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Genetic improvement, without control of inbreeding, can go to loss of genetic variability, reducing the potential for genetic gains in the domestic populations. The aim of this study was to analyze the population structure and the inbreeding depression in Campolina horses. Phenotype information from 43 465 individuals was analyzed, data provided by the Campolina Breeders Association. A pedigree file containing 107 951 horses was used to connected the phenotyped individuals. The inbreeding coefficient was performed by use of the diagonal of the relationship matrix and the genealogical parameters were computed using proper softwares. The effective population size was estimated based on the rate of inbreeding and census information, and the stratification of the population was verified by the average relationship coefficient between animals born in different regions of Brazil. The effects of inbreeding on morphological traits were made by the use of inbreeding coefficient as a covariate in the model of random regression. The inbreeding coefficient increased from 1990 on, impacting effective population size and, consequently, shrinking genetic variability. The paternal inbreeding was greater than maternal, which may be attributed to the preference for inbred animals in reproduction. The average genetic relationship coefficient of animals born in different states was lower than individuals born within the same state. The increase in the inbreeding coefficient was negatively associated with all studied traits, showing the importance to avoid genetic losses in the long term. Although results do not indicate a severe narrowing of the population until the present date, the average relationship coefficient shows signs of increase, which could cause a drastic reduction in genetic variability if inbred mating is not successfully controlled in the Campolina horse population. [ABSTRACT FROM AUTHOR]

Copyright of Arquivo Brasileiro de Medicina Veterinaria e Zootecnia is the property of Universidade Federal de Minas Gerais, Escola de Veterinaria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Arquivo Brasileiro de Medicina Veterinaria e Zootecnia is the property of Universidade Federal de Minas Gerais, Escola de Veterinaria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Inbreeding has been associated with the impairment of reproductive performance in many cattle breeds. Although the usage of reproductive biotechnologies has been increasing in bovine populations, not much attention has been given to the impact of inbreeding over cow’s performance on artificial reproduction. The objective of this study was to estimate the impact of inbreeding on in vitro embryo production in a Guzerá breed population. The inbreeding coefficient (F), calculated as half of the co-ancestry of the individual’s parents, was used as an estimate of inbreeding. The inbreeding coefficients of the donor, sire (used on in vitro fertilization) and of the embryos were included, separately, in the proposed models either as classificatory or continuous variables (linear and quadratic effects). The percentage of non-inbred individuals (or embryos) and mean F of donors, embryos and sires were 29.38%; 35.76%; 42.86% and 1.98±2.68; 1.32±3.13; 2.08±2.79, respectively. Two different models were considered, one for oocyte production traits and other for embryo production traits. The increase of F of the donor significantly (P<0.05) impaired the number of viable oocytes (NOV), number of grade I oocytes (NGI) and number of cleaved embryos (NCLV). Moreover, the donor’s F influenced the percentage of grade I oocytes (PGI), percentage of viable embryos (PEMB) and percentage of cleaved embryos that turned into embryos (PCXE). No significant (P>0.05) effects were observed for the sire (father of the embryos) inbreeding coefficient over the traits analysed. Embryo’s F influenced (P<0.05) the number of viable embryos (NEMB), percentage of viable embryos (PEMB) and percentage of cleaved embryos that turn into embryos (PCXE). Results suggested that an increase in the inbreeding coefficient might impair the embryos ability to survive through challenges imposed by the in vitro environment. Submitting highly inbred Guzerá female donors to in vitro embryo production may, in the long-term, have negative implications on the number of embryos obtained per cow and increase the relative costs of the improvement programmes based on this technology. High levels of inbreeding should be avoided when selecting Guzerá female donors and planning in vitro fertilization mating. [ABSTRACT FROM PUBLISHER]

Four models for in vitro embryo production traits in Guzerá cattle were compared: Gaussian (untransformed variable – LIN and transformed in logarithmic scale – LOG), Poisson (POI) and zero-inflated Poisson (ZIP). Data consisted of 5716 ovum pick-up and in vitro fertilization records performed in 1205 cows from distinct regions of Brazil. Analyzed count traits were the number of viable oocytes (NOV), number of grade I oocytes (NGI), number of degenerated oocytes (NDG), number of cleaved embryos (NCLV) and number of viable produced embryos (NEMB). Heritability varied from 0.17 (LIN) to 0.25 (POI) for NOV; 0.08 (LOG) to 0.18 (ZIP) for NGI; 0.12 (LIN) to 0.20 (POI) for NDG; 0.13 (LIN) to 0.19 (POI) for NCLV; 0.10 (LIN) to 0.20 (POI) for NEMB depending on the considered model. The estimated repeatability varied from 0.53 (LOG) to 0.63 (POI) for NOV; 0.22 (LOG) to 0.39 (ZIP) for NGI; 0.29 (LIN) to 0.42 (ZIP) for NDG; 0.42 (LIN) to 0.59 (POI) for NCLV; 0.36 (LIN) to 0.51 (POI) for NEMB. The goodness of fit, measured by deviance information criterion and mean squared residuals, suggested superiority of POI and ZIP over Gaussian models. Estimated breeding values (EBV) obtained by different models were highly correlated, varying from 0.92 for NOV (between LIN-POI) and 0.99 for NGI (between POI-ZIP). The number of coincident animals on the 10% top EBV showed lower similarities. We recommend POI and ZIP models as the most adequate for genetic analysis of in vitro embryo production traits in Guzerá cattle. [ABSTRACT FROM PUBLISHER]

