Ruta Chalepensis Full Extract and Organic Phases Exhibit Nematocidal Activity Against Haemonchus Contortus Eggs and Infective Larvae (L3).

The ovicidal and larvicidal effect of a full aqueous extract (FE) and two phases: an aqueous (Aq-Ph) and an ethyl acetate (EtOAc-Ph) from Ruta chalepensis (Rc) stems and leaves against Haemonchus contortus (Hc) were assessed. The egg hatching inhibition (EHI) assay and larval mortality (LM) test were performed by triplicate in 96-well micro-titration plates (n=4 wells). The FE against Hc eggs and larvae was assessed at 1.25, 2.5, 5, 10 and 20 mg/mL; and 30, 60, 90, 120,150 and 200 mg/ mL, respectively. The ovicidal effect of Aq-F and EtOAc-F was assessed at 1.25, 2.5, 5, 10 and 20 mg/mL. Plates were incubated at 28 °C for 48 (ovicidal assay) and 72 h (larvicidal assay). The EHI results were considered based on the mean number of eggs hatching failure after 48 h exposure. The LM was recorded after 72 h exposure to the Rc phases and expressed as mortality percentage. The Rc FE caused 96 and 100% EHI at 10 and 20 mg/mL, respectively; meanwhile, 74% LM was recorded at 200 mg/mL (p<0.05). The Aq-Ph showed 78.5% EHI at 2.5 mg/mL. Likewise, the EtOAc-Ph caused 100% EHI in almost all concentrations. Eighteen compounds including alkaloids, cumarins, triterpens, flavonoids, tannins, saponins and sterols were identified by GC-MS analysis. The results indicate that the aqueous extract from Rc possesses bioactive compounds with in vitro nematocidal activity against Hc; mainly in the EtOAc-Ph. Further studies should be performed to elucidate those compounds searching for alternative methods of control of the sheep haemonchosis.

Artificial Haemonchus contortus infection as a strategy to induce protective immune response to natural infection in Pelibuey lambs.

The objective of this study was to evaluate the reduction in nematode faecal egg count (FEC) in Pelibuey lambs segregated as resistant (RES), susceptible (SUS) and intermediate (INT) to gastrointestinal nematodes. Twenty-nine weaned Pelibuey lambs, aged five months old, free of nematode infection, were used. Nine lambs were RES, six were SUS and 14 were INT lambs. The study consisted of two phases: in Phase 1 the lambs were infected experimentally with Haemonchus contortus. In Phase 2, the lambs were naturally infected by grazing. Faecal and blood samples were taken every week. The packed cell volume and total protein were quantified. The FEC value (FECmax) per lamb was recorded together with a natural reduction in FEC in the two phases. The data were analysed with a model of measures repeated over time. During Phase 1, the RES lambs showed the lowest FEC (1061 ± 1053) compared to the other groups (INT: 2385 ± 1794 eggs per gram of faeces (EPG); and SUS: 3958 ± 3037 EPG). However, in Phase 2 no significant differences (p > 0.05) were observed between the groups of lambs (RES: 275 ± 498 EPG; SUS: 504 ± 1036 EPG; and INT: 603 ± 1061 EPG). At the end of Phase 1, the FEC of RES lambs was naturally reduced by 75.5% in respect to FECmax (p < 0.05), and at the end of Phase 2 the reduction in FEC was 90% in respect to FECmax (p > 0.05); the same behaviour was observed in RES and SUS lambs. It is concluded that the artificial infection in the lambs induced a more rapid immune response in RES than SUS lambs, and all lambs developed high acquired resistance by continuous infection.

Consumption of nutritional pellets with Duddingtonia flagrans fungal chlamydospores reduces infective nematode larvae of Haemonchus contortus in faeces of Saint Croix lambs.

