Performance,gut morphology and carcass characteristics of fattening rabbits as affected by particle size of pelleted diets

A review of past literature revealed inconsistencies in recommended feed particle size for optimal growth and productive performance of rabbits. Changing diet formulation and subsequent processing conditions may improve pellet texture and potentially affect rabbit performance. In the current study, two isoenergetic and isonitrogenous pelleted diets were formulated, which varied in the particle size of the concentrates (2 and 8 mm, respectively). The objective was to evaluate the effect of different particle sizes of compound diets on performance, nutrient utilisation, gut morphology, and carcass characteristics of fattening Italian White breed rabbits. The finely ground diet led to a significant improvement in feed efficiency and apparent digestibility of crude protein, ether extract, crude fibre and NDF, without any negative effect on gut morphology. Furthermore, a smaller particle size of concentrates in pelleted diets improved carcass traits. Meat colour parameters showed significant differences in longissimus lumborum and biceps femoris due to dietary treatments, but in both muscles pH values 1 h and 24 h after slaughter remained unchanged. It is concluded that a finely ground pelleted diet can be used to improve growth performance of rabbits without affecting carcass parameters.     

Effects of different handling systems on pig feed quality

Separation of feed mixtures and its effect on the production traits of growing-finishing pigs was studied in three experiments. In Experiments I and II the effects of different types of equipment to prevent separation in a silo were studied. Experiment III dealt with separation along a feed transport chain.Experiments I and II clearly demonstrated an increase in feed quality variation by filling a silo without any arrangement to reduce separation. The last feed to be extracted from a silo filled in this manner showed an increasing amount of small particles and contents of crude fibre and ash, a decrease in the bulk density and also in the digestibility of nutrients and in the performance of the pigs. Filling a silo equipped with chutes by an auger or pneumatically through a cyclone did not create separation problems, and consequently there were no differences between these treatments in the production experiments.Separation measured by particle size, bulk density or chemical composition was not noticeable along the feed transport chain (Experiment III). There was no effect on performance of the pigs of their location along the chain.     

Effects of particle size and moisture levels in mixed rations on the feeding behavior of dairy heifers

Two experiments on replacement heifers (175±12 days of age) assessed the effects of forage particle length and moisture on feeding behavior. Both experiments used a replicated 3×3 Latin square design, with nine heifers per replication and three periods of 9 days each. Each group of nine heifers was housed in one pen with access to three electronic feed bins. In Experiment 1, hay chopped at different lengths was incorporated into three total mixed rations (TMR) all having the same ingredient and nutrient composition but differing in the percentage of long particles (>19 mm): 60% (Short), 64% (Medium) and 72% (Long). In Experiment 2, heifers were fed a TMR with the same ingredient and nutrient composition but differing in moisture content: 65% DM (Dry), 50% DM (Moderate), and 35% DM (Wet). In both experiments, feeding behavior during the last 5 days of each period was analyzed using a mixed model accounting for the fixed effects of treatment and period, and the random effects of replication and animal. In Experiment 1, dry matter intake (DMI) and eating rate (DMI/min) tended to increase, whereas daily eating time decreased as the feed particle size decreased. Heifers fed the Long diet selected in favor of long particles (>19 mm) and against Short (1.18 to 8 mm) and fine (<1.18 mm) particles; heifers fed the Short diet selected against long particles and in favor of short and fine particles. Heifers fed the Medium diet showed a preference for medium particles with no preference for the other particle sizes. In Experiment 2, heifers fed the Dry diet tended to consume more feed than those fed the Moderate and Wet diets, with no differences in feeding behavior or sorting activity. In conclusion the Medium diet minimized sorting without reducing eating rates and intake, and adding water to TMR to achieve a dry matter less than 65% tended to decrease DMI without reducing sorting.     

