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The aim of this study was to investigate the effects of castration on carcass characteristics and fatty acid profile of visceral fat and meat from lambs. Eighteen six-month-old Santa Inês male lambs (18.9 ± 2.4 kg of body weight (BW)) were used. Animals were assigned to two treatments according to their sexual condition: uncastrated (U) or castrated (C). During a 98-day experimental period, animals were kept on an Andropogon gayanus grass pasture area of 1 ha and supplemented with 200 g/animal/day of concentrate mixture. Water and mineral salt were available ad libitum. The lambs were weighed fortnightly, and at the last day of the trial, they were slaughtered for evaluation of carcass characteristics and fatty acids profile of perirenal fat and longissimus lumborum muscle samples. Castrated lambs showed higher BW than U during most part of the experiment (p < 0.05). Fat deposition was higher in C lambs as evidenced by their increased carcass fat cover. Meat from U lambs showed lower content of C 16:0 and higher polyunsaturated fatty acids (PUFA) (p < 0.05) than that from C (U, 14.3 and C, 10.5%). Conjugated linoleic acid (CLA) content was not affected by castration (p > 0.05) (U, 0.74 and C, 0.76%). The cis-9, cis-12 C 18:2n-6 (U, 10.6 and C, 6.86%) fatty acid and the PUFA:SFA (saturated fatty acids) ratio (U, 0.36 and C, 0.25) were higher in the muscle of U lambs (p < 0.05), indicating that the meat from U animals may provide more benefits to human health than that of C.

This study consisted of two experiments with the following objectives: to evaluate the effects of tannins from the tropical legume macrotiloma (Macrotyloma axillare) on total gas and methane (CH 4 ) production, as well as on ruminal fermentation parameters by performing an in vitro bioassay, with samples incubated with and without polyethylene glycol (PEG) in a semi-automatic system; and secondly in a 17 day in vivo experiment, to determine apparent total tract digestibility (ATTD) of dietary nutrients and ruminal fermentation parameters of 12 intact 8- to 9-month-old Santa Inês (averaging 24.95 ± 1.8 kg body weight) ewes fed tropical grass hay supplemented with macrotiloma hay. The ewes were divided into two treatment groups depending on their diet: chopped aruana grass hay (Panicum maximum cv. Aruana) (control-CON); and aruana grass hay supplemented with chopped macrotiloma hay (macrotiloma-MAC). The animals were kept for 5 consecutive days in metabolic cages for the ATTD assay, and at the end of this period, samples of rumen fluid were collected from each ewe to determine ammoniacal nitrogen (NH 3 -N) and short-chain fatty acid (SCFA) production, and protozoa count. For the in vitro assay, a decrease in total gas and CH 4 production was observed for samples incubated without PEG (p < .05). No differences were observed for the other parameters evaluated (p > .05). In the in vivo experiment, increased intake and ATTD of crude protein were observed for the animals fed MAC when compared to CON (p < .05). For rumen fermentation parameters, increased NH 3 -N, total SCFA and isobutyrate concentrations, as well as reduced protozoa count were observed for MAC when compared to CON (p < .05). The results observed here indicated the potential of macrotiloma for use as a ruminant feed, and antimethanogenic potential of this plant was noted., (© 2017 Blackwell Verlag GmbH.)

