Evaluation of different silvicultural management techniques and water seasonality on yield of eucalyptus stands

ABSTRACT: Appropriate management of factors that influence forest development is essential to increase yield of forest plantations. The objective of this study was to evaluate the influence of water seasonality, nutritional management, and uniformity on yield of eucalyptus plantations and estimate the potential, attainable, and observed yield of adult eucalyptus stands. We evaluated Eucalyptus clonal stands in six regions of Minas Gerais State, Brazil, in a system of first and second rotation across four age classes using the twin-plots method (TP). In the study, 142 TPs were allocated alongside 142 plots in a continuous forest inventory (CFI) network of a private enterprise. The CFI received operational fertilization and additional fertilization was carried out in the TP. The trees were measured at the beginning of the experiment and at every six months to quantify the production in the wet (PW) and dry (PD) periods of the year. Uniformity of plantations was evaluated using Pvar 50 % and the optimal uniformity index. Potential, attainable, and observed yields were estimated using the average annual increase at seven years of age. The PW showed higher plant yield. There was an effect due to water availability and nutrient level on the yield of the stands. The driest semester of the year produces approximately 30 % of the current annual increase. The stands under the second rotation tend to have less uniformity than the in the first rotation. Potential yield varied depending on rainfall intensity where wetter regions had the highest yield.

The impact of heterogeneity of variances on the genetic evaluation of performance traits in Nellore cattle

The objective was to evaluate the existence of heterogeneity of variances and its impact on the genetic evaluation of ponderal performance in sires of the Nellore breed. We used records of adjusted body weights at 210 (W210), 365 (W365), and 450 (W450) days of age. Both W365 and W450 were combined by principal component analyses using the first component (PC). Average daily gain (ADG) was obtained by difference between W450 and W210. The classes of standard deviations (SD) for W210, PC, and ADG were obtained by the standardization of means of herd-year means subclasses, with positive values composing the high SD and values equal and less than zero composing the SD. The model included the fixed effects of contemporary group and age at calving as a covariate, random genetic additive, and maternal genetic (except for PC) effects, and the permanent maternal environment. Variance components were obtained by Gibbs sampling. Posterior means of heritability in analyses without considering heterogeneity of variances ranged from 0.15±0.01 to 0.31±0.01. Posterior means of genetic correlations between the two classes of SD for W210, PC, and ADG were equal to 0.85±0.04, 0.83±0.03, and 0.71±0.08, respectively. Spearman correlation to breeding values of sires for ADG as the selection intensity increased in them, and the correlations between breeding values in general analyses were more correlated with those predicted in the high DP. Therefore, when there is a higher selection intensity on the sires only for the ADG criterion, there is a significant presence of the heterogeneity of variances and impact on the genetic evaluation of the sires. Thus, for ADG, the predictions of breeding values obtained by the genetic evaluation model in which the heterogeneity of variances are not considered are more weighted by the class of greater heterogeneity.(AU)

Growth predictability models in Mangalarga marchador horses / Modelos de previsibilidade de crescimento em cavalos Mangalarga marchador

This study evaluated the suitability of the Brody, logistic, and quadratic response plateau models to describe chest and cannon girth data obtained cross-sectionally in Mangalarga Marchador horses, in order to select the best model and predict the growth and maturity of males and females of this breed. Data were collected from 230 horses aged 6 to 176 months, divided by sex and age (16 age classes). The studied models were compared according to each quality evaluator by computing the adjusted coefficient of determination (R²adj) and residual standard deviation (RSD) with R statistical software. The chest girths obtained by the models ranged from 172.06 (males) to 181.50 cm (females) (Brody), 172.51 (males) to 181.89 cm (females) (logistic), and 177.67 (males) to 183.09 cm (females) (plateau). For cannon girth, the values were 18.18 (females) to 19.33 cm (males) (Brody), 18.11 (females) to 19.41 cm (males) (logistic), and 18.70 (females) to 19.40 cm (males) (plateau). The logistic model was best suited to describe the growth in chest girth of male and female Mangalarga Marchador horses. For cannon girth growth, the model best suited for males was the logistic model, and the one best suited for females was the Brody model.

RESUMO: O objetivo deste estudo foi avaliar o ajuste dos modelos Brody, Logístico e Platô de resposta quadrática aos dados de perímetros torácico e de canela em equinos Mangalarga Marchador obtidos pelo método transversal, a fim de selecionar o melhor modelo e predizer sobre o crescimento e a maturidade de machos e fêmeas desta raça. Foram utilizados dados de 230 equinos de seis a 176 meses de idade que foram divididos por sexo e em 16 classes de idade. Os modelos estudados foram comparados segundo os avaliadores de qualidade: coeficiente de determinação ajustado (R²adj) e desvio padrão residual (DPR), utilizando-se o software estatístico R. Os perímetros torácicos obtidos pelos modelos variaram de 172,06 a 181,50 cm (Brody), 172,51 a 181,89 cm (Logístico) e 183,09 a 177,67 cm (Platô) para fêmeas e machos, respectivamente. Para o perímetro de canela os valores variaram de 18,18 a 19,33 cm (Brody), 18,11 a 19,41 cm (Logístico) e 18,70 a 19,40 cm (Platô) para fêmeas e machos, respectivamente. O modelo logístico é mais indicado para expressar o crescimento em perímetro torácico de machos e fêmeas da raça Mangalarga Marchador. Já para a variável perímetro de canela, o modelo mais indicado para os machos foi o modelo Logístico e para as fêmeas o modelo de Brody.

