Fecal Gas Production of Ten Common Horse Feeds Supplemented With Saccharomyces cerevisiae

The study aimed to assess the nutritive value of 10 feeds (grains and forages) commonly used in horse nutrition in Mexico, on the basis of their chemical composition, in vitro organic matter digestibility (IVOMD) and in vitro gas production measurements with or without the supplementation of Saccharomyces cerevisiae (SC) at 4 mg/g DM. Fecal inoculum was obtained from 4 adult English Thoroughbred horses fed on restricted amount of concentrate and oat hay ad libitum. Substrates tested were: 6 concentrates (corn gluten meal, soybean meal, steam-rolled corn, steam-rolled barley, oat grain, and wheat bran) and 4 roughages (soybean hulls, corn stover, alfalfa hay, and oat hay). Gas production (GP) was recorded at 2, 4, 6, 8, 10, 12, 14, 24, 48, and 70 hours using the pressure transducer technique. Some ingredient × yeast interactions were observed (P ≤ .020) for the asymptotic GP and GP at 48 and 70 hours of incubation. Yeast addition increased (P < .001) the asymptotic GP of concentrates compared to roughages. Concentrate feeds had higher (P < .05) GP and lower (P < .001) rate of GP compared to roughages without yeast. From 24 to 70 hours of incubation, forages with or without yeast had lower (P < .05) GP compared to concentrates supplemented with SC. Forages had higher fermentation pH compared to concentrates but lower (P < .05) metabolizable energy, IVOMD, and microbial protein production compared to concentrates. Supplementation with SC increased (P < .05) the asymptotic GP of oat grain, soybean meal, soybean meal, steam-rolled barley, steam-rolled corn, wheat bran, corn stover, and oat hay, without affecting the rate of GP or lag time of oat grain, soybean meal, wheat bran, corn stover, and oat hay. Moreover, supplementation with SC increased (P < .05) metabolizable energy, IVOMD, and microbial protein production of steam-rolled barley, wheat bran, and corn stover, without affecting (P > .05) the fermentation of other feeds. Supplementation with SC improved fermentation of feeds with higher effects on concentrates compared to roughages. It was concluded that although SC mainly improves concentrate utilization by horses, it also improves fiber digestion when used on high-roughage diets fed to horses.     

Effect of Partial Replacement of Steam Rolled Corn With Soybean Hulls or Prickly Pear Cactus in the Horse's Diet in the Presence of Live Saccharomyces cerevisiae on In Vitro Fecal Gas Production

The aim of the study was to evaluate the fecal fermentation of partial replacing steam rolled corn with soybean hulls (SH) or prickly pear cactus (PC) as energy source in horse diets, in the presence of Saccharomyces cerevisiae. Steam rolled corn was replaced with SH at 0% (control), 7.5% (SH75), and 15% (SH150) in the first trial, whereas it was replaced with PC at 0% (control; the same of the first trial), 7.5% (PC75), and 15% (PC150) in the second trial. Yeast of S. cerevisiae was added at 0, 2, and 4 mg/g dry matter (DM) of incubated substrates. Fecal inoculum was obtained from four adult English Thoroughbred horses fed on an amount of commercial concentrate and oat hay ad libitum. Interactions observed between PC rations and yeast doses for the asymptotic gas production (GP), the rate of GP and carbon dioxide (CO₂) production during some incubation hours. Moreover, with no effect due to SH rations (P > .05), increased (P < .05) rate of GP was observed with the ration PC75 compared with other rations. Besides, PC75 and PC150 rations with 0 mg yeast/g DM linearly decreased (P < .05) CO₂ production at some incubation hours. However, SH75 and SH150 ration had increased (P = .005) DM degradability (DMD). Yeast addition at 2 mg/g DM increased the asymptotic GP (P = .048) with the SH75 and PC150 rations. The level of 4 mg yeast/g DM increased the asymptotic GP (P = .048) from the SH150 ration. Yeast addition at 2 and 4 mg/g DM increased (P < .05) ​the asymptotic GP from PC75 and PC150 rations, respectively, with increasing DMD with the both doses. Yeast addition increased (P < .05) CO₂ production from SH75, SH150, PC75, and PC150 rations. It could be concluded that SH and PC can replace steam rolled corn at levels of 7.5% to 15% without negative effect of fermentation kinetics and with better fermentation performance in the presence of yeast at 2 mg/g DM of substrates.     

