Assessment of the adaptive capacity of Morada Nova ewes with different coat coloration.

Coat color is a factor affecting heat tolerance in tropical ruminant and a particular coat color can determine which is more resilient to environmental changes. The aim of this study was to measure the level of adaptation of Morada Nova sheep with different coat color by using an Adaptability Index (AI). Adult ewes were used, including two different coat colors of Morada Nova sheep (red and white) with mean of body weight of 28.02 ± 5.70 kg and 31.47 ± 3.41 kg, respectively. Physiology parameters, hematology, electrolytes, acid-base status, mineral, renal functions, metabolites, enzymes, and proteins were measured. AI was designed using a multivariate approach (principal component analysis) to "weigh" the influence of each variable in the animal responses. The variables more important for adaptive aspects of Red Morada Nova were: haematology, electrolytes and acid-base status. The hemoglobin (HG), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), sodium (Na+), oxygen pressure (PO2), glucose (GLU) and albumin (ALB) were significantly higher in Red Morada Nova sheep and hydrogen carbonate (HCO3), base excess (BE), total carbon dioxide concentration (TCO2) and URE were significantly higher in the white phenotype. The variables more important for adaptive aspects of White Morada Nova sheep were: (K+), total protein (TP), PO2, HG, cholesterol (CHO), rectal temperature (RT) and glucose (GLU). Both phenotypes showed a high adaptation level, however, a higher value was generated for the Red Morada Nova sheep (81.97). This study concludes that both phenotypes of the Morada Nova sheep breed are well adapted to the climatic condition of the Brazilian tropical region using different adaptive mechanisms.

Productive, thermoregulatory, and hormonal responses of dairy goats supplemented with selenium-enriched yeast in the Brazilian semi-arid region.

The aim of this study was to evaluate the effect of adding selenium-enriched yeast (SE) in the diet of dairy goats during 60 days of lactation and its effect on productive, thermoregulatory, and hormonal responses of animals managed in a semi-arid region. Sixteen Saanen × Toggenburg crossbred goats were used in a completely randomized design. Goats were weighed, and their milk yield was monitored weekly. Before the animals entered the treatments and at every 20-day milk producing, blood samples were collected to determine the SE levels. At 20, 40, and days of the lactation cycle, individual milk samples were collected to determine composition, casein, urea nitrogen, and selenium content. Measurements of respiratory rate (RR), rectal temperature (RT), coat surface temperature (CST), and epidermal temperature (ET) were performed weekly during the experimental period in two shifts, one in the morning (9 am) and the other in the afternoon (3 pm). No difference (P > 0.05) was detected for body weight, milk yield, composition, selenium concentration, and urea nitrogen. Lower RR and ET (P < 0.05) were observed for animals that received SE supplementation. Thyroid hormone concentrations were similar between treatments (P > 0.05). The positive results of the SE supplementation were concentrated in thermoregulatory responses, and there was no effect on productive, hormonal responses, and plasmatic concentration of selenium in the milk. The SE supplementation for dairy goats managed in a Brazilian semi-arid region was able to promote reduction of RR and coat temperatures.

Adaptive dynamics of indigenous sheep in Canary Islands, Spain: A machine learning approach.

