Changes in blood and spleen lymphocyte populations following antigen challenge in immature male chickens

1. The effects of antigen (Ag) injection on the distribution of lymphocyte populations of Cornell K‐strain male chickens were studied.

2. Two experiments were conducted. In the first, chickens were injected with Brucella abortus (BA), a purported T‐independent antigen. In the second, chickens were injected with sheep red blood cells (SRBC), a T‐dependent antigen. Peripheral blood lymphocytes (PBL) and spleen lymphocytes isolated at 0, 3, 6, 9, 12 and 24 h following Ag injection were stained with monoclonal antibodies (mAb) detecting B‐lymphocytes, CD4⁺ and CD8⁺ cells.

3. B‐lymphocytes in the blood or spleen showed no significant changes following either BA or SRBC injection. In contrast, CD4⁺ cells were decreased in the blood and increased in the spleen following BA and SRBC injections. CD8⁺ cells were decreased in both blood and spleen following BA injection but were unchanged in either blood or the spleen following SR8C injection.

4. These results indicate that there is a change in both spleen and circulating lymphocyte populations, especially T‐helper cells, following Ag injection. T‐helper cells are apparently the primary population involved in the initiation of humoral immunity.     

Effects of Saccharomyces cerevisiae extract on haematological parameters, immune function and the antioxidant defence system in breeder hens fed aflatoxin contaminated diets

1. The study was conducted to investigate the efficacy of Saccharomyces cerevisiae extract (SC) on haematological parameters, immune function, and the antioxidant defence system in breeder hens fed a diet contaminated with low level aflatoxin (AF).

2. Forty-eight Ross 308 breeder hens were fed on diets containing AF (0 or 100?µg/kg) and SC (0 or 1?g/kg) in a 2?×?2 factorial arrangement. Red blood cell (RBC), white blood cell (WBC), and platelet counts, differential leucocyte counts, blood CD3⁺, CD4⁺, CD8⁺ and CD5⁺ T cell ratios, phagocytic activity and oxidative burst of heterophils, plasma and liver catalase activity, and malondialdehyde (MDA) and ascorbic acid concentrations were measured.

3. Plasma and liver MDA concentrations increased (P?P?P?=?0·082) in hens fed the contaminated diet. WBC count, monocyte percentage, phagocytic activity and oxidative burst of heterophils increased (P?P?=?0.088) in SC extract supplemented hens. There was a significant interaction between AF and SC on heterophil, lymphocyte, CD5⁺ cell percentages, and plasma catalase activity. Blood heterophil percentage decreased but lymphocyte percentage increased in hens fed on the AF contaminated diet without SC supplementation. SC supplementation counteracted the negative effect of AF on heterophils and lymphocytes. The CD5⁺ cell percentage decreased in unsupplemented hens fed the AF contaminated diet and this negative effect was minimised in SC supplemented hens. Plasma catalase activity increased in SC supplemented hens fed the uncontaminated diet whereas the effect of SC decreased in hens fed the AF contaminated diet.

4. The SC reduced some of the some adverse effects of AF, and improved functions of the non-specific immune system. Therefore, the SC extract which has been used for improving productive performance in birds and mammals may also be useful for modulating some of the effects of a low level, chronic dosage of AF.     

Anti‐allergic effects of Lactobacillus crispatus KT‐11 strain on ovalbumin‐sensitized BALB/c mice

In this study, we investigated the effects of oral ingestion of Lactobacillus crispatus KT‐11 strain (KT‐11) on the immune response in an allergic rhinitis mouse model, ovalbumin (OVA)‐sensitized BALB/c mice. Sneezing activity in mice that were administered a KT‐11‐supplemented diet was significantly lower than that in mice administered a KT‐11‐free diet (control diet) at age 11 weeks. We found that serum OVA‐specific immunoglobulin E (IgE) levels and total number of interleukin (IL)‐4⁺CD4⁺ spleen cells in mice that were administered a KT‐11‐supplemented diet were significantly lower than in mice administered a control diet. The ratio of spleen interferon‐γ⁺CD4⁺/IL‐4⁺CD4⁺ cells was higher in the mice administered the KT‐11‐supplemented diet compared to that in mice administered the control or L. rhamnosus GG‐supplemented diet. In contrast, the number of CD11b⁺CD80⁺ and FcεRIα⁺CD117⁺ cells was significantly lower in mice administered the KT‐11‐supplemented diet. These results suggested that KT‐11 reduced OVA‐induced allergic symptoms in BALB/c mice via the adjustment of the T helper type 1/T helper type 2 balance, and a decrease in the number of antigen‐presenting cells and high affinity IgE receptor‐positive mast cells.     

