Sole Diet Research Articles

Digestion and nitrogen excretion by Holstein-Friesian cows fed grasses with lucerne or lucerne and plantain

Forages and forage mixtures with greater tolerance of dry conditions than perennial ryegrass (Lolium perenne L.) are desirable for dairy farming in New Zealand, and a low urinary nitrogen (N) excretion is desirable to lessen pollution of waterways and ground water, and nitrous oxide emissions. Measurements were undertaken with late-lactation Holstein-Friesian cows (5/treatment) fed tall fescue (Festuca arundinacea Schreb.) with a substantial incursion of weed grasses, as either a sole diet (Grass), or with lucerne (Medicago sativa L.) or lucerne and plantain (Plantago lancelota L.), in metabolism stalls. Approximate ratios (DM basis) of Grass with lucerne (GL) were 55:45, and Grass with lucerne and plantain (GLP) were 55:25:20. Measurements included intakes, production, digestion, rumen function, and urinary excretion, including the circadian patterns of metabolite excretion with a focus on nitrogenous aspects. The DM intakes (kg/day) of cows fed Grass, GL and GLP were 14.9, 12.7 and 15.0 (P = 0.006), and DM digestibility (%) was 58.0, 59.8 and 61.9 (P = 0.006), respectively. Milk yields (kg/day) were Grass, 9.0; GL, 8.7 and GLP, 11.7 (P = 0.003) but composition was not affected by diet. Rumen digesta weight was greatest in cows fed Grass, averaging 23.4% of liveweight after morning feeding. The microbial growth (g/kg organic matter digested) was 16.8 in cows fed Grass and ~24.0 in the other diets. Dietary crude protein concentrations (g/100 g DM) were Grass, 15.4, GL, 20.1 and GLP, 18.3 and urinary N excretion (g/day) was lowest with the Grass diet but urinary N concentration was lowest from cows fed GLP. Daily creatinine excretion was unaffected by diet but there was a 2-fold range in excretion rates within 24 h and values from cows fed fresh forages are lower than published values from cows fed dry diets. Results showed that supplementation of poor quality pasture with lucerne or lucerne with plantain had minor effects on digestibility, and measurements of urinary N suggest a need for caution when predicting urinary N excretion from spot urine sampling in grazing trials.

Formula versus donor breast milk for feeding preterm or low birth weight infants.

When sufficient maternal breast milk is not available, alternative forms of enteral nutrition for preterm or low birth weight (LBW) infants are donor breast milk or artificial formula. Donor breast milk may retain some of the non-nutritive benefits of maternal breast milk for preterm or LBW infants. However, feeding with artificial formula may ensure more consistent delivery of greater amounts of nutrients. Uncertainty exists about the balance of risks and benefits of feeding formula versus donor breast milk for preterm or LBW infants. To determine the effect of feeding with formula compared with donor breast milk on growth and development in preterm or low birth weight (LBW) infants. We used the Cochrane Neonatal search strategy, including electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 6), Ovid MEDLINE, Embase, and the Cumulative Index to Nursing and Allied Health Literature (until 8 June 2017), as well as conference proceedings and previous reviews. Randomised or quasi-randomised controlled trials (RCTs) comparing feeding with formula versus donor breast milk in preterm or LBW infants. Two review authors assessed trial eligibility and risk of bias and extracted data independently. We analysed treatment effects as described in the individual trials and reported risk ratios (RRs) and risk differences (RDs) for dichotomous data, and mean differences (MDs) for continuous data, with respective 95% confidence intervals (CIs). We used a fixed-effect model in meta-analyses and explored potential causes of heterogeneity in subgroup analyses. We assessed the quality of evidence for the main comparison at the outcome level using "Grading of Recommendations Assessment, Development and Evaluation" (GRADE) methods. Eleven trials, in which 1809 infants participated in total, fulfilled the inclusion criteria. Four trials compared standard term formula versus donor breast milk and seven compared nutrient-enriched preterm formula versus donor breast milk. Only the four most recent trials used nutrient-fortified donor breast milk. The trials contain various weaknesses in methodological quality, specifically concerns about allocation concealment in four trials and lack of blinding in most of the trials.Formula-fed infants had higher in-hospital rates of weight gain (mean difference (MD) 2.51, 95% confidence interval (CI) 1.93 to 3.08 g/kg/day), linear growth (MD 1.21, 95% CI 0.77 to 1.65 mm/week) and head growth (MD 0.85, 95% CI 0.47 to 1.23 mm/week). We did not find evidence of an effect on long-term growth or neurodevelopment. Formula feeding increased the risk of necrotising enterocolitis (typical risk ratio (RR) 1.87, 95% CI 1.23 to 2.85; risk difference (RD) 0.03, 95% CI 0.01 to 0.06).The GRADE quality of evidence was moderate for rates of weight gain, linear growth, and head growth (downgraded for high levels of heterogeneity) and was moderate for neurodevelopmental disability, all-cause mortality, and necrotising enterocolitis (downgraded for imprecision). In preterm and LBW infants, feeding with formula compared with donor breast milk, either as a supplement to maternal expressed breast milk or as a sole diet, results in higher rates of weight gain, linear growth, and head growth and a higher risk of developing necrotising enterocolitis. The trial data do not show an effect on all-cause mortality, or on long-term growth or neurodevelopment.