The objective of the study was to characterize the adaptive profile of Ibero-American sheep of the Canaria breed, evaluating the possible changes in thermoregulatory responses and coat characteristics to which the animals are exposed in the different seasons of the year. Data collected over a period of 12 months were analyzed, with information being observed in the interval of 15 days of each month, in 23 adult ewes kept in an intensive breeding system. The rectal temperature (RT) of Canaria ewes was higher (P < 0.001) in the summer and spring seasons. In contrast, the respiratory rate (RR) of the animals was higher in autumn. The surface temperature (ST) of the herd was lower during the spring. It was observed that the hair length (HL) and the hair density (NH) did not vary during the seasons. However, the hair diameter (HD) and the coat thickness (CT) varied, being in the spring, the season in which the animals had the highest HD and autumn, the season in which they had the lowest. The performance was similar throughout the seasons (P > 0.05). The morphological variables of the coat presented 63.8% of original cases grouped, which may characterize the morphological responses of the coat of these animals as an important trait of the adaptive profile of the breed, whereas the opposite occurred for thermoregulatory responses. The variables most used by the herd and that were most important were autumn (CT, NH, HD, HR, RT, and HL), summer (ST and RR), spring (RR, ST, and RT), and winter (RT, HD, HR, and RR). Sheep of the Canaria breed have an adaptive profile that dynamically uses thermoregulatory and morphological responses, molding themselves according to climate changes resulting from seasonal periods on the Island of Tenerife, Spain. The Canaria sheep stood out for the modification of the morphological characteristics of the coat, especially during autumn and spring, and can be considered an excellent genetic resource with excellent adaptive characteristics for arid environments such as those found in the Canary Islands.

Africanized honeybee (Apis mellifera) semen freezing using Tris-based and Collins extenders.

This study is aimed at evaluating the effect of different extenders on the cryopreservation of semen from Africanized honeybees (A. mellifera). Semen from honeybee drones from 10 different colonies was obtained by endophallus exposure technique and immediately evaluated for motility, viability using fluorescent probes, functional membrane integrity using the water test, and morphology. Samples from each colony were divided in three aliquots and subjected to a dilution ratio of 12:1 (diluent: semen) using Tris, Tris + egg yolk (Tris+EY), and Collins extender. Samples were cryopreserved and stored in liquid nitrogen for one week and then rewarmed and reevaluated. Immediate dilution provoked no significant effect on sperm motility and functional membrane integrity, regardless of the extender used; however, the greatest values (P < 0.05) for normal sperm morphology were found at the use of isolate Tris (69.3 ± 1.9%). After thawing, there were no significant differences among extenders with relation to the preservation of sperm motility, viability, and functional membrane integrity, but the Tris extender provided the highest post-thawing values (P < 0.05) for sperm normal morphology (49.2 ± 4.9%) while the Collins extender provoked the highest amounts (P < 0.05) of curled tail defects (67.5 ± 3.2%). Moreover, the Tris was the only extender at preserving the proportion of normal sperm after thawing similar to what was verified for fresh samples. In summary, we suggest the use of a Tris-based extender for the cryopreservation of Africanized honeybee semen.

A serum NMR metabolomic analysis of the Corynebacterium pseudotuberculosis infection in goats.

Caseous lymphadenitis (CLA), an infectious disease caused by Corynebacterium pseudotuberculosis in small ruminants, is highly prevalent worldwide. Economic losses have already been associated with the disease, and little is known about the host-pathogen relationship associated with the disease. The present study aimed to perform a metabolomic study of the C. pseudotuberculosis infection in goats. Serum samples were collected from a herd of 173 goats. The animals were classified as controls (not infected), asymptomatic (seropositives but without detectable CLA clinical signs), and symptomatic (seropositive animals presenting CLA lesions), according to microbiological isolation and immunodiagnosis. The serum samples were analyzed using nuclear magnetic resonance (1H-NMR), nuclear Overhauser effect spectroscopy (NOESY), and Carr-Purcell-Meiboom-Gill (CPMG) sequences. The NMR data were analyzed using chemometrics, and principal component analysis (PCA) and partial least square discriminant analysis (PLS-DA) were performed to discover specific biomarkers responsible for discrimination between the groups. A high dissemination of the infection by C. pseudotuberculosis was observed, being 74.57% asymptomatic and 11.56% symptomatic. In the evaluation of 62 serum samples by NMR, the techniques were satisfactory in the discrimination of the groups, being also complementary and mutually confirming, demonstrating possible biomarkers for the infection by the bacterium. Twenty metabolites of interest were identified by NOESY and 29 by CPMG, such as tryptophan, polyunsaturated fatty acids, formic acid, NAD+, and 3-hydroxybutyrate, opening promising possibilities for the use of these results in new therapeutic, immunodiagnosis, and immunoprophylactic tools, as well as for studies of the immune response against C. pseudotuberculosis. KEY POINTS: • Sixty-two samples from healthy, CLA asymptomatic, and symptomatic goats were screened • Twenty metabolites of interest were identified by NOESY and 29 by CPMG • 1H-NMR NOESY and CPMG were complementary and mutually confirming.