Effect of Restricted Grazing on Hindgut pH and Fluid Balance

Six mature idle geldings were used in a crossover design to determine the effects of restricted grazing on hindgut pH and fluid balance. Initially, horses were randomly assigned to a control group (CTRL: n = 3) having access to warm-season grass pasture continuously, or a restricted grazing (RG: n = 3) group having access to pasture for 12 consecutive hours (1900-700 hours) per 24-hour period for 7 days; they were then reassigned to the opposite treatment for an additional 7 days (i.e., CTRL: n = 6; RG: n = 6). Fecal samples were collected from each horse at 700 hours on day 7 of each period and analyzed for pH and dry matter (DM) as indicators of hindgut pH and fluid balance, respectively. Jugular blood samples were also collected at 700, 1300, and 1900 hours on day 7 and were analyzed for plasma protein as an indicator of systematic fluid balance. Fecal pH and DM data were analyzed using a paired t test. Plasma protein data were analyzed as a repeated-measures design. The mean (± SE) difference between CTRL and RG for fecal pH (.01 ± .16) and fecal DM (.68 ± .6%) was not significant (P = .93 and .52, respectively). Mean plasma protein concentrations were not affected by treatment or by treatment × sample time interaction, but tended to increase (P = .07) during the sampling period regardless of treatment. In conclusion, 12 hours of grazing restriction followed by 12 hours of grazing did not negatively impact hindgut pH or fluid balance.     

Gas and short‐chain fatty acid production from feeds commonly fed to red deer (Cervus elaphus L.) and incubated with rumen inoculum from red deer and sheep

Efficient red deer supplementary feeding depends on estimations of the nutritive value of offered feeds, frequently estimated with the use of equations derived from domestic ruminants. The aim of this study was to compare the 24‐hour in vitro true dry matter degradability (ivTD₂₄), in vitro gas production (GP) kinetic parameters, GP in 24 hr of incubation (GAS₂₄) and short‐chain fatty acid (SCFA) and microbial biomass (MBS) produced after 24‐hour incubation of feeds in inoculum prepared from sheep and red deer rumen fluid. Eleven feeds, frequently consumed by red deer in Slovenia, which occur either naturally (two fresh grasses, chestnut fruits and common and sessile oak acorns) or are fed as winter supplemental feeds (two grass hays, two grass silages, apple pomace, fresh sugar beetroot), were investigated. The in vitro GP kinetic parameters, GAS₂₄ and ivTD₂₄, did not differ between animal species. Amounts of SCFAs were greater (p < 0.05) when feeds were incubated in sheep inoculum, while molar proportions of acetic and propionic acids did not differ. Molar proportions of butyric acid produced during incubation of high fibre feeds did not differ between animal species, but were higher (p < 0.05) when feeds high in starch or sugar were incubated in red deer inoculum. Greater production of SCFA by sheep rumen microbes suggests better coverage of host animal with energy precursors, while greater production of MBS by red deer rumen microbes suggests better coverage of host animal with protein. Results also suggest that rumens of sheep and red deer are inhabited by different microbial communities, which did not affect the extent of in vitro GP and degradation of feeds used in the present experiment. However, the possibility exists that the divergent nutrient use could be a consequence of different priming by different feeds of the donor animal diets.     

Effects of Sodium Caseinate and Varying Protein Sources on In Vitro Fermentation of Forages by Mixed Equine Cecal Microorganisms

To assess the impact of protein on fermentation by equine cecal microorganisms, cecal fluid from 4 cecally cannulated horses was used to inoculate fermentation bottles containing buffer, forage, and supplemental protein. In experiment 1, sodium caseinate (SC) provided 0, 0.5%, 1%, 2%, or 4% additional crude protein (CP) to bottles containing alfalfa or native warm-season prairie grass hay. Bottles were equipped with continuous gas pressure monitors and placed into a shaking incubator for 48 hours at 39°C. Cultures with alfalfa had greater (P < .0001) in vitro dry matter disappearance (IVDMD), neutral detergent fiber disappearance (NDFD), acid detergent fiber disappearance (ADFD), cumulative gas production, and total volatile fatty acid (VFA). Sodium caseinate increased gas production (P ≤ .05) and decreased pH (P < .003) in cultures with grass hay. Sodium caseinate at 1%, 2%, or 4% additional CP increased IVDMD, NDFD, and ADFD (P < .01), while 4% additional CP also increased total VFA (P < .01). For experiment 2, SC, fishmeal, soybean meal (SBM), whey, porcine blood plasma, and L-lysine hydrochloride were added to supply 2% additional CP to cultures with grass hay. All protein sources decreased pH and increased IVDMD, NDFD, and ADFD (P ≤ .01), with the largest effects elicited by SC, L-lysine, and whey (P ≤ .05). Total VFA (P ≤ .04) and gas (P ≤ .05) production increased with L-lysine, whey, SC, SBM, and fishmeal. While protein supplementation had minimal effects on cultures containing alfalfa, it altered fermentation of grass hay, more notably with more soluble protein sources.     

