In vitro predatory activity of nematophagous fungi <Emphasis Type="Italic">Duddingtonia flagrans</Emphasis> on infective larvae of <Emphasis Type="Italic">Oesophagostomum</Emphasis> spp. after passing through gastrointestinal tract of pigs

One isolate of predator fungi Duddingtonia flagrans (AC001) was assessed in vitro regarding the capacity of supporting the passage through pigs' gastrointestinal tract without loss of the ability of preying infective larvae Oesophagostomum spp. Fungal isolates survived the passage and were efficient in preying L₃ since the first 8 h of collection (p < 0.01) in relation to the control group (without fungus). Compared with control, there was a significant decrease (p < 0.01) of 59.6% (8 h), 71.7% (12 h), 76.8% (24 h), 81.0% (36 h), 78.0% (48 h), 76.1% (72 h), and 82.7% (96 h) in means of infective larvae Oesophagostomum spp. recovered from treatments with isolate AC001. Linear regression coefficients of L₃ of recovered Oesophagostomum spp. regarding the collections due to time were −0.621 for control, −1.40 for AC001, and −2.64 for NF34. Fungi D. flagrans (AC001) had demonstrated to be promising for use in the biological control of pig parasite Oesophagostomum spp.     

Biological control of horse cyathostomin (Nematoda: Cyathostominae) using the nematophagous fungus Duddingtonia flagrans in tropical southeastern Brazil

The viability of a fungal formulation using the nematode-trapping fungus Duddingtonia flagrans was assessed for the biological control of horse cyathostomin. Two groups (fungus-treated and control without fungus treatment), consisting of eight crossbred mares (3–18 years of age) were fed on Cynodon sp. pasture naturally infected with equine cyathostome larvae. Each animal of the treated group received oral doses of sodium alginate mycelial pellets (1 g/(10 kg live weight week)), during 6 months. Significant reduction (p < 0.01) in the number of eggs per gram of feces and coprocultures was found for animals of the fungus-treated group compared with the control group. There was difference (p < 0.01) of 78.5% reduction in herbage samples collected up to (0–20 cm) between the fungus-treated group and the control group, during the experimental period (May–October). Difference of 82.5% (p < 0.01) was found between the fungus-treated group and the control group in the sampling distance (20–40 cm) from fecal pats. During the last 3 months of the experimental period (August, September and October), fungus-treated mares had significant weight gain (p < 0.01) compared with the control group, an increment of 38 kg. The treatment with sodium alginate pellets containing the nematode-trapping fungus D. flagrans reduced cyathostomin in tropical southeastern Brazil and could be an effective tool for biological control of this parasitic nematode in horses.     

Standardization of the outbred BALB/c mice as a suitable animal model for <Emphasis Type="BoldItalic">Besnoitia caprae</Emphasis> studies

The Apicomplexan parasite Besnoitia caprae infects wild and domestic goats. Knowledge on Besnoitia caprae specially an optimized animal model is sparse. Experimental infections with tachyzoites of BC-Pars obtained from BALB/c mice were conducted in outbred mice to determine the infectivity and LD50 of Besnoitia caprae. Six groups of five mice were intraperitoneally infected with 12.5 × 10³, 25 × 10³, 5 × 10⁴, 1 × 10⁵ and 2 × 10⁵ tachyzoites and a control inoculum of DMEM, respectively. Although morbidity and mortality were observed in all groups, two mice in the 12.5 × 10³ group showed alopecia and skin lesions on 60 days post-infection (DPI). Histopathological and molecular examination of skins confirmed B. caprae infection. The LD₅₀ was calculated as 25 × 10^3.2 tachyzoites per mouse. The results indicate that outbred BALB/c mice can be used as a suitable model of besnoitiosis and to screen candidate treatments and to test the efficacy of vaccines for besnoitiosis.     