Understanding the environmental stress on thermoregulation actions of native goats using broken-line regression.

This study's objective was to evaluate the thermoregulation aspects of native goats through broken-line regression to understand the triggering of physiological responses in the homeothermy process. Data were collected from ten healthy dams of the Canindé breed once a week at hourly intervals (24 h) for eight consecutive weeks. Air temperature (AT; °C), relative humidity (RH; %) were measured and temperature-humidity index (THI) calculated. The thermoregulation parameters evaluated were: respiratory rate (RR; breaths.min-1), rectal temperature (RT; °C) and sweating rate (SR; g.m-2.h-1). All variables were subjected to analysis of variance with repeated measures over time. The hour was considered a fixed effect (00:00 h, 01:00 h, …, 23:00 h), and the animal was a random effect. Multiple regression analyses were also examined using General Linear Models and Variance Inflation Factors were calculated. Broken line non-linear regressions for RR, RT and SR were examined using independent variables. The highest average for AT and RH were 35.9 °C (13:00 h) and 92.4% (04:00 h), respectively. The lowest average of TA and RH were 22.1 °C (05:00 h) and 28.0% (12:00 h), respectively. The highest average THI was 102.1 (13:00 h), and the lowest 78.0 (05:00 h). The environmental thresholds at which RR, RT and SR began to increase for AT were between 17-21 °C and RH were > 17% (RR), ≥ 21 (RT) and > 23% (SR). For THI the limits were 108.4 for RR, 78.0 for RT and 100.1 for SR. Using THI, the thermoregulatory parameters are activated in the following order: SR, RR and RT. Estimates can serve as a basis to implement heat stress mitigation and improve animal welfare strategies for native goats.

Reference patterns for thermoregulation in Italian Massese ewes.

The Massese is an autochthonous Italian sheep breed, used for meat and mainly milk production and thermoregulatory variations can directly affect the performance of these animals. We evaluated the thermoregulatory patterns of Massese ewes and identified the changes due to environmental variations. Data was collected from 159 healthy ewes from herds of four farms/institutions. For thermal environmental characterization, air temperature (AT), relative humidity (RH) and wind speed were measured, and Black Globe Temperature, Humidity Index (BGHI) and Radiant Heat Load (RHL) were calculated. The thermoregulatory responses evaluated were: respiratory (RR), heart rate (HR), rectal temperature (RT) and coat surface temperature (ST). All variables were subjected to analysis of variance with repeated measures over time. A factor analysis was conducted to determine the relationship between environmental and thermoregulatory variables. Multiple regression analyses were also examined using General Linear Models, and Variance Inflation Factors were calculated. Logistic and Broken line non-linear regressions for RR, HR and RT were analyzed. The RR and HR values were outside reference values and associated with normal values of RT. In the factor analysis, most environmental variables were seen to affect the thermoregulation pattern of the ewes, except for RH. In the logistic regression analysis, RT was not affected by any of the variables studied, maybe because BGHI and RHL were not sufficiently high enough. Nevertheless, BGHI and RHL affected RR and HR. The study shows a divergence for Massese ewes from reference thermoregulatory values for sheep.

Effect of a 60-day organic selenium-supplemented diet on the decrease of somatic cell counts in goat milk.