In this study, the possibility of using Babassu (Orbignya phalerata) and Mofumbo (Combretum leprosum) leaves for lambs feed was verified. Performance, biochemical and haematological parameters, microbial protein synthesis, nutrient apparent digestibility and enteric production of methane (CH 4 ) were evaluated. The experimental treatments included diets with forage-to-concentrate ratios of 50:50, with the leaves of the experimental plants replacing 33% of the Cynodon dactylon (Tifton-85) hay with three treatments: control (no hay replacement) and substitution with Babassu or Mofumbo. For the performance study, 24 Santa Inês lambs were used, in a randomized experimental design with eight repetitions (5 male and 3 female) for each treatment and 48 days of experimental trial. After this period, for nine days, six animals from each treatment were allocated in metabolic cages to determine the apparent nutrient digestibility, microbial protein synthesis and nitrogen balance. Simultaneously, enteric CH 4 was measured in vivo. The control group showed higher (p < 0.05) apparent digestibility of acid detergent fibre. Enteric CH 4 production of lambs fed Mofumbo leaves did not differ from that of the control group, but was lower (p < 0.05) than in those fed with Babassu. The inclusion of Babassu and Mofumbo leaves showed no negative effects on animal health and did not compromise performance. Mofumbo also presented CH 4 mitigating potential, indicating that those plants can be used as ingredients in the composition of lamb diets with the advantage of reducing methane production., (Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.)

Heat stress is considered a limiting factor for sheep production. We used information from physiological characteristics linked to heat tolerance to determine whether infrared thermography temperatures were able to separate groups of animals and determine the most important variables in this differentiation. Forty-eight four-month-old male lambs from eight genetic groups were used. Physiological (rectal temperature-RT, heart rate-HR, respiratory rate-RR) and blood traits, infrared thermography temperatures, heat tolerance indices, body measurements, weight and carcass traits were measured. Statistical analyses included variance, correlations, factor, discrimination and regression. Observing the correlations between physiological characteristics (RT, RR and HR) with temperatures measured by infrared thermography, regions for further studies should include the mean temperature of flank, nose and rump. Results show that there are strong relationships between thermograph measurements and RR, RT and HR in lambs, which are suggested to be directly correlated with heat tolerance capacity of the different genetic groups evaluated in this study. The assessment of body surface temperature measured by the thermograph could be used as a noninvasive tool to assess heat tolerance of the animals.

The aim of this study was to evaluate the methane (CH4) emission of Santa Inês sheep fed cottonseed by-products, verifying if the gossypol content of these feedstuffs affects CH4 emission. Twelve late-lactating Santa Inês sheep (44.8 ± 7.5 kg body weight (BW)) were allocated in metabolic cages for an experimental period of 19 days, 14 days for adaptation and 5 days for measuring CH4 emission and dry matter intake (DMI). The animals were divided into four treatments, established in accordance with the cottonseed by-product used in concentrate formulation: Control (CON - no cottonseed by-product), Whole cottonseed (WCS), Cottonseed cake (CSC), and Cottonseed meal (CSM). The free gossypol level of the concentrates were 0, 1,276, 350, and 190 ppm for CON, WCS, CSC, and CSM, respectively. Also, the animals received Cynodon dactylon cv. Coast Cross hay, water, and mineral salt ad libitum. The ether extract content of the diets was balanced between treatments by including soybean oil in concentrates. The technique used to measure the CH4 emission was the sulfur hexafluoride (SF6) tracer technique, and the gas samples collected were quantified by analysis in gas chromatography system. The CH4 emission was evaluated considering the daily emission (g CH4/day); DMI (g CH4/kg DMI); and BW (g CH4/kg BW). No statistical difference was found (P > 0.05) between treatments for DMI and CH4 parameters. In the regression analysis, no significant relation (P > 0.05) between gossypol content and CH4 emission was observed. These results suggest that gossypol does not affect rumen methanogenesis.

In production systems the characterization of genetic resources in relation to their capacity to respond to environmental conditions is necessary. The objective of this study was to evaluate the use of infrared thermography for separation of animals from different genetic groups and determine which phenotypic traits are important for climatic adaptation. A total of 126 suckling lambs from four different genetic groups (Santa Inês--SI, Bergamasca--B, Bergamasca X Santa Inês--BS, and Ile de France X Santa Inês--IL) were used. The animals were divided into two groups, one housed and another in an outside paddock. Thermograph photographs were taken at four-hour intervals over three full days. Temperatures of the nose, skull, neck, fore and rear flanks and rump were measured, as well as coat depth, the density and length of hairs, reflectance and color. The daily temperature range during the experimental period was more than 20°C, with animals experiencing heat (12 h to 15 h) and cold (24 h to 4 h) stress. The three main phenotypic traits that influenced genetic group separation were hair density, height of coat, and length of hairs. Thermograph temperatures were able to detect different responses of the genetic groups to the environment. Therefore, infrared thermography is a promising technique to evaluate the response of animals to the environment and to differentiate between genetic groups.

