Effect of stocking density on performance, infection by Eimeria spp., intestinal lesions and foot pad injuries in broilers with outdoor access under tropical conditions.

1. The study was carried out to evaluate the effect of stocking density on performance, litter moisture, Eimeria oocyst shedding, intestinal and foot lesions in broilers.2. A total of 192 1-d-old male Cobb broilers were distributed with three different stocking densities (6, 8 or 10 chickens/m2) with outdoor access and eight replicates in a completely randomised design over two periods. Productive parameters were measured from 3 to 7 weeks of age.3. Oocyst counts (OPG) in both excreta and litter were performed at 3, 4 and 5 weeks of age. Intestinal and foot pad lesions were evaluated at 7 weeks old. The stocking density of 6 birds/m2 had the highest body weights (P < 0.05) (2129 ± 37.67, 2759 ± 50.82 and 3167 ± 75.64 g at weeks 5, 6 and 7 of age, respectively).4. Feed intake decreased with increasing stocking density at week 3 (r = -0.57), 4 (r = -0.48), 5 (r = -0.84), 6 (r = -0.68) and 7 (r = -0.65) of age (P < 0.05). Birds with stocking densities of 8 and 10/m2 consumed, respectively, up to 11% and 19.5% less feed than the lower stocking density groups.5. Stocking density affected (P < 0.05) feed conversion (1.61, 1.49 and 1.46) and litter moisture (40.88, 52.60 and 56.19%) at 3 weeks of age. Neither carcase yield nor mortality was different between densities (P > 0.05). Likewise, there was no effect of stocking density on OPG neither in excreta nor in litter, intestinal lesions, or foot pad and hock injuries (P > 0.05).6. In conclusion, the higher stocking density decreased both the feed intake and the live weight in broilers, but there were no effects in the number of Eimeria OPG in excreta or litter, neither intestinal lesions nor in foot pad injuries.

Impact of Dietary Condensed Tannins and Haemonchus contortus Infection in Growing Sheep: Effects on Nutrient Intake, Digestibility, and the Retention of Energy and Nitrogen.

PURPOSE: A controlled study evaluated the effect of condensed tannins (CT) from Gymnopodium floribundum leaf meal (GF), infection with Haemonchus contortus (I) and their interaction, on feed intake, diet digestibility and retention of N (NR) and energy (ER) in hair sheep lambs. METHODS: Thirty-six, worm-free hair sheep lambs (14.9 ± 1.56 kg body weight) were housed in metabolic cages. Eighteen animals were infected with 6000 H. contortus L3, while other 18 lambs were kept non-infected. On day 28th post-infection (PI), infected lambs were assigned to three diet groups: a diet without GF (I-NONGF), a diet with GF (I + GF) and a diet with GF + polyethylene glycol (PEG) (I + GF + PEG). Non-infected (NI) lambs were assigned to similar diet groups: NI-NONGF, NI + GF and NI + GF + PEG. The packed cell volume (% PCV), ante-mortem faecal egg counts and post-mortem worm burdens were also evaluated. RESULTS: Infection did not affect digestibility, NR and ER. Meanwhile, CT intake from the GF diet reduced the digestibility of dry matter, organic matter and crude protein, as well as NR, compared to lambs consuming the NONGF and GF + PEG diets (P < 0.05). Although, the digestible energy was similar between lambs consuming NONGF and GF + PEG diets, the ER was higher for lambs consuming the control NONGF diet. Diets did not affect the PCV, or the ante-mortem and post-mortem parasitological variables. CONCLUSION: The costs on N and energy metabolism were mainly associated with the CT content of the GF diet, but other features of the diet such as the high lignin content, seemed to affect animals consuming GF meal. Meanwhile, the H. contortus infection had a non-significant impact.

Nitrogen retention in hair sheep lambs with a gradient of Haemonchus contortus infection.