Supplementation of distiller's grains during late gestation in beef cows consuming low‐quality forage decreases uterine,but not mammary,blood flow

Positive effects have been observed in offspring from beef cows supplemented with corn dried distillers grain with solubles (DDGS) during late gestation. The hypothesis of this study was that late gestational DDGS supplementation to beef cows would increase blood flow (BF) to the gravid uterus and mammary gland thus impacting birthweight and post‐natal growth of the offspring. Experiment 1 investigated mammary gland BF in multiparous cows during late pregnancy. Beef cows were fed a control (CON1) diet of low‐quality hay (n = 5) or a supplement diet (SUP1) of low‐quality hay with DDGS [1.7 g/kg of body weight (BW); n = 6]. In Experiment 2, multiparous late pregnant beef cows were fed either a control (CON2) diet of a low‐quality hay (n = 4) or a supplement diet (SUP2) of low‐quality hay with DDGS (1.7 g/kg of BW; n = 5). Uterine and mammary gland BF were recorded every 21 days during late gestation. In Experiment 1, there were no effects of diet or day on mammary gland hemodynamics. In Experiment 2, total and ipsilateral uterine BF was less (p ≤ 0.04) in SUP2 vs. CON2 cows and similar BF to contralateral horns. Mammary gland BF was unaltered by maternal supplementation. Even when measured in two different years in two different environments, mammary gland BF remained unaltered to DDGS supplementation. Investigations on the mechanism that may impact uterine BF during late gestation remain to be known.     

Effect of feeding garlic leaf on microbial nitrogen supply,kinetics of plasma phenylalanine,tyrosine and protein synthesis in sheep

The objective of the present study was to assess the feeding effects of garlic leaf on microbial N supply (MNS), turnover rates of plasma phenylalanine (PheTR) and tyrosine (TyrTR) and whole body protein synthesis (WBPS) in sheep. The sheep were fed either mixed hay (Hay‐diet, as control) or hay plus garlic leaf diet (GL‐diet, at a ratio of 9:1) in a crossover design each for a 21 day period. The isotope dilution method using [²H₅]Phe and [²H₂]Tyr was performed on the 21st day of each dietary treatment. Nitrogen intake remained similar between the diets and N absorption and N digestibility were higher (P < 0.05) in the GL‐diet than Hay‐diet. Total purine derivatives excretion and MNS were greater (P < 0.05) in the GL‐diet than the Hay‐diet. Plasma PheTR tended to be higher (P = 0.06) during GL feeding and TyrTR did not differ between the diets. Further, WBPS tended to be greater (P = 0.05) for the GL‐diet compared with the Hay‐diet. Hence, the present results suggest that garlic leaf may have positive effects on N metabolism by influencing MNS in sheep and could be used as a potential ruminant feed in the future.     

Influence of the dietary potassium content on transepithelial potassium transport in rat jejunum

In a recent study, we found that the distal rat jejunum is able to secrete K⁺ under in vitro conditions. The question therefore arises as to whether the small intestine might participate in K⁺ homeostasis. Consequently, this study examined the influence of the dietary K⁺ content on transepithelial K⁺ transport in rat jejunum. Rats were fed two diets differing in K⁺ content (control diet 4.0 g K⁺/kg, low K⁺ diet (LK) 0.27 g K⁺/kg). After a minimal feeding period of 7 days, distal jejunal sheets were mounted in Ussing chambers and unidirectional ⁸⁶Rb⁺ fluxes (as a marker for K⁺ transport) were measured under short‐circuit conditions. Jejunum obtained from rats fed the control diet showed a net K⁺ secretion of 200 nmol Rb⁺/h/cm². Unidirectional Rb⁺ fluxes were smaller in distal jejunum from rats fed the LK diet. In these tissues, glucose‐induced short‐circuit current and tissue conductance were also smaller than in controls. However, net Rb⁺ fluxes were not significantly different in small intestine from K⁺‐restricted rats compared with jejunum from control animals. Based on the observation that the dietary K⁺ content does not affect transepithelial net K⁺ transport, we conclude that transcellular K⁺ secretion by the small intestine is not involved in K⁺ homeostasis.     

