the highest CH4 conversion rate (Ym 7.9%). Negligible amounts of CH4 were emitted from slurries stored at low temperature. No diet effect was found at 27°C (~33 L/kg volatile solids). The isotope ratios of enteric CH4 averaged −67.7‰ (C3 plants) and −57.4‰ (C4; maize). High temperature slurry storage resulted in different enrichment factors ϵCO2-CH4 for maize (33.2‰) and hay (35.9‰). Compared with the Intergovernmental Panel on Climate Change default values for Ym and slurry CH4 emission the results gained in the present experiment were higher and lower, respectively. Slurry-derived CH4 was less depleted in 13C than enteric CH4, which decreases the usefulness of this signature for global ruminant-derived CH4.