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Lactobacillus acidophilus was microencapsulated by complex coacervation followed by lyophilisation to be applied in buffalo milk yoghurt. The viability of the probiotics was evaluated for the microencapsulation process, during storage and under simulated gastrointestinal conditions. Four buffalo milk yoghurt-test trials were prepared varying the form of the microorganisms (free and microencapsulated) and the final fermentation pH (4.5 and 5). The acidity, pH and microorganisms' viability in the yoghurts were evaluated. Results showed that the microencapsulation technique used in this work preserved the counts of L. acidophilus higher than 107 UFC/g at refrigerated conditions, but it did not provide protection to the microorganisms at a pH similar to the human stomach. For the yoghurts, the final fermentation pH did not show significant effects on the variables evaluated. Yoghurts prepared with microencapsulated cultures presented lower values for post-acidification and greater stability compared to the product prepared with the addition of the free culture. The obtained product could represent an alternative for buffalo milk intake provided by the benefits of consumption of L. acidophilus. [ABSTRACT FROM AUTHOR]

The objective of the present study was to evaluate the stability (-18°C) of minced African catfish (MF) for 180 days. Microbiological aspects, lipid oxidation, and total volatile nitrogenous bases (TVB-N) of the MF were determined with and without washing. Washing of the MF caused an increase in moisture content, decrease in proteins, and leaching of the compounds responsible for lipid oxidation. The TVB-N remained stable during the storage period. The microbiological parameters of the MF remained within the legal limits. Thus, a 180-days storage period does not affect the quality of MF and could be a good alternative for the exploitation of this species in Brazil. [ABSTRACT FROM AUTHOR]

Spray chilling is a promising technology for immobilization of fat-soluble vitamins since solid lipid microparticles (SLM) can protect, release and improve their absorption in the gut. Thus, this work aimed to produce SLM loaded with 0.1% of vitamin D3 by spray chilling using vegetable fat as carrier, and some formulations were added of 1% beeswax and 1% soy lecithin to evaluate their effect on vitamin stability. SLM were characterized by scanning electron microscopy, laser diffraction and X-ray diffraction (XRD). Additionally, vitamin D3 stability was evaluated during 65 days of storage at 10 and 25 °C through periodic measurements by high-performance liquid chromatography (HPLC). SLM were spherical with unimodal size distribution and volume weighted mean diameter (D4,3) varied from 83.0 to 98.6 µm. XRD analyses revealed that SLM presented β' type crystals, which contributes to a better stability and sensorial properties. SLM increased vitamin stability at 25 °C, in which 86.3% of vitamin were detected after 65 days (formulation with 1% beeswax), compared with non-immobilized vitamin at same conditions (60.8%). These results are promising and demonstrate the potential of spray chilling for production of SLM loaded with vitamin D3, encouraging future applications in foods. [ABSTRACT FROM AUTHOR]

There is a world trend of replacing synthetic additives with natural ones. Thus, the purpose of this study was to evaluate the use of propolis, both free and microencapsulated, as a natural an-tioxidant in salami. For this, salamis were added with free propolis, propolis microencapsulated and other with sodium erythorbate (control). Weight loss, colour, pH, Aw, lipid oxidation, microbi-al spoilage and sensory acceptance were examined. Products containing propolis showed similar results to the control for colour, pH, weight loss and Aw. Propolis prevented the oxidation of sala-mi during storage; however, it led to a lower sensorial acceptance. [ABSTRACT FROM AUTHOR]

