Anthelmintic effects of indigenous multipurpose fodder tree extracts against <Emphasis Type="Italic">Haemonchus contortus</Emphasis>

Condensed tannins (CT) extracted from Balanites aegyptiaca, Tamarindus indica, and Celtis toka browses were used to evaluate their anthelmintic effect on different developmental stages of Haemonchus contortus. To achieve this objective, various serial concentrations of each CT extract of the foliages were used to test adult motility, inhibition of egg hatchability, and larval development. The fodders were selected based on their multipurpose advantage and accessibility to use as fodder for livestock in the low lands of the Gambella region. The fastest and slowest adult motility rate was observed in 2-ml (4 min) and 0.125-ml dose of C. toka, respectively, which is better than that in ivermectin. Egg hatchability inhibition was observed with dose difference within species, but there is no difference between B. aegyptiaca and T. indica. The foliage extracts of the studied browses were observed to inhibit the larvae by 100% at 2 ml, which is similar to ivermectin. There is no significant difference observed in larvae development inhibition between the species and ivermectin (p?>?0.05). CT extracts of studied plants have found to own significant anthelmintic activity in a dose-dependent manner. They could serve as anthelmintic economically and eco-friendly after further and series of in vivo experiments.     

In vitro control of parasitic nematodes of small ruminants using some plant species containing flavonoids

This study determined in vitro anthelmintic efficacy of three plant species: Trema orientalis, Urtica dioica and Zanthozylum capense on nematode larvae of small ruminants. Dried leaf samples (40 g) were extracted in 70% ethanol, in portions of 10 g and concentrated to 100 ml. Half and one quarter of the original crude extract were both made to 100 ml. Rectal faecal material from 10 Merino sheep and 25 Nguni goats was pooled within species and thoroughly hand-mixed. Dung samples, each of 5 g were cultured for 12 days at 27 °C. On day 13, 4 plates were watered and 4 others treated with ethanol to correct for solvent effect on mortality. The design was 2 (animal species)?×?3 (plant species)?×?3 (extract concentrations). In each of three runs, three plates were treated with each crude extract in three incremental concentrations. Surviving L3 larvae were isolated, counted and mortalities became indices of anthelmintic efficacy. Data from nematode larval mortality were analysed to determine the effect of animal species, plant species, concentration and their interactions. Efficacy was affected by concentration (P?=?0.0001), animal species (P?=?0.0046), plant species (P?=?0.0572), the interactions of animal species and concentration (P?=?0.0010), plant species and concentration (P?=?0.0123) and concentration × animal × plant species (P?=?0.0435).     

Antimicrobial susceptibility and phylotyping profile of pathogenic <Emphasis Type="Italic">Escherichia coli</Emphasis> and <Emphasis Type="Italic">Salmonella enterica</Emphasis> isolates from calves and pigs in Minas Gerais,Brazil