The impact of Haemonchus contortus infections on nitrogen retention (NR) of hair sheep lambs is unknown. This study estimated the feed intake, digestibility, NR, haematocrit (HT), and their relationship with the gradient of H. contortus infection in hair sheep lambs. Twenty-four hair sheep lambs, 3-4 months old, reared parasite-free were used (live weight (LW) 16.7 ± 1.7 kg). Six lambs were kept parasite-free, nine lambs received a dose of 300 H. contortus infective larvae (L3)/kg LW, and the remaining nine lambs received 500 H. contortus L3/kg LW. Infection doses ranged from 3870 to 9,500 L3. Lambs were individually fed for an average daily gain (ADG) of 100 g. On days 1 (P < 0.01) and 7 (P < 0.001) post-infection (PI), the L3 doses were positively associated with HT, possibly due to platelet recruitment. On week 1 PI, the infection (L3) reduced the crude protein (CP) intake (g/kg metabolic LW) (P < 0.05). A reduction of 1% HT corresponded to 1200 eggs per gram of faeces (EPG) for day 21 PI (P < 0.05), 2300 EPG for day 28 PI (P < 0.001), 2400 EPG for day 35 (P < 0.001), and 1300 EPG for day 41 PI (P < 0.001). However, the HT levels were never lower than 21 %. A lower CP digestibility was associated with EPG only on week 5 PI (P < 0.05). There was no significant association between EPG, Total egg in faeces, or worm burden (WB) with intake, dry matter digestibility (DMD), ADG or NR. The NR of lambs was positive along the different weeks of study irrespective of infection level. The WB was negatively associated only with HT on day 41 PI (P < 0.001), where a 1 % HT reduction was estimated for every 257 worms hosted. In conclusion, no relationship was found between H. contortus infection and DMD, ADG or NR in hair sheep lambs. The cost of H. contortus infection resulted only from the HT reduction and depended on the gradient and stage of the infection.

Gymnopodium floribundum fodder as a model for the in vivo evaluation of nutraceutical value against Haemonchus contortus.

This study validated a protocol to identify the nutraceutical value of Gymnopodium floribundum (GF) foliage based on its effects on sheep nutrition, production and health and its impact on adult Haemonchus contortus. Thirty animals (17.8 ± 3.44 kg BW) were distributed into five experimental groups (n = 6). Groups T1-T3 received feed including 20%, 30% and 40% GF content, respectively, and group T4 received feed with 0% GF. Groups T1-T4 were all infected with 6000 H. contortus infective larvae (L3). Group T5 included six worm-free lambs fed a diet without GF. Feed intake, dry matter digestibility (DMD) and organic matter digestibility (OMD) were measured, in addition to the faecal excretion of eggs per gram (EPG) and total faecal egg count (TFEC) of H. contortus. On day 39 post-infection, lambs were humanely slaughtered to recover and count adult parasites and assess the length and fecundity of female worms. Higher levels of GF in the diet reduced DMD and OMD (P < 0.05), with the lowest values in T3 (40% GF) (P < 0.05). Body weight gain was similar for all groups (0.18 to 0.2 kg/day; P > 0.05). EPG and TFEC were lower in T1 and T3 than in T4 (P < 0.05), and the number of adult female worms was lowest in T3 (P < 0.05). In conclusion, GF leaf meal can be considered a nutraceutical when included at 40% (T3) in the diet of lambs, based on its ability to decrease the EPG and TFEC of H. contortus by reducing the female worm burden. A 40% inclusion level had no negative impact on lamb diet intake, production and health, although a reduction of digestibility was observed.

Genetic diversity and patterns of population structure in Creole goats from the Americas.