Ovicidal activity of seven <Emphasis Type="Italic">Pochonia chlamydosporia</Emphasis> fungal isolates on <Emphasis Type="Italic">Ascaris suum</Emphasis> eggs

The ovicidal effect of the nematophagous fungus Pochonia chlamydosporia on eggs of Ascaris suum was tested under laboratory conditions. A. suum eggs were plated on 2% water–agar with seven fungal isolates (Isol. 5, Isol. 31, Isol. 1, VC1, Isol. 12, Isol. 22 and VC4) and control without fungus. After 5, 7, 10, 14, 15 and 21 days of incubation, approximately 100 eggs were removed from the plates and classified according to the following parameters: type 1, biochemical and physiological effect without morphological damage to the eggshell, type 2, lytic effect with morphological alteration of the eggshell and embryo and type 3, lytic effect with morphological alteration of eggshell and embryo showing hyphal penetration and internal egg colonization. The isolates effectively destroyed A. suum eggs and all types of effects were observed during the experiment. There was no variation in ovicidal capacity (type 3 effect) among the isolates (p > 0.05) throughout the experiment. After 21 days, isolate 5 showed the highest percentages of type 3 effect (58.33%). The results indicated that P. chlamydosporia (Isol. 5, Isol. 31, Isol. 1, VC1, Isol. 12, Isol. 22 and VC4) can destroy A. suum eggs and is, therefore, a potential biological control agent of nematodes.     

Prevalence and biology of goat warble fly infestation by <Emphasis Type="Italic">Przhevalskiana silenus</Emphasis> in Jammu province,India

Examination of 3,960 goats brought from six districts of Jammu province and slaughtered at Jammu abattoir from July 2005 to June 2006 revealed 47.22% prevalence of larval stages of warble fly (Przhevalskiana silenus Brauer, 1858) in goats. Highest prevalence was recorded in Udhampur (56.44%) and lowest in Doda district (13.49%). Classification of the study area into four zones based on height (meters above sea level), viz., zone I (300–325 m asl), zone II (325–800 m asl), zone III (800–1,500 m asl), and zone IV (>1,500 m asl), revealed significant (p < 0.01) difference in infestation among animals of zone II (71.68%), zone III (40.12%), and zone IV (22.41%). However, animals of zone I did not reveal any infestation. Statistical analysis in relation to age showed significant (p < 0.01) difference among different age groups, i.e., <1 year (2.81%), 1–3 years (51.17%), and >3 years (43.16%). Breed-wise analysis also showed significantly (p < 0.01) higher infestation rate among Bakerwali (51.51%) goats as compared to Beetal (42.59%). But no significant difference was recorded among male (47.81%) and female (46.82%) animals. The overall mean larva count (L1, L2, and L3) was observed to be 14.72 ± 0.34, ranging from 4 to 72. It was significantly (p < 0.05) higher in animals of zone II (22.20 ± 0.21) as compared to goats of zones III (14.21 ± 0.41) and IV (7.73 ± 0.90). Age-wise analysis of mean larva count also showed significant (P < 0.05) difference between animals of 1–3 years (16.25 ± 0.37) and >3 years of age (13.18 ± 0.40). Mean larvae count in relation to sex and breed did not reveal any significant difference. First-instar larvae (L₁) were recorded from May to mid-September, second larval stage (L₂) from mid-September to mid-December, and third-stage larvae (L₃) from mid-December to February. However, No larvae were recorded from March to April, which is suggestive of pupation period in this region. Thus, it is concluded that adult fly is active in April to June. The results further confirmed that internal life cycle of P. silenus is subcutaneous and no migration of larvae occurs. This is the first report from India, based on slaughter house study on the prevalence and biology of goat warble fly infestation. It will help in devising suitable prophylactic and eradication program to check the economic losses rendered by adult fly.     

