Many Australian marsupial species require active population management to ensure their survival in the wild. Such management should be based on a sound understanding of species biology. This thesis explores how knowledge of reproduction and genetics can be applied to the management of three Australian marsupial species faced with contrasting management scenarios. The ??vulnerable?? greater bilby is the sole remaining desert bandicoot in Australia. They are a secretive, solitary species whose mating system is unclear. This research examined temporal changes in genetic diversity within two captive breeding programs utilising different management strategies. Using seven microsatellite loci, this study found the regular translocation of new individuals into the population maintained genetic diversity. Parentage analysis revealed the bilby to have a promiscious mating system. Sires and non-sires could not be distinguished by morphological traits. The tammar wallaby is a polygynous, solitary species that is threatened on mainland Australia, but overabundant on some offshore islands. The population genetics of tammars from the Abrolhos Islands in Western Australia were examined using nine autosomal and four Y-linked microsatellite loci, and mitochondrial DNA. There was a relationship between island size, population size and genetic diversity. The Abrolhos populations have significantly lower genetic diversity and are more inbred than mainland tammars and all sampled populations were significantly differentiated. The Abrolhos and mainland populations should be treated as separate Management Units. The eastern grey kangaroo is a gregarious, polygynous species that is often locally overabundant. To determine traits influencing male reproductive success, behavioural, morphological, physiological and genetic data were examined and showed dominance status, body size and testosterone concentrations were important factors. Sires were also significantly more heterozygous and genetically dissimilar to females, than non-sires. As body condition influences individual fitness, and management decisions; five body condition indices (BCI) calculated from morphological data were validated using serum biochemistry and haematology in two kangaroo populations with contrasting body condition. Blood parameters were found to be more reliable indicators of condition, questioning the credibility of BCIs currently used in management. These studies demonstrate the importance of reproductive and genetic data in assisting wildlife management, regardless of a species conservation status.

Thesis (M.Sc.) Uppsala : Sveriges lantbruksuniversitet.

Submitted by Morgana Silva (morgana_linhares@yahoo.com.br) on 2016-08-31T17:34:17Z No. of bitstreams: 1 arquivototal.pdf: 1550430 bytes, checksum: 5a83e7b3851eedd2a38fae0034f6c1f2 (MD5) / Made available in DSpace on 2016-08-31T17:34:17Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1550430 bytes, checksum: 5a83e7b3851eedd2a38fae0034f6c1f2 (MD5) Previous issue date: 2013-11-29 / Chiroptera is the second largest order of mammals, being the only representatives with the ability of flight within this class, hibernate, long live, inhabit every continent except the poles and have diverse eating habits. The populations have a dynamic behavior that changes continuously in time. Thus, the characterization of the population is of great importance for the understanding of the ecological stability, allowing for better understanding of the relationship between the species and habitat. A tool that can be used to infer about population structure is the Body Condition Index, in which the main purpose is to separate the aspects of body mass related to the size and structural aspects which reflect fat and other components of energy reserve an individual to generate information that can assist it in the management, monitoring and knowledge of the species. Already activity patterns present character determinant for the survival and reproduction of a species, that associated with eating habits, can be of great importance to understand how bats manage their resources. Thus, this study aimed to know the population structure and activity pattern of Glossophaga soricina in order to add new information and complement existing in other regions of the country. / Chiroptera é a segunda maior ordem de mamíferos, sendo os únicos representantes com a capacidade de voo dentro desta classe, hibernam, longíveros, habitam todos os continentes, exceto os pólos e possuem diversidade de hábitos alimentares. As populações apresentam um comportamento dinâmico, que se modifica de forma continua no tempo. Assim a caracterização das populações é de grande importância para a compreensão da sua estabilidade ecológica, possibilitando o entendimento da relação entre a espécie e o habitat. Uma ferramenta que pode ser utilizada para inferir sobre a estrutura das populações é o Índice de Condição Corporal, este tem por principal finalidade separar os aspectos da massa corporal relacionados ao tamanho estrutural e os aspectos que refletem a gordura e outros componentes da reserva de energia de um indivíduo para gerar informações que possam auxiliar em trabalhos de gestão, monitoramento e conhecimento das espécies. Já os padrões de atividade apresentam caráter determinante para a sobrevivência e reprodução de uma espécie, isso associado a hábitos alimentares, pode ser de grande relevância para entender como morcegos gerenciam seus recursos. Dessa forma, objetivou-se conhecer a estrutura populacional e padrão de atividade de Glossophaga soricina, a fim de adicionar novas informações e complementar as existentes para outras regiões do país.

