[en] A radioimmunoassay for diethylstilbestrol (DES) in fecal samples of fattened calves is described. The antibody used in this test showed no cross reactions with natural estrogens or other steroids. Blank values (fecal samples without DES) varied between 0 an 4,9 ng DES-equivalent/g sample. The distribution of blank values shows the significant proof of existence of DES in concentrations above 10 ng/g sample. The method has been applied for the control of living calves at the producer. Examples of illegal DES applications are given. The described radioimmunoassay is suitable for routine analysis as a control for illegal estrogen treatment. (orig.)

[en] Studies on the immunization of calves against Dictyocalus viviparus using irradiated vaccines were carried out in two experiments at the Animal Sciences Division of Centro de Energia Nuclear na Agricultura (CENA). In the first experiment 18 calves were divided into 3 groups. Group A received the British commercial vaccine Dictor, Group B received the gamma irradiated vaccine prepared at CENA, both orally, and Group C was the unvaccinated control. One month after the second dose, the calves were challenged with normal D. viviparus infective larvae at the rate of 60 larvae per kg body weight and 5 weeks later all animals were killed. (author)

[en] Forty-eight pregnant zebu cows were equally divided in 2 groups (GO and GC). They were fed on natural pasture and only GC received a concentrate, 1.76 FU and 489.9 DNM/kg DM. From the 7th day post-partum to the 4th of lactation, cows in each group were reallocated in 2 lots, a control (GOO and GCO) and a complemented lot (GOC and GCC). Body weight (BW) and score were monthly recorded in cows and calves. Plasma progesterone was determined from weekly sampled blood. Cows BW at calving did not differ, 264.2 kg in GO and 269.7 kg in GC. Concentrate supply increased BCS (1.5 vs. 0.5, P < 0.05) at calving and complemented cows lost more BCS (-0.9 in GCO and -0.5 in GCC, P < 0.05). At week 21 of lactation, calves from cows in GCC gained more BW when compared to those in GOO (43.4 vs. 34.6 kg, P < 0.05). The intervals between calving and reactivation of the ovarian cycle were 31 d in GCC vs. 42 d in GCO, and 56 d in GOC vs. 78 d in GOO. The percentage of reactivation of the ovarian cycle was 50, 42.8, 27 and 25% in these respective groups. (author)

No abstract available

No abstract available

[en] A six-month-old 245 kg male Simmental calf was referred to the Veterinary Hospital in Cuiabá, MT, with closed comminuted diaphyseal fracture in metacarpus. It was given preference to external fixation as means of fracture immobilization, and transcortical pins and fiberglass cast were used. This technique showed effective immobilization of the fracture, less expensive and feasible to be done in the field

[en] Our laboratories have been engaged in development and in vivo testing of nuclear-fueled circulatory support systems. These efforts have focused on 4 major areas: (1) evaluations of the biologic effects of chronic intracorporeal heat and radiation; (2) the development of efficient and reliable energy converters (engines); (3) evaluations of the biocompatibility of the various system components, and (4) investigations of the hemodynamic effectiveness of the system in vivo. Previous in vivo experiments have been reported. Three systems are currently under investigation; each has undergone a number of modifications to improve overall thermal-mechanical efficiencies or to decrease physiologic alterations resulting from system size, intracorporeal heat and interactions between the prostheses and experimental animals. The purpose of this paper is to characterize the current systems and describe recent in vivo experiments