The aims of the present study were to determine (i) the profiles of phylogroup and (ii) the antimicrobial susceptibility of pathogenic Escherichia coli strains isolated from calves, and of Salmonella spp. strains isolated from calves and pigs in Minas Gerais State, Brazil. Sixty-one pathogenic E. coli strains and Salmonella spp. (n?=?24) strains isolated from fecal samples of calves and Salmonella spp. (n?=?39) strains previously isolated from fecal samples of growing/finishing pigs were tested. The minimum inhibitory concentration (MIC) using the agar dilution method was determined for nalidixic acid, amikacin, amoxicillin, ampicillin, cefoxitin, norfloxacin, gentamicin, tetracycline, and trimethoprim-sulfamethoxazole. All E. coli isolates were susceptible to amikacin. Tetracycline was the antimicrobial that presented the higher frequency of resistance among E. coli strains, followed by ampicillin, trimethoprim-sulfamethoxazole, amoxicillin, nalidixic acid, norfloxacin, gentamicin, and cefoxitin. E. coli (n?=?61) strains isolated from calves belonged to different phylogroup namely, phylogroup A (n?=?26), phylogroup B1 (n?=?31), phylogroup E (n?=?3), and phylogroup F (n?=?1). Phylogroups B2, C, and D were not identified among the E. coli in the present study. All Salmonella spp. (n?=?24) strains isolated from fecal samples of calves were susceptible to amikacin, amoxicillin, ampicillin, norfloxacin, gentamicin, tetracycline, and trimethoprim-sulfamethoxazole. Resistance to nalidixic acid and cefoxitin was detected in 16.66 and 8.33 % of the Salmonella spp. strains, respectively. Among the Salmonella spp. (n?=?39) strains isolated from fecal samples of pigs, the higher frequency of resistance was observed to tetracycline, followed by amoxicillin, gentamicin, ampicillin, trimethoprim-sulfamethoxazole, nalidixic acid, cefoxitin, and norfloxacin. All strains were susceptible to amikacin. Forty-eight (78.68 %) of the E. coli strains were classified as multidrug-resistant, whereas among Salmonella spp. strains, the percentage of multidrug resistance was 57.14 %, being all multidrug-resistant strains isolated from pigs (92.30 %). The results from the present study indicate a high frequency of antimicrobial resistance among pathogenic E. coli strains isolated from calves and Salmonella spp. strains isolated from pigs and a high rate of susceptibility to most antimicrobials tested among Salmonella spp. strains isolated from calves. Our study highlights the presence of multidrug-resistant strains of E. coli and Salmonella spp. isolated from food-producing animals in Minas Gerais, Brazil.     

<Emphasis Type="Italic">In vitro</Emphasis> larvicidal effect of a hydroalcoholic extract from <Emphasis Type="Italic">Acacia cochliacantha</Emphasis> leaf against ruminant parasitic nematodes

The aim of this study was to evaluate the in vitro lethal effect of a hydroalcoholic extract (HAE) from Acacia cochliacantha leaf against three gastrointestinal nematodes species (Haemonchus contortus, H. placei and Cooperia punctata) of domestic ruminants. The HAE was assessed using five concentrations: 100, 125, 175, 150 and 200 mg/ml; 0.5% Ivermectin was used as a positive control and distilled water, as negative control. The data were normalized using the square root and analysed with a completely randomized design through ANOVA analysis using the general lineal model (GLM) of the SAS program. The HAE tannin content was determined through spectrophotometry (UV-visible) and the other major phenols, were identified by chromatographic processes. The results showed an in vitro larvicidal activity of the HAE against the three assessed nematode species with all assessed concentrations. A clear HAE increased concentration dependence effect was observed. The highest activity of the HAE was obtained at the highest concentration (close to 100%, P < 0.05). This result was similar to the one obtained with Ivermectin. On the other hand, the chemical analysis of HAE showed the presence of tannins, caffeoyls and coumaroyl derivates and quercetin as the main compounds. The results suggest that the HAE from this plant species possess in vitro anthelmintic properties. The identified compounds in this study would good candidates for further in vivo researches.     

Frequency of enterotoxins,toxic shock syndrome toxin-1, and biofilm formation genes in <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> isolates from cows with mastitis in the Northeast of Brazil

Staphylococcus aureus is among the microorganisms more frequently associated with subclinical bovine mastitis. S. aureus may produce several virulence factors. This study aimed at determining the frequency of virulence factors such as enterotoxins, toxic shock syndrome toxin 1, and ica adhesion genes. In addition, we assessed antimicrobial drug resistance in S. aureus isolated from clinical and subclinical cases of mastitis. A total of 88 cows with clinical or subclinical mastitis were sampled, resulting in 38 S. aureus isolates, from which 25 (65.78%) carried toxin genes, including seb, sec, sed, tst, and icaD adhesion gene. These S. aureus isolates belong to 21 ribotypes and three S. aureus strains belonged to the same ribotype producing ica adhesion gene. Approximately 90% of S. aureus strains obtained in our study demonstrated multiple resistance to different antimicrobial agents. The most efficacious antimicrobial agents against the isolates were gentamicin, amoxicillin, and norfloxacin. Gentamicin was the most efficacious agent inhibiting 78.95% of the S. aureus isolates. The least efficacious were penicillin, streptomycin, and ampicillin. Our results can help in understanding the relationship between virulence factors and subclinical mastitis caused by S. aureus. Further research about diversity of S. aureus isolates and genes responsible for the pathogenicity of subclinical mastitis is essential.     