Selenium is an important element in nutrition, showing great potential in the udder health of dairy goats and in the control of subclinical mastitis. However, there are few studies that evaluated the influence of selenium supplementation on subclinical mastitis in goats. The aim of this study was to evaluate the incidence of subclinical mastitis in dairy goats supplemented with organic selenium (Se yeast) in a semi-arid region. Sixteen Saanen × Toggenburg crossbred lactating goats were allocated randomly into two treatments: with and without addition of organic selenium (Se) to the concentrate. Milk samples were collected every 20 days from each udder half to determine the somatic cell count (SSC), chloride content, pH, electrical conductivity, microbiological isolation, composition, and selenium contents. The highest serum selenium concentrations in the blood of these goats occurred at 42 days of supplementation (P < 0.001). Goats which received organic selenium supplementation had higher serum selenium concentrations (P < 0.05). The milk composition variables did not differ (P > 0.05) between the tested treatments, teats, and collections. After 60 days of supplementation, a difference was observed (P < 0.05) between treatments for SSC, chloride content, and pH. Addition of organic selenium to the diet of dairy goats after 60 days of supplementation was promising in reducing the somatic cell count, consequently improving milk quality.

Evaluation of homeothermy, acid-base and electrolytic balance of black goats and ewes in an equatorial semi-arid environment.

The aim of this study was to investigate the influence of environmental conditions and species on thermoregulatory responses, acid-base and electrolyte balance of black goats and ewes in an equatorial semi-arid environment. Ten Canindé goats and seven Morada Nova ewes with black coat color, all multiparous, aged between 2 and 3 years, non-lactating, non-pregnant, and body weight (BW) of 22.84 ± 4.17 kg for goats and 22.60 ± 3.18 kg for ewes were used in this study. Air temperature (AT) and relative humidity (RH) were measured. Respiratory rate (RR), Rectal temperature (RT), sweating rate (SR), hydrogen potential (pH), partial pressure of carbon dioxide (PCO2), venous oxygen pressure (PO2), bicarbonate (HCO3), base excess (BE), total carbon dioxide concentration (TCO2), venous oxygen saturation (SO2), sodium (Na+) and potassium (K+) were recorded. Animal species (caprine and ovine) and environmental conditions (Thermoneutral condition, TC and Heat condition, HC) were considered as fixed effects. Univariate and multivariate analysis techniques were used. Differences were observed between the two environmental conditions. Significant changes in all thermoregulatory responses for goats and ewes were observed according to the environmental condition effect. The general means of the species showed that only SR was high in ewes (P < 0.05), following a reverse change when compared to goat SR. For the environmental condition effect, only the blood pH of goats did not change under HC (P < 0.05), while the BE and TCO2 did not change for ewes. The general means of PCO2, HCO3, BE, TCO2 and SO2 were higher in ewes compared to goats. For electrolytic balance, Na + demonstrated elevations in HC. Brazilian black goats and ewes raised in an equatorial semi-arid environment tend to have particular homeothermy, acid-base and electrolytic balance which mostly depend on the environmental conditions they are raised. The results support the changes in physiological mechanisms between black goats and ewes; however, both are locally adapted.

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.

Coat color and morphological hair traits influence on the mechanisms related to the heat tolerance in hair sheep.