Immunological features of LPS from Ochrobactrum intermedium on sheep experimentally infected with Fasciola hepatica

The effects of the lipopolysaccharide (LPS) from Ochrobactrum intermedium in sheep with fasciolosis was reported previously, resulting in lower fecal egg counts and fluke burden. In the current study, we analyzed its immunological effects in two groups of sheep, treated (T) and controls (C). Fasciolosis induces a T helper (Th) type-2 response, characterized by IL-4 and IL-10 production; however, at the beginning of the infection, the IFN-γ production predominates (Th type-1 response). Although we did not find differences in IL-4 production or in the expression level of this gene in the hepatic lymph nodes, the expression level of IL-10 was higher (P < 0.05) in the T group at 4 wpi. The IFN-γ production was higher (P < 0.01) at 12 wpi as well as its level of expression at 4 wpi (P < 0.05) in the T group. We found a higher expression level of TGF-β at 4 wpi in the T group (P < 0.05), associated with the previous report of thicker fibrous tracks in a treated group. Immunoglobulin G1, related with a Th type-2 response, was higher (P < 0.01) in the T group at 4 and 12 wpi. In conclusion, the effects of LPS from O. intermedium could have resulted from a predominant Th type-2 immune response.     

Factors affecting seroprevalence of Toxoplasma gondii in the endangered Iberian lynx (Lynx pardinus)

Wild felids are considered important in maintaining the sylvatic cycle of Toxoplasma gondii. Although, T. gondii antibodies have been reported in several species of wild felids, little is known of the epidemiology and risk factors associated with T. gondii infection in wild cats. The Iberian lynx (Lynx pardinus) is the most endangered felid species in the world. In the present study, seroprevalence and associated risk factors for T. gondii infection in a large population of Iberian lynx in Spain were determined. Serum samples from 129 Iberian lynx collected from 2005 to 2009 and 85 wild rabbits (Oryctolagus cuniculus), sharing the habitat with the Iberian lynx, were tested for antibodies to T. gondii by the modified agglutination test (MAT) using a cut-off value of 1:25. Antibodies to T. gondii were found in 81 of 129 (62.8%) Iberian lynx. Seroprevalence to T. gondii in Iberian lynx significantly increased with age (P < 0.001). T. gondii seroprevalences were similar in free-ranging (66.7% of 93) and wild-caught captive lynx (69% of 84) but significantly lower in captive-born lynx (22.5% of 40). Seroprevalence was higher in lynx with concurrent Cytauxzoonfelis (88% of 25) but not with concurrent Feline Leukemia Virus (FeLV) infection (53.8% of 13). There were no significant differences in seroprevalence between sexes, geographic region and year of sample collection (2005–2009). Oocysts of T. gondii were not detected microscopically in fecal samples from 58 lynx. Wild rabbits are considered the most important food for the lynx. Antibodies to T. gondii were found in 14 (11.9%) of 85 rabbits tested. The present results indicate that T. gondii infection is widespread in the two areas where Iberian lynx survive in Spain. The fact that four captive-born lynx seroconverted was indication of contact with T. gondii also in the Captive Breeding Centers, hence, control measures to prevent T. gondii infection would be necessary in these centers.     