Polymorphisms of PRNP gene have been strongly correlated to the susceptibility/resistance to scrapie in sheep. Variants at the coding positions 136, 154 and 171 have been the most frequently associated to susceptibility to classical scrapie. The aim of this study was to estimate PRNP haplotype and genotype frequencies in a sample of 1400 sheep from 13 different breeds that are representative of the main production regions in Brazil. A total of four different alleles (ARR, ARQ, AHQ and VRQ) and nine genotypes were observed at different frequencies among the investigated breeds. There were distinct patterns of allelic distribution between naturalized and commercial/specialized breeds and different geographic regions. These results will influence the development and management of breeding and conservation programs and will help to develop Brazilian efforts to avoid scrapie epidemics., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Santa Inês is the most common hair sheep breed in Brazil and probably has the highest genetic diversity among sheep breeds in this country. Successful breeding programs for Brazilian sheep breeds are not common for various reasons, including a lack of control of parentage in the flocks. We developed an allele frequency database for 23 STR loci for the Santa Inês breed based on 285 animals sampled from five populations distributed across the central-western and north-eastern regions of Brazil. The marker set included seven microsatellites used in the 2011 International Society for Animal Genetics sheep genotyping comparison tests and all eight microsatellites currently approved by the Brazilian Agricultural Ministry laboratory accreditation guidelines for sheep identification. The microsatellites had an average of 10 alleles and a mean expected heterozygosity of 0.745. Combined paternity exclusion probabilities when no parent or one parent was known were >99.99%. A small proportion (5.8%) of the existing genetic variation was found to be among the Santa Inês populations, possibly derived from genetic drift and selection. We found that the marker panel proposed by the Agricultural Ministry, although generally useful, should be enhanced by including more markers for improved exclusionary power in parentage testing. This database provides a useful tool for parentage testing of this major Brazilian breed, contributing to improved management and breeding of existing herds.

The effects of chromium picolinate (CrPic) oral supplementation on the performance and ruminal protozoa population in sheep was investigated. Twenty-four male lambs were treated with four different levels of CrPic: placebo, 0.250, 0.375 and 0.500mg of chromium/animal/day during 84 days. The base ration was Panicum maximum cv Massai hay and concentrate. Feed intake was measured three times a week. Lambs were weighed every 2 weeks. Ruminal content was sampled five times during the trial to quantify ruminal protozoa. No difference (p>0.05) between treatments was recorded for any parameter measured: initial and final mean body weight, dry matter intake, daily gain and total body weight gain. There was a negative linear relationship between Cr supplementation and protozoa count (p=0.0013) with no additional decrease when CrPic supplemental levels were higher than 0.375mg/day. Therefore, Cr supplementation must be carried out carefully and more studies need to address stressed animals or possible toxic effects of Cr in the animal itself or to the ruminal protozoa population., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

The objective of this study was to evaluate and compare physical parameters in groups of sheep with different phenotypic characteristics in the Centre-west region of Brazil. Five groups of sheep, with nine animals per group, were selected, three groups of Santa Inês animals with different coat colours (white, brown and black), one group with crossbred animals (Santa Inês × Bergamasca) and one group with animals of the Bergamasca breed. The following traits were evaluated: coat thickness, number and length of hair, pigmentation level in the coat and the skin as well as the percentage area of sweats glands in the skin tissue, carried out by histological analysis. The number of hairs and the area of sweats glands were not significantly different between the evaluated groups. The Bergamasca breed showed low pigmentation of the skin and long hairs. The levels of pigmentation of the hair and of the skin were highly correlated. Between the Santa Inês groups, the group with white hair showed the better parameters for heat adaptation, while the brown hair group showed the lower heat adaptation when compared with another hair breed groups.