Isolation and characterization of two lytic bacteriophages against <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> from India: newer therapeutic agents against Bovine mastitis

Bovine mastitis causes severe economic losses to dairy farmers. Staphylococcus aureus, is one of the most important pathogen implicated in etiology of clinical and subclinical mastitis in bovines. In view of increasing antimicrobial resistance alternatives to antibiotic therapy are much needed. The present decade has witnessed a renewed interest in phage based therapeutics and diagnostics. The present study, describes isolation and characterization of two lytic phages SAJK-IND and MSP against Staphylococcus aureus having a potential to be used in therapy against mastitis. SAJK-IND and MSP phages belonged to Myoviridae and Podoviridae families, respectively. TEM imaging of the two phages revealed an iscosahedral head. MSP phage has a short non contractile tail. SAJK-IND and MSP have a burst size of 44?±?3 and 25?±?5 PFU/ infected cell, respectively. SAJK-IND and MSP phages revealed ? 12 and ?16 proteins, respectively on SDS-PAGE analysis. The lytic activity of the phages was specific for Staphylococcus aureus. SAJK-IND revealed 100% lytic activity against several strains of Staphylococcus aureus isolated from mastitis milk samples whereas, MSP had only 40% lytic activity. SAJK-IND phage genome was sequenced, assembled and deposited in Genbank under accession no MG010123.     

SCC <Emphasis Type="Italic">mec</Emphasis> typing and antimicrobial resistance of methicillin-resistant <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> (MRSA) from pigs of Northeast India

Staphylococcus aureus is one of the most important pathogens of both humans and animal. Methicillin-resistant Staphylococcus aureus (MRSA) is an important human pathogen that causes serious infections both in hospitals and communities due to its multidrug resistance tendency. This study was undertaken to characterize the MRSA isolates from pigs and to determine the antimicrobial resistance of these isolates. Forty nine MRSA strains (one strain per positive pig) isolated from pigs of Northeast India were characterized by SCCmec typing and antimicrobial resistance. The overall prevalence of MRSA was 7.02 % with the highest prevalence recorded in pigs aged 1–3 months (P = 0.001) and in nasal samples (P = 0.005). Two SCC mec types (type III and V) were found in Indian pigs with predominance of type V. All isolates were resistant to penicillin. Seventeen resistance groups were observed where 87.75 % isolates showed multidrug resistance (showed resistance to three or more classes of antimicrobials). The most predominant resistance pattern observed was Oxytetracycline + Penicillin + Sulfadiazine + Tetracycline accounting 12.24 % of the isolates. The present study contributes to the understanding of characteristics and antimicrobial resistance of porcine MRSA isolates which in turn will help in devising strategy for the control of this pathogen. Findings of the study also throw light on multidrug resistance MRSA and emphasize the need for judicious use of antimicrobials in animal practice.     

Control of <Emphasis Type="Italic">Haemonchus contortus</Emphasis> in sheep using basidiocarps of <Emphasis Type="Italic">Agaricus blazei</Emphasis> Murril

Objective

This study evaluated the effects in vitro and in vivo of Agaricus blazei against Haemonchus contortus in sheep.

Methods

The in vitro efficacy of aqueous extract on egg hatching inhibition (EHI) was investigated and after 72 h incubation with varying concentrations the effects on, blastomeres, embryonated eggs, and first stage larvae (L1) were evaluated. Larval development inhibition (LDI) for dry powder and the aqueous extract were evaluated in fecal cultures of sheep infected with H. contortus. In vivo efficacy was determined by reduction in fecal egg count (FEC). Lambs were treated with powder A. blazei (11.4 g/kg pc) or trichlorfon, or were untreated and the possible toxicity of this fungus was monitored by plasmatic enzyme analysis.

