S. N. Esteves

Haemonchus contortus: A multiple-resistant Brazilian isolate and the costs for its characterization and maintenance for research use

The aim of this work was to determine the resistance level of Haemonchus contortus isolated from the Santa Inês flock of the Embrapa (Brazilian governments Agricultural Research Company), Southeast Livestock Unit (CPPSE), as well as to determine costs of characterizing and maintaining this isolate in host donors. Forty-two male Santa Inês lambs were experimentally infected with 4000 H. contortus infective larvae of the field isolate of CPPSE, called Embrapa2010, and divided into six treatment groups, which received triclorfon, albendazol plus cobalt sulfate, ivermectin, moxidectin, closantel and levamisole phosphate, as well as a negative control group (water). Egg per gram (EPG) counts were performed at 0, 3, 7, 10 and 14 days post treatment when the animals were slaughtered for parasite count. The data were analyzed using the RESO statistical program, considering anthelmintic resistance under 95% of efficacy. EPG and worm count presented a linear and significant relation with 94% determination coefficient. The susceptibility results obtained by RESO through both criteria (EPG and worm count) were equal, except for closantel, showing that the isolate Embrapa2010 is resistant to benzimidazoles, macrocyclic lactones and imidazothiazoles. The need of a control group did not appear to be essential since the result for susceptibility in the analyses with or without this group was the same. Suppression in egg production after treatment did not occur in the ivermectin and moxidectin groups. In the control group, the establishment percentage was just 12.5 because of the low number of third-stage larvae, resistance (innate and infection immunity) of the animals studied plus good nutrition. Drug classes presented similar efficacy between adults and immature stages. The costs for isolate characterization were calculated for 42 animals during 60 days. The total cost based on local market rates was approximately US

Peso de abate de machos não-castrados para produção do bovino jovem. 2. Peso, idade e características da carcaça

8000. The precise identification of Brazilian isolates and their establishment in host donors would be useful for laboratorial anthelmintic resistance diagnoses through in vitro tests, which has an annual cost of approximately US

Efeitos da implantação de técnicas agropecuárias na intensificação de sistemas de produção de leite em estabelecimentos familiares

2500 for maintenance in host donors.

Eficiência de utilização de nutrientes em novilhas das raças Canchim e Nelore e cruzadas Canchim-Nelore

To obtain slaughter weight and age and the carcass characteristics of young bulls, a feedlot study was conducted at Embrapa Pecuaria Sudeste. A total of 215 animals from Embrapa and private farms, 3 / 8 and ½ Blonde dAquitaine x Nellore; ½ Canchim x Nellore; ½ Limousin x Nellore; ½ Piedmontese x Nellore; Canchim (CA) and Nellore (NE), were used in 1994, 1995 and 1997. The slaughter weights (TRAT) of 400 (I); 440 (II) and 480 kg (III), except for NE cattle (380, 410 and 440 kg), were tested. All animals received, ad libitum, a diet based on 50% whole plant corn silage and 50% concentrate, on a dry matter basis. The live weight of the animals were obtained after fasting of 16 hours. The animals were slaughtered at a commercial packing plant. The data were submitted to the analysis of variance and the means were compared by SNK tests. The straightbred Canchim and all crossbred animals were slaughtered at 231, 252 and 273 kg of hot carcass weight with an average age of 15.4; 16.1 and 16.8 months, for TRAT I, II and III, respectively; while straightbred Nellore were slaughtered at 211.5; 219 and 228 kg hot carcass weight with an average age of 16.4; 17.2 and 17.5 months, for TRAT I, II and III, respectively. The estimated means of days on feedlot, yield of carcass, rib eye area and backfat thickness were: 70.9; 95.1 and 114.7 days; 57.2; 57.7 and 58.3%; 31.4; 30.9 and 30.2 cm 2 /100 kg carcass weight; 2.5; 3.1 and 3.6 mm, for TRAT I, II and III, respectively. The percentage of saleable meat from the hindquarter gunbit cut was similar for all three slaughter weights; while a reduction of the percentage of bones was compensated for by an increase in the percentage of trimmed excess fat with an increase of slaughter weight. There were significant interactions between genetic group and TRAT for estimated slaughter weights, percentage of hindquarter, hindquarter gunbit and forequarter cuts and the rib eye area.

