This study investigated the effects of different levels of dietary L-arginine (L-Arg) supplementation on the abdominal fat pad, circulating lipids, hepatic fatty acid synthase (FAS) gene expression, gene expression related to fatty acid β-oxidation, and the performance of broiler chickens. We tested whether the dietary L-Arg levels affected the expression of genes related to lipid metabolism in order to reduce body fat deposition. A total of 192 broiler chickens (Cobb 500) aged 21 days with an average BW of 920 ± 15 g were randomly assigned to four groups (six broilers per replicate and eight replicates per treatment). The control group was fed a basal diet, whereas the treatment groups were fed basal diets supplemented with 0.25%, 0.50%, or 1.00% L-Arg for 3 weeks. The average daily feed intake, average daily gain and feed : gain ratio were not affected by the dietary L-Arg levels. However, chickens supplemented with L-Arg had lower abdominal fat content, plasma triglyceride (TG), total cholesterol (TC) concentrations, hepatic FAS mRNA expression and increased heart carnitine palmitoyl transferase1 (CPT1) and 3-hydroxyacyl-CoA dehydrogenase (3HADH) mRNA expression. These findings suggest that the addition of 0.25% L-Arg may reduce the plasma TC concentration by decreasing hepatic 3-hydroxyl-3-methylglutaryl-CoA reductase mRNA expression. This may lower the plasma TG and abdominal fat content by suppressing hepatic FAS mRNA expression and enhancing CPT1 and 3HADH (genes related to fatty acid β-oxidation) mRNA expression in the hearts of broiler chickens.

This work was part of a project designed to assess whether organic selenium (Se) can protect against the toxic effects of cadmium (Cd). A total of 300 1-day-old, as hatched, broilers were randomly distributed in four dietary treatments with five replicate pens per treatment. In T1 treatment, broilers were fed a diet with 0.3 mg/kg added Se, as Se-yeast, without added Cd; in T2, broilers were fed a diet with 0.3 mg/kg Se and 10 mg/kg Cd; in T3, broilers were fed a diet with 0.3 mg/kg Se and 100 mg/kg of Cd; and in T4 treatment broilers were fed a diet with 3 mg/kg Se and 100 mg/kg Cd. The Cd was added to diets T2, T3 and T4 as CdCl2. On the 4th and 6th week, two broilers per replicate pen were killed in order to obtain whole blood, liver, kidney and breast samples. Body mass, feed conversion ratio and mortality were assessed and haematological analyses were performed. Se and Cd levels in tissues were analysed by inductively coupled plasma mass spectrometry. Broilers supplemented with 0.3 mg/kg Se can tolerate low levels of Cd added to the diets, as there were no significant negative effects on the examined performance parameters, whereas addition of excess Cd led to an impairment of broilers’ performance. Mortality of broilers did not differ between the four dietary treatments at any interval point or the whole period. The examined haematological parameters such as haematocrit, total blood protein concentration, and leukocytes types ranged within physiological values, revealing no negative health effects after simultaneous Cd and Se addition. The present study indicated that Se can help against the negative effects of Cd, but cannot counteract all of its negative effects.

In rabbits, the bacterial and archaeal community of caecal ecosystem is composed mostly of species not yet described and very specific to that species. In mammals, the digestive ecosystem plays important physiological roles: hydrolysis and fermentation of nutrients, immune system regulation, angiogenesis, gut development and acting as a barrier against pathogens. Understanding the functioning of the digestive ecosystem and how to control its functional and specific diversity is a priority, as this could provide new strategies to improve the resistance of the young rabbit to digestive disorders and improve feed efficiency. This review first recalls some facts about the specificity of rabbit digestive microbiota composition in the main fermentation compartment, and its variability with some new insights based on recent molecular approaches. The main functions of the digestive microbiota will then be explained. Finally, some possible ways to control rabbit caecal microbiota will be proposed and a suitable timing for action will be defined.