The principal focus of this study was to describe how the coat characteristics could affect the heat exchanges in animals managed in a hot environment. The Morada Nova ewes were monitored once a month, during 10 consecutive months, in three commercial flocks. Initially, an analysis was performed to measure the differences regarding the coat color in the thermoregulation mechanisms. The animals were grouped into 4 different groups according to coat tonality, as follows: dark red animals (group 1, N = 23), intermediate red color (group 2, N = 27), light red animals (group 3, N = 30), and white-coated animals (group 4, N = 30). The data were collected from 1100 to 1400 h, after the animals were exposed to 30 min of direct sunlight. The cluster analysis was performed considering the hair structural characteristics such as coat thickness (CT, cm), hair length (HL, mm), hair diameter (HD, m), and number of hairs (NH, hairs per unit area), after that these clusters were compared in relation to thermoregulatory mechanisms that include rectal temperature (RT, °C), respiratory rate (RR, breaths min-1), cutaneous evaporation (CE, °C), and respiratory evaporation (RE, W m-2). The groups were characterized and compared using mean and standard deviation, and the differences between the clusters were compared using the Tukey test with a 5% probability of error. In relation to coat color, no differences were found in groups 1, 2, and 3 regarding the activation of the thermoregulation mechanisms. The most different was observed in the totally white coat that presented different thermoregulatory responses as the highest sweating rate. White-coated animals showed a non-pigmented epidermis, and the hair structure is responsible to promote skin protection as necessary, such as a dense coat (1242.7 hair cm-2), long hair (14.2 mm), and thicker coat (7.38 mm). In red-coated animals, the hair structure favored heat loss to the environment, such as short hairs, less thick coat, and less hairs per square centimeter. All evaluated animals showed the rectal temperature within the reference limits for the ovine species, regardless of the coat color. In the analysis of clusters related to the physical structure of hair, it was possible to observe that the animals with thick hair, short hair, and less dense coat tended to have a higher capacity to eliminate heat through their respiratory rate and showed less intense heat loss by cutaneous evaporation. We verified that coat color presents a direct influence on the hair structure and the activation of mechanisms related to thermoregulation.

Locally adapted goats efficiently gain and lose heat in an equatorial semi-arid environment.

The aim of this study was to gain insights in respect to how locally adapted goats exhibit dynamic body heat in an equatorial semi-arid environment. Ten Canindé goats were used in the study (22.90 ± 2.70 kg). Respiratory rate (RR; min breaths-1), rectal temperature (RT; °C) and sweating rate (SR; g m-2 h-1) were measured for 8 days, once a week, for 8 consecutive weeks in each animal, with collection intervals of 1 h throughout the day (24 h), together with the meteorological variables. Air temperature (AT, °C) and relative humidity (RH, %) were measured, and then, the temperature humidity index (THI) was calculated. First, we determined 2 days with stressful climatic conditions and similar environmental characteristics (day 1 and 2) among the 8 experimental days. The RT was evaluated on these 2 days using the means of each hour as the cut-off point, and determining whether the animals are efficient (EF) or inefficient (INEF) in heat loss (ß1) and gain (ß2). The RT was separated in ß1 and ß2 for 24 h, setting times to obtain the angular coefficients (ß) for both. The days with stressful climatic conditions and similar environmental characteristics were day 1 and 2. The hours in which the Canindé goats gained and lost heat were respectively 11 a.m. to 3 p.m. and from 4 p.m. to 10 a.m. The animals classified as EF lost more or equal the amount of heat represented for RT. When the mean of all animals was evaluated for efficiency in heat control, the flock was classified as EF. Differences (P < 0.05) were observed for RR and SR between periods. The efficiency in dynamic body heat of the locally adapted goats in this study was determined and showed that the flock as a whole possesses an excellent heat dynamic in an equatorial semi-arid environment.

Are locally adapted goats able to recover homeothermy, acid-base and electrolyte equilibrium in a semi-arid region?