Inclusion of 10% seaweed meal in diets for juvenile and on-growing life stages of Senegalese sole (Solea senegalensis)

The long-term inclusion of 10% seaweed meal (Ulva rigida and Undaria pinnatifida) was evaluated in diets for Senegalese sole (Solea senegalensis). Triplicate groups of fish with an initial body weight of 23 g were fed the experimental diets (ULVA and UNDARIA) and compared to fish fed a control diet with no seaweed included (CTRL), both in juvenile (after 5 months of feeding, up to 60 g) and on-growing stages (after 9 months of feeding, up to 160 g). In the early juvenile phase, the inclusion of seaweeds did not affect fish growth, but final body weight was significantly lower in on-growing fish fed the UNDARIA diet. Overall, growth performance was also reduced in fish fed the UNDARIA diet, with a significantly lower daily growth index. Whole-body composition and nutrient retention (% intake) remained unaffected by the dietary treatment, but by the end of the growth trial fish fed the UNDARIA diet had a significantly lower protein gain associated with significantly lower intestinal villi width. At the end of the experiment, fish fed the UNDARIA diet had a significantly higher iodine flesh content (375.7 μg kg−1) than those fed the CTRL (187.5 μg kg−1) or ULVA (199.3 μg kg−1) diets, whereas selenium content was similar in all groups of fish. In conclusion, U. rigida seems a valid ingredient for Senegalese sole diets without affecting fish growth or nutrient utilization. Undaria pinnatifida was an effective way of naturally fortifying the nutritional value of sole fillets for human consumption, but resulted in growth impairment, so a lower inclusion level should be further evaluated.

Donor human milk and risk of surgical necrotizing enterocolitis: A meta-analysis

The prevention of necrotizing enterocolitis (NEC) is a primary goal in the care of preterm and low birth-weight infants. Donor-banked milk (DM)-feeding has been reported to have a protective effect towards NEC with respect to formula-feeding. All the meta-analysis published so far, have been focused on the protective effect of DM on the overall risk of NEC, none of them focused on the risk of the most severe cases on NEC only, that are those requiring surgery. We conducted a meta-analysis of available evidences on the risk of developing surgical cases of NEC in DM-fed preterm and/or low birth weight infants with respect to those formula-fed. A search for articles published between January 1960 and January 2018 and addressing the association between DM and surgical NEC was conducted via PubMed, Embase and Cochrane database. We included randomized controlled clinical trials, reporting primary data and involving preterm and/or low birth weight infants fed with preterm formula compared to DM, both as sole diet or complementing own mother's milk. Estimates were pooled using random-effects. Study quality was assessed by GRADE score and risk of bias by the Review Manager software tool. Four papers were included in the meta-analysis. DM did not exert a beneficial effect of DM on the risk of preventing surgical NEC with respect to formula (RR: 0.45; 95% CI: 0.19-1.09). This meta-analysis indicates that DM does not exert a clear protective effect, on the surgical cases of NEC with respect to preterm formula. Since DM feeding implies remarkable extra cost for the preparation, storage and delivery of the milk with respect to preterm formula, stronger evidences are required to recommend this type of feeding as a preventive strategy for surgical NEC. Mother's milk, when available, could represents the best choice. CRD42015020296.