Milk production, fertility, longevity and health records, were extracted from databases of two milk recording organisations in the United Kingdom for the first three lactations of the Holstein–Friesian breed. These included data related to health events (mastitis and lameness), voluntarily recorded on a proportion of farms. The data were analysed to calculate disease incidence levels and to estimate genetic parameters for health traits and their relationships with production and other functional traits. The resulting dataset consisted of 124 793 lactations from 75 137 animals of 1586 sires, recorded in 2434 herds. Incidence of health events increased with parity. The overall incidence of mastitis (MAS) and lameness (LAM), defined as binary traits, were 17% and 16%, respectively. Heritability estimates for MAS and LAM were 0.04 and 0.02, respectively, obtained from repeatability linear sire models. Heritability estimates of mastitis and lameness as count traits were slightly higher, 0.05 and 0.03, respectively. Genetic correlations were obtained by bivariate analyses of all pair-wise combinations between milk 305-day yield (MY), protein 305-day yield (PY), fat 305-day yield (FY), lactation average loge transformed lactation average somatic cell count (SCS), calving interval (CI), days to first service (DFS), non-return at 56 days (NR56), number of inseminations (NINS), mastitis (MAS), number of mastitis episodes (NMAS), lameness (LAM), number of lameness episodes (NLAM) and lifespan score (LS). As expected, MAS was correlated most strongly with SCS (0.69), which supports the use of SCS as an indicator trait for mastitis. Genetic correlations between MAS and yield and fertility traits were of similar magnitude ranging from 0.27 to 0.33. Genetic correlations between MAS with LAM and LS were 0.38 and −0.59, respectively. Not all genetic correlations between LAM and other traits were significant because of fewer numbers of lameness records. LAM had significant genetic correlations with MY (0.38), PY (0.28), CI (0.35), NINS (0.38) and LS (−0.53). The heritability estimates of mastitis and lameness were low; therefore, genetic gain through direct selection alone would be slow, yet still positive and cumulative. Direct selection against mastitis and lameness as additional traits should reduce incidence of both diseases, and simultaneously improve fertility and longevity. However, both health traits had antagonistic relationships with production traits, thus genetic gain in production would be slower.

Thirty various pelleted diets were given to broilers (8/diet) for in vivo measurements of dietary metabolisable energy (ME) value and digestibilities of proteins, lipids, starch and sugars from day 27 to day 31, with ad libitum feeding and total collection of excreta. Water excretion was also measured. Amino acid formulation of diets was done on the basis of ratios to crude proteins. Mean in vivo apparent ME values corrected to zero nitrogen retention (AMEn) were always lower than the AMEn values calculated for adult cockerels using predicting equations from literature based on the chemical analyses of diets. The difference between mean in vivo AMEn values and these calculated AMEn values increased linearly with increasing amount of wheat in diets (P = 0.0001). Mean digestibilities of proteins, lipids and starch were negatively related to wheat introduction (P = 0.0001). The correlations between mean in vivo AMEn values and diet analytical parameters were the highest with fibre-related parameters, such as water-insoluble cell-walls (WICW) (r = −0.91) or Real Applied Viscosity (RAV) (r = −0.77). Thirteen multiple regression equations relating mean in vivo AMEn values to dietary analytical data were calculated, with R2 values ranging from 0.859 to 0.966 (P = 0.0001). The highest R2 values were obtained when the RAV parameter was included in independent variables. The direct regression equations obtained with available components (proteins, lipids, starch, sucrose and oligosaccharides) and the indirect regression equations obtained with WICW and ash parameters showed similar R2 values. Direct or indirect theoretical equations predicting AMEn values were established using the overall mean in vivo digestibility values. The principle of indirect equations was based on the assumption that WICW and ashes act as diluters. Addition of RAV or wheat content in variables improved the accuracy of theoretical equations. Efficiencies of theoretical equations for predicting AMEn values were almost the same as those of multiple regression equations. Water excretion was expressed either as the water content of excreta (EWC), the ratio of water excretion to feed intake (WIR) or the residual value from the regression equation relating water excretion to feed intake (RWE). The best regression predicting EWC was based on sucrose, fermentable sugars (lactose + oligosaccharides) and chloride variables, with positive coefficients. The best equations predicting WIR or RWE contained the sugar and chloride variables, with positive coefficients. Other variables appearing in these equations were AMEn or starch with negative coefficients, WICW, ‘cell-wall-retained water’, RAV or potassium with positive coefficients.

