Evaluation of non-linear models for growth curve in Brazilian tropical goats.

In the present study, 1060 body weight-age records were measured on 300 Canindé goats. The records were collected from Rio Grande do Norte state, North-eastern part of Brazil, and used for evaluation of non-linear models (Brody, Von Bertalanffy, Logistic, and Gompertz) describing growth curve in goats. The non-linear models were compared applying mean squared error of prediction (MSEP), mean squared residue (MSR), mean absolute deviation (MAD), adjusted coefficient of determination (R2aj), and convergence percentage (%C) for determining the most appropriate model describing the growth curve in Canindé goats. The absolute growth rate (AGR) was estimated based on the adjusted model as a function of time to describe the growth rate of the animals, and the effect of sex on the curve parameters was assessed. The Brody model was the most indicated to represent the average growth curve of Canindé goats. Furthermore, the growth curves estimated by the models under study show that the Brody model displayed the best fit, indicating a greater association between observed and estimated weights, suggesting that it can be used to describe the growth behavior and development of the animals analyzed of both sexes.

Locally adapted Brazilian ewes with different coat colors maintain homeothermy during the year in an equatorial semiarid environment.

The present paper aimed to show the thermoregulatory responses of locally adapted Morada Nova sheep with different coat colors that were exposed to direct solar radiation in an equatorial semiarid region. Animals were classified into four groups according to the coat color as follows: (1) dark red, (2) intermediate red, (3) light red, and (4) white coats. Forty Morada Nova ewes were observed in for 7 consecutive months. The experimental variables measured were rectal temperature (RT), skin surface temperature (ST), respiratory rate (RR), skin surface evaporation (CE), respiratory evaporation (RE), and heat exchange by convection (HC) and radiation (R). Data were collected from 1100 to 1400 h after the animals were exposed to 30 min direct sunlight. The results showed that all groups maintained homeothermy. The RR was higher in the animals of groups 1 to 3, which also showed higher values for ST when compared to the white-coated animals. Sensible heat exchange mechanisms were not important for heat loss, and R was a significant source of heat gain from the environment for the animals. Groups 1, 2, and 3 used RR more intensely than group 4 (P value = 0.001); however, CE was higher for the white-coated animals. It was concluded that Morada Nova sheep are well adapted to the semiarid environment, regardless of coat color.

A multivariate approach to the diagnosis of gastrointestinal infection in ewes.

Diagnosing the effects of helminth infections is an efficient way to manage the problem in ruminant production systems. Selection of animals in a flock that are infected with Haemonchus has traditionally involved differential packed cell volume measurements (PCV), and in recent years, the FAMACHA© system has been used. However, few small analytical changes have been made. The objective of this study was to examine the influence of different diagnoses linked to packed cell volume (PCV) and FAMACHA© system scores in native ewes, using a multivariate approach. Ewes were classified into three categories according to their score in the FAMACHA© system (FS) and their packed cell volumes (PCV) as follows: Group AG (FS between 1 and 2 and PCV ≥ 30%); Group BG (FS score of 3 and PCV between 21 and 29%); Group CG (FS between 4 and 5 and PCV ≤ 20%). The animals were evaluated using performance characteristics, parasitological examinations, blood values and serum biochemistry. The data show that the use of a multivariate approach for different diagnoses using the FAMACHA© system and PCV measurements gives similar results, although they have particular pathophysiological indicator patterns.

Performance, endoparasitary control and blood values of ewes locally adapted in semiarid region.

This study evaluated the variation in the prevalence of endoparasitoses and their impact on body condition and blood values of sheep of the Morada Nova breed. A total of 138 ewes were examined for their morphology (body weight, BW; body condition score, BCS), parasitology (faecal egg count, FEC; Famacha© score; coproculture), hematology (red blood cell count,RBC); hemoglobin concentration, HE; packet cell volume, PCV; mean corpuscular volume, MCV,; mean corpuscular hemoglobin, MCH; mean corpuscular hemoglobin concentration, MCHC; leukocytes, WBC) and serum biochemistry (glucose, cholesterol, triglycerides, urea, creatinine, total protein, albumin, globulin, AST and ALT). Overall the animals presented higher BW and BCS in the months of September and December, however, with high FEC, in addition to a large number of animals with Famacha score 4 and 5. The results showed that the main hematophagous worm affecting the sheep, the genus Haemonchus ssp, appeared in a greater proportion (30-71.66%) than the other worms in all months of the study, except in March. About 30% of the hematological values found in the study are outside the reference ranges for suable sheep e 45.50% for serum biochemistry. These findings demonstrate the most healthy period of the year was from March to June for endoparasites control, however, in the months of September and December the animals showed better performance measures.