Lactobacillus plantarum BS22 promotes gut microbial homeostasis in broiler chickens exposed to aflatoxin B1

Probiotics promote the health of the host by maintaining intestinal microbial homeostasis. This study aimed to investigate the benefits of Lactobacillus plantarum BS22 (LP) in the gastrointestinal tract (GIT) microbial homeostasis of broiler chickens exposed to aflatoxin B₁ using the PCR‐DGGE, viable count and real‐time PCR. The toxin adsorption experiment demonstrated that treatment R5 (1.0 × 10⁸ CFU/g LP) exhibited good absorptive effect in adsorbing the aflatoxin B₁ (AFB₁) in vitro. DGGE showed that the composition and structure of gut microbiota were more similar in the mucosa than in the content of all the samples. In addition, higher diversity of the microbiota was observed in the caecum and glandular stomach than in other segments. Lactobacillus, Enterococcus and Enterobacteriaceae were more abundant in the ileum than in the other segments. Enterobacteriaceae in groups I (basal diet) and II (basal diet+50 μg/kg AFB₁) showed a significant difference in group III (basal diet + 50 μg/kg AFB₁ + 1 × 10⁸ CFU/g LP) in the crop content and duodenum mucosa (p < .05). This investigation indicates that the L. plantarum BS22 promotes GIT microbial homeostasis in broiler chickens exposed to AFB₁, particularly for the intestine mucosa microbiota. Thus, L. plantarum BS22 is a possible candidate for degrading AFB_1.     

Ouabain-sensitive respiration and protein synthesis in duodenal mucosa and liver in rats fed increasing levels of pea fibre or protein and housed in 18 or 28°C environments

Seventy‐two Wistar rats were used in two studies to investigate the effect of environmental temperature (18 or 28°C), and increasing levels of dietary fibre (low, 68 g/kg dry matter (DM); medium 110 g/kg DM; high, 157 g/kg DM) and protein (low, 91 g/kg DM; medium, 171 g/kg DM; high, 262 g/kg DM) on respiration attributable to Na⁺,K⁺‐ATPase activity and protein synthesis in duodenal mucosa and liver of rats. In vitro O₂ consumption in tissues was measured polarographically using a Clark‐style YSI biological O₂ monitor. Whole‐body O₂ consumption was measured with two open‐circuit respiration chambers. Whole‐body O₂ consumption was higher (p < 0.05) at 18°C than at 28°C. Rats fed the low protein diet had significantly higher (p < 0.05) whole‐body O₂ consumption than those fed the medium or high protein diet. Compared with 28°C, the environmental temperature of 18°C caused an increase (p < 0.05) in total O₂ consumption and O₂ consumption attributable to Na⁺,K⁺‐ATPase activity in duodenal mucosa. There was no effect (p > 0.05) of environmental temperature on total O₂ consumption, Na⁺,K⁺‐ATPase activity attributable to protein synthesis dependent on O₂ consumption in the liver. Total O₂ consumption and O₂ consumption attributable to Na⁺,K⁺‐ATPase activity increased (p < 0.05) in duodenal mucosa in rats fed the low level of dietary fibre compared with rats fed the medium level of dietary fibre. In vitro O₂ consumption determined in duodenal mucosa and in liver did not always correspond to whole‐body O₂ consumption. This may indicate that respiration in the duodenum and liver adapts differently and may not reflect changes in whole‐body respiration in response to dietary modification and changes in thermal environment.     