The objective of this study was to evaluate the thermoregulatory responses, acid-basic and electrolytic equilibrium of locally adapted goats under natural heat conditions in a semi-arid region. Ten (10) Canindé goats aged between 2 and 3 years, non-lactating, non-pregnant and having a body weight (BW) of 22.90 ± 2.70 kg were used in this study. Air temperature (AT) and relative humidity (RH) were measured, and the radiant heat load (RHL) was subsequently calculated. Rectal temperature (RT), respiratory rate (RR), sweating rate (SR) and heat shock (S) were recorded at 1-h intervals for 24 continuous hours. Hydrogen potential (pH), partial pressure of carbon dioxide (PCO2), partial pressure of oxygen (PO2), bicarbonate (HCO3), base excess (BE), total carbon dioxide concentration (TCO2), oxygen saturation (SO2), sodium (Na+) and potassium (K+) were recorded at three moments during the day (5 a.m.; 1 p.m.; 6 p.m.). There were also significant differences between the means of hours of the day for AT and RH. RR was the thermoregulatory response which most closely followed RHL, with important elevations in the periods between 10 a.m. to noon. It was observed that the goats activated their SR mechanism before RR, more precisely between the hours of 9 a.m. and 1 p.m. The acid-base and electrolytic equilibrium for the goats which showed great association with the first components contributed the most to the total variation of the data. The most important variables in the adaptive profile of these animals in order of importance were: SO2, PO2, RR, RT, SR, HCO3, BE, TCO2 and pH. An association between all variables grouped in each period was observed, where the thermoregulatory responses in the periods of 5 a.m. and 6 p.m. were closer than when compared to 1 p.m., showing a physiological return to the initial state. Therefore, the variation in thermoregulatory responses, acid-base and electrolytic equilibrium indicated that the goats have the ability to recover after a challenging environmental condition.

Development of an animal adaptability index: Application for dairy cows.

The objective of this study was designed to evaluate the association between thermoregulatory responses, hormonal, hematological and serum biochemical values features aiming to propose an adaptability index (AI) for dairy cows under tropical conditions. Thirty adult dairy cows were used, including 15 Sindi and 15 Girolando breeds with mean weight of 338.52 ± 42.79 kg and 487.54 ± 60.67 kg, respectively. These data included rectal temperature (RT) and respiratory rate (RR). For the serum of blood sample, the levels of glucose (GLU), cholesterol (CHO), triglycerides (TRI), total protein (TP), creatinine (CRE), albumin (ALB), urea (URE), aspartate aminotrasferase (AST) and alanine aminotrasferase (ALT) and hormonal concentrations (triiodothyronine - T3 and thyroxine - T4). For the total blood samples were analyzed for hematology variables: red blood cell count (RBC); hemoglobin concentration (HC); packet cell volume (PCV); mean corpuscular volume (MCV); white blood cell (WBC). The AI was development using multivariate analysis to "weigh" the influence of each variable in the animal responses. The variables more important for adaptive aspects of Sindi and Girolando cows were respectively: GLU; MCV; AST; PCV; RBC; HE; TP; ALB; ALT; RR; T4; RT; T3; URE; CHO; TRI; CRE; WBC and ALB; GLU; TP; AST; RR; ALT; CRE; CHO; RT; RBC; T4; HE; PCV; MCV; URE; TRI; WBC; T3. The difference between breeds was just over 8% for AI. We developed a preliminary AI, able to measure the level of adaptability of dairy cows under tropical region. The methodological framework has potential to inform decision-makers on the adaptability animal conditions and high inference of the blood values from adaptability of cows.

Adaptive profile of dairy cows in a tropical region.

The objectives of this study were to determine the main variables which act in the adaptive profile and the dynamic of the thermoregulatory responses of Sindi and Girolando dairy cows in tropical conditions using multivariate analyses as the auxiliary method. Thirty dairy cows were evaluated, in which the data were collected monthly during 12 months. Rectal temperature (RT) and respiratory rate (RR) were measured twice a day (morning and afternoon), along with meteorological variables (air temperature, relative humidity, and wind speed), and later the Black Globe and Humidity Index and Radiant Heat Load were calculated. Blood samples were collected for estimating the levels of triiodothyronine (T3), thyroxine (T4), hemoglobin concentration (HC), red blood cells (RBC), packet cell volume (PCV), mean corpuscular volume (MCV), white blood cells (WBC), glucose (GLU), cholesterol (CHO), triglycerides (TRI), creatinine (CRE), total protein (TP), urea (URE), albumin (ALB), aspartate aminotransferase (AST), and alanine aminotransferase (ALT). The more active variables in the adaptive profile for Sindi cows were T4, PCV, RBC, WBC, TRI, CRE, HC, T3, and URE, while PCV, RBC, ALB, TP, RT, RR, URE, ALT, and AST variables were more active for Girolando cows. All animals were classified according to their corresponding group when considering all variables under study. The classification error percentage was > 40% in the Sindi cows when the physiological responses were considered, whereas an 80% success rate was observed in Girolando cows in the winter and summer seasons. The physiological responses of the dairy cows are similar in winter and distinct in summer in tropical conditions.