The effect of round-bale feeder design and roughage type on feed wastage in sheep feeding

Feeding big round-bales in round-bale feeders are known to reduce labor and costs. However, one disadvantage is the high feed wastage. The aim of these experiments was therefore to investigate the effect of feeder design, type of roughage and size of round-bales on feed wastage in sheep. Four round-bale feeders (Diagonal Rail Sheep Circular Feeder (RD), Knarrhult Flexible Round-Bale Feeder (KR), Telemark Round-Bale Feeder (TR) and Standard Sheep Circular Ring Feeder (RV)) were distributed into four identical experimental pens and used in both experiments. In Experiment 1, two types of roughages were used; Roughage 1: low-quality, grass silage harvested at late stage of maturity with dry matter (DM) content of 560 g/kg and Roughage 2: high-quality, hay harvested at an early stage of maturity with DM content of 738 g/kg. In Experiment 2, ewes were offered hay harvested at the late stage of maturity with DM content of 766 g/kg as half and whole round-bales. In both experiments, four groups of 10 ewes of the Norwegian White breed were rotated between the experimental pens and each treatment lasted for 4 days. Feed wastage (roughage on the ground surrounding the feeder) was collected daily. The amount of feed wastage was generally high. The type of roughage (Experiment 1) had a large effect on feed wastage (P < 0.001), where Roughage 1 had a mean feed wastage of 1.88 kg DM/day per ewe and Roughage 2 had 0.48 kg DM/day per ewe. When Roughage 1 was provided, it was evident that the ewes pulled out the long fibrous stems of the feeders and left them as wastage while selecting the leaves. This was not the case for Roughage 2. When feeding half round-bales (Experiment 2), the mean feed wastage was 1.50 kg DM/day per ewe compared to 2.88 kg DM/day per ewe when feeding whole round-bales (P < 0.001). This is probably due to the ewes spending more time eating with their heads inside the feeder when fed half round-bales (P < 0.001) and thus dropped more of the potential wastage inside the feeder. Less feed inside the feeder may also be the reason that feed wastage decreased gradually from Day 1 to Day 4 in both experiments (P < 0.001). Feeder design also had a significant impact on feed wastage (P < 0.001). We conclude that providing early harvested roughage and feeding half round-bales significantly reduced feed wastage.     

Characterisation of particle dynamics and turnover in the gastrointestinal tract of Holstein cows fed forage diets differing in fibre and protein contents

An improved understanding of the role of forage quality on the processes of particle dynamics and turnover is important for the development of healthier and cost-effective feeding strategies that aim at lowering the proportions of concentrates in the diets of cattle. The aim of this study was to evaluate the effects of feeding hays of different qualities on particle dynamics, digestion kinetics and turnover in the gastrointestinal tract (GIT). Three non-lactating, rumen fistulated Holstein cows were fed diets consisting exclusively of hay with either low quality [Group LH; 605 ± 12.4 g/kg neutral detergent fibre (NDF) and 63 ± 4.7 g/kg crude protein (CP)] or good quality (Group GH; 551 ± 20.1 g/kg NDF and 116 ± 3.6 g/kg CP). Data showed that in situ dry matter (DM) disappearance of the soluble fraction was greater for Group GH (p < 0.05). Feeding good quality hay also lowered the proportion of particles >1.18 mm particularly during the eating process (p < 0.05). Changes in the particle size occurring afterwards were greater for Group GH as well (p < 0.05); approximately 30% in the comminution in the particle size occurred postruminally. Feeding hay of good quality lowered DM content of solid rumen digesta (p < 0.05), accelerated (p < 0.05) the turnover rate of DM and NDF in the GIT and increased DM intake (p < 0.05). In conclusion, feeding forages of better quality significantly promoted degradation processes and kinetics in the GIT with positive effects on turnover rate of digesta and feed intake in Holstein cows.     

Effects of diets differing in protein source and technical treatment on digestibility,performance and visceral and biochemical parameters of fattening pigs