Producing organic fish diets requires that the use of both fishmeal and fish oil (FO) be minimized and replaced by sustainable, organic sources. The purpose of the present study was to replace FO with organic oils and evaluate the effects on feed intake, feed conversion ratio (FCR), daily specific growth rate (SGR) and nutrient digestibility in diets in which fishmeal protein was partly substituted by organic plant protein concentrates. It is prohibited to add antioxidants to organic oils, and therefore the effects of force-oxidizing the oils (including FO) on feed intake and nutrient digestibility was furthermore examined. Four organic oils with either a relatively high or low content of polyunsaturated fatty acids were considered: linseed oil, rapeseed oil, sunflower oil and grapeseed oil. Substituting FO with organic oils did not affect feed intake (P > 0.05), FCR or SGR (P > 0.05) despite very different dietary fatty acid profiles. All organic plant oils had a positive effect on apparent lipid digestibility compared with the FO diet (P < 0.05), whereas there were no effects on the apparent digestibility of other macronutrients when compared with the FO diet (P > 0.05). Organic vegetable oils did not undergo auto-oxidation as opposed to the FO, and the FO diet consequently had a significantly negative effect on the apparent lipid digestibility. Feed intake was not affected by oxidation of any oils. In conclusion, the study demonstrated that it is possible to fully substitute FO with plant-based organic oils without negatively affecting nutrient digestibility and growth performance. Furthermore, plant-based organic oils are less likely to oxidize than FOs, prolonging the shelf life of such organic diets.

Two in vitro and one in vivo experiments were conducted to investigate the effects of a selection of plant compounds on rumen fermentation, microbial concentration and methane emissions in goats. Treatments were: control (no additive), carvacrol (CAR), cinnamaldehyde (CIN), eugenol (EUG), propyl propane thiosulfinate (PTS), propyl propane thiosulfonate (PTSO), diallyl disulfide (DDS), a mixture (40 : 60) of PTS and PTSO (PTS+PTSO), and bromochloromethane (BCM) as positive control with proven antimethanogenic effectiveness. Four doses (40, 80, 160 and 320 µl/l) of the different compounds were incubated in vitro for 24 h in diluted rumen fluid from goats using two diets differing in starch and protein source within the concentrate (Experiment 1).The total gas production was linearly decreased (P<0.012) by all compounds, with the exception of EUG and PTS+PTSO (P⩾0.366). Total volatile fatty-acid (VFA) concentration decreased (P⩽0.018) only with PTS, PTSO and CAR, whereas the acetate:propionate ratio decreased (P⩽0.002) with PTS, PTSO and BCM, and a tendency (P=0.064) was observed for DDS. On the basis of results from Experiment 1, two doses of PTS, CAR, CIN, BCM (160 and 320 µl/l), PTSO (40 and 160 µl/l) and DDS (80 and 320 µl/l) were further tested in vitro for 72 h (Experiment 2). The gas production kinetics were affected (P⩽0.045) by all compounds, and digested NDF (DNDF) after 72 h of incubation was only linearly decreased (P⩽0.004) by CAR and PTS. The addition of all compounds linearly decreased (P⩽0.009) methane production, although the greatest reductions were observed for PTS (up to 96%), DDS (62%) and BCM (95%). No diet–dose interaction was observed. To further test the results obtained in vitro, two groups of 16 adult non-pregnant goats were used to study in vivo the effect of adding PTS (50, 100 and 200 mg/l rumen content per day) and BCM (50, 100 and 160 mg/l rumen content per day) during the 9 days on methane emissions (Experiment 3). The addition of PTS and BCM resulted in linear reductions (33% and 64%, respectively, P⩽0.002) of methane production per unit of dry matter intake, which were lower than the maximum inhibition observed in vitro (87% and 96%, respectively). We conclude that applying the same doses in vivo as in vitro resulted in a proportional lower extent of methane decrease, and that PTS at 200 mg/l rumen content per day has the potential to reduce methane emissions in goats. Whether the reduction in methane emission observed in vivo persists over longer periods of treatments and improves feed conversion efficiency requires further research.

Imputation of high-density genotypes from low- or medium-density platforms is a promising way to enhance the efficiency of whole-genome selection programs at low cost. In this study, we compared the efficiency of three widely used imputation algorithms (fastPHASE, BEAGLE and findhap) using Chinese Holstein cattle with Illumina BovineSNP50 genotypes. A total of 2108 cattle were randomly divided into a reference population and a test population to evaluate the influence of the reference population size. Three bovine chromosomes, BTA1, 16 and 28, were used to represent large, medium and small chromosome size, respectively. We simulated different scenarios by randomly masking 20%, 40%, 80% and 95% single-nucleotide polymorphisms (SNPs) on each chromosome in the test population to mimic different SNP density panels. Illumina Bovine3K and Illumina BovineLD (6909 SNPs) information was also used. We found that the three methods showed comparable accuracy when the proportion of masked SNPs was low. However, the difference became larger when more SNPs were masked. BEAGLE performed the best and was most robust with imputation accuracies >90% in almost all situations. fastPHASE was affected by the proportion of masked SNPs, especially when the masked SNP rate was high. findhap ran the fastest, whereas its accuracies were lower than those of BEAGLE but higher than those of fastPHASE. In addition, enlarging the reference population improved the imputation accuracy for BEAGLE and findhap, but did not affect fastPHASE. Considering imputation accuracy and computational requirements, BEAGLE has been found to be more reliable for imputing genotypes from low- to high-density genotyping platforms.