Biodiversity studies are more efficient when large numbers of breeds belonging to several countries are involved, as they allow for an in-depth analysis of the within- and between-breed components of genetic diversity. A set of 21 microsatellites was used to investigate the genetic composition of 24 Creole goat breeds (910 animals) from 10 countries to estimate levels of genetic variability, infer population structure and understand genetic relationships among populations across the American continent. Three commercial transboundary breeds were included in the analyses to investigate admixture with Creole goats. Overall, the genetic diversity of Creole populations (mean number of alleles = 5.82 ± 1.14, observed heterozygosity = 0.585 ± 0.074) was moderate and slightly lower than what was detected in other studies with breeds from other regions. The Bayesian clustering analysis without prior information on source populations identified 22 breed clusters. Three groups comprised more than one population, namely from Brazil (Azul and Graúna; Moxotó and Repartida) and Argentina (Long and shorthair Chilluda, Pampeana Colorada and Angora-type goat). Substructure was found in Criolla Paraguaya. When prior information on sample origin was considered, 92% of the individuals were assigned to the source population (threshold q ≥ 0.700). Creole breeds are well-differentiated entities (mean coefficient of genetic differentiation = 0.111 ± 0.048, with the exception of isolated island populations). Dilution from admixture with commercial transboundary breeds appears to be negligible. Significant levels of inbreeding were detected (inbreeding coefficient > 0 in most Creole goat populations, P < 0.05). Our results provide a broad perspective on the extant genetic diversity of Creole goats, however further studies are needed to understand whether the observed geographical patterns of population structure may reflect the mode of goat colonization in the Americas.

Effect of physical, chemical and environmental characteristics on arbuscular mycorrhizal fungi in Brachiaria decumbens (Stapf) pastures.

AIM: To evaluate the effects of soil physical and chemical factors (pH, conductivity, humidity, available phosphorus and organic matter) and environmental factors (temperature, relative air humidity, altitude and atmospheric pressure) on arbuscular mycorrhizal fungi (AMF)-Brachiaria decumbens grass relationship. Furthermore to establish patterns of microbiological responses that allow to differentiate the study sites in two relief types. METHODS AND RESULTS: Mycorrhizal characteristics (spore density, external hyphae and root colonizations by hyphae, vesicles and arbuscules), physical and chemical factors in soil and environmental factors were measured. CONCLUSIONS: The effect of physical, chemical and environmental factors on microbiological variables was related to the type of relief 'valley and hilly terrain'; the AMF behaviour was affected only over narrower ranges of evaluated variables. Similarly, the colonization of B. decumbens roots by AMF hyphae, vesicles and the mycorrhizal spore density follow different patterns according to the relief type. SIGNIFICANCE AND IMPACT OF THE STUDY: The type of relief is one of the factors to be taken into consideration to evaluate the AMF inoculum and root colonization of these pastures, because of the influence of slope - as physical property of soil - on AMF.

O centro de saude como unidade-base do programa de controle da malaria : parte I analise da situacao da malariaLuis Almeida Franco

Endemic malaria continues to be one of the major public health problems in Mozambique; lack of information impedes monitoring of preventive measures and thus an improvement in malaria control. In this article; we suggest the use of health units; in particular health centres; as basis for the information system of the national malaria control programme. Health centres should be selected on the basis of their capacity to carry out certain tasks; principally reliable microscopy; so that the quality of information collected can be guaranteed. The health centre should act as a sentinel site; with the responsibility to collect and organize standardized information about malaria in its catchment area. Together; these sentinel sites will constitute a basis for the future national malaria surveillance system. To test the practicability of this idea; a project was implemented in the Jose Macamo Health Centre in Maputo City. It was designed to obtain more systematic information about the clinical and epidemiological features of malaria that is most important for improving malaria control in Mozambique. The project lasted for two years from July 1991. Through the establishment of a malaria clinic; the clinical and epidemiological features of malaria in the centre's catchment area were studied. The results will be published subsequently. In this article; we present an outline of the features of endemic malaria in Maputo City and the principal factors influencing the disease