Body mass index at calving on performance and efficiency of Zebu cow herds / Índice de massa corporal ao parto no desempenho e eficiência de rebanhos de vacas Zebuínas

This study examines the impact of the body mass index (BMI) at calving on the development and postpartum efficiency of cows of Zebu origin. The study involved 87 cows and their calves [pure Nellore (N) or predominant Nellore composition in a cross with Charolais (C) (3/4N1/4C and 5/8N3/8C)]. The mothers were grouped into classes according to their BMI at calving, namely, 'small', 'moderate' and 'large'. Body mass index was determined by dividing the body weight of the cows by their length and by hip height and then dividing the result by 10. Cows were weighed at calving, at weaning, at the end of the breeding period and at the diagnosis of pregnancy. Calves were weighed at birth, at early weaning (63 days) and at 210 of age. To evaluate milk yield and quality, milk was collected at 21, 42 and 63 days after calving. Milk yield was measured by the direct method, with manual milking, followed by analysis of the lactose, fat, total solids and crude protein contents. Pregnancy rate was similar between the three BMI groups; however, cows with a lower BMI were more efficient at calving in producing kilograms of calf per kilogram of cow kept. Higher BMI provide higher milk yields, without affecting its quality, as well as heavier calves at early weaning and at 210 days of age.(AU)

O objetivo dessa pesquisa foi avaliar o impacto do índice de massa corporal (IMC) ao parto no desenvolvimento e eficiência pós-parto de vacas de origem zebuína. Utilizou-se 87 vacas e seus bezerros [Nelore (N) puros ou com predominância em cruzamento com Charolês (C) (3/4N1/4C e 5/8N3/8C)], agrupadas em classes segundo o seu IMC ao parto, em 'pequenas', 'moderadas' e 'grandes'. O índice de massa corporal foi determinado através da divisão do peso corporal das vacas pelo seu comprimento e pela altura de quadril e posteriormente o resultado dividido por 10. As vacas foram pesadas no parto; ao desmame; final da monta e no diagnóstico de gestação. Os bezerros foram pesados ao nascimento, na desmama precoce (63 dias) e aos 210 dias de idade. Para a avaliação da produção e qualidade do leite das vacas foram realizadas três coletas aos 21, 42 e 63 dias após o parto. A medida da produção de leite foi realizada pelo método direto, com ordenha manual, seguida de análise do teor de lactose, gordura, extrato seco total e proteína bruta. A taxa de prenhez foi similar para os três índices de massa corporal, no entanto vacas de menor IMC foram mais eficientes ao parto na produção de quilogramas de bezerros por quilograma de vaca mantida. O IMC alto propicia maior produção de leite sem que a qualidade seja alterada e bezerros mais pesados no desmame precoce e no peso aos 210 dias.(AU)

Evaluation of different silvicultural management techniques and water seasonality on yield of eucalyptus stands

Appropriate management of factors that influence forest development is essential to increase yield of forest plantations. The objective of this study was to evaluate the influence of water seasonality, nutritional management, and uniformity on yield of eucalyptus plantations and estimate the potential, attainable, and observed yield of adult eucalyptus stands. We evaluated Eucalyptus clonal stands in six regions of Minas Gerais State, Brazil, in a system of first and second rotation across four age classes using the twin-plots method (TP). In the study, 142 TPs were allocated alongside 142 plots in a continuous forest inventory (CFI) network of a private enterprise. The CFI received operational fertilization and additional fertilization was carried out in the TP. The trees were measured at the beginning of the experiment and at every six months to quantify the production in the wet (PW) and dry (PD) periods of the year. Uniformity of plantations was evaluated using Pvar 50 % and the optimal uniformity index. Potential, attainable, and observed yields were estimated using the average annual increase at seven years of age. The PW showed higher plant yield. There was an effect due to water availability and nutrient level on the yield of the stands. The driest semester of the year produces approximately 30 % of the current annual increase. The stands under the second rotation tend to have less uniformity than the in the first rotation. Potential yield varied depending on rainfall intensity where wetter regions had the highest yield.

Evaluation of different silvicultural management techniques and water seasonality on yield of eucalyptus stands

Appropriate management of factors that influence forest development is essential to increase yield of forest plantations. The objective of this study was to evaluate the influence of water seasonality, nutritional management, and uniformity on yield of eucalyptus plantations and estimate the potential, attainable, and observed yield of adult eucalyptus stands. We evaluated Eucalyptus clonal stands in six regions of Minas Gerais State, Brazil, in a system of first and second rotation across four age classes using the twin-plots method (TP). In the study, 142 TPs were allocated alongside 142 plots in a continuous forest inventory (CFI) network of a private enterprise. The CFI received operational fertilization and additional fertilization was carried out in the TP. The trees were measured at the beginning of the experiment and at every six months to quantify the production in the wet (PW) and dry (PD) periods of the year. Uniformity of plantations was evaluated using Pvar 50 % and the optimal uniformity index. Potential, attainable, and observed yields were estimated using the average annual increase at seven years of age. The PW showed higher plant yield. There was an effect due to water availability and nutrient level on the yield of the stands. The driest semester of the year produces approximately 30 % of the current annual increase. The stands under the second rotation tend to have less uniformity than the in the first rotation. Potential yield varied depending on rainfall intensity where wetter regions had the highest yield.