This study was designed to analyse the evolution in the use of beef bull semen for dairy cattle insemination and, mainly, to assess calving difficulty, gestation length and proportion of stillbirths after breeding pure Holsteins or crossbreeding. Data were collected during 2004 to 2011 for 552 571 Holstein calvings (457 070 Holstein × Holstein, 43 384 Holstein × Limousine, 32 174 Holstein × Belgian Blue and 19 943 Holstein × Galician Blonde). The highest calving difficulty, compared with pure Holsteins was for crosses with Belgian Blue followed by Limousine and Galician Blonde. The Holstein × Limousine and Holstein × Galician Blonde crossbred calves had significantly longer gestation lengths than Holstein × Holstein and Holstein × Belgian Blue calves. Between the latter two, pure Holstein had the shortest gestation length. Calving difficulty and gestation length decreased as the age of the dam advanced. The most difficult calvings were observed in twin calvings, followed by the calvings of male calves and female calves. The gestations leading to the birth of male calves were longer than those leading to female calves and twin calves. Stillbirths were not related to the breed used for mating. Through examining these parameters, sire breed should be considered when selecting a beef breed for the insemination of milk-producing dams.

Although livestock production accounts for a sizeable share of global greenhouse gas emissions, numerous technical options have been identified to mitigate these emissions. In this review, a subset of these options, which have proven to be effective, are discussed. These include measures to reduce CH4 emissions from enteric fermentation by ruminants, the largest single emission source from the global livestock sector, and for reducing CH4 and N2O emissions from manure. A unique feature of this review is the high level of attention given to interactions between mitigation options and productivity. Among the feed supplement options for lowering enteric emissions, dietary lipids, nitrates and ionophores are identified as the most effective. Forage quality, feed processing and precision feeding have the best prospects among the various available feed and feed management measures. With regard to manure, dietary measures that reduce the amount of N excreted (e.g. better matching of dietary protein to animal needs), shift N excretion from urine to faeces (e.g. tannin inclusion at low levels) and reduce the amount of fermentable organic matter excreted are recommended. Among the many ‘end-of-pipe’ measures available for manure management, approaches that capture and/or process CH4 emissions during storage (e.g. anaerobic digestion, biofiltration, composting), as well as subsurface injection of manure, are among the most encouraging options flagged in this section of the review. The importance of a multiple gas perspective is critical when assessing mitigation potentials, because most of the options reviewed show strong interactions among sources of greenhouse gas (GHG) emissions. The paper reviews current knowledge on potential pollution swapping, whereby the reduction of one GHG or emission source leads to unintended increases in another.

Polyphenols are chemically and biologically active compounds. Grape seed extracts (GSEs) have been widely used as a human food supplement for health promotion and disease prevention. However, there is little information regarding its application in animal feeds. An experiment was conducted to investigate the effect of inclusion of GSE at 0.025, 0.25, 2.5 and 5.0 g/kg in a wheat soya bean control diet on growth performance, protein and amino acid (AA) digestibility and plasma lipid and mineral concentrations in broiler chickens at 21 days of age. Performance was not affected by dietary treatment except in the case of birds fed the diet with the highest GSE concentration, which showed a worsening of weight gain and feed conversion. Apparent ileal digestibility (AID) of protein was significantly reduced in the birds fed the highest concentration of GSE, which also had a reduction on the AID of arginine, histidine, phenylalanine, cystine, glutamic acid and proline compared with those fed control diet. The inclusion of graded concentration of GSE in the chicken diets caused a significant linear decrease in the concentrations of plasma copper, iron and zinc. Plasma cholesterol, triglycerides and lipoproteins (high-density lipoprotein, low-density lipoprotein and very-low-density lipoprotein) concentrations were not affected by dietary GSE. In conclusion, this study demonstrated that incorporation of GSE in chicken diets up to 2.5 g/kg had no adverse effect on growth performance or protein and AA digestibility. Feed conversion was reduced and growth rate was retarded, when chickens were fed 5 g/kg of GSE. This study also indicated that grape polyphenols reduce the free plasma minerals.