The main objective of this study was to verify genetic trends for milk production (MY305) and age at first calving (AFC). Were also considered levels of inbreeding practiced in the Brazilian dual-purpose Guzerá population (T POP ) comparing it with the same parameters estimated for two sub-populations derived from the reference (T POP ): female donors submitted to ovum-pick up (D POP ) and in vitro embryos produced (E POP ) between 2003 and 2013. Estimated breeding values (EBV) and inbreeding coefficients (F) were regressed by the year of birth (or year of in vitro fertilization) of each animal or embryo in order to obtain annual trends for these parameters separately for each of the three populations studied. A positive quadratic (β 2  = +0.000075) effect was detected for the F values in T POP . Both D POP and E POP showed positive linear coefficients (β 1 ), respectively, +0.00084 (P < 0.001) and +0.00024 (P > 0.05). Annual mean F for E POP was higher than T POP and D POP through the time series studied. The frequency of individuals with more than 7% F was higher in D POP . Genetic trends for AFC were -0.187 days/year (P > 0.05); -0.557 days/year (P < 0.05) and -1.48 days/year (P < 0.05), respectively for T POP ; D POP and E POP . Genetic trends for MY305 were +6.75 kg/year (P < 0.001); +8.2 kg/year (P < 0.001) and +10.5 kg/year (P < 0.05), respectively for T POP ; D POP and E POP . For both traits analyzed, E POP showed the highest regression coefficients, which confirms a higher selection pressure and lower generation intervals previously expected from this sub-population. Results reported in the present study suggest that mean F is increasing in the Guzerá population. Efforts for controlling inbred mating on in vitro fertilization should be considered, as the presence of a bottleneck effect seems to be getting shape on D POP and E POP ., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Feed intake assessment is a valuable tool for herd management decisions. The use of markers, either internal or external, is currently the most used technique for estimating feed intake in production animals. The experiment used 10 multiparous Holstein cows fed a corn silage-based diet, with 55:45 forage-to-concentrate ratio, the average fecal recovery (FR) of TiO 2 was higher than FR of Cr 2 O 3 , and both FR were more than unity. With internal markers, acetyl bromide lignin and cutin FR were lower than unity, and average FR for indigestible neutral detergent fiber (iNDF) and indigestible acid detergent fiber (iADF) was 1.5. The FR was unaffected by the fecal sampling procedure and appears to be an intrinsic property of each molecule and how it interacts with digesta. Of the 2 external markers, only Cr 2 O 3 produced accurate fecal output (FO) estimates and the same happened to dry matter digestibility (DMD) when iNDF and iADF were used. Estimates for DMD and FO were affected by sampling procedure; 72-h bulk [sub-sample from total feces collection (TFC)] sampling consistently produced accurate results. The grab (sub-samples taken at specific times during the day) sampling procedures were accurate when using either of the indigestible fibers (iNDF or iADF) to estimate DMD. However, grab sampling procedures can only be recommended when concomitant TFC is performed on at least one animal per treatment to determine FR. Under these conditions, Cr 2 O 3 is a suitable marker for estimating FO, and iNDF and iADF are adequate for estimating DMD. Moreover, the Cr 2 O 3 +iADF marker pair produces accurate dry matter intake estimates and deserves further attention in ruminant nutrition studies. The method of dosing the external markers is extremely important and greatly affects and determines results. Whichever the method, it must allow the animals to display normal feeding behavior and not affect performance. The grab sampling procedures can replace TFC (once FR is established), which may open new possibilities for pasture-based or collectively housed animals., (Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

The objectives of this study were to characterize the allelic and genotypic frequencies of polymorphisms in the µ-calpain and calpastatin genes, and to assess their association with meat tenderness and animal growth in Nellore cattle. We evaluated 605 Nellore animals at 24 months of age, on average, at slaughter. The polymorphisms were determined for the molecular markers CAPN316, CAPN530, CAPN4751, CAPN4753, and UOGACAST1. Analyses of meat tenderness at 7, 14, and 21 days of maturation were performed in samples of longissimus thoracis obtained between the 12th and 13th rib and sheared using a Warner Bratzler Shear Force. Significant effects were observed for meat tenderness at days 7, 14, and 21 of maturation for the marker CAPN4751, at day 21 for the marker CAPN4753, and at days 14 and 21 for the marker UOGCAST1. For genotypic combinations of markers, the results were significant for the combination CAPN4751/UOGCAST1 in the three maturation periods and CAPN4753/UOGCAST1 at days 14 and 21 of maturation.

The objective of this study was to estimate variance components for oocyte and embryo production traits in Guzerá breed female donors, and investigate their associations with age at first calving (AFC). The traits analyzed were the number of viable oocytes (NOV), the number of grade I oocytes (NGI), the number of cleaved embryos (NCLV), and viable embryos produced (NEMB), and the percentages of viable oocytes (POV), grade I oocytes (PGI), cleaved embryos (PCLV), and viable embryos (PEMB). Data were obtained from 5173 ovary puncture and in vitro fertilization (IVF) sessions using 1080 Guzerá female donors of different ages, occurred from March 2005 to July 2013. Variables were log-transformed (logeX+1) prior to analysis. (Co)variance components were estimated by restricted maximum likelihood (REML), using one- and two-trait animal models. Permanent environment and IVF sire (father of the embryos) random effects were included. Estimated heritabilities for NOV, NGI, NCLV, NEMB, POV, PGI, PCLV, and PEMB were 0.19, 0.08, 0.16, 0.14, 0.04, 0.03, 0.01, and 0.07, respectively. Repeatabilities for count traits (NOV, NGI, NCLV, and NEMB) varied from 0.14 and 0.32, higher than estimated for percentage traits (POV, PGI, PCLV, and PEMB), which varied from 0.01 to 0.08. Selection for NOV may be more appropriate in breeding programs than selection for NEMB, because of its strong genetic correlation (0.68) with NEMB and its greater time- and cost-effectiveness. AFC was only weakly associated with the oocyte and embryo production traits, which indicates that there would be no effect on AFC when selecting for these traits.

The glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) are key components in the regulation of the hypothalamic-pituitary-adrenal neuroendocrine axis and coordinate the physiological response to stress agents to reestablish homeostasis. Genetic variations of GR (NR3C1) and MR (NR3C2) genes could explain the alterations in animals to adapt to challenges, and therefore, their influence on production traits. The present study aimed to identify single-nucleotide polymorphisms (SNPs) in the bovine NR3C1 and NR3C2 genes and explore their associations to relevant traits of beef cattle production. Genotypes and phenotypes were collected from 241 male Nellore cattle (119 noncastrated and 122 castrated surgically) with an average of 24 ± 1.2 mo of age and live weight of 508 ± 39 kg. The traits evaluated were concentrations of plasma adrenocorticotropic hormone (ACTH) and cortisol, muscle glycogen and lactate content, and pH, color, cooking loss, and shear force of longissimus thoracis measured on the 1st, 7th, and 14th days postmortem. Five SNPs were identified, 2 in the NR3C1 gene and 3 in the NR3C2 gene. There was an associative relationship between the SNP NR3C1&#95;1 g.3293A>G and postmortem plasma concentration of cortisol (P = 0.0008). The SNPs NR3C2&#95;1 g.115T>C and NR3C2&#95;2 g.570T>C were associated with muscle glycogen content (P = 0.0306 and P = 0.0158), postmortem plasma concentration of ACTH (P = 0.0118 and P = 0.0095), and cooking loss of the steak aged 1 d (P = 0.0398 and P = 0.0423). Haplotype analysis showed associations of GR haplotypes with postmortem plasma concentrations of cortisol and MR haplotypes with meat color, cooking losses, muscle glycogen content, and plasma concentrations of ACTH. The associations observed in the present study show that SNPs in GR and MR genes are related with changes of hypothalamic-pituitary-adrenal axis activity and metabolic profile in cattle, leading to individual variation in meat quality traits., (Copyright © 2015 Elsevier Inc. All rights reserved.)

The objectives of this study were to characterize and define homogenous production environments of composite beef cattle in Brazil in terms of climatic and geographic variables by using multivariate exploratory techniques; to evaluate the presence of genotype by environment interaction (GxE) for post-weaning weight gain (PWG), yearling scrotal circumference (SC), and yearling muscling (MUS). Hierarchical and nonhierarchical cluster analysis was used to group farms located in regions with similar environmental variables into clusters. Six clusters of farms were formed. The effect of sire-cluster interaction was tested by single-trait analysis. Genetic parameters were estimated by multi-trait analysis considering the same trait to be different in each cluster. The effect of sire-cluster interaction was significant (P <0.01) for PWG and MUS. Estimates of genetic correlations among clusters ranged from 0.31 to 0.93 for PWG, 0.64 to 0.89 for SC, and 0.18 to 0.80 for MUS. These results indicate the need for a genetic analysis on a regional basis or inclusion of the GxE effect in the statistical model to permit appropriate evaluation of the animals.

Meat quality is an important feature for the poultry industry and is associated with consumer satisfaction. The calpain 1 (CAPN1) gene is related to the tenderness process of meat post- mortem, and the calpain 3 (CAPN3) gene plays an important role in myofibrillar organization and growth. The objective of the present study was to identify polymorphisms in these genes and to determine the association between these polymorphisms and traits of economic interest in poultry. Eleven animals (F₁) from an experimental poultry population at Embrapa Swine and Poultry were used to identify the polymorphisms. Four single nucleotide polymorphisms (SNPs) were found in the CAPN1 gene, and one SNP was found in the CAPN3 gene. A polymorphism from each gene was selected for genotyping in 152 chickens from the Embrapa F₂ experimental population and 311 chickens from a commercial population. Polymorphism g.2554T>C (CAPN1) was associated with body weight at 35 to 42 days, thigh weight, breast weight, carcass weight, and meat lightness content. SNP g.15486C>T (CAPN3) was associated with thigh yield, thawing-cooking loss, and shear force. Results suggest the possibility of using molecular markers in CAPN1 and CAPN3 genes as a tool for performance and meat quality traits in poultry breeding programs.