The aim of the experiment on 100 cross-bred barrows was to compare commercial diets for fattening pigs based on either soya bean meal (SBM) imported from non-European countries with diets based on a mixture of locally produced rape seed meal, distillers’ dried grains with solubles and soya beans as main protein sources. In addition, these both types of diets were processed by two different technical feed treatments, i.e. coarse grinding without hydrothermal treatment or fine grinding and pelleting. With only few exceptions, nutrients of the diet without SBM were more digestible (p < 0.05) resulting in a higher metabolisable energy (ME) content. Fine grinding and pelleting increased also the ME content and the nutrient digestibility with the exception of crude fibre. Higher feed intake of animals that fed diets without SBM (p < 0.01) resulted in higher average daily gain (p < 0.01). However feeding this diet, the higher digestibility was not reflected in a decreased feed-to-gain ratio (FGR), but fine grinding and pelleting reduced FGR (p < 0.001). A higher pH value and a lower DM content of caecal chymus were detected in animals that received coarsely ground feed (p < 0.05). Animals that fed finely ground and pelleted feed had higher slaughter and relative liver weights and higher blood cholesterol concentrations (p = 0.040). The urea concentrations of blood were lower (p = 0.019) after feeding diets without SBM. In conclusion, SBM imported from non-European countries can be replaced by alternative local protein sources without compromising digestibility or performances of animals. Although fine grinding and thermal treatment particularly seemed to be advantageous for digestibility and performance, the possible risk of development of stomach lesions should be considered.     

Getting the most out of waste: how dung beetles boost the nitrogen content in their food

The life cycle of almost all dung beetles revolve around mammalian dung, the feed on dung, look for mating partners on dung and lay eggs in the dung. We know they feed on dung, but we still do not understand how exactly they filter‐feed on the dung and which particles size range they are ingesting. The aim on this study was to investigate the filter feeding by particle selection by adult dung beetles using Scarabaeus goryi and how that improves the nutrient quality of the ingested particles. We compared the particle sizes and nutrient content of the dung with the ingested material in the foregut, hindgut and the faeces of the dung beetle. Adult dung beetles do select smaller dung particles when feeding, we found the maximum particle size for the ingested particle to be around 1400 μm. The average particle size increased through the gut length. Dung beetles also selected particles with higher nitrogen content when feeding, the nitrogen content increased from about 1.5% in the dung to just over 5% in the foregut which then decreased to the level of the unprocessed dung in the dung beetle faeces. Carbon content did not increase from the unprocessed dung to the foregut but decreased through the gut length. Feeding by particle size selection by dung beetles helps in selecting particles with higher nitrogen content to compensate for the low levels found in dung.     

Diurnal and circadian variations in indole contents in the goose pineal gland

ABSTRACT

The diurnal and circadian profiles of pineal indoles, except melatonin, are poorly characterized in birds. Moreover, there are no data on the effect of sudden changes in the light–dark cycle on these profiles. Therefore, we investigated the diurnal (Experiment I) and circadian variation (Experiment II) of nine pineal indoles (tryptophan, 5-hydroxytryptophan, serotonin, N-acetylserotonin, melatonin, 5-hydroxyindole acetic acid, 5-methoxytryptophol, 5-methoxyindole acetic acid, 5-methoxytryptamine) in geese, as well as the changes in the profiles of these substances in geese subjected to a reversed light–dark cycle (Experiment III). For the first 12 weeks of life, all geese were kept under a diurnal cycle of 12 h of light and 12 h of darkness (12L:12D). In Experiment I (n = 48), they were kept under these conditions for another 14 days before being sacrificed at 2-h intervals for sampling of the pineal glands. In Experiment II, the geese (n = 48) were divided into three groups (12L:12D, 24L:0D, 0L:24D) for 10 days before sampling at 6-h intervals. In Experiment III, 24 geese were exposed to a reversed light–dark cycle before sampling at 14:00 and 02:00 on the first, second and third days after light–dark cycle reversal. To determine the content of the indoles in the goose pineals, HPLC with fluorescence detection was used. We found that, with the exception of tryptophan, all the investigated indoles showed statistically significant diurnal variation. When geese were kept in constant darkness, most of the indoles continued to show this variation, but when geese were kept in constant light, the indoles did not show significant variation. When the light–dark cycle was reversed (12L:12D to 12D:12L), the profiles of NAS, melatonin, 5-MTAM and 5-MTOL reflected the new cycle within 2 days. The content of serotonin in geese in 12L:12D was higher than that observed in other birds under these conditions, which suggests that this compound may play a special role in the pineal physiology of this species. In conclusion, our results show that the daily variations in the metabolism of melatonin-synthesis–related indoles in the goose pineal gland are generated endogenously and controlled by environmental light conditions, as in other birds. However, comparison of the results obtained with the goose to those obtained with other species (chicken, duck) unambiguously shows that the profiles of pineal indoles differ markedly between species, in both the quantitative proportions of the compounds and the characteristics of the diurnal changes. These findings provide strong arguments for the need for comparative studies.     