Dinamica da malaria numa area de saude da Cidade de Maputo : parte II

The authors present the results of study of the dynamics of endemic malaria in the catchment area of Jose Macamo Health Centre. They established a malaria clinic in this centre; integrated in a pilot project designed to test malaria control using health centres as base. Data was collected in this clinic from July 1993; covering two periods in which the epidemiological characteristics of malaria were determined by different rainfall patterns. In the first year; there was a severe drought; despite this; a focal outbreak occurred in January 1992 in suburbs situated along the drainage system of the influence valley. Through data collected on residence of patients with malaria; we detected a greater incidence in some suburbs and; within these suburbs; areas with differing incidences. An environmental survey in these areas showed numerous breeding sites of the malaria vector. These were small wells; dug by the population to obtain water for their fields. A parasitological survey in February 1992 showed a high prevalence (38) of malaria in the same areas; confirming a relationship between breeding sites and prevalence rates. A new peak occurred later in April-May; coinciding with a period of heavy rainfall. During the first year; 6011 patients with malaria were observed; 1.102 in the period of low transmission (July-December 1991) and 4.909 from January to June; 1992. In the second year; the pattern was very different; above average rainfall gave rise to an epidemic which covered a larger area. 23.028 patients were observed in this period; of whom 17.151 during the higher transmission period. The geographic transmission of the reported cases was higher during the 2 study period; but most patients came from suburbs adjoining the health centre. We analyse the possible causes of this epidemic; principally the relationship between the seasonal characteristics of endemic malaria and the immunity of the population. We consider that the implementation of a similar system of data collection in other health centres with good quality microscopy could; in the future; permit the development of efficient epidemiological surveillance for endemic malaria

Effects on testosterone, LH and cortisol concentrations, and on testicular ultrasonographic appearance of induced testicular degeneration in bulls.

It is well known that heat stress has a detrimental effect on testicular functions. In addition to the alteration of semen quality and testicular damage, reproductive hormone secretion can be altered. The objective of this study was to describe changes in plasma concentrations of testosterone, LH and cortisol, as well as in testicular ultrasonographic appearance after induced testicular degeneration. Four Swedish Red and White bulls, aged 3 years, were used. They were fed according to Swedish standards. The scrotum was covered with an insulation device during 96 h. Semen was collected weekly 3 times before and up to 4 months after insulation. Testicular ultrasonography and clinical genital examination were performed with the same intervals. Heparinized blood samples were taken from the jugular vein at 2 h interval during 24 h every 2 weeks during the study. Blood samples were tested for the content of testosterone, LH and cortisol. Data were analysed, using one way analysis of variance of seminal data, clinical examination data as well as 24 h hormonal output data as percentage of mean individual pretreatment values. The use of a 5 MHz B-mode ultrasound unit did not contribute with an objective estimation of the degree of testicular degeneration. In 3 of the bulls testosterone levels had a tendency to decrease and LH to increase during the time of severe degeneration, whereas an opposite trend was seen during the regenerative phase, changes becoming significant 15 weeks after scrotal insulation. Variation between animals was big. Cortisol levels had a decreasing trend, changes being significant only in individual bulls at 10 and 15 weeks after scrotal insulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Phase I trial of aclacinomycin-A. A clinical and pharmacokinetic study.

Aclacinomycin-A is a new anthracycline antibiotic with a broad spectrum of antitumor activity in animals. Compared to doxorubicin, it was found to produce less cardiotoxicity and alopecia. A Phase I trial of aclacinomycin-A given as a weekly 15 min IV infusion was conducted in 20 previously treated patients with advanced solid tumors. Four dose levels ranging from 40 to 100 mg/m2 were studied; myelotoxicity was dose-limiting at 85 and 100 mg/m2. Other toxicities were moderate to severe nausea and vomiting in 9 patients, mild phlebitis in 2 patients, and mild abnormality of liver function tests in 3 patients. No cardiac or renal toxicities were seen, but two partial responses were observed. The pharmacokinetic profile of aclacinomycin-A in plasma and urine was studied in 3 patients given 65 mg/m2 using a high performance liquid chromatography assay. The data obtained were consistent with a two compartment model of drug disposition with initial and terminal half-life values of 6.6 min and 13.3 h, respectively. The major fluorescent metabolite was eliminated with a terminal half-life of 25 h. Two metabolites as well as the parent drug were excreted in the urine as less than 10% of the doses given. This pharmacokinetic profile is similar to that of other anthracyclines, although aclacinomycin-A appears to have lower blood levels than doxorubicin given at equivalent doses. On this weekly schedule, the recommended dose is 65 mg/m2 for Phase II trials.