In the past, the focus of broiler breeding programs on yield and carcass traits improvement led to problems related to meat quality. Awareness of public concern for quality resulted in inclusion of meat quality traits in the evaluation process. Nevertheless, few genes associated with meat quality attributes are known. Previous studies mapped quantitative trait loci for weight at 35 and 42 days in a region of GGA4 flanked by the microsatellite markers, MCW0240 and LEI0063. In this region, there are 2 fibroblast growth factor binding protein (FGFBP) genes that play an important role in embryogenesis, cellular differentiation, and proliferation in chickens. The objective of this study was to identify and associate single nucleotide polymorphisms (SNPs) in FGFBP1 and FGFBP2 with performance, carcass, and meat quality in experimental and commercial chicken populations. In the commercial population, SNP g.2014G>A in FGFBP1 was associated with decreased carcass weight (P < 0.05), and SNP g.651G>A in FGFBP2 was associated with thawing loss and meat redness content (P < 0.05). Four haplotypes were constructed based on 2 SNPs and were associated with breast weight, thawing loss, and meat redness content. The diplotypes were associated with thawing loss, lightness, and redness content. The SNPs evaluated in the present study may be used as markers in poultry breeding programs to aid in improving growth and meat quality traits.

Given the important role of leptin in metabolism, we looked for a possible association of leptin and leptin receptor polymorphisms with carcass and growth traits in Nellore cattle. We examined associations of leptin and leptin receptor SNPs with ultrasound carcass (longissimus dorsi muscle area (ribeye area), backfat thickness and rump fat thickness and growth traits (weaning weight adjusted to 210 days of age, yearling weight adjusted to 550 days of age, weight gain of weaning to yearling and scrotal circumference adjusted to 550 days of age) of 2162 Bos primigenius indicus (Nellore) animals. Allele and genotypic frequencies were calculated for each marker. Allele substitution, additive and dominance effects of the polymorphisms were also evaluated. Some alleles of the molecular markers had low frequencies, lower than 1%, in the sample analyzed, although the same polymorphisms described for B. p. taurus cattle were found. Due to very low allelic frequencies, the E2JW, A59V and UASMS2 markers were not included in the analysis, because they were almost fixed. E2FB was found to be significantly associated with weight gain, ribeye area and backfat thickness. The promoter region markers, C963T and UASMS1, were also found to be significantly associated with ribeye area. T945M was significantly associated with weight gain. We conclude that the leptin and receptor gene markers would be useful for marker-assisted selection.

Our objective was to estimate Bos primigenius taurus introgression in American Zebu cattle. One hundred and four American Zebu (Nellore) cattle were submitted to mtDNA, microsatellite and satellite analysis. Twenty-three alleles were detected in microsatellite analysis, averaging 4.6 ± 1.82/locus. Variance component comparisons of microsatellite allele sizes allowed the construction of two clusters separating taurus and indicus. No significant variation was observed when indicus and taurus mtDNA were compared. Three possible genotypes of 1711b satellite DNA were identified. All European animals showed the same restriction pattern, suggesting a Zebu-specific restriction pattern. The frequencies of B. primigenius indicus-specific microsatellite alleles and 1711b satellite DNA restriction patterns lead to an estimate of 14% taurine contribution in purebred Nellore.

The effect of melatonin during in vitro maturation (IVM) on DNA damage of cumulus cells (CCs) from bovine cumulus-oocyte complexes (COCs) and embryo development was evaluated. COCs from abattoir ovaries were cultured in maturation medium (MM) with 0.5μg/ml FSH and 5.0μg/ml LH (FSH-LH); 10(-9)M melatonin (MEL) or FSH-LH+MEL (FSH-LH-MEL). After 24h of in vitro maturation, the CCs surrounding the oocyte were subjected to DNA analysis by Comet assay. After in vitro fertilization and in vitro embryo culture, the embryo development rates were evaluated on day 2 post insemination (cleavage) and days 7-8 (blastocyst). The percentage of CCs with no DNA damage was significantly superior in MEL group (37.6±2.4) than in FSH-LH-MEL (28.0±2.4) and FSH-LH (17.8±2.41) groups. Cleavage and blastocysts rates were similar among groups. Melatonin during IVM protects the CCs from DNA damage but this effect did not influence embryo development in vitro., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

The effect of genetic and non-genetic factors for carcass, breast meat and leg weights, and yields of a commercial broiler line were investigated using the restricted maximum likelihood method, considering four different animal models, including or excluding maternal genetic effect with covariance between direct and maternal genetic effects, and maternal permanent environmental effect. The likelihood ratio test was used to determine the most adequate model for each trait. For carcass, breast, and leg weight, and for carcass and breast yield, maternal genetic and permanent environmental effects as well as the covariance between direct and maternal genetic effects were significant. The estimates of direct and maternal heritability were 0.17 and 0.04 for carcass weight, 0.26 and 0.06 for breast weight, 0.22 and 0.02 for leg weight, 0.32 and 0.02 for carcass yield, and 0.52 and 0.04 for breast yield, respectively. For leg yield, maternal permanent environmental effect was important, in addition to direct genetic effects. For that trait, direct heritability and maternal permanent environmental variance as a proportion of the phenotypic variance were 0.43 and 0.02, respectively. The results indicate that ignoring maternal effects in the models, even though they were of small magnitude (0.02 to 0.06), tended to overestimate direct genetic variance and heritability for all traits.