Effects of combined α-galactosidase and xylanase supplementation on nutrient digestibility and growth performance in growing pigs

Two experiments were conducted to investigate the effect of combined supplementation of α-galactosidase and xylanase on nutrient digestibility and growth performance in growing pigs. Experiment 1 had a 2 × 2 Latin square design, where eight barrows (45.0 ± 0.52 kg body weight [BW]) were fitted with a simple T-cannula in the distal ileum and received a basal diet without or with supplementation of α-galactosidase (12 U/kg diet) and xylanase (15 AXC/kg diet) within two periods of 10 d. The apparent ileal digestibility (AID) and apparent total tract digestibility of nutrients, pH, viscosity of digesta and digestive enzyme activities were assessed. In Experiment 2, a total of 432 growing pigs (initial BW 44.7 ± 0.66 kg) were allocated to four treatments. Diets were based on corn and soybean meal and had a normal or reduced nutrient level (reduced by 0.42 kJ digestible energy [DE] per kg and 0.8% crude protein). Both diets were offered without or with supplementation of α-galactosidase and xylanase. The growth performance was assessed within a 43-d feeding period, where at the end, biochemical serum indices were estimated. In Experiment 1, the enzyme-supplemented diet had a greater contents of DE and DE/gross energy ratio (p < 0.05), and a higher AID of Arg, raffinose, stachyose and arabinoxylan (p < 0.05). In Experiment 2, the low nutrient level caused lower daily gain (p < 0.05), which was partially compensated by enzyme addition. Enzyme addition also increased the serum concentration of Lys (p < 0.05). Moreover, it appears that the tested enzyme supplementation could increase dietary DE, serum total amino acid concentrations and decrease serum urea nitrogen.     

Micronization of a Soft Material: Air-Jet and Micro-Ball Milling

The air-jet and ball-mill are frequently used in fine micronization of active pharmaceutical ingredients to the order of 1–5 μm, which is important for increasing dissolution rates, and also for pulmonary delivery. In this study, we investigated the ability of air-jet and ball-mill to achieve adequate micronization on the lab scale using a model soft material, Pluronic® F-68. Material mechanical properties were characterized using the nanometer 600. Pluronic® F-68 was ball-milled in a micro-mill at different material weights and durations in liquid nitrogen vapor. In comparison, a lab scale air-jet mill was used at various milling parameters according to a full factorial design, where the response factors were particle yield and particle size distribution, which was analyzed using laser diffraction and scanning electron microscopy. The yield achieved with the micro-ball mill was 100% but was ~80% for the air-jet mill, which reduced the size of Pluronic® F-68 from 70 μm to sizes ranging between 23–39 μm median diameters. Ball milling produced particles less than 10 μm after 15 min. Although air-jet milling proved capable of particle size reduction of the relatively soft material Pluronic® F-68, limitations to the lower size range achievable were observed. The feed rate of the material into the air jet mill was a significant factor and slower feed rates lead to smaller sizes by allowing more time for particle collisions and subsequent particle breakage to occur. Micro-ball milling under cold condition was more successful at achieving a lower range particle size reduction of soft materials.     

Effects of fermentation products of Ganoderma lucidum on growth performance and immunocompetence in weanling pigs

The purpose of this study was to test fermentation, for its products of a Chinese medicinal mushroom, Ganoderma lucidum, cultured by submerged fermentation for its effect on growth performance and immunocompetence in weanling piglets. In Experiment 1, 72 weanling piglets were allotted to one of four treatments receiving these fermentation products (GLF, expressed as amount of β-glucans) at 0 (control), 50, 100, and 150 mg/kg feed for 4 weeks. The results showed that at a supplementation level of 50 mg/kg feed, GLF caused the best growth performance, the highest pseudorabies antibody titre, and a decrease of blood glucose level. It was also demonstrated that GLF up-regulated the cell-mediated immune response related cytokines (IL-2, IFN-γ, and TNF-α) expression in different lymphoid tissues. After challenging with porcine circovirus (PCV) type 2 (Experiment 2), a supplementation with 50 mg GLF per kg feed also inhibited PCV-2 virus amplification, and ameliorated lymphocyte depletion in different lymphoid tissues. Conclusively, feed supplemented with GLF at 50 mg/kg could be beneficial to counteract the physiological stress in weanling piglets.     