Improving the amino acid (AA) profile of the diet by using l-Lys, l-Thr, dl-Met, l-Trp and l-Val helps to reduce the dietary CP content, thereby reducing nitrogen excretion while maintaining the performance of pigs. Valine is the fifth limiting AA in cereal–soybean meal-based diets. The extent to which the CP content in the diet can be reduced further without compromising performance depends on the requirement of the next limiting AA. In cereal–soybean meal-based diets, Ile, His and Leu may be the limiting AAs after Val, although information on the requirements for these AAs is scarce. Six experiments were conducted to determine the effect of supplementing a low-CP diet with l-Ile, l-His and l-Leu on the performance of pigs weighing 10 to 20 kg. Experiment 1 was designed to determine the most limiting AA with respect to performance among Ile, His and Leu. A diet 10% deficient in Ile, Leu and His relative to the National Research Council (NRC, 1998) requirement estimates tended to decrease daily feed intake and daily gain by 6% and 8%, respectively. A 10% deficiency in His alone had no effect, whereas a 10% deficiency in Ile or Leu slightly reduced daily feed intake and gain. In the remaining experiments, the standardized ileal digestible (SID) Ile : Lys, His : Lys and Leu : Lys requirements were estimated. In Experiments 2, 3, 4, 5 and 6, 14 blocks of six pigs each were assigned to six levels of SID Ile : Lys (40%, 43%, 46%, 49%, 52% and 55%), His : Lys (20%, 24%, 28%, 32%, 36% and 40%), His : Lys (21%, 24%, 27%, 30%, 33% and 36%), Leu : Lys (70%, 78%, 86%, 94%, 102% and 110%) and Leu : Lys (80%, 90%, 100%, 110%, 120% and 130%), respectively. Across experiments, the estimated SID Ile : Lys, His : Lys and Leu : Lys requirements for maximizing daily gain were 49%, 32% and 102%, respectively, using a curvilinear plateau model. When Ile, His and Leu levels were 10% below the requirement estimate, daily gain was reduced by 9%, 3% and 3%, respectively. The results of this study indicate that the Ile requirement estimate is lower than the current NRC requirement estimate, whereas the Leu and His requirements correspond to those proposed by the NRC.

In most countries, male pigs are physically castrated soon after birth to reduce the risk of boar taint and to avoid behaviours such as fighting and mounting. However, entire male pigs are more feed efficient and deposit less fat than barrows. In addition, many animal welfare organizations are lobbying for a cessation of castration, with a likelihood that this could lead to inferior pork unless an alternative method is used to control boar taint. An alternative to physical castration is immunization against gonadotrophin releasing factor (GnRF) which allows producers to capitalize on the superior feed efficiency and carcass characteristics of boars without the risk of boar taint. From a physiological perspective, immunized pigs are entire males until shortly after the second dose, typically given 4 to 6 weeks before slaughter. Following full immunization, there is a temporary suppression of testicular function and a hormonal status that resembles that of a barrow. Nutrient requirements will be different in these two phases, before and after full immunization. Given that there have been few published studies comparing the lysine requirements of entire males and barrows in contemporary genotypes, it is useful to use gilt requirements as a benchmark. A series of meta-analyses comparing anti-GnRF immunized boars and physical castrates and use of nutritional models suggest that the lysine requirement of entire males before the second immunization is 5% higher than for gilts, from 25 to 50 kg BW, and by 8% from 50 to 95 kg. Given that the penalty in growth performance for having inadequate dietary lysine is greater in males than in gilts or barrows, it is important to ensure that lysine requirements are met to obtain the maximum benefits of entire male production during this phase. After the second immunization, the lysine requirement of immunized males decreases and may become more like that of barrows. In addition, a consistent effect of full immunization is a marked increase in voluntary feed intake from about 10 days after the second dose. Putting these together, the estimated lysine requirement, expressed in terms of diet composition, falls to 94% of the gilt level. Although general principles can be described now, further research is needed to fully define the lysine requirements of immunized boars. It is important that the temporal pattern of tissue deposition rates and feed intake be explored to be incorporated into models to predict nutrient requirements over the period of rapidly changing metabolism.