Biological control of <Emphasis Type="Italic">Ascaris suum</Emphasis> eggs by <Emphasis Type="Italic">Pochonia chlamydosporia</Emphasis> fungus

Ascaris suum is a gastrointestinal nematode parasite of swines. The aim of this study was to observe Pochonia chlamydosporia fungus on biological control of A. suum eggs after fungus passage through swines gastrointestinal tract. Eighteen pigs, previously dewormed, were randomly divided into three groups: group 1, treated with the fungus isolate VC4; group 2, treated with the fungus isolate VC1 and group 3 did not receive fungus (control). In the treated groups, each animal received a 9 g single dose of mycelium mass containing P. chlamydosporia (VC1 or VC4). Thereafter, animal fecal samples were collected at the following intervals: 8, 12, 24, 36, 48, 72 and 96 h after treatment beginning and these were poured in Petri dishes containing 2% water-agar culture medium. Then, 1,000 A. suum eggs were poured into each dish and kept in an incubator at 26°C and in the dark for 30 days. After this period, approximately 100 eggs were removed from each Petri dish and morphologically analyzed under light microscopy following the ovicidal activity parameters. The higher percentage observed for isolated VC4 eggs destruction was 57.5% (36 h) after fungus administration and for isolate VC1 this percentage was 45.8% (24 h and 72 h) (p > 0.01). P. chlamydosporia remained viable after passing through the gastrointestinal tract of swines, maintaining its ability of destroying A. suum eggs.     

Immune responses to haemorrhagic septicaemia (HS) vaccination in <Emphasis Type="Italic">Trypanosoma evansi</Emphasis> infected buffalo-calves

To assess the immunosuppressive effect of Trypanosoma evansi infection in buffalo-calves on immune responses to heterologous antigen, the study was planned to examine the responses of haemorrhagic septicaemia vaccination in simultaneously and previously (80 days before vaccination) T. evansi-infected buffalo-calves. Eight buffalo-calves were divided into three groups. Buffalo-calves of group A (n = 3) were previously (80 days before primary vaccination with haemorrhagic septicaemia [HS] vaccine) infected with T. evansi (1 × 10⁷ tryps.calf⁻¹; sc) and that of group B (n = 3) were infected with T. evansi (1 × 10⁷ tryps.calf⁻¹; sc) on the day of primary vaccination with HS vaccine. Two healthy uninfected control calves given only HS vaccine were kept in group C. All the buffalo-calves were given a booster dose of vaccine 21 days post-primary vaccination (PPV). Twenty eight days PPV, animals of group A were given trypanocidal quinapyramine prosalt at 6.66 mg kg⁻¹. Immunosuppressive effect of T. evansi infection was evident from day 7 PPV with HS vaccine. The effect was more pronounced in previously T. evansi-infected buffalo-calves as compared with simultaneously infected buffalo-calves. Group A buffalo-calves appeared to have recovered from the immunosuppressive effect after 28 days post-trypanocidal treatment as observed by humoral and cell-mediated immune responses. Immunosuppressive effect to HS vaccination was observed in T. evansi-infected buffalo-calves, and trypanocidal therapy enabled the calves to mount the responses similar to uninfected controls.     

Effect of supplementation with corn oil on postpartum ovarian activity,pregnancy rate,and serum concentration of progesterone and lipid metabolites in F<Subscript>1</Subscript> (<Emphasis Type="Italic">Bos taurus</Emphasis> × <Emphasis Type="Italic">Bos indicus</Emphasis>) cows