The animal and its environment make up an integrated system, where each acts on the other. Tropical regions are characterized by high levels of solar radiation and environmental temperature which may adversely affect animal production. This study carries out a multivariate analysis of physical and physiological traits in sheep in the Federal District of Brazil to test the ability to separate groups of animals and determine which traits are most important in the adaptation of animal to heat stress. The variables studied included coat thickness, number and length of hairs, pigmentation of the skin and coat, number of sweat glands as well as heart and respiratory rates, rectal and skin temperatures, sweating rate, and blood parameters. Five groups of ten animals were used depending on breed (Bergamasca, crossbred, or Santa Inês) or coat color (Santa Inês--brown, white, and black). The data underwent multivariate statistical analyses including cluster, discriminate, and canonical, using Statistical Analysis System--SAS®. The tree diagram showed clear distances between groups studied and canonical analysis was able to separate individuals in groups, especially Bergamasca and white Santa Inês. The canonical correlation redundancy analysis showed that coat reflectance as well as hair length and number of hairs per unit area were the most useful in explaining changes in physiological traits. Skin and coat traits such as hair length, coat reflectance, percentage of epithelial area occupied by sweat glands, skin reflectance and thickness, as well as heart and breathing rates were the most important in separating these groups.

Thirty Santa Ines adult, non-lactating, non-pregnant ewes, ten with a brown coat, ten black coated and ten white coated, as well as ten Bergamasca and ten of mixed breed were used to evaluate the effect of climate on physiological and blood parameters in sheep. Two sample collections were taken (6 AM: and 2 PM: ) on six days. Sweating rate (SR), heart (HR) and breathing rates (BR), complete hemogram, rectal (RT) and skin temperatures (ST) were measured. Variance analyses were carried out using SAS(R). In general, there were significant differences between animals due to skin type, time and day of collection. White coated animals showed lower HR, BR and RT, with afternoon parameters higher than morning. Correlations between HR, BR, RT, SR and ST were medium and positive. Correlations between physiological and blood traits were in general negative and medium. Packed Cell Volume (PCV), total plasma proteins, red blood cell count and hemoglobin concentration had high positive correlations between each other. The first two autovectors explained 49% of variation between traits. White coated Santa Ines animals were shown to be better adapted to climatic conditions in Central Brazil and wool sheep more affected by heat.

Heat is a major factor limiting the production of animals in the tropics. Sheep are well adapted to diverse ecosystems, however, temperature and relative humidity can influence animal husbandry. Therefore, this study was carried out to verify the thermoregulation in rams of six breeds (Bergamasca, Dorper, Ile de France, Hampshire Down, Santa Ines and Texel) through the evaluation of physiological traits, body measures, laser and thermographic infrared temperatures as well as testicle morphometry associated with heat tolerance. Animals were measured and weighed, coat and hair colour determined, as well as physiological traits and laser and thermographic infrared temperatures measured twice a day. Data were analyzed with the Statistical Analysis System ® . There were differences among breeds for most of the traits linked to heat tolerance, with the Santa Ines showing better adaptation to heat stress compared to other breeds. The Dorper was not significantly better than Bergamasca or Hampshire Down breeds, while Texel and Ile de France were less well adapted. Scrotal temperatures were lowest in Hampshire Down and Dorper, while highest in Texel. Temperature gradient measured by thermography identified Hampshire Down as the least heat tolerant breed. Traits linked to heat tolerance should be taken into consideration when choosing breeds for lamb production in tropical regions. [ABSTRACT FROM AUTHOR]