Integration of forage legumes with cereal crops. I. Effects of supplementation with graded levels of lablab hay on voluntary food intake,digestibility, milk yield and milk composition of crossbred cows fed maize–lablab stover or oats–vetch hay ad libitum

This study examined the effect of lablab hay supplementation of crossbred cows fed forages from cereal+forage legume intercropping (maize–lablab (ML) stover or oats–vetch (OV) hay) basal diets on feed intake, apparent digestibility, milk yield and milk composition of crossbred cows. Forty eight multiparous (parity 2–4) cows approximately 60 days prepartum and mean live weight 445 S.D.±57 kg at the beginning of the experiment were used in the study. The experiment lasted 200 days each cow, covering 60 days prepartum and 140 days postpartum. Lablab hay supplementation significantly (P<0.05) increased total DM intake and DM digestibility as compared with the unsupplemented diets but there was no significant (P>0.05) difference in total DM intake among the supplemented cows. Cows fed ML stover or OV hay supplemented with lablab hay had improved rumen environment as reflected in the rates of DM, OM, N and NDF degradation greater than 0.03 (i.e. 3%) per h. The degradation parameters; a, b, c and the effective degradability (ED) were higher (P<0.001) for lablab hay supplemented diets than for ML stover or OV hay basal forages fed alone. ML stover fed alone resulted into significantly (P<0.001) higher Ca, P, and Mg intake than OV hay fed alone while K intake was significantly (P<0.05) higher with OV hay. Increasing levels of lablab hay supplementation significantly (P<0.001) increased Ca, P and Mg intakes but did not significantly (P>0.05) affect K intake in both ML stover and OV hay diets. OV hay and ML stover basal forages fed to unsupplemented crossbred cows resulted into average milk yields of 6.82 and 8.25 kg/cow per day, respectively, over a lactation period of 140 days after calving. Supplementation with lablab hay significantly (P<0.001) increased milk yield of crossbred cows fed OV hay but for ML stover based diets, supplementation was only significant (P<0.05) at the lowest level (0.4% BW) of lablab offer. For ML stover based treatments, the highest daily milk yield (9.5 kg/head) was obtained at 0.4% of body weight (BW) lablab hay supplementation, while for OV hay treatments, the highest milk yield of 9.7 kg/head was obtained at 1.2% BW lablab hay supplementation. Mean concentrations of milk fat, protein and total solids were similar for both ML stover and OV hay diets fed alone but lablab hay supplementation did not significantly affect the concentration of milk components of cows fed both forages. It was concluded that for optimum milk production from crossbred cows fed ML stover and OV hay basal diets, supplementation should be at 0.52 and 0.85% of BW level of lablab hay, respectively. The lack of response to higher levels of lablab hay supplement despite the increased protein intake was interpreted as resulting from a deficit of dietary energy.     

Evaluation of the in vitro growth-inhibitory effect of epoxomicin on Babesia parasites

Epoxomicin potently and irreversibly inhibits the catalytic activity of proteasomal subunits. Treatment of proliferating cells with epoxomicin results in cell death through accumulation of ubiquinated proteins. Thus, epoxomicin has been proposed as a potential anti-cancer drug. In the present study, the inhibitory effects of epoxomicin on the in vitro growth of bovine and equine Babesia parasites were evaluated. The inhibitory effect of epoxomicin on the in vivo growth of Babesia microti was also assessed. The in vitro growth of five Babesia species that were tested was significantly inhibited (P < 0.05) by nanomolar concentrations of epoxomicin (IC₅₀ values = 21.4 ± 0.2, 4 ± 0.1, 39.5 ± 0.1, 9.7 ± 0.3, and 21.1 ± 0.1 nM for Babesia bovis, Babesia bigemina, Babesia ovata, Babesia caballi, and Babesia equi, respectively). Epoxomicin IC₅₀ values for Babesia parasites were low when compared with diminazene aceturate and tetracycline hydrochloride. Combinations of epoxomicin with diminazene aceturate synergistically potentiated its inhibitory effects in vitro on B. bovis, B. bigemina, and B. caballi. In B. microti-infected mice, epoxomicin caused significant (P < 0.05) inhibition of the growth of B. microti at the non-toxic doses of 0.05 and 0.5 mg/kg BW relative to control groups. Therefore, epoxomicin might be used for treatment of babesiosis.     