Herbivores are a significant source of nitrous oxide (N2O) emissions. They account for a large share of manure-related N2O emissions, as well as soil-related N2O emissions through the use of grazing land, and land for feed and forage production. It is widely acknowledged that mitigation measures are necessary to avoid an increase in N2O emissions while meeting the growing global food demand. The production and emissions of N2O are closely linked to the efficiency of nitrogen (N) transfer between the major components of a livestock system, that is, animal, manure, soil and crop. Therefore, mitigation options in this paper have been structured along these N pathways. Mitigation technologies involving diet-based intervention include lowering the CP content or increasing the condensed tannin content of the diet. Animal-related mitigation options also include breeding for improved N conversion and high animal productivity. The main soil-based mitigation measures include efficient use of fertilizer and manure, including the use of nitrification inhibitors. In pasture-based systems with animal housing facilities, reducing grazing time is an effective option to reduce N2O losses. Crop-based options comprise breeding efforts for increased N-use efficiency and the use of pastures with N2-fixing clover. It is important to recognize that all N2O mitigation options affect the N and carbon cycles of livestock systems. Therefore, care should be taken that reductions in N2O emissions are not offset by unwanted increases in ammonia, methane or carbon dioxide emissions. Despite the abundant availability of mitigation options, implementation in practice is still lagging. Actual implementation will only follow after increased awareness among farmers and greenhouse gases targeted policies. So far, reductions in N2O emissions that have been achieved are mostly a positive side effect of other N-targeted policies.

The aim of this study was to estimate (co)variance components for milk coagulation properties (MCP) predicted by mid-infrared spectroscopy (MIRS) during routine milk recording, and to assess their relationships with yield and quality traits. A total of 63 470 milk samples from Holstein-Friesian cows were analyzed for MCP, pH and quality characteristics using MIRS. Casein to protein and protein to fat ratios were calculated from information obtained by MIRS. Records were collected across 1 year on 16 089 cows in 345 herds. The model used for genetic analysis included fixed effects of parity and stage of lactation, and random effects of herd-test-day, cow permanent environmental, animal additive genetic and residual. (Co)variance components were assessed in a Bayesian framework using the Gibbs Sampler. Estimates of heritabilities were consistent with those reported in the literature, being moderate for MCP (0.210 and 0.238 for rennet coagulation time (RCT) and curd firmness (a30), respectively), milk contents (0.213 to 0.333) and pH (0.262), and low for somatic cell score (0.093) and yield traits (0.098 to 0.130). Repeatabilities were 0.391 and 0.434 for RCT and a30, respectively, and genetic correlations were generally low, with estimates greater than 0.30 (in absolute value) only for a30 with fat, protein and casein contents. Overall, results suggest that genetic evaluation for MCP predicted by MIRS is feasible at population level, and several repeated measures per cow during a lactation are required to estimate reliable breeding values for coagulation traits.

This study was designed to evaluate the effects of algal and yeast β-glucans on the porcine gastrointestinal microbiota, specifically the community of Lactobacillus, Bifidobacterium and coliforms. A total of 48 pigs were fed four diets over a 28-day period to determine the effect that each had on these communities. The control diet consisted of wheat and soya bean meal. The remaining three diets contained wheat and soya bean meal supplemented with β-glucan at 250 g/tonne from Laminaria digitata, Laminaria hyperborea or Saccharomyces cerevisiae. Faecal samples were collected from animals before feeding each diet and after the feeding period. The animals were slaughtered the following day and samples were collected from the stomach, ileum, caecum, proximal colon and distal colon. Alterations in Lactobacillus in the gastrointestinal tract (GIT) were analysed using denaturing gradient gel electrophoresis (DGGE) profiles generated by group-specific 16S rRNA gene PCR amplicons. Plate count analysis was also performed to quantify total coliforms. DGGE profiles indicated that all β-glucan diets provoked the emergence of a richer community of Lactobacillus. The richest community of lactobacilli emerged after feeding L. digitata (LD β-glucan). Plate count analysis revealed that the L. hyperborea (LH β-glucan) diet had a statistically significant effect on the coliform counts in the proximal colon in comparison with the control diet. β-glucan from L. digitata and S. cerevisiae also generally reduced coliforms but to a lesser extent. Nevertheless, the β-glucan diets did not significantly reduce levels of Lactobacillus or Bifidobacterium. DGGE analysis of GIT samples indicated that the three β-glucan diets generally promoted the establishment of a more varied range of Lactobacillus species in the caecum, proximal and distal colon. The LH β-glucan had the most profound reducing effect on coliform counts when compared with the control diet and diets supplemented with L. digitata and S. cerevisiae β-glucans.