Two groups of six Haemonchus contortus infected Saint Croix lambs each received different diets for 11 weeks: control group, commercial food, molasses and lucerne hay; and treated group, nutritional pellets (NPs) containing Duddingtonia flagrans at 2 × 106 chlamydospores/kg body weight (BW), sorghum and lucerne hay. Mean BW gain (BWG), body condition score (BCS) and packed cell volume (PCV) and also eggs/g of faeces (EPG) and recovered L3 were compared using a repeated measures across time model. Groups had similar BWG (control 139.7 ± 0.035 g/day and treated 167.7 ± 0.041 g/day), BCS (control 3.6 ± 0.39 and treated 3.4 ± 0.46) and PCV (control 32.5 ± 1.68% and treated 30.0 ± 1.68%). The mean EPG of the control group was 1215 ± 1040 and in the treated group it was 2097.91 ± 2050. No reduction in larval population was observed during weeks 2 and 3. The greatest larval population reduction in the faeces of treated lambs was observed during the first week (70.5%) and from weeks 6 to 11, with a mean value close to 70% (P < 0.05). In general, both experimental groups showed a similar feed conversion. It was concluded that both diets resulted in similar lamb growth, PCV, BCS and H. contortus EPG. However, NP consumption significantly reduced the H. contortus L3 population in lamb faeces.

Dietary supplemented and meat-added antioxidants effect on the lipid oxidative stability of refrigerated and frozen cooked chicken meat.

The oxidation of fatty acids decreases the quality and shelf-life of meats. To reduce this process, dietary supplemented and meat-added antioxidants were evaluated on the lipid oxidative stability of cooked chicken meat. Broilers were fed 2 levels of vitamin E (10 or 100 mg•kg(-1) of feed; VE-10 and VE-100, respectively) or oregano essential oil (100 mg•kg(-1) of feed; OR-100). Additionally, honey (3%) or butylated hydroxytoluene (0.02%; BHT) were added to chicken meat from the control treatment (VE-10). Breast meat was ground, formed into patties, and cooked on electric grills until it reached an internal temperature of 74°C. Cooked meat was cooled at room temperature, packaged, and stored under refrigeration for 9 d (4°C) or frozen for 45 d (-20°C). The 2-thiobarbituric acid reactive substance test was used to quantify malondialdehyde (MDA) values in the meat. Data were analyzed using a repeated measures design, 5 treatments with 12 replications each, and the least squares means were compared with 4 orthogonal contrasts. The results showed that the meat of the VE-10 treatment had higher values of MDA (P ≤ 0.05) compared with the other antioxidant treatments in all the storage days. There were no differences (P ≥ 0.05) in MDA values between the dietary supplemented and meat-added antioxidant treatments. The meat added with honey had lower MDA values than the one with BHT (P ≤ 0.05). Meat of the VE-100 treatment showed lower MDA values than the one of OR-100 (P ≤ 0.05) in most storage days. In conclusion, supplementation of 10 mg•kg(-1) of vitamin E to the diet resulted in a higher development of lipid oxidation in the meat. Both dietary supplemented or meat-added antioxidants had similar effects on the lipid oxidative stability. The addition of honey maintained longer the lipid oxidative stability of the meat than BHT. Finally, dietary supplementation of vitamin E at the same level of oregano oil, 100 mg•kg(-1), resulted in a higher antioxidant effect on the meat.

Effects of dietary oregano essential oil and vitamin E on the lipid oxidation stability of cooked chicken breast meat.