Serum Chemistry and Hematology Changes in Neonatal Stock-Type Foals During the First 72 Hours of Life

Limited research has characterized blood chemistry in healthy stock-type foals. Our objectives were to determine foal serum chemistry and hematology changes during the first 72 hours postnatal and compare these with adult horse reference ranges. Over 3 foaling seasons, serum chemistry and hematology were determined for 16 healthy stock-type foals born to similarly managed mares. Blood was collected at 0 hours (before nursing but after standing, within 85 minutes of birth) and 6, 12, 24, 48, and 72 hours after initial sampling. Data were analyzed with sampling hour, year, and their interaction as fixed effects. Serum glucose and triglyceride concentrations increased (P < .001) from 0 to 24 hours. Triglycerides increased (P < .001) and glucose decreased (P = .01) between 24 to 48 hours. Serum nonesterified fatty acids increased (P = .04) from 0 to 6 hours and decreased (P ≤ .01) from 6 to 24 hours. Serum urea nitrogen increased (P < .001) between 0 and 6 hours and decreased (P < .001) from 12 to 72 hours. Serum total protein and globulin concentrations increased (P < .001) from 0 to 12 hours, albumin decreased (P ≤ .01) from 0 to 24, and creatinine decreased (P ≤ .02) from 0 to 72 hours. Hour also affected (P ≤ .03) electrolytes, metabolic enzymes, and all hematological components except for mean corpuscular hemoglobin (P = .77). These data demonstrate dynamic blood biochemical and hematological changes throughout the first 72 hours in foals, suggesting that sampling time should be considered when evaluating individual neonates.     

Production and economic performance of F1-crossbred dairy cattle fed non-conventional protein supplements in Zimbabwe

The effects of supplementing crossbred cows with non-conventional protein sources on dry matter intake, milk yield parameters and economic returns were investigated. Twenty-five lactating F₁ Holstein-Mashona crossbreds averaging 115?±?24 days in milk were used. Five treatments, total mixed ration (TMR), urea-treated maize stover, untreated maize stover, Macroptilium atropurpureum (Siratro) hay and veld hay, were randomly assigned to cows and replicated five times in a completely randomised design. Nutrient composition, intake, milk yield and economic returns were determined. M. atropurpureum hay, urea-treated maize stover and TMR had equal crude protein content. Daily dry matter intake and yield differed significantly among the treatment diets (P?<?0.05). Cows on TMR, urea-treated maize stover and M. atropurpureum consumed more (P?<?0.05) than cows on untreated maize stover and veld hay. Supplementing with TMR, urea-treated maize stover and M. atropurpureum hay increased (P?<?0.05) milk yields. Mean daily milk yield was highest for cows supplemented with urea-treated maize stover. Percent fat, protein and total solids in milk from cows fed urea-treated stover compared favourably to that of milk for cows supplemented with TMR. Income over supplement cost was highest for cows supplemented with M. atropurpureum hay and urea-treated maize stover. Urea-treated maize stover and M. atropurpureum can therefore be used as a replacer protein supplements for dairy cattle in Zimbabwe.     

Effects of dietary Crotalaria pallida seeds on the health and performance of laying hens and evaluation of residues in eggs

The effect of three dietary concentrations of Crotalaria pallida (C. pallida) seeds (0, 1, 2, and 3% w/w) of their normal diet were investigated in commercial laying hens during a 35 day feeding trial. All concentrations of C. pallida decreased body weight and feed intake (P < 0.05). Egg mass production and average egg weight were decreased by feeding of ≥2% C. pallida seeds (P < 0.05). All concentrations of C. pallida increased relative lung weight and serum activity of ALT, AST and LDH (P < 0.05); 3% C. pallida seeds decreased liver weight (P < 0.05). Analysis of the C. pallida seeds for dehydropyrrolizidine alkaloid content detected usaramine and its N-oxide at a total alkaloid concentration of 0.18% (dry weight). Usaramine was also detected in the eggs of all hens fed C. pallida seeds.     

Effect of coconut oil and garlic powder on in vitro fermentation using gas production technique