[en] Full text: Both revealed and stated preference approaches were employed to determine the values attached to the different features of indigenous cattle in central Ethiopia. For the revealed preference analysis a hedonic model was employed to examine the determinants of cattle prices in the primary rural markets of central Ethiopia. Transaction level data of cattle farmers and farmer-traders were used in the analyses. Data collected in rural markets to identify cattle price determinants result in estimates with standard errors that are mostly heteroscedastic. We employed SHM estimations to account for heteroscedastic errors. The empirical estimation of revealed preferences showed that market place, seasonal differences, sex and function based classification of cattle, body size, and age were very important factors influencing the market prices cattle sellers receive. The significance of the characteristics of animals in influencing prices paid for the animals reveals the importance of the preferences for traits in the decision-making process related to buying and selling of cattle. These preferences at the farmers and farmer-traders levels are the ones that matter most in shaping up the diversity of animals kept at farm level. This diversity of the cattle genetic resources is essential for generating or identifying best-suited breeds of cattle in the context of the livelihood objectives of the target community. Thus, the cattle breeding strategies and activities should duly consider the preferences expressed through the prices paid for animals in such markets, where the cattle keepers are the main sellers and buyers. For the stated preference analysis the study employed choice experiments (CE) and random parameters logit to elicit and analyze cattle trait preferences of buyers in the semi-subsistence livelihood systems of rural central Ethiopia. The results of the cows CE revealed that in areas where livestock serve multitude of purposes and where the production and marketing system is semi-subsistence, cows have other functions more important than milk production. Fertility, disease resistance and strength of the calves they bear are as much or more important than milk. The breed concept, which is very much associated in Ethiopia with the area where the animal is brought from, was found to be less important as such and it appears that farmers are interested in obtaining animals from the district or locations in which they live in. This is essentially because cattle buyers, who are mostly farmers, are more concerned about adaptability and therefore give high value to the fact that they know the pedigree of the cattle they buy. The results of the CE for bulls indicate that cattle buyers assign high values for good traction potential, disease resistance, calf vigour, and for places of origin when choosing bulls in the market. The preferences cattle buyers have for these attributes do vary essentially due to differences in occupation, education and age. The primary objective of the rural community to produce sufficient food for the family for each year was manifested through the value assigned to traction potential which is more than twice that of disease resistance. These results are consistent with the basic reasons why animals are kept in the area, but appear to be incoherent with the government funded interventions of livestock development. Given the importance of livestock, bulls in particular, for the livelihoods of the communities in rural Ethiopia, such consistent valuation of the traits show that the objectives of the agrarian life are quite clear among the community - farmers, farmer traders, traders, and others - that production and marketing decisions are made on broader considerations than just milk and meat production. The government of Ethiopia needs to revise the structure of the livestock improvement programs still running and needs to make note of the important details that influence the production, marketing and utilization of livestock products. The small-holder community in this part of Ethiopia depends on semi subsistence agriculture and so livestock development interventions should focus on reproductive and adaptive traits that stabilize the herd structure, rather than focusing on traits that are only important for commercial purposes. It can also be observed that improving these traits of cattle owned by smallholder farmers in the area will facilitate adoption of the innovations or improvements instead of bringing over cattle from unknown sources and obviously with low adaptability. (author)

No abstract available

[en] This work investigates the effect of concurrent calf infection with E. wenyonii on T. annulata development. In group I, calves simultaneously were inoculated with both parasites, E. wenyonii parasitaemia appeared 7 days post-inoculation (PI), peaked (62 peryth./rbc) 21 days PI and disappeared 31 days PI. T. annulata parasitaemia appeared 28 days PI, peaked (87%) 35 days PI and disappeared 50 days PI. T. annulata parasitaemia in calves infected only with T. annulata (control) appeared 15 days PI and peaked (90%) 30-35 days PI when the calves died. In group 2 calves, inoculated with E. wenyonii first, parasitaemia appeared one week PI, peaked (65 eperyth./rbc) 21 days PI and disappeared 35 days PI. Parasitaemia of T. annulata, inoculated 2 weeks later, appeared 25 days PI, reached a low peak (27%) 45 days PI and disappeared 65 days PI. After splenectomy (AS) of groups I and 2 calves, E. wenyonii parasitaemia reappeared 15 days AS, peaked (52 eperyth./rbc) 29 days AS and disappeared 57 days AS. T. annulata parasitaemia reappeared 27 days AS, reached a low peak (42%) 47 days AS and disappeared 87 days AS. Group I and 2 calves survived AS. In group 3, calves, inoculated with E. wenyonii 5 days after the appearance of T. annulata parasitaemia (15%), T. annulata developed as in the control group and all calves died before E. wenyonii development. Alteration of T. annulata development may be attributed to modulation of the host immune system and/or competition with E. wenyonii for a certain substrate. (author)