Effect of adjuvants on in ovo vaccination against Newcastle disease on hatchability,performance and antibody titres in commercial pullets

This study was conducted to investigate the efficacy of in ovo administration of aluminium hydroxide (AH) and/or mannan oligosaccharide (MOS) adjuvants along with lentogenic VG/GA strain‐Avinew to alleviate the embryonic pathogenicity of Newcastle disease virus. Six hundred and thirty fertilized Bovans eggs were divided into nine groups of 70 each incubated in a commercial hatchery and administered with eight types of in ovo injections in a factorial design of 2 × 2 × 2 including with/without AH, MOS and Newcastle disease vaccine (NDV), and one uninjected group on day 18 of incubation. Hatchability was higher in the eggs received MOS and/or AH adjuvants plus NDV compared those injected with NDV alone which confirmed the attenuation of NDV. However, the average daily feed intake and feed conversion ratio of pullets hatched from NDV‐injected eggs were significantly reduced, but did not affect growth performance during 0‐42 days of age. The performance of pullets hatched from eggs injected with AH, MOS or their mixture with NDV was not significantly different during all growth periods. Pullets from MOS + vaccine injected eggs had significantly higher antibody titres against NDV compared to those hatched from either injected with saline or uninjected on d 28 (p < .05). In addition, AH plus vaccine and MOS significantly improved total anti‐SRBC and IgG respectively. Histological observation revealed that injection of MOS adjuvant into eggs led to increase crypt depth, whereas AH injection caused a reduction in villus surface area of jejunum in chicks on d 14 post‐hatch. It is concluded that in ovo MOS injection as compared to AH may be more effective to attenuate the embryonic pathogenicity of in ovo NDV injection.     

Effects of Chinese traditional herbal medicine complex supplementation on the growth performance,immunity and serum traits of pigs

The purpose of this study was to investigate the effects of a traditional Chinese herbal medicine complex supplementation on the growth performance, immunity and serological traits of pigs, and the feasibility of its use as a substitute for antibiotics. Thirty‐six weaned pigs LYD with average initial body weight of 10 ± 0.55 kg were randomly divided into three treatments with three replicates. These constituted the control, the antibiotics group (chlortetracycline 100 µg/kg, oxytetracycline 100 µg/kg), and 0.3% Chinese herbal medicine complex group (CHM). Experiment results indicated that the CHM group exhibited significantly increased average feed intake and peripheral blood CD3⁺CD8⁺ T cell percentage as compared with those of the antibiotics group (P < 0.05). High‐density lipoprotein (HDL) level was greater while low‐density lipoprotein + very low‐density lipoprotein (LDL + VLDL) level was lower in the CHM group than the control group (P < 0.05). The in vitro results indicated that peripheral blood mononuclear cells (PBMC) stimulated by Con‐A produced a greater interleukin (IL)‐6 level in the CHM group and IL‐6 level stimulated by lipopolysaccharide was greater than the antibiotics groups (P < 0.05). Above all, this study has indicated that the addition of Chinese traditional herbal complex to pigs' diets has beneficial results.     

Effect of dietary supplementation of calcium butyrate on growth performance,carcass traits,intestinal health and pro‐inflammatory cytokines in Japanese quails

The objective of the present study was to evaluate the potential effect of dietary calcium butyrate on growth performance, carcass traits and gut health in Japanese quails. In total, 320 one‐day‐old Japanese quails were randomly assigned to 4 equal treatments, with 8 replicates of 10 Japanese quails, for 4 weeks. The Japanese quails in control treatment were fed control diet whereas in the other treatments the Japanese quails were fed diet supplemented with calcium butyrate at 0.3, 0.5 and 0.7 g/kg diet. Data concerning performance measurements were recorded weekly. In addition, eight Japanese quails (one/replicate) from each treatment were selected randomly for serum collection to measure pro‐ and anti‐inflammatory cytokines. Pooled faecal samples from each replicate of each treatment were also collected at three time points (0, 2 and 4 weeks) for count E. coli and C. perfringens. The results showed that after 7 days of the experimental period, Japanese quails fed calcium butyrate supplemented diet at 0.7 g/kg showed a greater (p < .05) body weight and a favourable (p < .05) feed conversion ratio than the other treatments. Moreover, serum superoxide dismutase and catalase activities were increased (p < .05) in Japanese quails fed calcium butyrate supplemented diet at 0.7 g/kg. Calcium butyrate supplementation at 0.7 g/kg was associated with reduction (p < .05) in TNF‐α, IL‐6 and IL1‐β, while IL‐10 was increased (p < .05). In addition, after 2 weeks of calcium butyrate supplementation, a reduction (p < .05) in E. coli and C. perfringens counts was observed in excreta of Japanese quails fed 0.5 and 0.7 g calcium butyrate/kg diets. It is concluded that calcium butyrate supplementation improves body weight gain, reduces E. coli and C. perfringens counts and has anti‐inflammatory/anti‐oxidant effect in Japanese quails.     