An in vitro gas technique trial was conducted to investigate the effect of coconut oil (Co), garlic powder (G) and their mixtures on in vitro fermentation. Incubation was carried out using rumen fluid obtained from swamp buffaloes. The experimental design was a completely randomized design (CRD). The dietary treatments were ratio of Co and G supplementation at 0:0, 16:0, 8:4, 4:8 and 0:16 mg with rice straw as a roughage source. Cumulative gas production was recorded at 0, 2, 4, 6, 8, 12, 18, 24, 36, 48, 60 and 72 h of incubation. In vitro true digestibility (IVTD) was determined after 48 h incubation. Cumulative gas production at 72 h was significantly lowest (P < 0.05) at Co:G, 16:0 mg. Garlic powder supplementation at 16 mg decreased (P < 0.05) NH₃–N concentration and increased (P < 0.05) in vitro true digestibility (IVTD) while supplemented coconut oil at 16 mg decreased (P < 0.05) IVTD. Total volatile fatty acids (VFAs) were lowest (P < 0.05) by garlic powder supplementation at 16 mg. However, supplementation of Co:G, 8:4, 4:8 and 0:16 mg tended to increase the proportion of propionate, decrease C2:C3 ratio and reduce (P < 0.05) methane (CH₄) production. Protozoal population was significantly lowest (P < 0.05) at Co:G, 8:4 mg. Moreover, application of quantitative PCR to quantify predominant cellulolytic bacteria (16S rRNA) and fungi (18S rRNA) targets revealed that treatments did not have an effect on Ruminococcusflavefaciens and total fungi population. However, it was found that supplementation of Co:G at 8:4 mg increased Ruminococcusalbus population (P < 0.05). Based on this study, it suggests that supplementation of Co:G at 8:4 and 0:16 mg could improve ruminal fluid fermentation in terms of volatile fatty acid profile, reduced methane losses and reduced protozoal population.     

The onset of puberty of Pelibuey male hair sheep is not delayed by the short term consumption of Morus alba or Hibiscus rosa-sinensis foliage

The present trial evaluated the effect of phytoestrogens consumed from Mulberry (Morus alba) or Hibiscus (Hibiscus rosa-sinensis) foliage, on the onset of puberty of Pelibuey male lambs. The design of the study aimed at identifying possible acute changes on the onset of puberty. Eighteen male lambs were used (107±9 days of age, 16±3 cm scrotal circumference (SC), 3.4±0.1 body condition score (BCS) and 17±1 kg bodyweight (BW)). At weaning, the lambs were distributed in three groups (n=6 each): (i) Control group (balanced feed based on grains+star grass), (ii) Mulberry Group (Mulberry foliage+balanced feed) and (iii) Hibiscus Group (Hibiscus foliage+balanced feed). BW, SC and body condition score (BCS) were determined every 14 days. An estrogenized adult female was used to attempt the collection of semen samples from the males two times per week. The onset of puberty was determined as the presence of sperm showing progressive movement in the ejaculate. From then, semen collections continued in the males (once a week) until the first normal ejaculate was obtained. The nutritional value of the foliages, as well as the content of total phenols, total tannins and condensed tannins, was determined. The phytoestrogen content (Equol, 4′7-dimetoxyisoflavone, Genistein, Rutin and Ononin) was determined from the methanolic extract of both plants. Total dry matter consumptions were similar between the Control and Mulberry groups and both were higher than the Hibiscus group (P<0.05). The total consumption of phytoestrogens and tannins was similar in the Mulberry and the Hibiscus group. The short-term consumption of phytoestrogens from Mulberry or Hibiscus foliage failed to delay the onset of puberty. The mean age at the onset of puberty was similar in the three groups (146 days in the control and Mulberry groups and 154 days in the Hibiscus group; P>0.05). The mean age at the first normal ejaculate was also similar between groups (167 days for Mulberry and Hibiscus groups and 169 days in the control group; P>0.05). The BW (Control: 21.6±3.1; Mulberry: 20.7±1.9; Hibiscus: 19.8±2.8 kg), the BCS and the SC were similar between groups at the onset of puberty. The present trial showed that a short exposure to M. Alba or H. rosa-sinensis foliage through diet did not influence the onset of puberty of Pelibuey male lambs.     

Effects of salinomycin and Bacillus subtilis on growth performance and immune responses in broiler chickens

The present study was undertaken to compare the effect of salinomycin and Bacillus subtilis on growth performance, serum antibody levels against Clostridium spp. and Eimeria spp., and cytokine mRNA expression levels in broiler chickens raised in the used litter. Broiler chickens fed a diet containing salinomycin showed lower (P < 0.05) body weights compared with the control diet-fed counterparts. Serum nitric oxide levels were significantly (P < 0.05) elevated in chickens fed the B. subtilis-enriched diet compared with those on either the salinomycin-fed or control diet-fed chickens. None of the dietary treatments affected (P > 0.05) serum antibody levels against Clostridium perfringens toxins. Both salinomycin and B. subtilis significantly lowered (P < 0.05) the serum levels of Eimeria-specific antibodies compared with the control group. Salinomycin, but not B. subtilis, significantly modulated (P < 0.05) the expression of cytokines encoding interferon-γ (IFN-γ), interleukin10 (IL-10) and tumor necrosis factor superfamily 15 (TNFSF15) compared with the control group. In conclusion, dietary salinomycin and B. subtilis affected serum anticoccidial antibody and intestinal cytokine expression, but failed to improve growth performance in broiler chickens. Further study is warranted to investigate the mode of action of salinomycin on host immune response and growth performance in broiler chickens.     