Results

Concentrations equal to and higher than 3.62 mg/mL and of aqueous extract were 100% effective in the EHI test. In the LDI test, LC90 was estimated for 5.66 and 106.0 mg/g fecal culture for aqueous extract and powder, respectively. The mean FEC in lambs 14 days post-treatment with A. blazei powder was significantly lower than observed for the negative control, and the serum levels of aspartate transaminase and alanine transaminase were normal.

Conclusion

The fungi supplementation promotes, respectively, high and moderate anthelmintic efficacy with in vitro and in vivo tests, respectively, suggesting it as an alternative or complementary treatment for haemonchosis in sheep.

     

Genotypic and phenotypic detection of capsular polysaccharide and biofilm formation in <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> isolated from bovine milk collected from Brazilian dairy farms

Staphylococcus aureus is a pathogen that frequently causes mastitis in bovine herds worldwide. This pathogen produces several virulence factors, including cell-associated adhesins, toxic and cytolytic exoproteins, and capsular polysaccharides. The aim of the present study was to test for the presence of genes involved in capsular polysaccharide production and biofilm formation in S. aureus isolated from bovine mastitis samples collected from 119 dairy herds located in three different Brazilian regions, as well as to assay the production of capsular polysaccharides and biofilm, in vitro. The detection of the cap, icaAD, and bap genes was performed using PCR. The detection and quantification of capsular polysaccharide production was performed using ELISA assays. The ability of the isolates to form a biofilm was examined using the polystyrene surface of microtiter plates. All 159 S. aureus isolates investigated harboured the cap gene: 80 % carried the cap5 gene and 20 % carried the cap8 gene. Sixty-nine percent of the isolates expressed capsular polysaccharide (CP) in vitro, 58 % expressed CP5 and 11 % expressed CP8. All of the isolates harboured the icaA and icaD genes, and 95.6 % of the isolates carried the bap gene. Of the 159 isolates analysed, 97.5 % were biofilm producers. A significant association between the capsular genotype and phenotype and the amount of biofilm formation was detected: cap5/CP5 isolates tended to form more biofilm and to produce a thinner CP layer than cap8/CP8 isolates. The results indicate a high potential for pathogenicity among S. aureus isolated from bovine milk collected from three different regions in Brazil.     

Performance and carcass characteristics of lambs fed diets with increasing levels of <Emphasis Type="Italic">Mimosa tenuiflora</Emphasis> (Willd.) hay replacing Buffel grass hay

This study evaluated the performance and carcass characteristics of lambs fed diets with increasing levels of Mimosa tenuiflora (Willd.) hay replacing Buffel grass (Cenchrus ciliaris). Twenty-eight Santa Inês male lambs with an average body weight (BW) of 20.3 ± 1.49 kg(mean ± SD) were allocated in individual stalls and distributed in a completely random design with four treatments (0, 20, 40, and 60 g/100 g total DM M. tenuiflora hay replacing Buffel grass hay in diet) with seven replications. M. tenuiflora hay at the level of 20% dry matter (DM) total replacing Buffel grass hay increased final weight (P = 0.006), total weight gain (P < 0.001), average daily weight gain (ADWG; P < 0.001), DM intake (P < 0.001), and feed efficiency (P < 0.001). Intake of crude protein, NDF_ap, ADF_ap, ash, ether extract, total and non-fibrous carbohydrates, and total digestible nutrients presented a positive quadratic effect with M. tenuiflora hay replacing Buffel grass hay and 40 g/100 g total DM level presented greater intake. There were positive quadratic effects by M. tenuiflora hay inclusion at 20 g/100 g total DM level on slaughtering weight (P = 0.005), hot carcass weight (P = 0.002), cold carcass weight (P = 0.002), empty body weight (P = 0.001), hot carcass yield (P = 0.002), cold carcass yield (P = 0.003), and increase linear on biological yield (P = 0.003). There was no influence on cooling weight loss (P = 0.284). M. tenuiflora hay may be included in lamb diets at amounts up to 20 g/100 g total DM substitution of Buffel grass hay because increase in the nutrients intake, growth performance, and carcass characteristics.     