Effects of varying sweet lupin dietary inclusion levels on feather classes, leather traits and meat composition of feedlot ostriches

CITATION: Brand, T. S., et al. 2018. Effects of varying sweet lupin dietary inclusion levels on feather classes, leather traits and meat composition of feedlot ostriches. South African Journal of Animal Science, 48(1):186-197, doi:10.4314/sajas.v48i1.20.

Potential of Leucaena (Leucaena leucocephala) for Compensatory Growth on Anglo-Nubian Crossbred Male Goats

This study was carried out to evaluate the potential of leucaena (Leucaena leucocephala) as the sole diet after restriction of feeding in order to elevate compensatory growth during re-alimentation. Twelve Anglo-Nubian crossbred male goats, with an average body weight of 17.50 kg, were assigned to 3 treatments, with 4 replicates, in a completely randomized design (CRD), where all treatments were under 3 feeding regimes, viz. pre-feed restriction, feed restriction, and re-alimentation. All animals were allotted to normal feeding and fed with Pangola hay and meal concentrate to promote an average daily gain (ADG) of 100 g in the initial period for 3 weeks. During the feed restriction period, animals in Treatment 1 were continuously fed at the same level as in the pre-restriction (normal growth/control group), while the animals in Treatments 2 and 3 (restricted groups) were kept at feeding levels of 47.5 and 67.5 % below maintenance, based on NRC (2007), for 4 weeks. In the final period of re-alimentation (7 weeks), the normal growth group was given Pangola hay and meal concentrate at the same level as in the pre-restriction period while restricted groups were subjected to ad libitum sole leucaena feeding until the end of the trial. The results showed that average daily gain (ADG) and feed intake did not differ among the treatments during the pre-feed restriction while, in the restriction feeding period, the restricted groups had lower means (P < 0.01) than the normal growth group. In the re-alimentation period, total dry matter intake was not significantly different among treatments. It is pointed that there were 2 sub-periods during the re-alimentation period where total dry matter intake during the compensatory growth and the normal growth were not significantly different. However, the compensatory growth had been achieved within 2 weeks, indicating a higher ADG of 141.25 and 158.57 g in the restricted groups, compared to 106 g in the control group. Afterwards, the sub-period of normal growth (5 weeks) was followed with a lower ADG in the restricted groups than that in the control group. It can be concluded that the potential of single leucaena feeding for compensatory growth after restriction feeding can be achieved within a short period during re-alimentation, due to the limitation of fiber enrichment in leucaena.

Ileal and total tract apparent crude protein, dry matter, gross energy and amino acids digestibility of soybean meal, solvent-extracted canola meal, and corn distillers dried grain with solubles for growing pigs

The present study was conducted to determine the apparent total tract digestibility (ATTD) and apparent ilealdigestibility (AID) of dry matter (DM), gross energy (GE), crude protein (CP), and amino acids (AA) in soybeanmeal (SBM), solvent-extracted canola meal (SECM) and corn distiller dried grain with solubles (corn-DDGS) forgrowing pigs. Three growing barrows (Landrace × Yorkshire × Duroc, 33.37±1.11 kg of BW) fitted with a simpleT-cannula at the distal ileum were fed 31.61% SBM, 39.33% SECM, or 52.17% corn-DDGS as the sole proteinsource diets in a 3 × 3 Latin square design with 3 diets and 3 periods. The ATTD and AID for DM, CP, and GE inSBM were greater than in corn-DDGS. Similarly, the ATTD and AID of CP in SBM were greater than in SECM.SBM had greater AID for phenylalanine, cystine, proline, and tyrosine than corn-DDGS. SBM had greater AID forlysine, methionine, threonine, valine, aspartic acid, glutamic acid, glycine, serine, total essential AA, total nonessential AA, and total AA than SECM and corn-DDGS. SECM had greater AID for lysine, aspartic acid, glycine,and tyrosine, but less glutamic acid than corn-DDGS. In conclusion, the results imply that SBM had greater ATTDand AID of DM and GE than corn-DDGS. The values of AID of N and the majority of AA were higher in SBM thanin SECM and corn-DDGS.