Use of fibrolytic enzymes additives to enhance in vitro ruminal fermentation of corn silage

Two experiments were conducted to evaluate the effect of four enzyme additives on ruminal fermentation of corn silage using a 48 h batch culture in vitro assay with buffer and ruminal fluid. Experiment 1 (Exp. 1) and Experiment 2 (Exp. 2) were conducted as completely randomized designs each with two runs and four replicates. The enzyme additives (E1, E2, E3, and E4) were commercial products that provided a range in endoglucanase, exoglucanase, and xylanase activities. For both xylanase (birch wood and oat spelt substrate) and endoglucanase (carboxymethylcellulose substrate), the enzyme products (per ml) were ranked E4>E1>E2>E3. In Exp. 1, the four enzymes were added at 0, 2, 4, and 8 μl/g of corn silage dry matter (DM), whereas in Exp. 2 enzymes were added at 0, 0.5, 1, 2, and 4 μl/g DM. Gas production (GP) was measured at 3, 6, 12, 18, 24, and 48 h after incubation. Disappearance of DM (DMD), neutral detergent fiber (NDFD), and acid detergent fiber (ADFD), and volatile fatty acid concentrations (VFA; total and individual molar proportions) were determined after 24 and 48 h. In Exp. 1, E1 and E2 had higher NDFD and ADFD at 24 and 48 h of incubation (P<0.001) compared with E3 and E4. Increasing dose rate increased NDFD and ADFD for all enzymes (except ADFD for E4 at 48 h), with the optimum dose rate dependant on the enzyme additive (dose×enzyme; P<0.01). There were some treatment effects on DMD and total GP at 24 and 48 h, but these responses were not consistent with responses in NDFD and ADFD. Experiment 2 was conducted to confirm the effects and optimum dose rate of each enzyme additive. In Exp. 2, DMD was not affected by enzyme after 24 and 48 h incubation. There were no enzyme×dose interactions for DMD, NDFD, or ADFD after 24 or 48 h of incubation (except for ADFD at 48 h). After 24 h, DMD, NDFD, and ADFD increased linearly with increasing dose (P<0.05); after 48 h DMD increased linearly, whereas NDFD increased quadratically with increasing enzyme dose (P<0.05). The ADFD increased linearly after 48 h for E3 and E4, but after 48 h ADFD increased quadratically for E1 and E2. Total GP was consistently lowest for E4 at both incubation times (P<0.05). There were no enzyme×dose interactions (P>0.05) for any of the fermentation variables at either 24 or 48 h of incubation in Exp. 2. There were differences amongst the additives for total VFA at 24 and 48 h (P≤0.05); increasing enzyme dose decreased total VFA after 24 h but increased total VFA at 48 h, such that all doses were higher than the control (P<0.001). Overall, the enzyme additives increased NDFD and ADFD of corn silage in vitro; however, E1 and E2 were more effective than E3 or E4. Responses to increasing dose of enzyme were generally linear or curvilinear, and the optimum dose rate differed amongst the products evaluated. Evaluation of the enzymes at 24 and 48 h generally led to the same ranking of the additives, and the degradation of NDF and ADF was more useful in differentiating the enzymes compared with DM and total GP.     

Fermentation Capacity of Fecal Microbial Inocula of Przewalski Horse,Kulan, and Chapman Zebra and Polysaccharide Hydrolytic Activities of Fecal Microbial Constituents (Ciliates and Bacteria) of Kulan and Chapman Zebra