Effect of added dietary threonine on growth performance,health, immunity and gastrointestinal function of weaning pigs with differing genetic susceptibility to Escherichia coli infection and challenged with E. coli K88ac

Threonine (Thr) is important for mucin and immunoglobulin production. We studied the effect of added dietary Thr on growth performance, health, immunity and gastrointestinal function of weaning pigs with differing genetic susceptibility to E. coli K88ac (ETEC) infection and challenged with ETEC. Forty‐eight 24‐day‐old weaned pigs were divided into two groups by their ETEC susceptibility using mucin 4 (MUC4) gene as a marker (2 MUC4^?/?, not‐susceptible, and 2 MUC4^+/+, susceptible, pigs per litter). Within genotype, pigs were fed two different diets: 8.5 (LThr) or 9.0 (HThr) g Thr/kg. Pigs were orally challenged on day 7 after weaning and slaughtered on day 12 or 13 after weaning. Before ETEC challenge, HThr pigs ate more (p < 0.05). The diet did not affect post‐challenge growth, but HThr tended to increase post‐challenge feed efficiency (p = 0.087) and overall growth (p = 0.087) and feed efficiency (p = 0.055). Before challenge, HThr pigs excreted less E. coli (p < 0.05), while after challenge, diet did not affect the number of days with diarrhoea and ETEC excretion. MUC4^+/+ pigs responded to the challenge with more diarrhoea, ETEC excretion and anti‐K88 IgA in blood and jejunal secretion (p < 0.001). HThr pigs had a higher increase of anti‐K88 IgA values in jejunal secretion (p = 0.089) and in blood (p = 0.089, in MUC4^+/+ pigs only). Thr did not affect total IgA and IgM values, morphometry of jejunum, goblet cells count in colon, total mucin from jejunum and colon, but varied jejunal goblet cells counts (p < 0.05). In the first two post‐weaning weeks, 8.5 g Thr/kg diet may be not sufficient to optimize initial feed intake, overall feed efficiency and intestinal IgA secretion and to control the gut microbiota in the first post‐weaning week, irrespective of the pig genetic susceptibility to ETEC infection.     

Effects of astaxanthin and esterified glucomannan on hematological and serum parameters,and liver pathological changes in broilers fed aflatoxin‐B1‐contaminated feed

The effects of astaxanthin (ASTA) and esterified glucomannan (EMG) on hematological and serum parameters, and liver pathological changes in broilers fed on aflatoxin‐B1 (AFB1) contaminated diet were investigated. Two hundred and forty 10‐day‐old broilers were randomly assigned to one of five dietary treatments including: (i) control diet; (ii) AFB1‐contaminated diet; (iii) AFB1 + EGM diet; (iv) AFB1 + ASTA diet; and (v) AFB1 + EGM + ASTA diet. At 35 days old, blood and liver tissue samples were collected for analysis. Results indicated that total white blood cell (WBC) number, hemoglobin (Hgb) concentration, hematocrit (Hct) level, serum alanine amino transferase (AST) and γ‐glutamyl transferase (GGT) activities, red blood cell (RBC) number, serum globulin (GLB) and urea nitrogen (BUN) concentrations (P < 0.05) were increased by feeding AFB1‐contaminated diet. EMG and ASTA alleviated the alteration of RBC, WBC, Hgb and AST caused by AFB1‐contaminated diet. Liver superoxide dismutase (SOD) activity was reduced, while myeloperoxidase (MPO) activity was increased by AFB1‐contaminated diet (P < 0.05). Both EGM and ASTA restrained the increase of MPO activity (P < 0.05). Degeneration of the liver tissues was found in broilers fed AFB1‐contaminated diet. It suggested that feeding 0.4 mg/kg AFB1‐contaminated diet resulted in adverse effects on blood parameters and liver morphology. Dietary addition of EGM addition at 5 g/kg diet, ASTA at 10 mg/kg diet and especially their combination showed positive protection effects on alleviating the alteration of feeding AFB1. The results indicated that supplementation of 5 g EGM/kg diet, 10 mg ASTA/kg diet and their combination could partially or greatly alleviate the adverse effects caused by AFB1, with the EGM+ASTA group receiving the most effective treatment.     