Genotypic analysis of virulence genes and antimicrobial profile of diarrheagenic <Emphasis Type="Italic">Escherichia coli</Emphasis> isolated from diseased lambs in Iran

The aim of the present study was to determine the analysis of virulence genes and antimicrobial profile of diarrheagenic Escherichia coli isolated from diseased lambs. Two hundred ninety E. coli isolates were recovered from 300 rectal swabs of diarrheic lambs and were confirmed by biochemical tests. The pathotype determination was done according to the presence of genes including f5, f41, LTI, STI, bfp, ipaH, stx ₁ , stx ₂ , eae, ehlyA, cnf ₁ , cnf ₂ , cdIII, cdIV, and f17 by PCR method. Sixty-six isolates (23.72%) possessed the STI gene and categorized into entrotoxigenic E. coli (ETEC). Nine isolates (3.1%) and five isolates (1.72%) were positive for the cnf1 and cnf2 genes which categorized into necrotoxic E. coli (NTEC). Hundred and seventeen isolates (40.34%) harbored stx ₁ and/or stx ₂ and classified as Shiga toxin-producing E. coli (STEC). Thirteen isolates (4.48%) were assigned to atypical entropathogenic E. coli (aEPEC) and possessed eae gene. Two isolates (0.68%) were positive for ipaH gene and were assigned to entroinvasive E. coli (EIEC). Statistical analysis showed a specific association between eae gene and STEC pathotype (P?<?0.0001). The most prevalent resistance was observed against lincomycin (96.5%) and the lowest resistance was against kanamycine (56.02%), respectively. The high prevalence of STEC and ETEC indicates that diarrheic lambs represent an important reservoir for humans. ETEC may play an important role for frequent occurrence of diarrhea in lambs observed in this region. Due to high antibiotic resistance, appropriate control should be implemented in veterinary medicine to curb the development of novel resistant isolates.     

Helminthiasis characterization and anthelmintic efficacy for ewes and lambs raised in tropical semiarid region

In this study the helminthiasis and anthelmintic effectiveness in ewes and lambs were evaluated in a semiarid region of Brazil. Twelve sheep farms were investigated using semi-structured questionnaires and fecal egg count (FEC) reduction test was employed to analyze the profile of anthelmintic resistance. Groups of at least 10 animals with FEC ≥ 300 were selected. After 12 h of fasting, homogeneous groups of lambs or ewes were treated with albendazole, levamisole moxidectin, or oxfendazole and control groups were not treated. Feces were collected before treatments and 14 days after, and larvae genera were identified after cuprocultures in both periods. Extensive grazing was the predominant creation system, using hybrid Santa Ines animals. The separation by age was promoted in 75% of herds; however, maternity pickets there were only in three farms. The strategic treatments were performed only in 8.4% of sheep farms and 16.6% used the anthelmintic efficacy test and alternated anthelmintic classes after 1 year. The initial FEC means for lambs were significantly higher than ewe FEC averages. For lamb tests, moxidectin and levamisole showed higher efficacy (p ≤ 0.05) than benzimidazoles. For ewe tests, moxidectin and levamisole showed efficiencies >75%. Haemonchus spp. and Trichostrongylus spp. were the most frequent nematodes before treatments and the genus Haemonchus was the most prevalent after anthelmintic treatments (p < 0.05). Variations of anthelmintic susceptibility were observed for categories and herds evaluated, which emphasizes the importance of the effectiveness tests for the choice of anthelmintics for ewes and lambs.     