The antioxidant effect of oregano essential oil and vitamin E was evaluated in cooked chicken breast meat. In total, 480 broilers were randomly assigned to 6 treatments and 4 replications. Broilers were raised with a corn-soybean meal diet including either crude soybean oil or acidulated soybean oil soapstock, each supplemented with vitamin E at 10 or 100 mg or oregano essential oil at 100 mg/kg of feed. At 42 d, broilers were slaughtered and their breast meat was prepared into strips (1.5 × 10 cm) or patties (150 g). Fatty acid composition of the muscle was determined. For lipid oxidation stability, both meat strips and patties were cooked to an internal temperature of 74°C and malonaldehyde contents were assessed during 0, 3, 6, and 9 d of storage at 4°C. Each storage day had 4 replications per treatment. The meat lipid oxidative stability was estimated by content of malonaldehyde values. Results showed that feed consumption, weight gain, and feed conversion were not affected by the dietary oils or antioxidants, except for the mortality in acidulated soybean oil soapstock with the 10-mg vitamin E treatment. The fatty acid composition of the meat was similar between the 2 diets given the same antioxidant supplement. The oxidation stability of meat lipids in both types of meats showed a significant (P < 0.05) interaction between oils, antioxidants, and storage time. In the crude soybean oil oil diet, the malonaldehyde value in the 10-mg vitamin E treatment was the highest, followed by oregano essential oil, and then the 100-mg vitamin E treatment at 9 d of storage, whereas the value of oregano essential oil in the acidulated soybean oil soapstock diet was the highest, followed by the 10-mg vitamin E, and then the 100-mg vitamin E treatment during the 9 d of storage. In conclusion, the dietary oils and antioxidants used can be included in broiler diets without negative effects on their productivity. The antioxidant effect of vitamin E was higher with a higher supplementation level, regardless of the oil treatment, whereas the antioxidant effect of oregano essential oil was better in crude soybean oil than in the acidulated soybean oil soapstock diet.

Comparison of parasitological and productive traits of Criollo lambs native to the central Mexican Plateau and Suffolk lambs experimentally infected with Haemonchus contortus.

The study compares the parasitological and productive traits of Criollo lambs native to the central Mexican Plateau (CNCMP) and Suffolk (SU) lambs experimentally infected with Haemonchus contortus. CNCMP lambs (n=20) and SU lambs (n=15) were infected with L3 of H. contortus while five lambs of each genotype were kept as controls. Fecal egg count (FEC), packed cell volume (PCV), blood eosinophil number (BEN), ocular mucous membrane color (as measured by the FAMACHA index), changes in body condition score (BCS) and cumulative live weight gain (CLWG) were measured weekly during a 20-week period. On week 20, all animals were euthanized and the number of adult worms (AW) in the abomasum was counted. Infected SU lambs had higher (p<0.05) FEC and AW mean values compared to CNCMP lambs, which had a higher mean BEN count (p<0.05). Infected lambs had lower PCV values than controls, regardless of genotype, and had a negative correlation (r=-0.84, p<0.05) with the FAMACHA index. BCS tended to decline for infected SU lambs and increased slightly for infected CNCMP lambs. CLWG differed in all groups (p<0.05); infected SU lambs gained 12.1+/-1.9kg, infected CNCMP lambs gained 18.8+/-0.7kg, control SU lambs gained 34.6+/-1.6kg, and control CNCMP lambs gained 26.9+/-0.8kg. In conclusion, CNCMP lambs had a smaller worm burden, a better ability to maintain their productive traits, and were less affected by infection with Haemonchus contortus.

Inferring genetic parameters of lactation in Tropical Milking Criollo cattle with random regression test-day models.

This study inferred genetic and permanent environmental variation of milk yield in Tropical Milking Criollo cattle and compared 5 random regression test-day models using Wilmink's function and Legendre polynomials. Data consisted of 15,377 test-day records from 467 Tropical Milking Criollo cows that calved between 1974 and 2006 in the tropical lowlands of the Gulf Coast of Mexico and in southern Nicaragua. Estimated heritabilities of test-day milk yields ranged from 0.18 to 0.45, and repeatabilities ranged from 0.35 to 0.68 for the period spanning from 6 to 400 d in milk. Genetic correlation between days in milk 10 and 400 was around 0.50 but greater than 0.90 for most pairs of test days. The model that used first-order Legendre polynomials for additive genetic effects and second-order Legendre polynomials for permanent environmental effects gave the smallest residual variance and was also favored by the Akaike information criterion and likelihood ratio tests.