Genetic parameters for traits related to postweaning growth in Braunvieh cattle, reared under tropical and sub-tropical conditions in Brazil, were studied. Weight traits were weight at 365 days of age (W365, N = 4055), at 450 days (W450, N = 3453), and at 550 days (W550, N = 1946), while weight gains were gain from weaning to 365 days of age (WGW365, N = 3060), from weaning to 450 days (WGW450, N = 2764), from weaning to 550 days (WGW550, N = 1531), from 365 to 550 days of age (WG365550, N = 1528), from 365 to 450 days (WG365450, N = 2401), and from 450 to 550 days (WG450550, N = 1563). A full animal model was used for estimating the variance components, using the MTDFREML software. The dataset contained 18,688 animals with phenotypic measures and 35,188 animals in the relationship matrix. Heritability estimates for postweaning weights decreased with age. For W365, W450 and W550, respectively, the direct heritability estimates were 0.29 +/- 0.061, 0.25 +/- 0.057, 0.16 +/- 0.060, maternal heritability was 0.20 +/- 0.035, 0.18 +/- 0.035, 0.13 +/- 0.052, and total heritability was 0.30, 0.35, 0.26. In this breed, maternal influence was found to be important up to 550 days of age. The greater genetic correlations between weights were observed for weights measured at shorter intervals. A large environmental effect was observed for weight gain between weaning and 550 days; this effect was greater for the gains between 365 and 550 days.

Data from the slaughter of 24,001 chickens that were part of a selection program for the production of commercial broilers were used to estimate genetic trend for absolute carcass (CW), breast meat (BRW), and leg (LW) weights, and relative carcass (CY), breast meat (BRY), and leg (LY) weights. The components of (co)variance and breeding values of individuals were obtained by the restricted maximum likelihood method applied to animal models. The relationship matrix was composed of 132,442 birds. The models included as random effects, maternal additive genetic and permanent environmental for CW, BRW, LW, CY, and BRY, and only maternal permanent environmental for LY, besides the direct additive genetic and residual effects, and as fixed effects, hatch week, parents' mating group and sex. The estimates of genetic trend were obtained by average regression of breeding value on generation, and the average genetic trend was estimated by regression coefficients. The genetic trends for CW (+6.0336 g/generation), BRW (+3.6723 g/generation), LW (+1.5846 g/generation), CY (+0.1195%/generation), and BRY (+0.1388%/generation) were positive, and they were in accordance with the objectives of the selection program for these traits. The genetic trend for LY (-0.0019%/generation) was negative, possibly due to the strong emphasis on selection for BRY and the negative correlations between these two traits.

The objective of this study was to estimate genetic parameters for pre-weaning traits of Braunvieh cattle raised under tropical conditions in Brazil. The weight and weight gain parameters were birth weight (BW, N = 9955), weight at 120 days of age (W120, N = 5901), weaning weight at 205 days (WW, N = 6970), weight gain from birth to 205 days (GAIN205, N = 6013), weight gain from birth to 120 days (GAIN120, N = 5135), and weight gain from 120 to 205 days (GAIN85, N = 4482). Variance components were estimated using the animal model with the MTDFREML software. The relationship matrix included 35,188 animals; phenotypic measures were available for 18,688. Direct and maternal heritability increased from birth to weaning, with estimates of 0.23 +/- 0.037, 0.25+/- 0.050, 0.41+/- 0.059 for direct heritability for BW, W120 and WW, respectively, 0.08 +/- 0.012, 0.15 +/- 0.032, 0.22 +/- 0.036 for maternal genetic effects, and 0.18, 0.14 and 0.16 for total heritability estimates. For pre-weaning gains, estimates of heritability were 0.36 +/- 0.059, 0.30+/- 0.059, 0.12 +/- 0.035 for direct genetic effects of the traits GAIN205, GAIN120 and GAIN85, respectively, 0.23 +/- 0.038, 0.17 +/- 0.037, 0.03 +/- 0.029 for estimates of maternal heritability, and 0.12, 0.13, 0.16 for total heritability, respectively. Genetic correlations between weights were greater between measures taken at shorter intervals. This information can be used to optimize the design of programs for genetic improvement of Braunvieh cattle raised under tropical conditions.