Virulence traits of avian pathogenic (APEC) and fecal (AFEC) <Emphasis Type="Italic">E. coli</Emphasis> isolated from broiler chickens in Algeria

Avian pathogenic E. coli (APEC) is the etiologic agent of avian colibacillosis, the most common disease responsible for chicken morbidity in the world. Although multiple virulence-associated factors were identified, their prevalence in Algeria is still poorly known. In the present research, 92 avian pathogenic E. coli (APEC) isolates were recovered from broilers with clinical signs and lesions of colibacillosis. In addition, 32 E. coli isolates collected from feces of healthy birds (AFEC) were included for comparison. All isolates were investigated by PCR for the presence of a total of 11 virulence-associated genes described for avian pathogenic (iroN, ompT, hlyF, iss, iutA, and fimC) and diarrheagenic E. coli (eae, stx, elt/est, ipaH, and aggR). The sensitivity of 39 APEC isolates to 16 antibiotics was also determined using antimicrobial pretreated microplates. Here, we report that 98% of the examined isolates host at least one of the tested virulence factors. The most prevalent genes in APEC were iutA (90.6%), ompT (86.9%), and iss (85.8%); whereas, iutA (78.1%), fimC (78.1%), and iroN (68.7%) were the highest prevalent genes in AFEC. Our data showed that none of the AFEC isolates harbor any of the tested diarrheagenic genes. Moreover, only elt/est (5.4%), stx (2.1%), and ipaH (2.1%) genes were carried by APEC isolates. We further established that ceftazodime, ceftiofur, mequindox, amoxicillin/clavulanic acid, and meropenem were the most efficient antibiotics against the analyzed APEC isolates. Overall, our findings provide more insights about APEC and AFEC virulence potential in Algeria which could participate in the fight against colibacillosis.     

An assessment of benzimidazole resistance against caprine nematodes in Central India

Current status of resistance to benzimidazole (BZ) group of anthelmintic drugs against caprine nematodes in Central India at Amanala goat farm, Jabalpur, Madhya Pradesh (M. P.), was systematically investigated using faecal egg count reduction (FECR) test and egg hatch test (EHT). Besides, allele-specific PCR (AS-PCR) was deployed to ascertain the susceptible genotype (alleles) especially of the Haemonchus contortus. Randomly selected 30 goats, irrespective of age and sex, were divided into three groups of 10 each, to serve as treated and untreated controls. It was ensured that the animals were not administered with an anthelmintic drug for the past 3 months prior to undertaking the study, and faecal egg counts were estimated. FECR test evidenced fenbendazole resistance by partial elimination (24.90%) copro-egg counts in the treated group of animals vis-à-vis controls with a lower confidence interval of ?26%. Further, EHT revealed ED-50 value of 0.335 μg of thiabendazole/ml, confirming benzimidazole resistance in the animals of that farm. AS-PCR showed that 62% of H. contortus larvae were homozygous resistant (rr), 24% heterozygous (rS) and 14% homozygous susceptible (SS). The genotypic frequencies of three genotypes (rr, rS and SS) were significantly (P < 0.01) different. The prevalence of benzimidazole resistance allele (r) was also significantly (P < 0.01) higher (74%) as compared to susceptible allele (S) (26%). The resistance to benzimidazole has been discussed while emphasizing improved managemental practices designed to reduce exposure of the goat population to parasites, minimize frequency of anthelmintic use at optimum dose and rotational use of different chemical groups of medicines with different mode of action, so as to overcome and combat the upcoming problem in the field.     

Antibiotic resistance and molecular characteristics of <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> isolated from backyard-raised pigs and pig workers

Staphylococcus aureus is a commensal and pathogenic bacterium with impact on public health and livestock industry. The study investigated nasal carriage, antibiotic resistance, and molecular characterization of S. aureus in pigs and pig workers. Nasal swabs from 300 backyard-raised pigs and 101 pig workers were used for the study. Resulting isolates were confirmed using MALDI-TOF MS, tested for antibiotic resistance, and three different multiplex PCRs were used to detect enterotoxin, mecA, spaA, scn, and pvl genes. spa typing was used to annotate the isolates into MLST clonal complexes (CC). Structured questionnaire was used to access possible risk factors for S. aureus carriage. The prevalence of S. aureus in pigs and pig workers were 5.3 and 12.9%, respectively. The isolates were resistant to beta-lactams (97%), tetracycline (62%), sulfonamide (52%), aminoglycoside (20.6%), fluoroquinolone (24%), and mupirocin (3.4%). Twenty seven (93%) of the isolates carried scn, 7(24%) pvl, and 12 (41%) enterotoxin genes, respectively. Questionnaire survey showed medical-related occupation of household members was associated (p?<?0.5) with S. aureus carriage. This study suggests the presence of human multidrug resistant strains of S. aureus, high carriage of pvl, and enterotoxin genes, and CC5, CC15, and CC152 were the CC-groups shared among pigs and pig workers.     