Reproduction phenology of a high conservation priority cracid - the Bare-faced Curassow (Crax fasciolata; Aves, Galliformes, Cracidae)

Knowledge of the reproductive biology of Bare-faced Curassows (BFC) from their natural habitats is very limited. Our study covers a two-and-a-half year breeding phenology on BFC in the northern Pantanal (Mato Grosso State, Brazil) with the main objective of collecting information on reproduction biology to contribute to future conservation management strategies of this cracid, which received a recent status of "High Conservation Priority". The study was conducted at the SESC Pantanal, Baía das Pedras, Mato Grosso, Brazil (16°29′55″S, 56°24′46″W), a private protected area of approximately 4,200 ha. Between July 2015 and December 2017, 37 sampling locations were monitored with camera traps placed in a regular grid with a spacing of 1 km. Offspring were detected at least once at 8 locations, namely, in March, April, and May 2016 and in June, July, October, and November 2017, always together with parent(s). Territorial overlap between different family groups was detected. The camera trap dataset was supplemented by data from Citizen Science Projects (i.e., eBird) and the Global Biodiversity Information Facility (GBIF). Based on feather developmental stages and body size, offspring were classified into different age classes. Age determination indicates that breeding occurs year-round in the northern Pantanal region, supported by eBird and GBIF data. The use of a grid-based design for future camera-trapping studies of BFCs is strongly recommended. Our study is of biological relevance for conservation management projects since data were collected in an area with low anthropogenic disturbance and intact ecosystem services.(AU)

Relationships between antral follicle counts and ovarian morphology of Bos indicus of different ages / Relações entre a contagem de folículos antrais e a morfologia ovariana de Bos indicus de diferentes idades

This study aimed to evaluate the relationship between the antral follicle count (AFC) and the ovarian morphology of Bos indicus in different age groups: 12-23 months (G1), 24-35 months (G2), 36-47 months (G3), 48-59 months (G4), and >60 months (G5). Ovaries were collected individually and sent to the laboratory, where we measured AFC, the diameter and weight of the ovaries, dominant follicle (DF, >8mm), corpus luteum (CL), and small follicles (SF, <8mm). AFC were classified as high, intermediate-high, intermediate-low, and low. A group of ovaries was subjected to follicular aspiration to evaluate the morphological quality of the recovered cumulus oocyte complexes (COCs). Mean AFC did not vary between ages. The morphological characteristic that was most closely correlated with AFC was the weight of the small follicles. There was no relationship between AFC and the weight and diameter of the DF and CL. Quality of the COCs was superior in ovaries in which the CL was present, but it did not vary between the AFC classes. We conclude that AFC can be performed on a single ovary, regardless of the presence, diameter, and weight of the CL and DF in zebu between 12 and 60 months old.

O presente estudo teve como objetivo avaliar a relação entre a contagem de folículos antrais (CFA) e a morfologia ovariana de Bos indicus em diferentes faixas etárias: 12-23 meses (G1), 24-35 meses (G2), 36-47 meses (G3), 48-59 meses (G4) e >60 meses (G5). Os ovários foram coletados individualmente e enviados ao laboratório, onde suas características morfológicas foram medidas: CFA, diâmetro e peso dos ovários, do folículo dominante (FD, ≥8 mm), do corpo lúteo (CL) e dos folículos pequenos (SF, <8 mm). A CFA foi classificada como alta, intermediária-alta, intermediária-baixa e baixa. Um grupo de ovários foi submetido à aspiração folicular para avaliar a qualidade morfológica dos complexos cumulus oócitos (COCs) recuperados. A CFA média não variou entre as idades. A característica morfológica que se correlacionou mais intimamente com a CFA foi o peso dos folículos pequenos. Não houve relação entre a CFA e o peso e o diâmetro do FD e do CL. A qualidade dos COCs foi superior em ovários em que o CL estava presente, mas não variou entre as classes de CFA. Concluiu-se que a CFA pode ser realizada em um único ovário, independentemente da presença, do diâmetro e do peso do CL e do FD em zebuínos entre 12 e 60 meses de vida.

Gastrointestinal parasites of Leontopithecus chrysomelas in the Atlantic Forest, Brazil / Parasitas gastrintestinais de Leontopithecus chrysomelas na Floresta Atlântica, Brasil

Abstract We performed coproparasitological testing of free-living golden-headed lion tamarins, Leontopithecus chrysomelas, using the Hoffmann-Pons-Janner method. In total, we collected 118 samples from ten groups: four living in Federal Protected Area and six living in Non-Protected Areas of cocoa farms. Eggs from parasites of the Acanthocephala phylum and Spiruridae, Ancylostomatidae, Ascarididae and Oxyuridae families were identified, as well as the genus Strongyloides (Nematode: Strongyloididae) and phylum Apicomplexa. This is the first description of infection with coccidian, Trichuridae family and Strongyloides spp. in L. chrysomelas. A total of 48% (n= 57) of the animals were infected and the highest prevalence (37.2±SD 8.72, n = 44) was for Acanthocephalidae, followed by Spiruridae (8.5±SD 5.03, n = 10). There was no difference in parasite prevalence by age classes or sex. However, we found higher diversity and prevalence of parasites in animals living in the Federal Protected Area. These results suggest that intestinal parasites may be influenced by environmental factors, such as the management of the areas where the animals live, in addition to the feeding behavior of L. chrysomelas and distinct transmission strategies of parasites. The combination of ecological and demographic data combined with parasitological studies may contribute to conservation programs for this species.