The aim was to evaluate the effect of corn oil supplementation during postpartum anoestrus on ovarian activity, pregnancy rate, progesterone (P₄), and lipid metabolites (cholesterol, CHO; low and high density lipoproteins; LDL and HDL, respectively) concentrations in blood of F₁ (Bos taurus × Bos indicus) grazing cows. Cows were randomly assigned to an experimental group, fed with a supplement containing 4% corn oil on dry matter basis (OG, n = 11), and a control group with the same supplement without corn oil (CG, n = 12). Both supplements contained equivalent amounts of crude protein and metabolizable energy and were fed for 34 days continuously. All cows were induced to estrous 12 days after beginning of supplementation by using a synthetic progestagen and artificially inseminated 56 h after retiring the implants. Pregnancy diagnosis was performed by transrectal palpation 45 days after insemination, evaluating simultaneously ovarian activity. P₄ and lipid metabolites (CHO, HDL, LDL) concentrations were determined in blood samples collected at 3-day intervals, from the beginning of corn oil supplementation and up to 10 days after artificial insemination. Ovarian activity was affected by treatment (p < 0.05), finding ovarian structures in 72.7% of OG cows and in 50% of CG cows. Concentration of P₄ and CHO was higher for OG with respect to CG (2.52 ± 0.65 vs 1.88 ± 0.62 ng/ml and 117.79 ± 11.57 vs 85.71 ± 12.11 mg/dl, respectively), whereas pregnancy rate and blood concentrations of HDL and LDL were not affected by treatment (p > 0.05). Addition of corn oil to the supplement stimulated ovarian activity and increased serum concentrations of progesterone and cholesterol in grazing B. taurus × B. indicus cows with low body condition score showing postpartum anoestrus.     

Dietary folate and vitamin B<Subscript>12</Subscript> supplementation and consequent vitamin deposition in chicken eggs

We determined the effects of dietary supplementation with folate and vitamin B₁₂ on lipid metabolism and the deposition of these vitamins in eggs of laying hens (age 64–72 weeks). Four levels of folate (0, 0.5, 4 and 10 mg/kg) and three levels of vitamin B₁₂ (0, 0.01 and 0.08 mg/kg) were added to the basal diet for 8 weeks in a 4 × 3 factorial completely randomized design study. No significant physiological interaction between folate and vitamin B₁₂ was evident under our experimental conditions. There was no effect of vitamins supplementation on egg production or feed intake. Supplementation with folate significantly elevated serum (p < 0.01) and yolk (p < 0.05) folate levels. Supplementation with vitamin B₁₂ did not significantly affect serum or egg yolk vitamin B₁₂ levels. Supplementation with folate or vitamin B₁₂ did not significantly affect triglyceride or total phospholipid levels in serum or egg yolk although a positive relationship was observed between dietary folate supplementation and total serum phospholipid (r ²  = 0.68, p < 0.05). The study showed that it is possible to produce folate-enriched eggs. An increase in serum total phospholipids due to dietary supplementation with folate may provide physiological benefits to hens, although we did not observe any strong effects of these vitamins on lipid composition.     

Effect of supplementation of mustard oil cake on intake,digestibility and microbial protein synthesis of cattle in a straw-based diet in Bangladesh

The objective of this study was to analyse the effects of different levels of rumen-degradable protein (RDP) on intake, digestibility and microbial protein synthesis by supplementing mustard oil cake (MOC) on rice straw-based diet of cattle (Bos indicus) in Bangladesh. A 4 × 4 Latin square design was applied. Four diets having constant energy (7.0 MJ/kg of dry matter (DM)) with varying levels of RDP (M ₀ = 4.1 g/MJ (control), M ₁ = 6.3 g/MJ, M ₂ = 8.3 g/MJ and M ₃ = 12.4 g/MJ of metabolizable energy (ME)) were received by each animal for a period of 28 days. A metabolism trial was conducted for 7 days. Results indicate that with increasing levels of RDP, crude protein (CP) and RDP intake increased significantly (P < 0.01). The significant (P < 0.01) increase in digestibility values are obtained for DM, organic matter, CP and digestible organic matter in the rumen. The digestibility of neutral detergent fibre and acid detergent fibre was also increased significantly (P < 0.05). The total nitrogen (N), ammonia-N and total volatile fatty acids increase significantly (P < 0.01) while the rumen pH increased from M ₀ to M ₂ and decreased thereafter. The efficiency microbial N intake increased significantly (P < 0.01) but showed a curvilinear response with higher RDP level (12.40 g/RDP/MJ ME). This study concludes that supplementation of RDP from MOC enhances the intake, digestibility and microbial protein synthesis which ultimately increases utilization of low-quality feed resources that can be used for developing cost-effective feeding systems on a straw-based diet in tropical regions.     