Sensitivity and specificity of the FAMACHA© system in tropical hair sheep.

The aim of this research was to evaluate the sensitivity and specificity of the FAMACHA© (F©) system in Morada Nova ewes. The conjunctivae of 562 ewes were evaluated using the F© system. Packed cell volume (PCV) served as the gold standard for clinical F© evaluation. To calculate the sensitivity and specificity of the F© system, different criteria were adopted: animals classified as (I) F© 4 and 5 or (II) 3, 4, and 5 were considered to be anemic and animals classified as (I) F© 1, 2, and 3, or (II) 1 and 2 were considered to be non-anemic. Three standard values of PCV, namely, ≤ 19%, ≤ 18%, or ≤ 15%, were used to confirm anemia. The percentage of correct treatments was always high when the F© values 4 and 5 were used as criteria for positive tests. For all the PCV cut-off values, more animals were classified as false positives when evaluated using F© 3, 4, and 5 as criteria for a positive test and more true negative animals when evaluated using only F© 4 and 5 as criteria for a positive test. For both sets of criteria for the positive tests, few animals were classified as false negatives and true positives. Eliminating the classification of F© 3 as anemic decreased the sensitivity and increased the specificity for all the PCV cut-off values for the ewes. The F© system can be used as a reliable alternative to reduce selection pressure for anthelmintics in relation to routine non-selective blanket treatment for worm control in the Morada Nova ewes.

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.

Daily rhythmicity of the thermoregulatory responses of locally adapted Brazilian sheep in a semiarid environment.

The goal of this study was to evaluate the daily rhythmicity of the thermoregulatory responses of Morada Nova ewes that were raised in a semiarid environment. The experiment was conducted during the dry season. Data were collected from 5:00 a.m. to 4:00 a.m.. Samples were taken over the course of 8 days, with a 1-week interval between sampling periods. During each day that the data were collected, animals were measured once an hour for 24 h in an area directly exposed to solar radiation. The environment was characterized by measuring the following variables: air temperature (TA), relative humidity (RH), Black Globe Humidity Index (BGHI), radiant heat load (RHL), and wind speed (WS). Physiological variables that were measured included rectal temperature (RT, °C), respiratory rate (RR, breaths/min), surface temperature (ST, °C), and sweating rate (SR, g m2 h-1). We observed that RT, RR, and ST increased as environmental conditions became more stressful. Specifically, environmental conditions became more stressful as RHL, air temperature, and BGHI increased, while RH decreased. All physiological variables of the animals were strongly affected by the time of the day: environmental variables changed drastically between nighttime and noon. Physiological parameters increased sharply from the morning (7:00 a.m.-10:00 a.m.) until noon (11:00 a.m.-2:00 p.m.), except for sweating rate. After noon, these variables began to drop until nighttime (11:00 p.m.-6:00 am), and values of the main physiological indexes were stable during this period. The Morada Nova breed exhibited daily cyclic variations in thermoregulatory responses. Evaporative heat loss mechanisms were triggered during the most stressful times of the day. The first mechanism that animals used was panting, which was an immediate response to environmental heat stress. Cutaneous evaporation had a slower response mechanism to environmental heat stress. Homeothermy conditions were restored to the animals at approximately 5:00 p.m.; however, these findings confirm the importance of providing environmental protection during critical periods of the day, even for locally adapted breeds. These responses suggest that the use of thermal storage allowed the animals to achieve equilibrium with the environment and maintain a stable body temperature.