Proposition of classification models for the direct evaluation of the quality of cattle and sheep leathers using laser-induced breakdown spectroscopy (LIBS) analysis

The economic viability of milk production in small family farms (SFF) in Sao Carlos, SP, from 1998 to 2001, after implementation of several technical and management actions in order to increase production was studied. Six SFF with sizes varying from 4.2 to 27.2 hectares and milk production as the main economical activity were selected. The technical actions implemented in each SFF were: agricultural: a) feeding: cropping and feeding sugar-cane + urea in the dry-season, concentrate supplementation according to the cow milk production level and rotational grazing in the rainy-season, b) animal welfare: identification and improvement of animal welfare, c) reproduction: use of artificial insemination and/or bulls and reproductive control of the herd, d) disease control: control of ectoparasites and endoparasites as well as brucellosis and tuberculosis tests, and e) genetic breeding: use of selected bulls, environment: recovery and conservation of natural resources, improvement of water quality and recovery of soil fertility, and administration techniques: culling of low-production animals, herd productivity control, practice of partnership and economical analysis. For statistical analysis was used an ANOVA model that included effects of the six SFF and fixed effects of year and months within year. The year effect was confounded with the technical and management actions and was assessed by orthogonal polynomials in order to estimate the quantitative changes in the response variables related to the year of 1998. The estimated means of the six SFF for annual milk production, milk production/ha/year, milk production/cow, net income and assets increased by 24%, 36%, 38%, 70% and 27%, respectively comparing year 2001 with 1998. Operational and total costs reduced 24.1% and 15.8%, respectively, while profit increased 4%. Two out of six SFF were chosen as extension units and used as models of SFF. It was concluded that implementation of technologies were efficient in all SFF investigated in this study.

Polpa de Citros Peletizada na Alimentação de Eqüinos

The objective of this work was to study the efficiency of nutrient utilization by Canchim (CA), Nellore (NE) and crossbreed 1/2 Canchim + 1/2 Nelore (CANE) growing heifers, in three diets: maintenance, forage:concentrate ratio (RFC) of 75:25 (test 1), diet for weight gains up to 700 g/animal/day, RFC of 60:40 (test 2) and diet for weight gains up to 1200 g/animal/day, RFC of 40:60 (test 3). Twenty-four heifers were used in each test, eight of each genetic group. Each test had by three phases: a) performance, of 90 days,where the dry matter intake and daily weight gains were determined; b) coefficients of apparent digestibility and nitrogen balance of animals; and c) liquid phase digesta passage rates. The heifers from CA, NE and CANE showed similar results, within each diet, for all analyzed variables.

Peso de Abate de Machos não-castrados para Produção do Bovino Jovem. 1. Desempenho em Confinamento e Custos de Produção

This study proposes classification models for the prediction of the quality parameters of cattle and sheep leathers. In total, 375 leather samples were directly analyzed by laser-induced breakdown spectroscopy (LIBS). Exploratory analysis using principal component analysis (PCA) and classification models employing K-nearest neighbor (KNN), soft independent modeling of class analogy (SIMCA), and partial least squares – discriminant analysis (PLS-DA) were the chemometric tools used in the multivariate analysis. The goal was to classify the leather samples according to their quality. The calculated models have satisfactory results with correct prediction percentages ranging from 75.2 (for SIMCA) to 80.5 (for PLS-DA) for the calibration dataset and from 71.6 (for SIMCA) to 80.9 (for KNN) for the validation samples. The proposed method can be used for preliminary leather quality inspection without chemical residues generation.

Thermoregulation of male sheep of indigenous or exotic breeds in a tropical environment

The objective of this research was to study three levels of pelleted citrus pulp (PCP) in substitution to corn in diets of growing fillies. Twenty-one purebred and crossbred Arabian fillies averaging 278+9.6 kg of initial live weight and 18 months of age were used. The animals were maintained in individual pens and were daily exercised. A completely randomized design with three treatments: basal diet (T1), 7.5% PCP (T2) and 15.0% PCP (T3) with seven replicates, and with the filly as the experimental unit. The experimental period was of 16 weeks. The diets were formulated with 40% of coast-cross (Cynodon dactylon Pers) hay and 60% of concentrate, 14.5% of crude protein (CP), 2.77 kcal/g of digestible energy, on the dry matter (DM) basis. Weight gain, voluntary feed intake (gDM/kg.75) and the hearth girth did not differ among the treatments. The average withers height for T1 (6.8+1.0 cm) was higher than T2 (3.4+1.0 cm) and T3 (4.6+1.0 cm). The DM apparent digestibility coefficient for T2 (68.7+1.2%) and T3 (67.5+1.2 %) were higher than T1 (58.6+1.2 %). The same result was obtained for the CP, T2 (77.1+ 1.5 %) and T3 (78.6+1.5 %) were higher than that for T1 (70.8+1.5 %). For the gross energy, T2 (59.8+0.4%) was lower than both T1 (62.0+0.4%) and T3 (61.2+0.4%). There were no differences among the treatments for neutral detergent fiber, acid detergent fiber and the solid and liquid passage rate of the digesta. The pelleted citrus pulp can be used up to 15,0% in the diets of growing fillies, without affecting the animal performance.