Intake,digestibility and nitrogen balance in Mithun (<Emphasis Type="BoldItalic">Bos frontalis</Emphasis>) offered urea-treated paddy straw based feed blocks

The aim of the study was to determine the effect of feeding feed blocks containing varying proportion of urea-treated paddy straw (UTPS) on dry matter (DM) intake (DMI), nutrient utilization and N balance in Mithun. For the purpose, four adult male Mithun (279.5 ± 8.2 kg) were selected and offered four experimental rations viz. R₁ (Napier fodder + concentrate at 60:40), R₂ (UTPS + concentrate at 50:50), R₃ (UTPS + concentrate at 60:40) and R₄ (UTPS + concentrate at 70:30) in 4 × 4 Latin square design. The DMI % of body weight was 2.59, 2.96, 2.85 and 2.77 and the DMI g kg⁻¹ W^0.75 was 107, 123, 118 and 115 in Mithun fed R₁, R₂, R₃ and R₄, respectively. The mean DMI was (P < 0.01) higher in animals fed R₂ and R₃ than R₁ and R₄, whereas the water intake was (P < 0.01) higher in Mithun fed R₂, R₃ and R₄ than R₁. The digestibility of DM, organic matter, crude protein, crude fibre, neutral detergent fibre and cellulose were (P < 0.05) higher in animals fed R₂, R₃ and R₄ than R₁. A positive N balance was observed in all the experimental animals, with higher (P < 0.05) values among the animals offered R₂, R₃ and R₄ than R₁. The digestible crude protein and total digestible nutrient intakes were higher (P < 0.05) in Mithun fed R₂ and R₃ than R₁ and R₄. It is concluded that the UTPS can be incorporated up to 70% to formulate the complete feed/feed block and can be used for feeding of Mithun under complete confinement system.     

Effect of source and dose of probiotics and exogenous fibrolytic enzymes (EFE) on intake,feed efficiency,and growth of male buffalo (<Emphasis Type="BoldItalic">Bubalus bubalis</Emphasis>) calves

Probiotics of Lactobacillus acidophilus, Saccharomyces cerevisiae, and Aspergillus niger and three commercial exogenous fibrolytic enzymes (EFE) were tested in vitro to select best source and optimum dose followed by in vivo studies on male buffalo calves. Bacterial (P < 0.001) and protozoal population were increased significantly (P < 0.001) with probiotics and EFE. In vitro dry matter digestibility was more (P < 0.001) on L. acidophilus and then on S. cerevisiae. Dose required for L. acidophilus and S. cerevisiae probiotics was 1 × 10⁹ and 3 × 10⁹ cfu/flask, respectively. Cellulase and xylanase were effective at 4,000 and 12,500 IU/kg DM. In vitro cell wall digestibility was increased (P < 0.001) when probiotics and EFE were used together. Best source and optimum dose of probiotics and EFE were fed to 18 male buffalo calves with concentrate supplement (CS). Calves were randomly divided into three groups either without probiotics and EFE (CG) or with probiotics (EG₁) or probiotics combined with EFE (EG₂) on wheat straw diet. Organic matter, neutral detergent fiber, and acid detergent fiber digestibility was improved significantly. Average daily weight gain (ADG) and feed efficiency were significantly higher (P < 0.001) in EG₂ than EG₁ or CG. Final body weight was 4% and 12% and feed efficiency was 2.6% or 1.6% more (P < 0.001) in EG₂ compared to CG or EG₁, respectively. Fortification of CS with probiotics and EFE together had more impact on FE and ADG in buffalo calves.     