Resumo Foram realizados testes coproparasitológicos de micos-leões-dourados de vida livre, Leontopithecus chrysomelas, usando-se o método de Hoffmann-Pons-Janner. No total, foram coletadas 118 amostras de dez grupos: quatro grupos residentes em Área de Conservação Federal e seis grupos em Área não protegida de fazendas de cacau. Ovos de parasitas do filo Acantocephala e das famílias Spiruridae, Ancylostomatidae, Ascarididae, Oxyuridae foram identificados, bem como o gênero Strongyloides (Nematoda: Strongyloididae) e o filo Apicomplexa. Esta é a primeira descrição de infecção de coccídeos, família Trichuridae e Strongyloides spp. em L. chrysomelas. Um total de 48% (n = 57) dos animais estavam parasitados e a maior prevalência (37,2 ±DP 8,72, n = 44) foi para Acanthocephalan, seguido por Spiruridae (8,5±DP 5,03, n = 10). Não houve diferença na prevalência do táxon de parasita por idade ou sexo. No entanto, foi encontrada maior diversidade e prevalência de parasitas em animais que vivem na Unidade de Conservação Federal. Esses resultados sugerem que os parasitas intestinais podem ser influenciados por fatores ambientais, como o manejo das áreas, além do comportamento alimentar de L. chrysomelas e distintas estratégias de transmissão dos parasitas. A combinação de dados ecológicos e demográficos com estudos parasitológicos podem contribuir para programas de conservação dessa espécie.

Adjustments in population and reproductive dynamics of native and non-native congeneric species during 26 years after invasion

We aimed to improve the understanding of the establishment of Serrasalmus marginatus (non-native), which was followed by a decrease in the abundance of Serrasalmus maculatus (native) in the upper Paraná River floodplain. We estimated age, mortality rate, length and age at first maturity and variations in gonad development in three time-periods along a 26-year truncated time scale for both species. Population and reproduction parameters of both species showed substantial fluctuations among periods. Most age classes were sampled in all time-periods, but with considerable difference in abundance, with predominance of older individuals in the second time-period and younger individuals in the third time-period for both species. The mortality rates decreased for both species in the second time-period, but increased for the native in the third time-period. Length and age at first maturity decreased in the second time-period for both species, increasing the number of mature individuals on their populations. In the third time-period, the number of immature individuals increased for both species. We suggest that species experienced stressful conditions during cooccurrence and this have resulted in physiological responses in both species, reflecting in population and reproductive adjustments that may have relaxed competitive interactions between them, optimizing survival, reproductive effort and coexistence.(AU)

Nosso objetivo foi aumentar o conhecimento sobre o estabelecimento de Serrasalmus marginatus (não nativa), que foi seguido pela diminuição na abundância de Serrasalmus maculatus (nativa) na planície de inundação do alto rio Paraná. Estimamos a idade, taxa de mortalidade, comprimento e idade de primeira maturação e variações no desenvolvimento gonadal em três períodos ao longo de 26 anos para as espécies. Os parâmetros populacionais e de reprodução das espécies mostraram flutuações substanciais. A maioria das faixas etárias foi amostrada em todos os períodos, mas com diferenças consideráveis na abundância, predominando indivíduos mais velhos no segundo período e indivíduos mais jovens no terceiro período para ambas as espécies. A taxa de mortalidade diminuiu para as espécies no segundo período, mas aumentou para a espécie nativa no terceiro período. O comprimento e a idade de primeira maturação diminuíram no segundo período para as espécies, aumentando o número de indivíduos adultos. No terceiro período, o número de indivíduos imaturos aumentou para ambas as espécies. Sugerimos que as espécies passaram por condições estressantes durante a coocorrência, resultando em respostas fisiológicas que desencadearam ajustes populacionais e reprodutivos que podem ter minimizado a interação competitiva entre elas, otimizando a sobrevivência, o esforço reprodutivo e a coexistência.(AU)

Adjustments in population and reproductive dynamics of native and non-native congeneric species during 26 years after invasion

We aimed to improve the understanding of the establishment of Serrasalmus marginatus (non-native), which was followed by a decrease in the abundance of Serrasalmus maculatus (native) in the upper Paraná River floodplain. We estimated age, mortality rate, length and age at first maturity and variations in gonad development in three time-periods along a 26-year truncated time scale for both species. Population and reproduction parameters of both species showed substantial fluctuations among periods. Most age classes were sampled in all time-periods, but with considerable difference in abundance, with predominance of older individuals in the second time-period and younger individuals in the third time-period for both species. The mortality rates decreased for both species in the second time-period, but increased for the native in the third time-period. Length and age at first maturity decreased in the second time-period for both species, increasing the number of mature individuals on their populations. In the third time-period, the number of immature individuals increased for both species. We suggest that species experienced stressful conditions during cooccurrence and this have resulted in physiological responses in both species, reflecting in population and reproductive adjustments that may have relaxed competitive interactions between them, optimizing survival, reproductive effort and coexistence.(AU)

Nosso objetivo foi aumentar o conhecimento sobre o estabelecimento de Serrasalmus marginatus (não nativa), que foi seguido pela diminuição na abundância de Serrasalmus maculatus (nativa) na planície de inundação do alto rio Paraná. Estimamos a idade, taxa de mortalidade, comprimento e idade de primeira maturação e variações no desenvolvimento gonadal em três períodos ao longo de 26 anos para as espécies. Os parâmetros populacionais e de reprodução das espécies mostraram flutuações substanciais. A maioria das faixas etárias foi amostrada em todos os períodos, mas com diferenças consideráveis na abundância, predominando indivíduos mais velhos no segundo período e indivíduos mais jovens no terceiro período para ambas as espécies. A taxa de mortalidade diminuiu para as espécies no segundo período, mas aumentou para a espécie nativa no terceiro período. O comprimento e a idade de primeira maturação diminuíram no segundo período para as espécies, aumentando o número de indivíduos adultos. No terceiro período, o número de indivíduos imaturos aumentou para ambas as espécies. Sugerimos que as espécies passaram por condições estressantes durante a coocorrência, resultando em respostas fisiológicas que desencadearam ajustes populacionais e reprodutivos que podem ter minimizado a interação competitiva entre elas, otimizando a sobrevivência, o esforço reprodutivo e a coexistência.(AU)