In vitro and in vivo experiments were designed to evaluate the effectiveness of laboratory-made di-d-fructose dianhydride (DFA)-enriched caramels. The DFA-enriched caramels were obtained from d-fructose (FC), d-fructose and sucrose (FSC), or d-fructose and β-cyclodextrin (FCDC). In the in vitro experiment, raftilose and all caramels increased (P<0.05) l-lactate concentration and decreased (P<0.05) pH. Total short-chain fatty acid concentration was higher (P<0.05) than controls in tubes containing raftilose, FSC, FCDC and commercial sucrose caramel (CSC). Raftilose, and all caramels tested except FSC and FC (1%), increased (P<0.01) lactobacilli log10 number of copies compared with the non-additive control. FSC, FCDC and CSC increased (P<0.01) the bifidobacteria number of copies as compared with controls. All additives, except FCDC, decreased (P<0.01) Clostridium coccoides/Eubacterium rectale log number of copies. Compared with controls, raftilose, FC and CSC led to lower (P<0.01) Escherichia–Shigella and enterobacteria. For the in vivo experiment, a total of 144 male 1-day-old broiler chickens of the Cobb strain were randomly assigned to one of the three dietary treatments for 21 days. Dietary treatments were control (commercial diet with no additive), inulin (20 g inulin/kg diet) and FC (20 g FC/kg diet). Final BW of birds fed FC diet was higher (P<0.01) than controls or inulin-fed birds, although feed: gain values were not different. Feed intake of chickens fed FC was higher (P<0.01) than that of inulin-fed birds but not statistically different from controls. Crop pH values were lower (P<0.01) in birds fed FC diet as compared with control diet, with inulin-fed chickens showing values not different from control- or FC-fed birds. Lower (P<0.05) lactobacilli number of copies was determined in the crop, ileum and caeca of birds fed the inulin diet compared with the control diet. Inulin supplementation also resulted in lower (P<0.05) C. coccoides/E. rectale, bacteroides and total bacteria in caecal contents. Addition of FC to broiler diets gave place to lower (P<0.05) enterobacteria and Escherichia–Shigella in crop and caecal contents compared with controls. The bacteroides number of copies increased (P<0.05) as compared with controls in the ileum, but decreased (P<0.05) in the caeca of chickens fed the FC diet. Energy, ADF, NDF and non-starch polysaccharides faecal digestibilities were greater (P<0.05) than controls in chickens fed diets containing inulin or FC. Fat digestibility was higher (P<0.05) in FC-fed birds compared with controls or inulin-fed chickens. In conclusion, DFA-enriched caramels tested here, particularly FC, may represent a type of new additives useful in poultry production.

The study investigates the effects of a post-weaning water restriction on performance, nutrient digestibility, carcass traits and meat quality of 84-day-old rabbits. A total of 1388 weaned rabbits (35 days) were randomly divided into two groups on the basis of BW and sex. The two groups were fed the same diets ad libitum both in the post-weaning (35 to 60 days) and fattening (61 to 84 days) periods. In the post-weaning period, one group (AL) also received drinking water ad libitum, whereas the other (WR) had a water restriction from 35 to 41 days 2 h/day; from 42 to 48 days 2.5 h/day; from 49 to 55 days 3 h/day; and from 56 to 60 days 4 h/day. During the fattening period, both groups had water-free access. Individual live weights and feed intake per cage were recorded weekly for 32 cages randomly chosen per group (64 rabbits) to calculate the BW gain, feed intake and feed conversion ratio (FCR). The apparent digestibility values of nutrients were measured using acid-insoluble ash. Carcass data were collected from 16 rabbits (8 males and 8 females) per group selected for similar final BW in both groups. Mortality from 35 to 60 days was higher in the AL group (10.1% v. 5.2%, for AL and WR, respectively, P < 0.0001). BW gain was higher for the AL group during both the post-weaning (+22.4%, P < 0.01) and the entire period (+7.5%, P < 0.05). Water restriction reduced feed intake both in the post-weaning (−17.4%, P < 0.0001) and in the entire period (−9.9%, P < 0.05). During the fattening period, FCR was lower for the WR group (5.15 v. 5.75 g/g, for WR and AL, respectively, P < 0.05). The apparent digestibilities of dry matter, organic matter, NDF, ADF and cellulose were greater in the restricted rabbits (+4.7%, +4.5%, +10.2%, +18.8% and +12.8%, P < 0.01, P < 0.01, P < 0.05, P < 0.01, P < 0.05, respectively). Perirenal and scapular fat percentages were higher in the AL rabbits (+30.7% and +116.6%, P < 0.01 and P < 0.001, respectively). Water restriction increased saturated fatty acids (C16:0, +12.9%, P < 0.05), lauroleic acid (C12:1, +75.0%, P < 0.01), n-3 polyunsaturated fatty acids (C20:5, +50.0%, P < 0.01 and C22:5, +16.6%, P < 0.05) and the n-3/n-6 ratio (+28.6%, P < 0.05). The applied water restriction between 35 and 60 days executed during the winter months improved the digestive health of rabbits, with no negative effects on carcass traits, or physical and chemical meat characteristics. However, from the animal welfare point of view, a water restriction can be criticized as a method to restrict feed intake.