Comparison of the pathogensis of two isolates of <Emphasis Type="Italic">Besnoitia caprae</Emphasis> in inbred BALB/c mice

This study was performed to evaluate the infectivity of bradyzoites of two Besnoitia caprae isolates, BC-1 and BC-2, to inbred BALB/c mice. Each group of inbred BALB/c mice was inoculated intraperitoneally with 1 × 10³, 1 × 10⁴, 1 × 10⁵, 5 × 10⁵ and 1 × 10⁶ of one of the two isolates of B. caprae bradyzoites. The mice were monitored daily for a period of 40 days for survival. After death of each mice, several passages from its peritoneal washing and tissues were analyzed using ribosomal DNA-specific PCR assay. Marked differences in pathogenicity between the isolates were seen. All the inbred BALB/c mice infected with BC-2 survived but all the mice that were administered with 1 × 0⁵, 5 × 10⁵ and 1 × 10⁶ BC-1 bradyzoites were died within 4–9 days post-infection (DPI). Histopathological examination of the tissues of the dead mice revealed hyperemia and necrosis with presence of mononuclear and polymorphonuclear cell infiltration in myocardium, spleen and intestines together with interstitial pneumonia and peritonitis. All inbred BALB/c mice in the 1 × 10³ and 1 × 10⁴ groups of BC-1 inoculated mice survived and they were euthanized after 40 DPI. Chronic inflammation with infiltration of mononuclear cells was evident in myocardium, spleen, alveolar septa of the lungs of most of the examined tissues with hemorrhagic enteritis in the mice infected with 1x10⁶ bradyzoites. The mice infected with different doses of BC-2 were euthanized after 40 DPI and no lesion was seen in histopathological sections of their organs. All peritoneal washings and examined tissues were PCR positive in BC-1 group. This experiment is the first report to show inbred BALB/c mice as a relevant model for B. caprae and demonstrates that this strain of inbred BALB/c mice is a suitable animal model for biological studies and examination of pathogenesis for this species of Besnoitia. The present findings also provide evidence for significant differences between the two isolates of B. caprae.     

Efficiency of feeding <Emphasis Type="Italic">Duddingtonia flagrans</Emphasis> chlamydospores to control nematode parasites of first-season grazing goats in France

A field trial, conducted over two consecutive years, was aimed at assessing the efficacy of the administration of spores of the nematophagous fungus Duddingtonia flagrans to young goats for the control of nematode parasite infections on a French commercial dairy goat flock. For both years, the first-year grazing kids were divided into two similarly managed groups (fungus and control groups): in 2003 a daily dose rate of 5 × 10⁵ spores/kg body weight was given to the fungus-group animals, while in 2004 a daily dose rate of 10⁶ spores/kg body weight was used; the other half of the kids, acting as control, did not receive the spores. Parameters measured every 3 weeks included nematode egg excretion, larval development in faecal cultures and pasture larval counts. Additionally, at the beginning, the middle and the end of each grazing season, the goats were weighed and blood samples for pepsinogen determination were collected. In 2003, similar results were recorded for all the measured parameters in the control and fungus groups. In contrast, in 2004, the kids receiving the spores showed lower faecal egg counts and pepsinogen levels at the end of the season and higher growth rate compared to kids of the control group.     

Effect of increasing levels of white mulberry leaves (<Emphasis Type="Italic">Morus alba</Emphasis>) on ruminal dry matter degradability in lambs

A study was conducted to estimate dry matter (DM) degradability in the rumen of lambs offered a basal soybean meal and sorghum grain diet with three levels of white mulberry (WM) leaves (Morus alba). Diets consisted of 90% concentrate and 10% sorghum straw, which was incrementally replaced by WM leaves at 0% (control diet, T1), 2.5% (T2), and 5% (T3) of the total ration. Crude protein (CP) in WM was 21.8% (DM basis). Diets had equal CP (14% DM basis) and metabolizable energy (10.8 MJ/kg DM) content. Three non-castrated Pelibuey male lambs fitted with permanent rumen cannula were utilized in a 3 × 3 Latin square design. Each experimental period consisted of 10 days of adaptation followed by sampling. DM degradability was determined using the nylon bag technique. Bags contained the experimental diets offered in each period and were incubated in rumen in pairs for 4, 8, 12, 24, and 48 h. The potential degradation was higher (P < 0.05) for T2, followed by T3 and T1. WM level did not influence the degradation rate or the effective degradation at the three passage rates modeled. It was concluded that WM forage may have useful application in feedlot diets for growing lambs, as this forage increases potential degradation of high-grain diets. The incorporation of WM in diets for feedlot lambs in tropics may reduce the use of expensive conventional protein supplements.     