Effects of temporary intensive feed restriction on performance,nutrient digestibility and carcass criteria of growing male Californian rabbits

The aim of the study was to evaluate the effect of a temporary quantitative feed restriction on growth performance, nutrient digestibility and carcass criteria of rabbits. A total of 80 weaned male Californian rabbits (30 d of age) were randomly assigned to four treatments of 20 rabbits each. The Control group was fed ad libitum during the whole experimental period (days 30–72 of age). For the three restricted fed groups the feed intake was reduced by 15%, 30% and 45% compared to the Control group, respectively. The feed restriction was applied after weaning and lasted for 21 d. Thereafter, at 51 d of age, in all treatments the feed supply returned to ad libitum intake till 72 d of age (AL period). The feed restriction decreased the body weight gain of rabbits (during the restriction period and the whole experimental period, p < 0.001) and improved feed conversion ratio during all tested periods (p < 0.001). In the AL period, the daily body weight gain of all groups was similar. After the AL period, the digestibility of all measured nutrients was significantly higher for animals fed restrictively. Furthermore, feed restrictions significantly decreased the proportion of perirenal and scapular fat and increased relative weight and length of the gastrointestinal tract. Therefore, it can be concluded that the applied feed restriction improved feed conversion, nutrient digestibility and reduced fat at the slaughter age of Californian rabbits, but the reduced body weight gain could not be compensated by a subsequent ad libitum feeding for 3 weeks.     

The current status of forest Macrolepidoptera in northern New Jersey: evidence for the decline of understory specialists

We compared most taxa of the forest Macrolepidoptera fauna of the northwestern corner of New Jersey documented from the late 1800s through the 1970s with that documented in 2003–2013. Over 95 % of documented species whose caterpillars feed on trees (n = 307) and forest litter (n = 27) were found. Among understory specialists, all eight specialists on ferns, which deer generally avoid, were found, as were all 12 specialists or oligophages on browse-tolerant lowbush blueberries. In contrast, only 11 of 20 specialists on non-ericaceous shrubs and 16 of 25 specialists on forest forbs were found, despite the bias of targeted sampling for most undetected forb feeders. Non-detections of understory species are highly consistent with deer impacts and most of those we did not find were still being found in the 1970s or 1980s. Most of the 13 undetected tree-feeders have last known collection dates in the 1950s or 1960s locally, and seven have reportedly declined more widely to the east. However, detection success for tree feeders was at least 90 % of all families.     

Impact of an energy- and nutrient-reduced diet containing 10% lignocellulose on animal performance,body composition and egg quality of dual purpose laying hens

In response to ethical concerns regarding the killing of day-old male chicks of layer breeds, the use of dual purpose chickens is increasingly discussed in public while data on nutritional requirements of dual purpose laying hens are not available. The present study examined the impact of an energy- and nutrient-reduced diet containing lignocellulose on performance, body composition and egg quality of dual purpose hens. Female Lohmann Dual chicks were allocated to 12 pens and fed two different diets for 52 weeks: a control (CON) and a treatment diet (LC), based on CON but diluted with 10% lignocellulose. During the trial, animal performance, whole-body composition and egg quality parameters of hens were consistently ascertained. The results showed that LC-fed hens had lower body weights compared to those receiving CON (p < 0.05). During the laying period, feed intake was increased in LC-fed hens (p < 0.001). LC-fed hens showed a higher egg production and egg mass resulting in an improved feed efficiency (p < 0.05) and laid smaller eggs compared to CON-fed hens (p < 0.001). At 52 weeks of age, bodies of LC-fed hens had higher protein and lower fat contents than those fed with CON diet (p ≤ 0.001). Mean body weight was positively correlated to the body fat content (p = 0.004) and body fat content was negatively correlated to the egg production (p = 0.043). Analyses of the egg quality showed that yolk mass at all sampling points and albumen mass at 27 and 42 weeks were lower in hens fed with diet LC compared to those fed with diet CON (p< 0.05). In conclusion, the feeding of energy- and nutrient-reduced diets containing 10% lignocellulose reduced the body fat content and simultaneously improved the laying performance in dual purpose hens.     