Ontogenetic skull variation in an Amazonian population of lowland tapir, Tapirus terrestris (Mammalia: Perissodactyla) in the department of Loreto, Peru

RESUMEN Se midió, analizó y comparó 54 cráneos de tapir sudamericano, Tapirus terrestris recolectados en el departamento de Loreto, Perú, para investigar el desarrollo craneal de esta especie. Se realizaron análisis univariados, multivariados y alométricos de los cráneos utilizando 32 variables mediante morfometría tradicional. Se detectó una variación significativa de la forma del cráneo entre clases ontogenéticas. Los individuos más jóvenes (clase I, n = 22) mostraron mayor variación que subadultos y adultos (clases II, n = 23 y III, n = 9), pero sin evidencia de dimorfismo sexual (machos = 35, hembras = 19). Un análisis de componentes principales y un análisis de función discriminante mostraron una separación casi completa de las clases ontogenéticas. El análisis alométrico indicó una tendencia de crecimiento craneal desproporcionado. Todas nuestras muestras provienen de la misma población que vive bajo la misma condición ecológica, lo que elimina el efecto de confusión de variables relacionadas con el hábitat sobre el patrón de variaciones ontogenéticas de esta estructura anatómica.

ABSTRACT The skulls of 54 specimens of the South American tapir, Tapirus terrestris collected in the department of Loreto, Peru were measured, analyzed and compared to investigate skull development of this species. Univariate, multivariate and allometric analyses were performed using 32 skull variables through traditional morphometrics. Significant skull shape variation was detected among ontogenetic classes. Young individuals (class I, n = 22) showed higher variation than subadults and adults (class II, n = 23 and class III, n = 9), without evidence of sexual dimorphism (males = 35, females = 19). Principal component analyses and discriminant function analysis showed almost complete separation of the age classes. Allometric analysis indicated a tendency of unproportioned cranial growth. All our samples come from the same population living under the same ecological condition, which eliminates the effect of confounding variables related to habitat on the pattern of ontogenetic variation of this anatomical structure.

Ontogenetic skull variation in an Amazonian population of lowland tapir, Tapirus terrestris (Mammalia: Perissodactyla) in the department of Loreto, Peru / Variación ontogenética de cráneos en una población amazónica del tapirsudamericano, Tapirus terrestris (Mammalia: Perissodactyla) en Loreto, Perú

The skulls of 54 specimens of the South American tapir, Tapirus terrestris collected in the department of Loreto, Peru were measured, analyzed and compared to investigate skull development of this species. Univariate, multivariate and allometric analyses were performed using 32 skull variables through traditional morphometrics. Significant skull shape variation was detected among ontogenetic classes. Young individuals (class I, n = 22) showed higher variation than subadults and adults (class II, n = 23 and class III, n = 9), without evidence of sexual dimorphism (males = 35, females = 19). Principal component analyses and discriminant function analysis showed almost complete separation of the age classes. Allometric analysis indicated a tendency of unproportioned cranial growth. All our samples come from the same population living under the same ecological condition, which eliminates the effect of confounding variables related to habitat on the pattern of ontogenetic variation of this anatomical structure.

Se midió, analizó y comparó 54 cráneos de tapir sudamericano, Tapirus terrestris recolectados en el departamento de Loreto, Perú, para investigar el desarrollo craneal de esta especie. Se realizaron análisis univariados, multivariados y alométricos de los cráneos utilizando 32 variables mediante morfometría tradicional. Se detectó una variación significativa de la forma del cráneo entre clases ontogenéticas. Los individuos más jóvenes (clase I, n = 22) mostraron mayor variación que subadultos y adultos (clases II, n = 23 y III, n = 9), pero sin evidencia de dimorfismo sexual (machos = 35, hembras = 19). Un análisis de componentes principales y un análisis de función discriminante mostraron una separación casi completa de las clases ontogenéticas. El análisis alométrico indicó una tendencia de crecimiento craneal desproporcionado. Todas nuestras muestras provienen de la misma población que vive bajo la misma condición ecológica, lo que elimina el efecto de confusión de variables relacionadas con el hábitat sobre el patrón de variaciones ontogenéticas de esta estructura anatómica.