Tedera proves its value as a summer and autumn feed for sheep in Mediterranean-like climates

Tedera (Bituminaria bituminosa C.H Stirt. vars. albomarginata and crassiuscula) is a traditional forage species for goats in the Canary Islands, Spain. It has agronomic characteristics ideally suited to Mediterranean-like climates that allows it to provide high quality green forage for grazing animals during summer and autumn. It can be used to extend the growing season into late spring and early summer and/or to reduce or eliminate the need for expensive hand feeding of grain and hay to sheep to fill the ‘feed gap’ during the dry season in southern Australian farming systems. Three sheep grazing experiments were carried out with the objective to evaluate sheep production during summer and autumn with tedera as the sole diet. A 3-ha site at Dandaragan, Western Australia was grazed during the summer and autumn of 2014–2015 and 2016 and a 2.4-ha site was grazed at Kojonup, Western Australia during the same period in 2016. At each site, two grazing treatments were evaluated, continuous grazing and rotational grazing with six plots (14 days of grazing and 70 days of recovery). The first hypothesis tested was that tedera plants would not survive continuous grazing during summer and autumn. The second hypothesis tested was that without hand feeding, 10 dry sheep equivalents/ha would be able to at least maintain weight and condition score during summer and autumn. The third hypothesis tested was that rotational grazing would improve the production of the sheep (liveweight and condition score) compared with continuous grazing. The first hypothesis was rejected, the population of tedera plants did not significantly decline due to being continuously grazed during summer and autumn. The second hypothesis was confirmed, at the three experimental sites, 10 dry sheep equivalents/ha were able to at least maintain weight and condition score without any hand feeding. The third hypothesis was partially rejected; continuous grazing had a better performance of the sheep than rotational grazing. However, the rotational grazing plots had more tedera on offer in the remaining grazing plots in the rotation with the potential for a longer grazing time. These three experiments clearly demonstrate that tedera can be used to reduce or eliminate expensive hand feeding during summer and autumn using the simplest and least expensive grazing management; continuous grazing.

Growth performance and hematology of Djallonké rams fed haulms of four varieties of groundnut (Arachis hypogaea L.).

The study was conducted to assess the chemical composition of the haulms of 4 dual-purpose groundnut (Arachis hypogaea L.) varieties and their effects on the growth and hematology of Djallonké rams. The groundnut varieties were ICGV 97049 (Obolo), ICGX SM 87057 (Yenyawoso), RMP 12 (Azivivi) and Manipinta. Rams (live weight 15.0 ± 3.0 kg) were randomly assigned to 4 sole groundnut haulm meal (GHM) treatments, with 4 rams each in an individual pen per treatment (total n = 16 rams). Samples of the groundnut haulms were milled and analyzed for crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF). The CP concentration was higher (P < 0.05) in Azivivi, Manipinta and Yenyawoso than in Obolo. The highest (P < 0.05) NDF and ADF fractions were obtained in Obolo. Whilst no significant difference was reported in total and daily dry matter (DM) intake among the varieties, CP, NDF and ADF intake all differed between Obolo and other varieties. The apparent nutrient digestibility did not differ (P > 0.05) when the Djallonké rams were fed the haulms. However, significant differences were observed in final live weight and average daily live weight gain. Rams fed the Yenyawoso variety had higher (P < 0.05) final live weight and average daily live weight gain compared with those fed Obolo and Azivivi varieties. Consumption of any of the 4 varieties of groundnut haulms by Djallonké rams did not have any harmful effect on their red and white blood cell numbers and hemoglobin concentration. The study revealed that the different varieties of groundnut haulms differ in nutrient composition and also affect the growth performance of the rams. The Yenyawoso variety may be used as a sole diet for fattening Djallonké rams.

Adrenal cortex reactivity in dairy cows differs between lactational stages and between different feeding levels