Effect of feed restriction on intake of <Emphasis Type="Italic">Moringa oleifera</Emphasis> and <Emphasis Type="Italic">Leucaena leucocephala</Emphasis> and growth performance of rabbits

Two experiments were conducted to evaluate the effect of feed restriction on intake of Moringa oleifera (MO) or Leucaena leucocephala (LL) and growth of rabbits. In experiment one, 45 rabbits (male and female) weighing 1.18 ± 0.15 kg were used. They were randomly distributed to three feed restriction treatments (20, 30, and 40%) with 15 rabbits each (9 females and 6 males) and they were offered M. oleifera (MO) ad libitum. In experiment two, 45 growing male rabbits weighing 0.63 ± 0.113 kg were used. They were randomly assigned to 0, 20, and 30% feed restriction diets, and they have free access to L. leucocephala (LL). Intake of MO increased (P < 0.05) conforming feed restriction increased (40.6, 52.9, and 55.2 g/day of MO for 20, 30, and 40%, respectively). Daily liveweight gain and feed conversion did not differ (P > 0.05), and economic efficiency was similar among treatments. Consumption of LL increased (P < 0.05) in rabbits under the 30% restriction treatment in comparison to that of rabbits restricted 20% (46.0 and 44.4 g/day, respectively). Total feed intake (LL + feed) was highest in 20% restricted rabbits (108.0, 100.8, and 93.2 g/day for 20, 30, and 0%, respectively). Daily liveweight gain and feed conversion were not affected by feed restriction (P > 0.05). Economic efficiency improved twice in feed-restricted rabbits (2.0 and 2.3 for 20 and 30%, respectively) in contrast to that of the control 0% group (1.1). The results suggest that rabbits restricted up to 30% and supplemented with either MO or LL did not affect growth performance and reduced feed cost.     

Influence of <Emphasis Type="Italic">Nigella sativa</Emphasis> seeds, <Emphasis Type="Italic">Rosmarinus officinalis</Emphasis> leaves and their combination on growth performance,immune response and rumen metabolism in Dorper lambs

The objective of this study was to determine the effects of dietary supplementation of Nigella sativa L. seeds, Rosmarinus officinalis L. leaves and their combination on rumen metabolism, nutrient intake and digestibility, growth performance, immune response and blood metabolites in Dorper lambs. Twenty-four entire male Dorper lambs (18.68?±?0.6 kg, 4–5 months old) were randomly assigned to a concentrate mixture containing on a dry matter basis either, no supplement (control, T1), 1% R. officinalis leaves (T2), 1% N. sativa seeds (T3) or 1% R. officinalis leaves +1% N. sativa seeds (T4). The lambs had ad libitum access to urea-treated rice straw (UTRS) and were raised for 90 days. Supplemented lambs had greater (P?< 0.05) intake of DM and UTRS than the control lambs. The T4 lambs had lower (P?< 0.05) nutrient digestibility than those fed other treatments. Total and daily weight gain was greater (P?< 0.05) in T2 lambs than those fed other diets. The T3 and T4 lambs had greater (P?< 0.05) ruminal pH than the T1 and T2 lambs. Supplemented lambs had lower (P?<?0.05) ruminal total volatile fatty acids, acetate, propionate, NH₃-N and C18:0 than the control lambs. The T4 lambs had lower (P?< 0.05) population of Fibrobacter succinogenes, Ruminococcus albus, methanogens and total protozoa compared with those fed other diets. Supplemented lambs had lower (P?< 0.05) neutrophils, basophils and serum urea and greater (P?<?0.05) serum IgA and IgG compared with the control lambs. The current results emphasised the variation in the efficacy of medicinal plants in ruminant nutrition.     