Effect of nerve growth factor (NGF) on the development of preimplantation rabbit embryos <Emphasis Type="Italic">in vitro</Emphasis>

This study aimed to investigate the effect of nerve growth factor (NGF) on the development of preimplantation rabbit embryos in vitro. Zygotes were collected from superovulated New Zealand rabbits 19 h after injection of hCG and immediately mating and cultured in TCM-199 plus fatty-acid free BSA with different concentrations of NGF. Zygotes not treated with NGF served as control. At 24 h, 48 h, 72 h and 96 h of the culture, the numbers of the early cleavage stage, morulae, blastocysts and hatching blastocysts were determined. The intrazonal diameter of the blastocyst and the total cell numbers per blastocyst were measured after 96 h of culture. The results showed: (1) NGF at 100 ng/mL and 1000 ng/mL could improve the numbers of the hatching blastocysts which developed compared to the control treatment (p < 0.05); (2) All concentrations of NGF increased the total cell numbers in the blastocysts compared to the control treatment (p < 0.05); (3) NGF had no significant effect on the blastocyst intrazonal diameter of the blastocysts at 96 h of culture (p = 0.493); (4) The proportion in the early cleavage stage at 24 h of culture (p = 0.635), of morulae at 48 h of culture (p = 0.812) and of blastocysts at 72 h of culture (p = 0.812) in all treatments were not significantly different.     

Energetic efficiency of milk synthesis in dual-purpose cows grazing tropical pastures

The aim of this study was to assess the energetic efficiency of milk synthesis by grazing dual-purpose cows with or without a starch-based supplement in tropical South Mexico. Forty-six Holstein × Zebu cows were used in a 2 × 2 × 2 factorial design. Factors analysed were diet (supplemented, unsupplemented), age (young: 1–2 calvings, mature: >3 calvings) and day of lactation (21 and 84 days post-calving). The supplement represented about 30% of estimated dry matter (DM) intake. Grass intake was measured using the n-alkane technique at 21 and 84 days post-calving when calculations of efficiency were performed. Efficiency for milk synthesis was reported as feed conversion efficiency (FCE, kilograms of milk per kilogram of DM intake), gross energetic efficiency (GEE, milk energy output/metabolisable energy (ME) intake) and efficiency of ME use for lactation (k _l, adjusted to zero energy balance). There were no interactions between factors. FCE and GEE were not different between diets, but supplemented cows had a lower (p < 0.01) k _l value (0.62) than unsupplemented cows (0.67), suggesting a diverted partition of nutrients towards body tissue. Mature cows were more efficient (p < 0.001) than young cows in terms of FCE (1.13 vs 0.87) and GEE (0.34 vs 0.26), but equal in terms of k _l (0.65). FCE (1.10 vs 0.90) and GEE (0.34 vs 0.27) were both higher on day 21 compared with day 84 post-calving, with a trend for a higher k _l in early lactation. Dual-purpose cows used tropical grasses efficiently for milk synthesis, and higher milk yield observed in supplemented cows was due to a higher intake of nutrients rather than a higher energetic efficiency.     