The aim of the present study was to evaluate the heterosis effects on weaning weight at 205 days (WW, n = 146,464), yearling weight at 390 days (YW, n = 69,315) and weight gain from weaning to yearling (WG, n = 59,307) in composite beef cattle. The fixed models were: RM, which included contemporary groups, class of age of dam, outcrossing percentages for direct and maternal effects, and additive direct and maternal (AM) breed effects; R, RM model, minus AM breed effects, and H, RM model, minus additive breed effects. The estimates for W205 were in general positive (P < 0.01). The R and H models resulted in similar estimates, but they were very different from the ones estimated by the RM model. For W390, the R and H models resulted in general positive estimates (P < 0.05). For WG, the RM model resulted in general significant heterosis effects (P < 0.05). It can be concluded that the RM model seems to supply estimates of better quality (P < 0.01).

Diabetes mellitus is the most common endocrine disturbance of domestic carnivores and can cause autonomic neurological disorders, although these are still poorly understood in veterinary medicine. There is little information available on the quantitative adaptation mechanisms of the sympathetic ganglia during diabetes mellitus in domestic mammals. By combining morphometric methods and NADPH-diaphorase staining (as a possible marker for nitric oxide producing neurons), type I diabetes mellitus-related morphoquantitative changes were investigated in the celiac ganglion neurons in dogs. Twelve left celiac ganglia from adult female German shepherd dogs were examined: six ganglia were from non-diabetic and six from diabetic subjects. Consistent hypertrophy of the ganglia was noted in diabetic animals with increase of 55% in length, 53% in width, and 61.5% in thickness. The ordinary microstructure of the ganglia was modified leading to an uneven distribution of the ganglionic units and a more evident distribution of axon fascicles. In contrast to non-diabetic dogs, there was a lack of NADPH-diaphorase perikarial labelling in the celiac ganglion neurons of diabetic animals. The morphometric study showed that both the neuronal and nuclear sizes were significantly larger in diabetic dogs (1.3 and 1.39 times, respectively). The profile density and area fraction of NADPH-diaphorase-reactive celiac ganglion neurons were significantly larger (1.35 and 1.48 times, respectively) in non-diabetic dogs compared to NADPH-diaphorase-non-reactive celiac ganglion neurons in diabetic dogs. Although this study suggests that diabetic neuropathy is associated with neuronal hypertrophy, controversy remains over the possibility of ongoing neuronal loss and the functional interrelationship between them. It is unclear whether neuronal hypertrophy could be a compensation mechanism for a putative neuronal loss during the diabetes mellitus.

The observation of bovine mitochondrial DNA (mtDNA) polymorphisms allows the separation of American zebu cattle, according to its maternal lineage ancestry, into two groups: one with Bos indicus mtDNA and other with Bos taurus mtDNA. The aim of the present study was to determine the productive and reproductive differences between these two groups, in a Guzerat dairy herd. The genotyping of a sample of 56 animals allowed the categorization of most of the 3835 animals in the pedigree file. The production file included 3528 calving and 3198 lactation records from 729 cows, born during the years 1947 to 2007. The traits considered were: lactation milk yield (LMY); days in milk (DIM); age at first calving (AFC), and calving interval (CI). Heritabilities and breeding values were estimated using an animal model. The regression of the average breeding values per year of birth indicated the genetic trends of the herd. The heritability coefficients estimated for LMY, DIM, AFC, and CI were 0.42, 0.43, 0.20, and 0.10, respectively. The genetic trends were similar for both groups, pointing to an improvement in the productive and a worsening in the reproductive traits. The two groups differed significantly regarding the average estimated breeding values for LMY, DIM and AFC, in the starting period, until 1970, but no differences were observed in the more recent years, after 1970. The segregation between the groups existed in the starting period, probably because the Bos taurus contributions to the herd had occurred more recently at that moment. The conclusion is that mtDNA has no significant effect on these traits.

The purpose of the present research was to investigate the effects of polymorphisms of luteinizing hormone receptor (LHR) and follicle-stimulating hormone receptor (FSHR) genes, evaluated by polymerase chain reaction-restriction fragment length polymorphism in European-Zebu composite beef heifers from six different breed compositions. The polymorphism site analysis from digestion with HhaI and AluI restriction endonucleases allowed the genotype identification for LHR (TT, CT and CC) and FSHR (GG, CG and CC) genes. A high frequency of heterozygous animals was recorded in all breed compositions for both genes, except in two compositions for LHR. The probability of pregnancy (PP) at first breeding was used to evaluate the polymorphism effect on sexual precocity. The PP was analyzed as a binary trait, with a value of 1 (success) assigned to heifers that were diagnosed pregnant by rectal palpation and a value of 0 (failure) assigned to those that were not pregnant at that time. Heterozygous heifers showed a higher pregnancy rate (67 and 66% for LHR and FSHR genes, respectively), but no significant effects were observed for the genes studied (P = 0.9188 and 0.8831 for LHR and FSHR, respectively) on the PP. These results do not justify the inclusion of LHR and FSHR restriction fragment length polymorphism markers in selection programs for sexual precocity in beef heifers. Nevertheless, these markers make possible the genotype characterization and may be used in additional studies to evaluate the genetic structure in other bovine populations.