Ontogenetic skull variation in an Amazonian population of lowland tapir, Tapirus terrestris (Mammalia: Perissodactyla) in the department of Loreto, Peru / Variación ontogenética de cráneos en una población amazónica del tapirsudamericano, Tapirus terrestris (Mammalia: Perissodactyla) en Loreto, Perú

The skulls of 54 specimens of the South American tapir, Tapirus terrestris collected in the department of Loreto, Peru were measured, analyzed and compared to investigate skull development of this species. Univariate, multivariate and allometric analyses were performed using 32 skull variables through traditional morphometrics. Significant skull shape variation was detected among ontogenetic classes. Young individuals (class I, n = 22) showed higher variation than subadults and adults (class II, n = 23 and class III, n = 9), without evidence of sexual dimorphism (males = 35, females = 19). Principal component analyses and discriminant function analysis showed almost complete separation of the age classes. Allometric analysis indicated a tendency of unproportioned cranial growth. All our samples come from the same population living under the same ecological condition, which eliminates the effect of confounding variables related to habitat on the pattern of ontogenetic variation of this anatomical structure.(AU)

Se midió, analizó y comparó 54 cráneos de tapir sudamericano, Tapirus terrestris recolectados en el departamento de Loreto, Perú, para investigar el desarrollo craneal de esta especie. Se realizaron análisis univariados, multivariados y alométricos de los cráneos utilizando 32 variables mediante morfometría tradicional. Se detectó una variación significativa de la forma del cráneo entre clases ontogenéticas. Los individuos más jóvenes (clase I, n = 22) mostraron mayor variación que subadultos y adultos (clases II, n = 23 y III, n = 9), pero sin evidencia de dimorfismo sexual (machos = 35, hembras = 19). Un análisis de componentes principales y un análisis de función discriminante mostraron una separación casi completa de las clases ontogenéticas. El análisis alométrico indicó una tendencia de crecimiento craneal desproporcionado. Todas nuestras muestras provienen de la misma población que vive bajo la misma condición ecológica, lo que elimina el efecto de confusión de variables relacionadas con el hábitat sobre el patrón de variaciones ontogenéticas de esta estructura anatómica.(AU)

Using osteological measurements to estimate body length in Amazonian manatees / Utilização de medidas osteológicas para estimativa de comprimento corporal em peixe-boi da Amazônia

Body length is an important parameter in morphological, ecological and behavioral studies of a species and contributes to the understanding of the body condition of individuals. This parameter is essential for conservation and management strategies by informing studies evaluating growth rates, physical maturity and classification of individuals into age groups, promoting better accuracy for the biological parameters of the species. The aim of this study was to identify predictors of body length for Amazonian manatees (Trichechus inunguis) using metric characters of osteological materials. Eleven linear measurements of skull, jaw, scapulae and humeri were collected from 41 Amazonian manatee skeletons of different age classes (calf, juvenile and adult). Data were analyzed by simple linear regression. The condylobasal length was the best predictor of body length for the species (R = 0.943), however, all bones evaluated showed at least one measurement with the capacity to predict body size (R2 > 0.9). Results of this study are useful for inferring body length of Amazonian manatees using bones deposited in museums and biological collections, expanding the informative potential of these materials.(AU)

O comprimento corporal é um importante parâmetro em estudos morfológicos, ecológicos e comportamentais de uma espécie e contribui para o entendimento da condição corporal de um indivíduo. Este parâmetro é essencial para estratégias de conservação e manejo, informando estudos que avaliam taxas de crescimento, maturidade física e classificação dos indivíduos em grupos de idade, promovendo uma melhor precisão aos parâmetros biológicos de uma espécie. O objetivo desse trabalho foi identificar preditores de comprimento corporal para o peixe-boi da Amazônia (Trichechus inunguis) utilizando caracteres métricos de material osteológico. Onze medidas lineares do crânio, mandíbula, escápula e úmero foram coletadas de 41 esqueletos de peixe-boi da Amazônia de diferentes classes de idade (filhote, juvenil e adulto). Os dados foram analisados por regressão linear simples. O comprimento côndilobasal foi o melhor preditor de comprimento corporal para a espécie (R = 0,943), entretanto, todos os ossos avaliados mostraram pelo menos um caractere com capacidade de predizer o comprimento corporal (R2 > 0,9). Os resultados deste estudo são úteis para inferir o comprimento corporal de peixes-boi da Amazônia a partir de ossos depositados em museus e coleções biológicas, expandindo o potencial informativo destes materiais.(AU)

Covariance functions under B-spline polynomials to model Polled Nellore cattle growth / Funções de covariâncias sob polinômios B-splines para modelagem do crescimento de bovinos Nelore Mocho

B-spline functions have been used in random regression models (RRM) to model animal weight from birth to adulthood because they are less vulnerable to common difficulties of other methods. However, its application to model growth traits of Polled Nellore cattle has been little studied. Therefore, this study aimed to evaluate polynomial functions of different orders and segment numbers to model effects associated with the Polled Nellore cattle growth curve. For this purpose, we used 15,148 weight records of 3,115 animals aged between 1 and 660 days and reared in northern Brazil and born between 1995 and 2010. Random effects were modeled using B-spline polynomials. As random effects, we considered the direct and maternal genetic additives, as well as direct and maternal permanent environments. As fixed effects were included contemporary group, cow age at calving (linear and quadratic) and fourth-order Legendre polynomials to represent average growth curve. The residue was modeled by considering seven age classes. The bestfitted model was the one that considered cubic B-spline functions with four knots for direct additive genetic effects and three knots for maternal genetic, animal permanent environment, and maternal permanent environment effects (C6555). Therefore, covariance functions under B-spline polynomials are efficient and can be used to model the growth curve of Polled Nellore cattle from birth to 660 days of age.(AU)