Effect of dietary probiotic,prebiotic and synbiotic supplementation on performance,immune responses,intestinal morphology and bacterial populations in broilers

This study was conducted to investigate the effects of probiotic (Primalac), prebiotic (TechnoMos) and synbiotic (Primalac + TechnoMos) supplementation on performance, immune responses, intestinal morphology and bacterial populations of ileum in broilers. A total of 240 one‐day‐old broiler chicks were randomly divided into four treatment groups which included 60 birds. Control group did not receive any treatment. The chicks in the second, third and fourth groups were fed probiotic (0.9 g/kg), prebiotic (0.9 g/kg) and probiotic (0.9 g/kg) plus probiotic (0.9 g/kg; synbiotic), respectively, at entire period. Daily feed intake, daily weight gain and feed conversion ratio were evaluated. The birds were immunized by sheep red blood cell (SRBC) on days 12 and 29 of age and serum antibody titres were measured on days 28, 35 and 42. Newcastle vaccines administered on days 9, 18 and 27 to chicks and blood samples were collected on day 42. Intestinal morphometric assessment and enumeration of intestinal bacterial populations were performed on day 42. The results indicated that consumption of probiotic, prebiotic and synbiotic had no significant effect on daily feed intake, daily body weight gain, feed conversion ratio, carcass traits, intestinal morphology and bacterial populations of ileum (p > 0.05). Consumption of prebiotic increased total and IgM anti‐SRBC titres on days 28 and 42 and antibody titre against Newcastle virus disease on day 42 (p < 0.05). Synbiotic increased only total anti‐SRBC on day 28 (p < 0.05). It is concluded that consumption of prebiotic increased humoral immunity in broilers. Therefore, supplementation of diet with prebiotic for improvement of humoral immune responses is superior to synbiotic supplementation.     

Impact of mash and crumble diets on intestinal amino acids transporters,intestinal morphology and pancreatic enzyme activity of broilers

The objective of this study was to evaluate effects of mash and crumble pre‐starter diets on pancreatic enzyme activity, intestinal morphology, gene expression of intestinal peptide and amino acid (AA) transporters of broilers. Broilers in battery cages were assigned to different feed forms of pre‐starter diet from 1 to 10 days of age. Significantly increased body weight gain (BWG), feed intake (FI) and lowered FCR were observed in birds fed crumble pre‐starter diet (CPD, p < 0.05). Feed forms had no effect on whole and small intestine length, but relative intestinal length and relative small intestinal length significantly increased in the broilers fed a mash pre‐starter diet (MPD, p < 0.05). Feeding CPD increased the weight of pancreas (p < 0.05), but relative weight of the pancreas was not influenced by treatments. Pancreatic protease and amylase activities significantly increased in the broilers fed CPD (p < 0.05) but the activity of lipase was not influenced. Crypt depth (CD) and villus height (VH) were higher in broilers fed CPD (p < 0.05) but villus width (VW), villus surface area (VSA) and villus height‐to‐crypt depth ratio (VCR) were not influenced by treatments. mRNA levels for peptide transporter 1 (PepT1), Na⁺‐independent cationic AA transporter1 (CAT1), Na⁺‐independent cationic and Na⁺‐dependent neutral AA transporter 1 (y⁺LAT1) and Na⁺‐dependent neutral AA transporter (B⁰AT) were lower in birds fed CPD (p < 0.05). There were no differences in mRNA abundance of Na⁺‐independent cationic and zwitterionic AA transporter (b^0,+AT) among treatments. Overall, the present data showed that feeding crumble diet during first 10 days of age, through higher FI, enhanced intestinal histomorphology, increased digestive enzyme activity is beneficial to growth performance of broilers. Indeed, dietary form can be an important factor in the expression of jejunal transporters.     

