ResumoObjetivou-se neste trabalho analisar os componentes de eficiência reprodutiva, expressos pelas características, intervalo do primeiro para o segundo parto (IEP), número de serviços por concepção para o primeiro parto (NSC1), número de serviços por concepção para o segundo parto (NSC2), período de serviço (PS) e período de gestação (PG), além da idade ao primeiro parto (IPP) e desenvolvimento ponderal até os 15 meses de idade. Foram utilizados dados de 377 novilhas, de dois rebanhos, sendo um em Santa Cruz do Rio Pardo, São Paulo e outro em Rolândia, Paraná. O modelo estatístico para IEP, NSC1, NSC2, PS e PG incluiu o efeito fixo de Grupo de Contemporâneas (GC). Para analisar PG, além de GC, foi também considerado o efeito de sexo da cria. Para avaliar o peso corrigido para 458 dias (P458), ganho médio diário do nascimento aos 15 meses (GMD) e IPP de 360 novilhas do rebanho pertencente à propriedade em Rolândia, foi utilizado um modelo fixo com efeito de GC. Para avaliar IPP foi utilizado GMD como covariável, além do efeito fixo de GC. As médias estimadas para IEP, NSC1, NSC2, PS e PG, foram respectivamente 14,96 ± 3,94 meses; 1,35 ± 0,71 serviços, 2,86 ± 2,37 serviços; 178,83 ± 118,73 dias; 276,67± 5,65 dias. Foram verificadas correlações entre as variáveis IEP e NSC2 de 72% (P<0,0001), entre IEP e PS de 98% (P<0,0001) e entre NSC2 e PS de 72% (P<0,0001). A duração da gestação de machos e fêmeas apresentaram médias estimadas de 277,53 ± 0,46 dias e 276,33 ± 0,40 dias, respectivamente, sendo o sexo da cria fonte de variação sobre PG (P<0,05). GC afetou IPP, P458 e GMD. A média estimada para IPP foi 24,18 ± 1,59 meses, para P458 foi 362,33 ± 36,24 kg e para GMD foi 0,704 ± 0,08 kg. Palavras-chave: Ganho médio diário, grupo de contemporâneas, intervalo entre partos, número de serviços por concepção, período de gestação, período de serviço AbstractThe objective of this study was to verify the reproductive efficiency expressed by traits, interval from first to second calving (IDP), number of services per conception to the first calving (NSC1), number of services per conception for the second calving (NSC2), service period from the first to the second calving (PS) and gestation lenght (PG) of Holstein heifers. Data from 377 heifers from two herds, one in Santa Cruz do Rio Pardo, São Paulo and another in Rolândia, Paraná were analysed. The statistical

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The aim of this study was to evaluate the interrelation among growth traits in Santa Inês lambs using principal component analysis. Data on 270 lambs born between 2008 and 2013 were used. The variables studied were weight at birth,adjusted weight from birth to weaning, and average daily gains at 14, 28, 52, and 70 days of age. The wither height, thoracic perimeter, and length at birth and adjusted at 28 and 70 days of age (weaning), were also used. The statistical model comprised the fixed effects of the contemporary group, the linear effect of julian date at birth, and the linear and quadratic effects of lambing weight. The first principal component explained approximately 89% and 85% of the total variation for body weight at different ages and average daily gains, respectively. The second principal component compared heavier animals or those that gained more weight at 14 days with lighter lambs or those that gained less weight at 14 days of age and explains the variation of approximately 5% and 10%, respectively, among the animals. The first principal component accounted for 77%, 91%, and 77% of the variation for weight, thoracic perimeter, wither height, and length at birth, 28 days, and 70 days of age, respectively, and compared large animals or animals with greater body volume. The second component, with values of 16%, 6%, and 14% of the total variation at the three ages, respectively, compared animals with distinct conformation to discriminate animals of different shapes and verified that the weights at the different ages and the thoracic perimeter are important sources of variability among the animals.

We aimed to evaluate environmental effects on pre-weaning traits of Santa Gertrudis cattle. We used 213 standardized records for adjusted 205-day weight at weaning (W205), average daily gain from birth to weaning (AGD), and number of days to gain 160 kg from birth to weaning (D160), obtained from the Santa Gertrudis Breeders' Association for animals born between 1990 and 1997. The files were edited with information regarding cow age at calving (CAC) and contemporary group (CG), for which the effects of year and season of birth, animal category, herd, and sex were considered. It was observed that cow age at calving, which had linear and quadratic effects, and effect of contemporary group were significant (P < 0.0001) for the evaluated traits. Estimated averages were 198.05 ± 40.64 kg, 0.790 ± 0.198 kg day-1, and 288.05 ± 67.18 days for W205, ADG, and D160, respectively. Males were 4.67 kg heavier (197.17 kg) than females, on average. Regarding the animal category effect, the classified females were 2.3% heavier than the unclassified, on average. On average, animals born in the dry season were 1.6% lighter than those born in the rainy season (197.18 kg). Thus, environmental effects are important and should be considered in any analysis model.

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The objective of this work was to study the influence of environmental effects, sex of the lamb, type of birth, year of birth, birth season, julian birth date, and lambing weight on the weights and biometric measurements of Santa Inês lambs from birth to weaning (70 days of age), and to define the best-adjusted statistical model. Data on weights, heights, body lengths, and thoracic perimeters obtained at birth and close to 28 and 70 days of age from 270 lambs were used. Three analyses were carried out considering different models; one with isolated environmental factors, one with animals grouped into contemporaries according to lamb sex, type of birth, year of birth, and season of birth (GC1), and one with animals gathered in groups of contemporaries according to lamb sex, type of birth, year of birth, season of birth, and the julian date of birth (GC2). Environmental factors influenced a large proportion of body weights and measurements from birth to weaning; the main factors were type of birth and year of birth. The GC2 evaluations presented higher determination coefficients and lower values for Akaike information criteria. However, many observations were discarded; 114, 111, and 103 compared with those rejected by the GC1 analysis, which included two, three, and four observations at birth, 28 days of age, and at weaning, respectively. This may lead to the exclusion of animals with genetic potential.