Os modelos de regressão aleatória (MRA) aplicando funções B-spline são uma alternativa para modelar pesos do nascimento até a idade adulta dos animais, pois estas funções são menos vulneráveis as dificuldades constantemente observadas em outras metodologias. No entanto, são escassas pesquisas sobre aplicação destas funções sobre as características de crescimento em bovinos Nelore Mocho. Funções polinomiais de diferentes ordens e números de segmentos foram avaliadas na modelagem dos efeitos associados à curva de crescimento de bovinos da raça Nelore Mocho. Foram utilizados 15.148 registros de peso de 3.115 animais com idade entre 1 e 660 dias, criados na região norte do Brasil e nascidos entre 1995 e 2010. Os efeitos aleatórios foram modelados usando polinômios do tipo B-splines. Como efeitos aleatórios, foram considerados os efeitos genéticos aditivo direto e materno e os efeitos de ambientes permanentes direto e materno. Foram considerados como efeitos fixos, os grupos de contemporâneos, a idade da vaca ao parto (efeito linear e quadrático) e os polinômios de Legendre de quarta ordem, representando a curva média de crescimento. O resíduo foi modelado por meio de sete classes distribuídas segundo a idade. O modelo que considerou funções B-splines cúbicas com quatro nós para o efeito genético aditivo direto e três nós para os efeitos genético materno, ambiente permanente animal e ambiente permanente materno (C6555) foi o mais adequado. Concluiu-se que funções de covariâncias sob polinômios B-splines são eficientes e podem ser utilizados como alternativas para modelar a curva de crescimento de bovinos da raça Nelore Mocho do nascimento até 660 dias de idade.(AU)

Growth curve for height at withers and body length of Mangalarga Marchador horses / Curva de crescimento em altura na cernelha e comprimento corporal de equinos Mangalarga Marchador

This study aimed to evaluate the logistic and quadratic response plateau models to describe the growth of Mangalarga Marchador horses to identify the model that best describes growth for the variables height at withers and body length. Data were used from 230 horses aged 6 to 176 months, divided by sex and 16 age classes. All computational work was performed using R statistical software. The logistic model was the best suited to express growth in height at withers and body length of male and female Mangalarga Marchadors aged 6 to 176 months. This allowed creating a table of reference values for these measurements over time based on the confidence interval of the model parameters. Estimates of height at withers obtained by the logistic model ranged from 144 to 154 cm in adult males and from 143 to 151 cm in adult females. For body length, values ranged from 146 to 156 cm in adult males and 143 to 156 cm in adult females. Females achieved stability in both height at withers and body length at earlier ages than did males.(AU)

O objetivo deste estudo foi avaliar os modelos logístico e platô de resposta quadrática na descrição do crescimento de equinos da raça Mangalarga Marchador identificando o que melhor descreve o crescimento das variáveis altura de cernelha e comprimento corporal. Foram utilizados dados de 230 equinos de 6 a 176 meses de idade que foram divididos por sexo e em 16 classes de idade. Toda a parte computacional envolvida foi realizada utilizando-se o software estatístico R. O modelo logístico foi o mais indicado para expressar o crescimento em altura na cernelha e comprimento corporal de machos e fêmeas da raça Mangalarga Marchador. Foi criada uma tabela de valores referência para estas medidas ao longo da idade com base no intervalo de confiança dos parâmetros deste modelo. Estimativas das alturas de cernelha adultas obtidas pelo modelo logístico variaram de 144 a 154 cm nos machos e de 143 a 151 cm para fêmeas. Já em comprimento corporal os valores adultos variaram de 146 a 156 cm nos machos e 143 a 156 cm para fêmeas. As fêmeas apresentam maior precocidade do que os machos para atingir a estabilidade em ambas variáveis estudadas.(AU)

The lizard that never sleeps: activity of the pampa marked gecko Homonota uruguayensis

RESUMEN La suposición general ha sido que los lagartos son activos cuando las condiciones climáticas son favorables. Homonota uruguayensis (Vaz-Ferreira & Sierra de Soriano, 1961) es la única lagartija nativa - y la lagartija nocturna - que vive en el norte de bioma Pampa. La ecología de esta especie es poco conocida y este estudio tuvo como objetivo describir su patrón de actividad diaria y anual y su relación con las temperaturas ambientales. El estudio se llevó a cabo en el extremo sur de Brasil (Rosário do Sul, Rio Grande do Sul), a partir de mayo 2010 - enero 2011, en un afloramiento rocoso situado en el bioma Pampa. El estudio totalizó cuatro excursiones de campo estacionales y 1185 horas. Los datos fueron recogidos a lo largo de los turnos de 6 horas durante el día y la noche. El área fue recorrida aleatoriamente en cada turno siempre registrandose la actividad y el microhabitat utilizado por los lagartos. A lo largo del estudio, 1541 especímenes se registraron. Homonota uruguayensis presentó hábito diurno y nocturno en las cuatro estaciones, con períodos de actividad diaria variando significativamente entre todas las estaciones en forma cíclica y multimodal, no se observó relación significativa con las temperaturas ambientales. No fue constatada diferencia entre los sexos con relación a la actividad y las clases de edad. La mayoría de los lagartos activos fue encontrada a temperaturas del aire que variaron de 14 °C a 32,9 °C (82% de lagartos activos) y a temperaturas del sustrato entre 10 °C y 32,9 °C (87% de lagartos activos).