A comparison of a new net energy system with the metabolisable energy system in broiler diet formulation,performance and profitability 1

Two trials were conducted with unsexed broilers to compare a net energy (NE) system and a metabolisable energy (ME) system on least‐cost broiler diet formulation, broiler performance and economic efficiency. Both energy systems were compared in the range of 3000 (2161) to 3400 kcal ME/kg (2560 kcal NE/kg) using rations with increasing energy concentration of about 100 kcal/kg food.

The two different energetic evaluation systems had considerable effect on dietary composition, the penalty cost of rejected ingredients, the marginal profit of some limiting constraints and the position of the least‐cost nutrient concentration. The starter and finisher rations, based on NE values, were on average 4.77 and 2.43 BF²/100 kg cheaper, respectively than those based on ME values. For equal NE contents, they contained 50 to 70 kcal less ME/kg and 1% less crude protein.

The broiler performances were on average better on the NE‐diets. The mean difference of 20 to 30 g in body weight was significant at 4 and 6 weeks (P < 0.01 and P < 0.05).

Regression analysis indicated no significant effect of rising energy concentration on food intake with the ME‐diets, but a significant (P < 0.05) linear decrease with the NE‐diets of 1.16 ± 0.34 and 1.72 ± 0.37 g/chick d at 6 and 8 weeks respectively for every 100 kcal/kg rise in the NE content of the ration. As a result body weight at 6 weeks improved linearly per increment of 100 kcal NE/kg with 37.2 ± 3.2 g (P < 0.05) on the ME‐diets and with 18.8 ± 6.8 g (P = 0.08) on the NE‐diets.

The efficiency of food utilisation, although slightly better on the NE‐diets, was not significantly affected by the energy systems. As expected, linear improvements (P < 0.001) of respectively 58 ± 6 and 62 ± 11 g food/kg weight gain at 6 and 8 weeks were noted for every increment of 100 kcal NE/kg diet.

Returns over food costs were for the whole energy range higher on the NE‐diets (average 0.66 BF/chick, variation 1.01 to 0.23 BF/chick). Gross profit increased with rising nutrient density from 16.33 to 17.97 BF/chick on the ME‐diets and from 17.34 to 18.23 BF/chick on the NE‐diets. The data illustrate that the economical efficiency of broiler production can be considerably improved by taking into account the effect of both energy content and energy system.     

Effect of zinc bacitracin and phytase on growth performance,nutrient digestibility,carcass and meat traits of broilers

A total of 336 one‐day‐old Hubbard broiler chickens were randomly distributed among 8 groups, each containing six replicates (7 chickens/replicate). From 1 to 40 days of age, the groups fed the same starter, grower and finisher diets. The control group was unsupplemented; zinc bacitracin (ZnB) group received the antibiotic at 0.5 g/kg; fungal phytase (FP) groups received 250, 500 and 1000 U/kg diet of Aspergillus niger phytase (FP_250, FP_500 and FP_1000 groups), respectively; bacterial phyatse (BP) groups received 250, 500 and 1000 U/kg diet of Escherichia coli phytase (BP_250EP, BP_500EP and BP_1000EP groups) respectively. Considering the whole experimental period, body weight gain was unaffected by ZnB and different concentrations of bacterial and fungal phytase; however, the feed conversion ratio of the group fed a diet supplemented with 500 U of BP was better (p < 0.01) than those fed with a diet supplemented with 500 U of FP. BP_250 group had a higher (p < 0.05) apparent digestibility of ether extract compared to FP_250 group. In conclusion, bacterial phytase at 500 U may enhance performance of broiler chickens fed during days 1–40 of age and yield similar growth performance and economic efficiency to those of eB‐supplemented groups.     