Changes in ACTH challenge test characteristics in dairy cows changing their physiological status at different lactational stages and different feeding levels were not investigated in terms of repeatability yet. In 23 multiparous Holstein cows (10 cows fed a sole fresh herbage diet without concentrate, 13 cows fed with concentrate), three ACTH challenge tests were performed: once during pregnancy shortly prior to drying off (T1), and in week 3 (T2) and 8 (T3) after parturition. Test characteristics were correlated to performance and metabolic parameters: DMI, BW, energy balance (EB), plasma concentrations of free fatty acids (NEFA) and beta-hydroxybutyrate (BHB). Basal plasma cortisol concentrations were higher at T1 compared with T2 and T3 (p<.05). The adrenal cortex sensitivity (expressed as total AUC (AUCt ) of cortisol response after ACTH application) was lowest at T2 compared with T1 and T3 (p<.05). Ranking of the individual animals' responses was not repeatable between time points of the ACTH tests. Enhancing the energy deficiency during early lactation by omission of concentrate did not affect baseline cortisol concentrations in plasma, but decreased peak height at T2 (p<.05). Baseline plasma cortisol concentrations were positively correlated with cortisol peak values after ACTH application, previous lactation performance, milk yield and BW (p<.05). The AUCt was positively correlated with baseline cortisol concentrations, EB and DMI. Cortisol release after ACTH injection was lower in animals with high plasma concentrations of NEFA, BHB and with higher contents of fat and free fatty acids in milk (p<.05). Cortisol peak height after ACTH administration was higher in cows with a more positive EB, higher DMI and lower plasma concentrations of NEFA and BHB. In summary, cortisol responses to ACTH challenges in this study were not repeatable in dairy cows changing their physiological status.

Effect of Feeding Supplemental Concentrate on Nutrient Utilization in Dromedary Camels under Sustained Working Conditions

An experiment was conducted using three dromedary camels (545–640 kg BW; 8–10 years old) to study the effect of feeding supplemental concentrates on nutrient utilization under sustained working conditions in rotary mode of operation. The camels were offered gram (Cicer arietinum) straw as basal diet (T1) in all the treatments; but in treatments T2 and T3 the camels were additionally supplemented with concentrate mixture having 65 and 75% TDN, respectively. The supplementation of concentrate to gram straw improved (P<0.05) nutrient digestibility. Likewise, DCP and TDN contents were higher in T3 followed by T2 and T1. The DM intake was also improved in response to supplementation of concentrates and was higher in T3 as compared to T2 and T1; this trend was also reflected in higher daily consumption of DCP and TDN. The voluntary water intake was significantly higher in treatment groups fed supplemental concentrates when compared to the control group fed gram straw alone. It is concluded that supplementation of sole gram straw diet with a concentrate having 75% TDN improved DM intake and nutrient utilization by working camels.

Total substitution of dietary fish oil by vegetable oils stimulates muscle hypertrophic growth in Senegalese sole and the upregulation of fgf6.

The long term effects of fish oil (FO) substitution by increasing the levels of vegetable oils (VO), 0% (CTR), 50% (VO50) and 100% (VO100), in diets for Senegalese sole were evaluated in terms of skeletal muscle cellularity and expression of related genes. After 140 days of feeding, all fish had similar body weight and length. The inclusion of 50% VO did not result in differences in muscle cellularity, but dorsal muscle cross-sectional area and fast-twitch fibre diameter increased in fish fed total FO substitution, whilst fibre density was reduced (P < 0.05) in relation to CTR. The total number of fibres was similar in all treatments. FO substitution did not affect the transcript levels of myogenic genes (myf5, mrf4, myog, myod1, myod2), but resulted in a two-fold increase of fgf6 transcript levels compared to CTR (P < 0.05). The relative expression of igf-I was higher in VO100 than in VO50, but was similar to CTR. FO substitution resulted in cellularity changes related to the stimulation of muscle hypertrophic growth, but not hyperplastic growth, and associated with a nutritional modulation of fgf6 by dietary VO. This study indicates that 50% VO does not affect the muscle phenotype, but total FO substitution stimulates muscle hypertrophy.

Nitrogen utilization efficiency and prediction of nitrogen excretion in sheep offered fresh perennial ryegrass ().