Untersuchungen zum Einsatz von ammonisierten Strohpellets als alleinige Grundration in der Wiederkäuerfütterung

Because legumes are a very important feed source for ruminants, the aim of this study was to evaluate the ideal inclusion level of hay Arachis pintoi cv. Belmonte in sheep diets by measuring the dry matter intake (DMI), concentration of volatile fatty acids, ammonia–nitrogen concentration, ruminal pH and the in situ degradability of dry matter (DM) and crude protein (CP). In the experiment with four sheep, a 4 × 4 Latin Square design was used with four periods and four treatments (0%, 30%, 60% and 100% Arachis replacing grass hay). Significant interactions were observed between treatments and sampling times for ammonia–nitrogen and acetate, propionate and butyrate concentration and the acetate:propionate ratio. The ruminal pH and total volatile fatty acids concentration were not affected by interaction between treatments and sampling time. The degradation of DM and CP was similar, rising with the increasing content of Arachis, showing a linear effect. The treatment containing 60% of Arachis showed best results, with good levels of daily weight gain and higher ruminal concentrations of volatile fatty acids. The legume showed high levels of CP, high digestibility and appropriate levels of fibre, with excellent standards of degradation and ruminal characteristics. The use of the legume Arachis for ruminants is a promising option of nutrient supply to meet production demands of these animals.     

A New Angle on Microscopic Suspension Feeders near Boundaries

Microscopic sessile suspension feeders are a critical component in aquatic ecosystems, acting as an intermediate trophic stage between bacteria and higher eukaryotic taxa. Because they live attached to boundaries, it has long been thought that recirculation of the feeding currents produced by sessile suspension feeders inhibits their ability to access fresh fluid. However, previous models for the feeding flows of these organisms assume that they feed by pushing fluid perpendicular to surfaces they live upon, whereas we observe that sessile suspension feeders often feed at an angle to these boundaries. Using experiments and calculations, we show that living suspension feeders (Vorticella) likely actively regulate the angle that they feed relative to a substratum. We then use theory and simulations to show that angled feeding increases nutrient and particle uptake by reducing the reprocessing of depleted water. This work resolves an open question of how a key class of suspension-feeding organisms escapes physical limitations associated with their sessile lifestyle.     

A New Angle on Microscopic Suspension Feeders near Boundaries

Microscopic sessile suspension feeders are a critical component in aquatic ecosystems, acting as an intermediate trophic stage between bacteria and higher eukaryotic taxa. Because they live attached to boundaries, it has long been thought that recirculation of the feeding currents produced by sessile suspension feeders inhibits their ability to access fresh fluid. However, previous models for the feeding flows of these organisms assume that they feed by pushing fluid perpendicular to surfaces they live upon, whereas we observe that sessile suspension feeders often feed at an angle to these boundaries. Using experiments and calculations, we show that living suspension feeders (Vorticella) likely actively regulate the angle that they feed relative to a substratum. We then use theory and simulations to show that angled feeding increases nutrient and particle uptake by reducing the reprocessing of depleted water. This work resolves an open question of how a key class of suspension-feeding organisms escapes physical limitations associated with their sessile lifestyle.     

Influence of feed provisioning prior to digesta sampling on precaecal amino acid digestibility in broiler chickens

A regression approach was applied to determine the influence of feed provisioning prior to digesta sampling on precaecal (pc) amino acid (AA) digestibility in broiler chickens. Soybean meal was used as an example test ingredient. Five feed-provisioning protocols were investigated, four with restricted provision and one with ad libitum provision. When provision was restricted, feed was provided for 30 min after a withdrawal period of 12 h. Digesta were sampled 1, 2, 4 and 6 h after feeding commenced. A diet containing 300 g maize starch/kg was prepared. Half or all the maize starch was replaced with soybean meal in two other diets. Average pc digestibility of all determined AA in the soybean meal was 86% for the 4 and 6-h protocols and 66% and 60% for the 2 and 1-h protocols, respectively. Average pc AA digestibility of soybean meal was 76% for ad libitum feed provision. Feed provisioning also influenced the determined variance. Variance in digestibility ranked in magnitude 1 h > ad libitum > 2 h > 6 h > 4 h for all AA. Owing to the considerable influence of feed-provisioning protocols found in this study, comparisons of pc AA digestibility between studies applying different protocols prior to digesta sampling must be treated with caution. Digestibility experiments aimed at providing estimates for practical feed formulation should use feed-provisioning procedures similar to those used in practice.     