Effects of fermented garlic powder supplementation on growth performance,nutrient digestibility,blood characteristics and meat quality in growing‐finishing pigs

One hundred pigs (BW = 50.7 ± 1.89 kg) were used to investigate the effects of fermented garlic powder (FGP) in growing‐finishing pigs. Pigs were allotted to one of five treatments, included: (i) NC (basal diet); (ii) PC (NC + 44 mg/kg of Tylosin); (iii) FGP1 (NC + 1 g/kg FGP); (iv) FGP2 (NC + 2 g/kg FGP); and (v) FGP4 (NC + 4 g/kg FGP). Supplemental FGP increased average daily gain (ADG) and gain/feed ratio compared with those fed NC diet throughout the experiment (P < 0.05, linearly). Dietary PC treatment increased the ADG and average daily feed intake during the first 6 weeks (P < 0.05). The inclusion of FGP2 and FGP4 treatments had higher apparent total tract digestibility of dry matter and nitrogen (P < 0.05) than those in the NC treatment. Dietary NC treatment exhibited lower (P < 0.05) lymphocyte count (6 and 12 weeks) and immunoglobulin G (12 weeks) than those in the other treatments. Marbling scores were higher (P < 0.05) in FGP treatment groups than the NC treatments. Pigs fed on FGP2 and FGP4 diets evidenced lower 2‐thiobarbituric acid reactive substances value (P < 0.05) than those in the NC and PC treatments. Collectively, our findings demonstrated that the administration of FGP at a level of 2 or 4 g/kg improved growth performance, nutrient digestibility and meat quality in growing‐finishing pigs.     

Effects of dietary oregano and garlic essential oils on carcass characteristics,meat composition,colour, pH and sensory quality of broiler meat

1. An experiment was conducted to determine the individual and combined effects of two essential oils, oregano and garlic, on carcass characteristics, meat composition, colour, pH and sensory quality of broiler meat.

2. The diets were supplemented with no essential oil (control), oregano essential oil or garlic essential oil at 300 mg/kg and oregano essential oil at 150 mg/kg + garlic essential oil at 150 mg/kg.

3. Dietary oregano and garlic oil supplementation did not affect carcass yields, the relative weight of carcass parts, breast and thigh meat composition, pH or b* value of breast meat. Oregano + garlic oil supplementation significantly decreased the L* value. The a* value of breast meat in birds given a diet supplemented with oregano oil was lower than that in birds given a diet supplemented with garlic oil and oregano oil + garlic oil. The essential oil addition had no positive effect on the oxidative stability. There was no difference between the treatments in breast appearance.

4. The juiciness, flavour, oxidised flavour and acceptability of breast meat samples were affected by treatments.     

Pharmacokinetics of tildipirosin in bovine plasma,lung tissue,and bronchial fluid (from live,nonanesthetized cattle)

Menge, M., Rose, M., Bohland, C., Zschiesche, E., Kilp, S., Metz, W., Allan, M., Röpke, R., Nürnberger, M. Pharmacokinetics of tildipirosin in bovine plasma, lung tissue, and bronchial fluid (from live, nonanesthetized cattle). J. vet. Pharmacol. Therap.  35 , 550–559. The pharmacokinetics of tildipirosin (Zuprevo^® 180 mg/mL solution for injection for cattle), a novel 16‐membered macrolide for treatment, control, and prevention of bovine respiratory disease, were investigated in studies collecting blood plasma, lung tissue, and in vivo samples of bronchial fluid (BF) from cattle. After single subcutaneous (s.c.) injection at 4 mg/kg body weight, maximum plasma concentration (C_max) was 0.7 μg/mL. T_max was 23 min. Mean residence time from the time of dosing to the time of last measurable concentration (MRT_last) and terminal half‐life (T_1/2) was 6 and 9 days, respectively. A strong dose–response relationship with no significant sex effect was shown for both C_max and area under the plasma concentration–time curve from time 0 to the last sampling time with a quantifiable drug concentration (AUC_last) over the range of doses up to 6 mg/kg. Absolute bioavailability was 78.9%. The volume of distribution based on the terminal phase (V_z) was 49.4 L/kg, and the plasma clearance was 144 mL/h/kg. The time–concentration profile of tildipirosin in BF and lung far exceeded those in blood plasma. In lung, tildipirosin concentrations reached 9.2 μg/g at 4 h, peaked at 14.8 μg/g at day 1, and slowly declined to 2.0 μg/g at day 28. In BF, the concentration of tildipirosin reached 1.5 and 3.0 μg/g at 4 and 10 h, maintained a plateau of about 3.5 μg/g between day 1 and 3, and slowly declined to 1.0 at day 21. T_1/2 in lung and BF was approximately 10 and 11 days. Tildipirosin is rapidly and extensively distributed to the respiratory tract followed by slow elimination.