Nitrogen excretion from sheep production systems is an important source of nitrate, ammonia, and nitrous oxide responsible for groundwater pollution and global warming. The present study aimed to identify key parameters influencing N utilization efficiency and develop prediction equations for manure N, feces N, and urine N outputs in sheep. Data used were collected from 82 sheep offered fresh perennial ryegrass () as the sole diet in 6 metabolism experiments (data from non-grass-only diets were not used). Sheep were from breeds of Highlander, Texel, Scottish Blackface, and Swaledale at the age of 5 to 18 mo and weighing from 24.5 to 62.7 kg. Herbage was harvested daily from 6 swards of contrasting harvest dates (May to December), offering wide variation in feed value to cover the range that would be offered in most practical farm situations. Before the commencement of each study, the experimental sward was harvested at a residual height of 4 cm and allowed to grow for 2 to 4 wk to target an average pregrazing sward height in a range of 8 to 15 cm depending on the time of year. Sheep were housed in individual pens for 14 d and then transferred to individual metabolism crates for 4 d with feed intake and feces and urine outputs measured. Data were analyzed using the linear mixed model procedure to develop prediction equations for feces N, urine N, and manure N outputs using N intake, herbage chemical composition, and digestibility with effects of sex, breed, and experimental periods removed. Nitrogen intake was the best single predictor for N output in feces, urine, and manure, and the value for prediction of manure N output was greater than those for feces N and urine N (0.86 vs. 0.70 and 0.77, respectively; < 0.001). Animal BW and herbage DM, ether extract, NDF, ADF, water soluble carbohydrate, and DE concentrations and N digestibility were also used to predict N outputs because N intake may not be available in commercial practice. The prediction equations for N utilization efficiency indicated that increasing feeding level and ME concentration and reducing N concentration could improve N utilization efficiency and shift N excretion into feces rather than urine ( < 0.001). The equations developed in the current study provide an approach for sheep producers to quantify N excretion against production and, consequently, to develop their own mitigation strategies to reduce the environmental impact of sheep production systems.

Recovered energy and efficiency of digestion in sheep and goats fed Atriplex nummularia compared to alfalfa hay

An experiment was carried out to examine differences between sheep and goats in utilizing forages varying in feeding value. Twenty four non-lactating females (Age=3.5 years; Barki sheep, n=12 and Balady goats, n=12) were individually housed in 1.0×1.5m pens with sand floor for a 25-d period and then moved to metabolic cages. Animals of each species were offered either alfalfa hay or Atriplex nummularia foliage as sole diet for ad libitum consumption. Dry matter intake and digestibility were greater (P<0.001) for animals fed alfalfa hay than Atriplex nummularia. Intake of organic matter (g/kg metabolic body weight (BW0.75)/d) and gross energy (kJ/kg BW0.75/d) was greater (P<0.05) for goats than sheep. The significant interaction between forage type and animal species indicated that digestibility (%) of organic matter and energy was only greater for goats than sheep fed Atriplex nummularia, while no significant differences were observed between animal species when fed alfalfa hay. However, NDF digestibility was similar between both animal species fed either roughage. Energy expenditure (kJ/kg BW0.75/d) was similar between goats and sheep, and greater (P<0.001) for animals fed alfalfa hay than Atriplex nummularia. The significant interaction between forage type and animal species indicate that recovered energy (RE, kJ/kg BW0.75/d) was similar for both animal species when fed alfalfa hay, while it was greater for goats than sheep when fed Atriplex nummularia. It is concluded that apparent digestibility and RE were practically similar in sheep and goats when they consumed the high quality forage (i.e. Alfalfa), while low quality forage (i.e. Atriplex nummularia) was better utilized by goats than sheep.

Using the F/R-ratio for an evaluation of the ability of the demosponge Halichondria panicea to nourish solely on phytoplankton versus free-living bacteria in the sea

ABSTRACTThe F/R-ratio (litres of water filtered per ml of oxygen respired) was determined for the filter-feeding demosponge Halichondria panicea to be 15.5 l H2O (ml O2)−1 which was used to evaluate the potential of the sponge to nourish solely on nano- (2–20 µm) and micro- (20–200 µm) phytoplankton cells in the sea. It was estimated that in order to balance the maintenance requirement of H. panicea the necessary content of suspended particulate organic carbon must be at least 0.03 mg C l−1, which may be compared with actually reported values of 0.04 to 0.2 mg C l−1 thus implying that H. panicea may be able to nourish on a sole diet of phytoplankton in nature. However, the amount of carbon represented by free-living heterotrophic bacteria, cyanobacteria and other small (0.2–2 µm) picoplankton which are also accessible to the sponge lies in the range of 0.05–0.10 mg C l−1, and therefore bacteria seem to be an important, although in many cases apparently a somewhat insufficient food source relative to phytoplankton. Video-microscope observations of the osculum cross-sectional area (OSA) and simultaneous measurement of the filtration rate of H. panicea showed that the filtration rate varied considerably over time concurrently with often pronounced variations in the OSA caused by disturbance when the aquarium through-flow was stopped during filtration rate measurements in the laboratory. It is concluded that the optimal and undisturbed filtration rate may be considerably higher than measured here, i.e. 6.1 ml water (ml sponge)−1 min−1, thus increasing the F/R-ratio to > 15.5 l H2O (ml O2)−1, which is comparable to values for more advanced eumetazoan filter-feeding marine invertebrates grazing on phytoplankton.