On the distribution and metabolism of Fusarium-toxins along the gastrointestinal tract of endotoxaemic pigs

The aim of this study was to investigate the potential modulatory effect of E. coli lipopolysaccharides (LPS) on residues of deoxynivalenol (DON), de-epoxy-deoxynivalenol (DOM-1), zearalenone (ZEN) and its metabolites α-zearalenol (α-ZEL), β-zearalenol (β-ZEL), zearalanone (ZAN), α-zearalanol (α-ZAL) and β-zearalanol (β-ZAL) after pre- or post-hepatic administration along the gastrointestinal axis. Fifteen barrows were exposed to a naturally mycotoxin contaminated diet (4.59 mg DON/kg feed and 0.22 mg ZEN/kg feed) and equipped with jugular (ju) and portal (po) catheters. On sampling day (day 29), the barrows were infused with LPS or a control fluid (LPS, 7.5 µg/kg body weight; control, 0.9% NaCl) either pre- or post-hepatically, resulting in three infusion groups: CON_ju-CON_po, CON_ju-LPS_po and LPS_ju-CON_po. At 195 min relative to infusion start (210 min post-feeding), pigs were sacrificed and content of stomach and small intestine (proximal, medial and distal part) as well as faeces were collected. In all LPS-infused animals, higher amounts of dry matter were recovered irrespective of LPS entry site suggesting a reduced gastric emptying and a decreased gastrointestinal motility under endotoxaemic conditions. DON metabolism in the gastrointestinal tract (GIT) remained unaltered by treatments and included an increase in the proportion of DOM-1 along the GIT, particularly from distal small intestine to faeces. Variables describing ZEN metabolism suggest a stimulated biliary release of ZEN and its metabolites in LPS-infused groups, particularly in the LPS_ju-CON_po group. In conclusion, the GIT metabolism of ZEN was markedly influenced in endotoxaemic pigs whereby a jugular induction of an acute phase reaction was more effective than portal LPS infusion hinting at a strong hepatic first-pass effect.     

Nutrient utilisation,growth performance and blood metabolites in Murrah buffalo calves (Bubalus bubalis) divergently selected for residual feed intake

The aim of this study was to evaluate differences in efficiency of feed utilisation between buffalo calves with low and high residual feed intake (RFI) by comparing feed intake, nutrient digestibility, growth traits and blood metabolites. Eighteen male Murrah buffalo calves (aged 4–6 months; 70 ± 1.0 kg body weight) were fed ad libitum with a total mixed ration for 120 d. Based on linear regression models involving dry matter intake (DMI), average daily gain (ADG) and mid-test metabolic body size, calves were assigned into low and high RFI groups. The RFI varied from ?0.33 to +0.28 kg DM/d with an average RFI of ?0.14 and 0.14 kg DM/d in low and high RFI calves, respectively. Calves had a mean DMI of 1.9 and 2.4 kg/d and an ADG of 0.5 and 0.6 kg/d in low and high RFI groups, respectively. Low RFI calves ate 19.0% less DM each day and required significantly less metabolisable energy for maintenance compared with high RFI calves (12.5 vs. 16.7 MJ/d). Nutrient digestibility and nitrogen balance did not differ among low and high RFI calves. In more efficient animals (low RFI calves) higher (p < 0.05) plasma level of growth hormone, insulin-like growth factor-1 (IGF-1), triiodothyronine (T₃) and lower concentration of thyroxin hormone were detected. No significant differences in levels of insulin, hydroxyproline, plasma and urine creatinine, total protein and albumin between high and low RFI groups were found. Blood metabolites showed significant (p < 0.05) differences at initial and final stages of study in both groups. At final stage of study, RFI showed negative correlations with growth hormone, IGF-1, T₃, urine creatinine and albumin. Low RFI buffalo calves are more efficient in feed utilisation and the differences in blood metabolites are probably due to differences in feed intake and body metabolism.