The objective of this study was to determine the concentration of total selenium (Se) and the proportions of total Se comprised as selenomethionine (SeMet) and selenocysteine (SeCys) in the postmortem tissues of female pheasants (Phasianus Colchicus Torquator) offered diets that contained graded additions of selenised-enriched yeast (SY) or a single comparative dose of sodium selenite (SS). Thiobarbituric acid reactive substances (TBARS) and tissue glutathione peroxidase (GSH-Px) activity of breast (Pectoralis Major) were assessed at 0 and 5 days postmortem. A total of 216 female pheasant chicks were enrolled into the study. Twenty-four birds were euthanased at the start of the study, and samples of blood, breast muscle, leg muscle (M. Peroneus Longus and M. Gastrocnemius), heart, liver, kidney and gizzard were collected for determination of total Se. Remaining birds were blocked by live weight and randomly allocated to one of four dietary treatments (n = 48 birds/treatment) that either differed in Se source (SY v. SS) or dose (control (0.17 mg total Se/kg), SY-L and SS-L (0.3 mg/kg total Se as SY and SS, respectively) and SY-H (0.45 mg total Se/kg)). Following 42 and 91 days of treatment, 24 birds per treatment were euthanased, and samples of blood, breast muscle, leg muscle, heart, liver, kidney and gizzard were retained for determination of total Se and the proportion of total Se comprised as SeMet or SeCys. Whole blood GSH-Px activity was determined at each time point. Tissue GSH-Px activity and TBARS were determined in breast tissue at the end of the study. There were increases in both blood and tissues to the graded addition of SY to the diet (P < 0.001), but the same responses were not apparent with the blood and tissues of selenite-supplemented birds receiving a comparable dose (SY-L v. SS-L). Although there were differences between tissue types in the distribution of SeMet and SeCys, there were few differences between treatments. There were effects of treatment on erythrocyte GSH-Px activity (P = 0.012) with values being higher in treatments SY-H and SS-L when compared with the negative control and treatment SY-L. There were no effects of treatment on tissue GSH-Px activity, which is reflected in the overall lack of any treatment effects on TBARS.

Concentrations of methane (CH4) in the atmosphere have almost doubled since the mid 1700s, and it is estimated that ∼30% of the global warming experienced by the planet in the last century and a half can be attributed to CH4. Between 25% and 40% of anthropogenic CH4, emissions are estimated to arise from livestock farming. Mitigating absolute emissions from livestock is extremely challenging technically and is made more difficult because of the need to increase food production to meet the demands of a burgeoning world population. Opportunities for manipulating the diet of intensively managed ruminant to reduce absolute CH4 exist, but in grazing livestock the opportunities are constrained practically and economically. Mitigating emissions per unit of product is more tractable, especially in the short term. Although the formation of CH4 is an anaerobic microbiological process, the host animal does seem to exert an influence, as animals differ in the quantity of CH4 they emit when fed the same diet. The reasons for this are not yet clear, but evidence is accumulating that these differences are consistent and have a genetic basis. Exploiting these between animal differences by animal breeding is an attractive mitigation option as it is potentially applicable to all animals and is open to continuous improvement. However, identifying the desired phenotype poses severe practical constraints. Vaccinating the host animal to produce antibodies that can modulate the activities of the organisms responsible for CH4 formation also presents a novel mitigation option.