Effect of three diets on the growth and fatty acid profile of the common ragworm Hediste diversicolor (O.F. Müller, 1776)

The polychaete Hediste diversicolor has a high physiological tolerance to extreme environmental factors, being easily farmed and reproduced in different types of conditions. Both in the field and under laboratory conditions, this worm can feed on different types of food. In order to highlight the potential of H. diversicolor for aquaculture, specific growth rate (SGR), daily growth rate (DGR), survival rate and fatty acid profile of juvenile worms, fed with three different diets, were assessed. The experiments were conducted using juvenile polychaete from a controlled reproduction with wild adults. H. diversicolor individuals were fed with two commercial diets, seabream dry feed (Aquagold) and semi-wet pellets for reared sole (Moist Sole), and with a non-processed diet consisting on mackerel's fillets (Trachurus trachurus). Juveniles fed with Aquagold had the highest final individual weight (0.89±0.10g). The SGR was higher in H. diversicolor fed with Aquagold and Moist Sole, (6.49±0.30% d−1 and 6.54±0.06% d−1, respectively. The highest DGR was observed for juveniles fed with Aquagold (0.146±0.02gd−1). The survival rate of ragworms under different treatments ranged from 96 to 100%. Regarding the protein content, the Moist Sole diet provided the highest percentage of protein in the reared worms (8.87%). Results showed that the total fat content of the diets was reflected in the fat content of the reared worms. The Moist Sole diet treatment had the highest fat content (2.25%) and individuals fed with seabream dry feed showed similar results (2.18%), while the lowest percentage was observed for the mackerel diet (0.85%). According to the fatty acid profile, the major fatty acids found in the juveniles fed with the three different diets were palmitic (C 16:0), with a higher value in the individuals fed with mackerel's fillets. Oleic (C 18:1 n9), eicosapentaenoic (C 20:5 n3), docosahexaenoic (C 22:6 n3) and stearic (C 18:0) acids presented high values in H. diversicolor fed with all the experimental diets. Statement of RelevanceThe common ragworm Hediste diversicolor is a potential high quality fatty acids source for reared fish and shrimp. Previous studies suggested that diet could be a relevant factor affecting the fatty acid composition of this polychaete (Luis and Passos, 1995). This study aimed to assess the effect of different diets on growth and survival of common ragworms juveniles (H. diversicolor), as well as the fatty acid profile and protein content in their tissues, aiming to find an appropriate diet to be used in commercial aquaculture.

Biological recovery and properties of poly(3-hydroxybutyrate) from Cupriavidus necator H16

Abstract In the present study, we observed that laboratory rats readily consumed lyophilized cells of Cupriavidus necator H16 cultivated using palm oil containing 39 wt% poly(3-hydroxybutyrate) [P(3HB)] as sole diet source. The test animals excreted whitish fecal pellets containing 82–97 wt% P(3HB). The remaining impurities could be easily removed by washing the pellets with water and/or low concentrations of detergent, which resulted in P(3HB) granules of a high purity. The molecular masses and thermal properties of P(3HB) obtained by this method were almost similar to P(3HB) extracted from bacterial cells using chloroform. The method reported here is simple and eliminates the need for solvents and strong chemicals, thus resulting in P(3HB) production that is more ecofriendly.

Prediction of enteric methane emissions from sheep offered fresh perennial ryegrass () using data measured in indirect open-circuit respiration chambers.