Anticoccidial effects of <Emphasis Type="Italic">Aloe secundiflora</Emphasis> leaf extract against <Emphasis Type="Italic">Eimeria tenella</Emphasis> in broiler chicken

Anticoccidial effects of Aloe secundiflora crude leaf extract was tested in broiler chickens following oral infection with Eimeria tenella. Sixty 22-day-old birds were divided into six groups of ten birds each. Three treatment groups A, B, and C were fed with the extract (100, 250, and 500 mg/day, respectively) mixed in feed for 10 days, and three control groups: group D (drug control) administered 300 mg/l of sulfachloropyrazine sodium soluble powder in drinking water for 5 days, group E (infected/non-medicated positive control), and group F (uninfected/non-medicated negative control). Except for group F, all groups were orally inoculated with 75,000 sporulated oocysts of E. tenella. The effects of the extract on E. tenella infection were evaluated by severity of bloody diarrhea, body weight (BW) gain, oocyst output, and lesion score. No bird in the treated groups died of coccidiosis, and severity of bloody diarrhea was milder than in the positive control group. BW gains in the treated groups were significantly higher than in group E (p < 0.05). The lesion scores of the treated groups were significantly lower than that of group E. Oocyst output in groups A, B, and C were 11.23, 8.24, and 6.82 × 10⁶, respectively. As compared with the negative control group (12.84 × 10⁶), the reductions in oocyst production were 12.54, 35.83, and 46.88%, respectively. Oocyst output significantly reduced with an increase in Aloe dosage. The findings of this study suggest that Aloe secundiflora extract presents an alternative anticoccidial agent for the control of avian coccidiosis.     

Antibiotic susceptibility of <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> isolated from subclinical bovine mastitis cases and in vitro efficacy of bacteriophage

Staphylococcus aureus is an opportunistic pathogen that may cause severe infections in livestock, and represents the major cause of mastitis in dairy cows. Currently, instead of using antibiotics, new strategies are sought to reduce this clinical health problem. The aim of this study was to determine the efficacy of phage therapy to kill S. aureus strains obtained from farms located at the State of Guanajuato, México. Thirty-six S. aureus strains from cow milk with subclinical mastitis were isolated and identified, and the susceptibility to antibiotics and four phages also isolated in this work was tested. It was found that more of 90% of S. aureus isolates were not susceptible to six or more antibiotics, and 100% were resistant to penicillin, dicloxacillin, cefotaxime, ampicillin and cephalothin, and 81 and 77%, to tetracycline and cefuroxime, respectively. Fortunately, 100% of S. aureus isolates were susceptible to phages used in this work, which was detected as clear zones using specific phage. It was shown for the first time, that phages used in this study are active against pathogenic S. aureus and might be incorporated into the therapy as an important tool for the control of staphylococcal bovine mastitis, specially to antibiotic-resistant S. aureus strains isolated in farm located at the state of Guanajuato, México; and its use might be extended to other regions inside or outside the country.     

<Emphasis Type="Italic">Staphylococcus aureus</Emphasis> intramammary infection affects milk yield and SCC of dairy cows

Staphylococcus aureus (S. aureus) is the most prevalent infectious microorganism affecting dairy cattle worldwide, and its pathogenic characteristics facilitate its spread in dairy herds. S. aureus intramammary infections (IMI) are mainly subclinical, and associated losses can exceed average herd losses where the pathogen is not isolated. However, the extent it affects milk composition at udder and quarter levels is still unknown, and cow composite milk losses may be underestimated due to the dilution effect. The aim of this study was to investigate the effects of S. aureus subclinical mastitis on mammary quarter milk yield and composition. In order to determine the effects of the pathogen on milk yield and composition at quarter level, a pairwise comparison of infected and non-infected mammary quarters (n?=?28) from two dairy herds was carried out. Quarters were individually milked, and milk production and composition were assessed. S. aureus has increased somatic cell counts at quarter level; however, no effect of S. aureus IMI on milk lactose, fat, and protein contents was observed. Fat yield from infected quarters decreased, but losses due to the infection caused by S. aureus were not associated with quarter positioning in cows.