Differences in the thermal sensitivity and seminal quality of distinct ovine genotypes raised in tropical conditions

To obtain the adequate slaughter weights and costs of production of young bulls, a feedlot study was conducted at Embrapa Pecuaria Sudeste, with 234 crossbred Blonde dAquitaine x Nellore (BN); Canchim x Nellore (CN); Limousin x Nellore (LN); Piedmontese x Nellore (PN); and straightbred Canchim (CA) and Nellore (NE) in 1994, 1995 and 1997. At the beggining of the experiment, the animals had 12 months of age and the BN, CA, CN, LN weighed 265 kg, the NE 214 kg and the PN 237 kg. The slaughter weights (TRAT) of 400 (I); 440 (II) and 480 kg (III), except for NE bulls (380, 410 and 440 kg), were tested. A diet with 13% crude protein and 70% total digestible nutrients, based on 50% whole plant corn silage and 50% concentrate, on a dry matter basis, was fed ad libitum. The measurement of weights of the animals were performed after fasting for 16 hours. Data were submitted to the analysis of variance and the means compared by SNK tests. The estimated means of daily weight gain (DWG), daily dry matter intake (DMI), kg and as a percentage of live weight, the feed:gain ratio (FG) and days on feed for TRAT I; II and III were 1.56; 1.49 and 1.44 ± 0.03 kg; 9.01; 9.01 and 9.21 ± 0.13 kg; 2.58; 2.44 and 2.45 ± 0.04%; 5.92; 6.26 and 6.49 ± 0.12; 71.3; 95.6 and 115.3 ± 2.1 days, respectively. The effects of year, genetic group and TRAT were significant for DWG, DMI and FG. The interactions between genetic group and TRAT were not significant. There was an increase in the cost of production of 15 kg of carcass in the feedlot from 39.14 to 40.31 or 40.49 reais with the increase in the slaughter weight from 400 to 440 or 480 kg live weigth, respectively. The monthly net income of the capital invested was reduced from 1.0% to 0.7% or 0.6% for TRAT I, II or III, respectively.

The intake of dry cashew apple fiber reduced fecal egg counts in Haemonchus contortus-infected sheep

Climate change has intensified the frequency of heat waves in the world, thereby exposing farm animals to stressful conditions. For better productive performance it is important to identify the most resilient genotypes. Thus, our objective was to evaluate the thermoregulatory responses of rams of tropical indigenous (Morada Nova and Santa Inês) and exotic breeds (Dorper and Texel), by monitoring the environmental and physiological indicators related to heat tolerance. The experiment was carried out in a tropical climate region (Cwa), in Brazil, for twelve months, which comprised spring, summer, autumn and winter. Thirty-three rams were divided into groups: Morada Nova (MN; n=8, red-coat), Santa Inês (SI; n=9, black-coat), Dorper (DO; n=8, white-coat) and Texel (TX; n=8, white-coat). The microclimatic variables were monitored, and the THI and BGHI comfort indices were calculated. Coat thickness and body surface temperatures were measured monthly, and serum triiodothyronine-T3 measurements and complete blood tests were performed. The physiological variables were evaluated every fifteen days and skin micro-biopsies were performed in the summer and winter for histological evaluation. During the warmer seasons, the THI and BGHI reached values that indicated thermal discomfort. TX showed higher coat thickness throughout the year, increased physiological variables related to thermolysis, and reduced T3 (P < 0.05). The internal temperature was permanently lower in the MN, SI and DO (P < 0.05). The body surface temperatures were affected by the coat characteristics and wool length. Hematological parameters varied in the seasons with the highest thermal conditions (P < 0.05). The MN showed larger sweat glands, while the area occupied by the sweat glands was higher in the SI. The DO showed higher hair density in the summer and winter (P < 0.05). The results indicated that the MN, SI and DO breeds overcome the thermal challenge more easily throughout the seasons due to specific adaptive morphological and physiological characteristics.