Development of effective methane (CH) mitigation strategies for grazing sheep requires accurate prediction tools. The present study aimed to identify key parameters influencing enteric CH emissions and develop prediction equations for enteric CH emissions from sheep offered fresh grass. The data used were collected from 82 sheep offered fresh perennial ryegrass () as sole diets in 6 metabolism experiments (data from non-grass-only diets were not used). Sheep were from breeds of Highlander, Texel, Scottish Blackface, and Swaledale at the age of 5 to 18 mo and weighing from 24.5 to 62.7 kg. Grass was harvested daily from 6 swards on contrasting harvest dates (May to December). Before the commencement of each study, the experimental sward was harvested at a residual height of 4 cm and allowed to grow for 2 to 4 wk. The feeding trials commenced when the grass sward was suitable to zero grazing (average grass height = 15 cm), thus offering grass of a quality similar to what grazing animals would receive under routine grazing management. Sheep were housed in individual pens for 14 d and then moved to individual calorimeter chambers for 4 d. Feed intake, fecal and urine outputs, and CH emissions were measured during the final 4 d. Data were analyzed using the REML procedure to develop prediction equations for CH emissions. Linear and multiple prediction equations were developed using BW, DMI, GE intake (GEI), and grass chemical concentrations (DM, OM, water-soluble carbohydrates [WSC], NDF, ADF, nitrogen [N], GE, DE, and ME) as explanatory variables. The mean CH production was 21.1 g/kg DMI or 0.062 MJ/MJ GEI. Dry matter intake and GEI were much more accurate predictors for CH emissions than BW ( < 0.001, = 0.86 and = 0.87 vs. = 0.09, respectively). Adding grass DE and ME concentrations and grass nutrient concentrations (e.g., OM, N, GE, NDF, and WSC) to the relationships between DMI or GEI and CH emissions improved prediction accuracy with values increased to 0.93. Models based on farm-level data, for example, BW and grass nutrient (i.e., DM, GE, OM, and N) concentrations, were also developed and performed satisfactorily ( < 0.001, = 0.63). These models can contribute to improve prediction accuracy for enteric CH emissions from sheep grazing on ryegrass pasture.

The application of headspace gas chromatography coupled to tandem quadrupole mass spectrometry for the analysis of furan in baby food samples

Selective methodology employing a tandem quadrupole mass spectrometer coupled to a gas chromatograph with headspace autosampler (HS-GC–MS/MS) was elaborated in this study. Application of the elaborated procedure resulted in a limit of detection of 0.021μgkg−1 and a limit of quantification of 0.071μgkg−1. The mean recoveries during in-house validation ranged from 89% to 109%, and coefficients of variation for repeatability ranged from 4% to 11%. The proposed analytical method was applied for monitoring the furan content of 30 commercial baby food samples available on the Latvian retail market. The level of furan found in these samples varied from 0.45 to 81.9μgkg−1, indicating that infants whose sole diet comprises baby food sold in jars and cans are exposed constantly to furan. Samples containing vegetables and meat had higher levels of furan than those containing only fruits.

Innate immune response, intestinal morphology and microbiota changes in Senegalese sole fed plant protein diets with probiotics or autolysed yeast.

The effects of using plant ingredients in Senegalese sole (Solea senegalensis) diet on immune competence and intestine morphology and microbial ecology are still controversial. Probiotics or immunostimulants can potentially alter the intestinal microbiota in a way that protects fish against pathogens. The current study aimed to examine the intestine histology and microbiota and humoral innate immune response in juvenile sole fed diets with low (35%) or high (72%) content of plant protein (PP) ingredients supplemented with a multispecies probiotic bacteria or autolysed yeast. Fish fed the probiotic diet had lower growth performance. Lysozyme and complement activities were significantly higher in fish fed PP72 diets than in their counterparts fed PP35 diets after 17 and 38days of feeding. At 2days of feeding, fish fed unsupplemented PP72 showed larger intestine section area and longer villus than fish fed unsupplemented PP35. At 17days of feeding, fish fed unsupplemented PP72 showed more goblet cells than the other dietary groups, except the group fed yeast supplemented PP35 diet. High dietary PP level, acutely stimulate fish innate immune defence of the fish after 2 and 17days of feeding. However, this effect does not occur after 73days of feeding, suggesting a habituation to dietary treatments and/or immunosuppression, with a reduction in the number of the goblet cells. Fish fed for 38days with diets supplemented with autolysed yeast showed longer intestinal villus. The predominant bacteria found in sole intestine were Vibrio sp. and dietary probiotic supplementation caused a reduction in Vibrio content, regardless of the PP level.