Phenotypic and Genotypic Study of Gelatinase and β‐Haemolysis Activities in Faecal Enterococci of Poultry in Portugal

The detection of gelatinase and β‐haemolysis activities was carried out in 83 faecal enterococci (43 Enterococcus faecalis, 33 E. faecium, five E. durans and two E. hirae) of poultry origin. In addition, the presence of genes of the gelE–fsrABC locus and of the cyl operon (cylL_L, cylL_S, cylA, cylB and cylM) were studied by polymerase chain reaction and correlated with gelatinase and β‐haemolysis production, respectively. Most of our E. faecalis isolates were gelatinase‐positive (88%), being this activity not frequent in the other enterococcal species (2.5%). Only one of the 33 E. faecium isolates showed a positive gelatinase reaction. All enterococci that showed gelatinase activity harboured the gelE and fsrABC genes, although these genes were also detected in four E. faecalis and one E. durans gelatinase‐negative isolates. Most of our non‐E. faecalis gelatinase‐negative isolates did not harbour gelE–fsrABC genes. A high proportion of faecal enterococci of poultry origin harboured genes of the cyl operon (71%), although only 7% contained the five cyl tested genes (all of them E. faecalis). Only one isolate of our series could express β‐haemolysis, harbouring the whole cyl operon. The cylL_S genotype was the most prevalent in our enterococci (39%) and also the most prevalent among our E. faecalis isolates (60%). Other genotypes detected were the following ones (% of enterococci): cylA + cylB + cylM (13%), cylL_L + cylA (4%), cylL_L (4%), cylL_L + cylA + cylB + cylM (2%), cylL_L + cylA + cylM (1%) and cylA + cylM (1%). Both phenotypic and genotypic assays are important to evaluate the virulence potential of enterococci.     

Comparative analysis of destruction of the infective forms of Trichuris trichiura and Haemonchus contortus by nematophagous fungi Pochonia chlamydosporia; Duddingtonia flagrans and Monacrosporium thaumasium by scanning electron microscopy

The present study aimed to demonstrate by scanning electron microscopy (SEM) the in vitro predatory activity of nematophagous fungi Pochonia chlamydosporia (VC1 and VC4 isolates) Duddingtonia flagrans (AC001 isolate) and Monacrosporium thaumasium (NF34a isolate) on eggs of Trichuris trichiura and infective larvae (L3) of Haemonchus contortus. The work was divided into two experimental tests (A and B). In tests A and B, the predatory activity of nematophagous fungi P. chlamydosporia, D. flagrans and M. thaumasium on eggs of T. trichiura and H. contortus L3 was observed. After 6 h, in test A, isolates P. chlamydosporia (VC1 and VC4) had a role in destroying eggs of T. trichiura. For fungi D. flagrans and M. thaumasium the ovicidal activity on T. trichiura eggs was not observed. Test B showed that D. flagrans (AC001) and M. thaumasium (NF34a) were capable of predating H. contortus L3, but no predation by the fungus P. chlamydosporia was seen. These fungi can offer potential for the biological control of nematodes.     

Huizache (<Emphasis Type="Italic">Acacia farnesiana</Emphasis>) whole pods (flesh and seeds) as an alternative feed for sheep in Mexico

Two experiments were undertaken to evaluate the use of pods from Huizache (Acacia farnesiana), common in the arid and semiarid regions of Mexico, on the perfromance and apparent digestibility in Pelibuey Mexican hair growing ewe lambs. Twenty-four Pelibuey ewe lambs were used in the animal performance experiment, with a mean live weight of 14.91 ± 1.48 kg, randomnly allocated to three groups which received ad libitum for 77 days (11 weeks) experimental whole rations T0 with 0%, T12 with 12% or T24 with 24% inclusión of dried and ground Huizache pods. Dry matter intakes (g/kg ^0.75 daily) were 83, 95, 90 for T0, T12, and T24 respectively (P > 0.05). Mean daily live-weight gain was 90, 75, and 63 g/day for T0, T12, and T24 (P < 0.001). Nine Pelibuey ewe lambs were used to determine apparent digestibility in vivo of the experimental diets using a 3 × 3 latin square design repeated three times. There were differences in the digestibility of dry matter (P < 0.001), organic matter (P < 0.001), nitrogen (P < 0.031), neutral detergent fibre (P < 0.002), and acid detergent fibre (P < 0.001) being lower in T24. Huizache pods may be an alternative feed when included up to 12% of dry matter in the diets for sheep growing moderately.