ABSTRACT It is generally assumed that lizards are active whenever climatic conditions are favorable. Homonota uruguayensis (Vaz-Ferreira & Sierra de Soriano, 1961) is the only native gecko - and nocturnal lizard - living in the northern Pampa biome, and its ecology is poorly known. This study aimed at describing this species pattern of daily and annual activity and its relation with environmental temperatures. The study was conducted in the extreme south of Brazil (Rosário do Sul, State of Rio Grande do Sul), between May 2010 and January 2011 at a rocky outcrop located in the Pampa biome. The study was carried out in a total of four seasonal field trips, totalizing 1185 hours of field work. The data were collected, both during the day and the night in 6-hour shifts (duration of the sampling period). The area was randomly covered at each shift to record activity and microhabitat use by the lizards. In total 1541 specimens were recorded throughout the study. Homonota uruguayensis showed diurnal and nocturnal activity in the four seasons, with periods of daily activity varying significantly between all seasons in a cyclic and multimodal pattern, with no significant relation with environmental temperatures. There was no difference in activity related to sex and age classes. Most active lizards were found when air temperatures ranged from 14 °C to 32.9 °C (82% of active lizards) and substrate temperatures ranged from 10 °C to 32.9 °C (87% of active lizards).

Desempenho de novilhos nelore castrados e não-castrados sob pastejo em Brachiaria humidicola (Rendle) Schweick (Poaceae) exclusiva e em consórcio com amendoim forrageiro / Performance of nelore steers and bulls grazing exclusive Brachiaria humidicola (Rendle) Schweick (Poaceae) and intercropped with forage peanut

This study aimed to assess the performance of intact and castrated beef cattle on the pasture of Brachiaria humidicola alone and intercropped with Arachis pintoi cv. BRS Mandobi. The experiment was carried out from February to June 2016 on the private property of a partner of Embrapa Acre. The experimental design was completely randomized in a 2×2 factorial arrangement, with two sex classes (intact and castrated) and two types of pasture (alone and intercropped). The leaf to stem ratio was high (P<0.05) in the pasture alone. No significant difference was found for stocking rates. Dry matter intake was high (P<0.05) in the intercropped pasture compared to that alone, with means of 8.96 and 6.66 kg/ day, respectively. Animals managed in intercropped pastures had better performance (P<0.05) than those castrated under pasture alone. Nelore steers castrated at 20 months of age, managed under intercropped pastures, showed similar productive performance (P>0.05) to intact animals.(AU)

O objetivo deste trabalho foi avaliar o desempenho de bovinos de corte castrados e não castrados em pasto exclusivo de Brachiaria humidicola e consorciado Arachis pintoi cv. BRS Mandobi. O experimento foi conduzido em propriedade particular de produtor parceiro da Embrapa Acre, de fevereiro a junho de 2016. O delineamento experimental foi inteiramente casualizado, em arranjo fatorial 2x2, sendo duas classes sexuais (castrados e não-castrados) e dois tipos de pasto (exclusivo e consorciado). A relação folha/ caule foi superior (P<0,05) no pasto exclusivo. Não houve diferença significativa para as taxas de lotação. O consumo de matéria seca foi superior (P<0,05) no pasto consorciado em relação ao exclusivo, com médias de 8,96 e 6,66 kg/ dia, respectivamente. Os animais manejados nos pastos consorciados tiveram desempenho superior (P<0,05) aos castrados do pasto exclusivo. Novilhos Nelore castrados aos 20 meses de idade, manejados em pastos consorciados, apresentam desempenho produtivo similar (P>0,05) a animais não castrados.(AU)

Fitting of fixed regression curves with different residual variance structures for Nellore cattle growth modeling / Ajuste da curva fixa da regressão sob estruturas de variância residual para modelagem de crescimento de bovinos Nelore

Different polynomial functions were tested for mean trajectory modeling with different residual variance structures. A total of 15,148 weight records of 3,115 Nellore Mocho cattle with ages between 1 and 660 days, raised in northern Brazil. First, the mean trajectory of cattle growth curve was fitted by a fixed regression using orthogonal polynomials with orders ranging from two to seven. Analyses were performed using the least-squares method, disregarding animal and/ or maternal random effects. Then, the best model was evaluated using different residual variance structures and homogeneous and heterogeneous classes. We considered as fixed effects those of groups of contemporary and of dam age at birth (as linear and quadratic covariate). The random model part included animal and maternal effects (direct genetic and permanent environments). We concluded that the estimates of variance components and genetic parameters were affected by both fixed regression curve polynomial order and residual variance structure. Moreover, random regression model considering an order-four polynomial function with a fixed curve and six-class residual variance showed better fits.(AU)

Diferentes funções polinomiais foram avaliadas para a modelagem da trajetória média de crescimento sob diferentes estruturas de variância residual. Utilizaram-se 15.148 registros de pesos de 3.115 bovinos da raça Nelore Mocho com idade entre 1 e 660 dias, criados na região Norte do Brasil. Inicialmente, a trajetória média da população foi ajustada por uma regressão fixa sob polinômios ortogonais da idade com ordens variando de dois a sete. Estas análises foram executadas por meio do método de quadrados mínimos ordinários, desconsiderando os efeitos aleatórios do animal e materno. Posteriormente, o melhor modelo foi avaliado sob diferentes estruturas de variância residual por meio de classes homogêneas e heterogêneas. Os efeitos fixos considerados foram os de grupos de contemporâneos e a idade da mãe ao parto (como covariável linear e quadrática). Na parte aleatória do modelo incluiu-se os efeitos do animal e materno (genéticos diretos e ambientes permanentes). Concluiu-se que as estimativas de componentes de variância e parâmetros genéticos foram afetados tanto pela ordem polinomial da curva de regressão fixa, como pela estrutura da variância residual, e o modelo de regressão aleatória que considerou uma função polinomial de ordem quatro na curva fixa e seis classes de variâncias residuais apresentou o melhor ajuste.(AU)