We examined fermentation capacity of fecal microbial inocula of Przewalski horse (Equus ferus przewalskii), Asian wild ass - kulan (Equus hemionus hemionus), and Chapman zebra (Equus quagga chapmani) in vitro. Interactions of the substrates (amorphous cellulose, wheat straw, meadow hay, xylan from oat spelt, and ground barley grain) and type of fecal inocula in the gas volume and in vitro dry matter digestibility were detected in all substrates after 72 hours of fermentation in five replicates for each substrate and type of inocula. No effects of fecal inocula sources were detected on total short-chain fatty acids concentrations. No live fecal ciliate population was present in kulan feces. Complex ciliate populations in zebra feces and the number and genera resembled ciliates from the colon of horses. Fresh feces of kulan and zebra were fractionated by galvanotaxis and centrifugation to separate fecal ciliates and bacteria. Specific activities (μmol of reducing equivalents/mL min mg protein) of carboxymethyl cellulase (CM-cellulase), xylanase, α-amylase, and inulinase were measured in crude cell-free extract of fecal ciliates (zebra), fecal bacteria (zebra and kulan), and total fecal preparation (zebra and kulan). All examined specific enzymatic activities were present in zebra fecal samples. We were unable to measure the inulinase activity and CM-cellulase activity in kulan fecal samples. Zebra ciliates are actively involved in the digestion of plant storage (α-amylase, 0.53 ± 0.02; inulinase, 1.77 ± 0.01, specific activities) and structural polysaccharides (CM-cellulase, 0.4 ± 0.15; xylanase, 0.26 ± 0.06). For the first time, we measured inulinase activity in intestinal ciliates.     

Associations between the Exposure to Airborne Virulent Rhodococcus equi and the Incidence of R equi Pneumonia among Individual Foals

Rhodococcus equi is a significant cause of pneumonia, resulting in disease and sometimes death of foals. It is believed that infection occurs by inhalation of dust contaminated with virulent R equi. Although association between the airborne concentration of virulent R equi and the incidence of foal pneumonia at breeding farms has been documented, studies at the level of individual foals have not been reported. Thus, the objective of this study was to determine whether the magnitude of airborne virulent R equi was significantly associated with risk of R equi pneumonia for individual foals. The concentration of virulent R equi was significantly (P < .001) greater in stalls than paddocks among samples collected from 47 foals at a breeding farm in central Kentucky. The presence of airborne virulent R equi in stalls was significantly (P = .045) more likely at 7 days of age for foals subsequently found to be affected by rhodococcal pneumonia. Additionally, airborne concentrations of virulent R equi in stalls were significantly greater at 7 and 14 days of age than at birth. Presence of the mare and foal at the time of sampling was significantly (P < .001) associated with increased airborne concentrations of virulent R equi in stalls. These findings suggest that environments containing airborne virulent R equi during the first week of life may influence the risk of subsequent disease for a foal.     

In vitro effects of Musa x paradisiaca extracts on four developmental stages of Haemonchus contortus

This study was carried out to evaluate the in vitro effect of Musa x paradisiaca stem and leaf against the parasitic nematode of small ruminants Haemonchus contortus. Three extracts (aqueous, methanolic and/or dichloromethane) of Musa x paradisiaca stem and leaf were tested in vitro on four developmental stages of H. contortus using egg hatch assay (EHA), larval development assay (LDA), L3 migration inhibition assay (LMI) and adult worm motility assay (AWM). The highly significant (P < 0.0001) ability to stop larval development (inhibition >67% for each extract) and the negative effect of the dichloromethane extract of leaf on adult worm motility (43% of inhibition of motility after 24 h of incubation) compared to the negative controls, suggest anthelmintic properties of Musa x paradisiaca stem and leaf against H. contortus. The active principles responsible for the activity could be secondary metabolites such as terpenoid and flavonoid compounds present in the leaf and stem of the plant.     

Effects of synbiotic-based Bifidobacterium animalis in female rats experimentally infected with Toxoplasma gondii

The aim of this study was to assess the effects of a synbiotic composed of Bifidobacterium animalis and fructooligosaccharides on female rats infected with Toxoplasma gondii. Female Wistar rats, treated or not with dexamethasone, were daily supplemented with synbiotics for 21 days. After 15 days of supplementation, the rats were orally infected with 10⁴T. gondii bradyzoites. Blood samples were collected to measure the levels of IFN-γ, IL-10 and T. gondii antibodies. All synbiotic-supplemented rats survived until the end of the experiment; however, non-supplemented dexamethasone-treated rats died between the fifth and the eighth days after T. gondii infection. Dexamethasone-treated rats supplemented with synbiotics (P < 0.05) were capable of synthesizing IFN-γ, and this immunological response was essential to ensure their survival. In addition, brain cysts were found in one rat not supplemented with synbiotics. Results suggest that the synbiotic composed of B. animalis and fructooligosaccharides may be beneficial to toxoplasmosis control.