With the aim of estimating the coefficient of heritability of average annual productivity of Nellore cows (COWPROD), a data set from 24,855 animals with known pedigree was analyzed. COWPROD is defined as the amount (in kilograms) of weaned calves produced yearly by one cow during her remaining time in herd ignoring a fixed period of 365 days. COWPROD was calculated regarding three standards: a) based on the post-weaning weight from the calves ignoring any kind of adjustment (COWPROD&#95;NAJ), b) adjusted weight for the fixed effects (COWPROD&#95;AJFIX) and c) adjusted weight for the fixed effects and for the genetic merit of the sire (COWPROD&#95;AJFIN). The obtained heritabilities were 0.15, 0.15 and 0.16 for COWPROD&#95;NAJ, COWPROD&#95;AJFIX and COWPROD&#95;AJFIN, respectively. A complete set composed of 105,158 COWPROD records on 130,740 animals in pedigree was also analyzed for predicting the genetic merit of all animals in the data set and for the calculation of the genetic, phenotypic and residual trends. Ranking correlation was high for the adjusted and non-adjusted data, yet, for some of the animals, the difference among the genetic values was large. This would be an indication that it would be better to work always with the adjusted weaning weights. The genetic trend was positive, but was of small magnitude (0.26% of the trait average) and the residual trend was negative as a consequence of the large intensification of the production system, which has been occurring in the last years in the farms studied. The phenotypic trend was also negative and intermediate between the genetic and the residual ones.

The objective of the present study was to estimate (co)variance components for length of productive life (LPL) and some alternative reproductive traits of 6-year-old Nellore cattle. The data set contained 57,410 records for age at first calving from Nellore females and was edited to remove animal records with uncertain paternity and cows with just one piece of calving information. Only animals with age at first calving ranging from 23 to 48 months and calving intervals between 11 and 24 months were kept for analysis. LPL and life production (LP) were used to describe productive life. LPL was defined as the number of months a cow was kept in the herd until she was 6 years old, given that she was alive at first calving and LP was defined as total number of calves in that time. Four traits were used to describe reproductive traits: two breeding efficiencies on original scale were estimated using Wilcox and Tomar functions (BEW and BET, respectively), and two breeding efficiencies transformed (ASBEW and ASBET, respectively), using the function [arcsine (square root (BEi/100))]. Estimates of heritability for measures of LPL and LP were low and ranged from 0.04 to 0.05. Estimates of heritability for breeding efficiencies on original and transformed scales oscillated from 0.18 to 0.32. Estimates of genetic correlations ranged from -0.57 to 0.79 for LPL and other traits and from 0.28 to 0.63 for LP and other traits.

The genetic analysis of composite data is very complicated, mainly because it is necessary to adjust data to the effects of heterosis and breed complementarity, and because there is usually considerable confounding of these data with several other effects, such as contemporary group effects, breed composition of the animal and maternal breed composition, among others. Data on birth weight (n = 151,083), weaning weight adjusted to 205 days (n = 137,257), yearling weight adjusted to 390 days (n = 61,410), weight gain from weaning to yearling (n = 56,653), and scrotum circumference (n = 23,323) and muscle score (n = 54,770), both adjusted to 390 days, from Bos taurus x Bos indicus composite beef calves born from 1994 to 2003 were analyzed to estimate (co)variance components and genetic parameters of growth traits. The animals belonged to the Montana Tropical program. Estimation was made by three models that approach adjustment to heterozygosis in order to suggest the best model. The RM model included contemporary groups, class of age of dam, outcrossing percentages for direct and maternal effects, and direct and maternal additive genetic breed effects as covariates; the R model was the same as RM, but without additive maternal breed effects, and H was the same as RM, but not considering any additive breed effect. Both R2 values and consistency of genetic parameters indicate that the more complex model (RM), which considers maternal and individual additive genetic breed effect, produces the best estimates when compared to other models. The R model seems to overestimate (co)variance components. The magnitudes of direct and maternal heritability estimates, obtained in this study, would permit genetic improvement for weight and growth traits, as much by selection of direct genetic effects for weight and growth as for the improvement of maternal performance, but in different lineages. Therefore, the correlations between these effects were unfavorable.