O experimento foi conduzido com o objetivo de avaliar o desempenho corporal e reprodutivo de 120 novilhas de corte de um rebanho comercial Braford do desmame ao fim do período reprodutivo aos 14/15 meses de idade, quando submetidas a três sistemas alimentares: pastagem de aveia preta (Avena strigosa Schreb.) e azevém (Lolium multiflorum Lam.) (AV+AZ), pastagem de aveia e azevém mais 1% do peso corporal de farelo de trigo (FT), pastagem de aveia e azevém mais 1% de peso corporal de farelo de trigo e 200ml/cabeça/dia de glicerina bruta (FTG) e da prenhez das novilhas aos 14/15 meses de idade ao fim da prenhez quando primíparas aos 24/25 meses de idade, quando submetidas a dois sistemas alimentares: pastagem de azevém (Lolium multiflorum Lam.) por 22 dias pós-parto e mais 22 dias em pastagem natural (PSS), pastagem de azevém por 22 pós-parto recebendo 1% de peso corporal de farelo de trigo e por mais 22 dias em pastagem natural (PCS). O delineamento experimental foi o inteiramente ao acaso, com medidas repetidas no tempo. Sem limitações na oferta forrageira, as suplementações não afetaram a taxa de prenhez, mas determinaram maior concepção nos primeiros 21 dias da temporada Novilhas prenhes, independentes dos tratamentos, têm melhores características fenotípicas de conformação, precocidade, musculatura e tamanho já ao desmame, têm maiores ganhos de peso e condição corporal até o início e ao fim dos tratamentos alimentares e início da temporada reprodutiva, o que permite uma seleção prévia, à idades menores, das bezerras a serem postas em sistemas para prenhez aos 14/15 meses de idade. Rebanhos com prenhez estabilizada aos dois anos de idade necessitam de seleção para maior precocidade sexual e prenhez aos 14/15 meses de idade, não somente ter pesos e condições corporais. Novilhas prenhas aos 14/15 meses de idade têm bom desenvolvimento em pastagem de tifton 85 nos meses de outono com a oferta de 2.500kg de MS/ha. Primíparas suplementadas por 44 dias no pré-serviço têm significativo maior ganho de peso, maior prenhez, com menores intervalo parto-concepção e intervalo entre partos do que as não suplementadas, porém ainda cerca de trinta dias a mais do que o recomendado em sistemas de cria de maior produtividade e eficiência. / This study aimed to evaluate the body development and reproductive performance of 120 Braford heifers from a commercial beef herd from the weaning to first breeding at 14/15 months of age, when submitted to three different feeding systems: black oat (Avena strigosa Schreb.) and Italian ryegrass (Lolium multiflorum Lam.) pastures (AV+AZ), black oat and Italian ryegrass plus supplementation with wheat bran at 1% of the body weight (FT), and black oat and Italian ryegrass plus supplementation with wheat bran at 1% of the body weight plus 200 mL head-1 day-1 of crude glycerol (FTG). We also evaluated the reproductive performance of primiparous cows first bred with 14/15 months of age at their second calving, when submitted to two feeding systems prior to the second breeding season: Italian ryegrass pasture for 22 days postpartum following another 22 days in natural pasture (PSS), and Italian ryegrass pasture for 22 days postpartum receiving 1% of the body weight of wheat bran, following another 22 days in natural pasture (PCS). Treatments were arranged in a completely randomized design with repeated measures in time. Without limitations on herbage allowance from the pasture, supplementation did not affect the pregnancy rate, but increased conception on the first 21 days of the breeding season Heifers that conceived, regardless of the treatments, had better phenotypic characteristics of body conformation, precocity, musculature and frame size at weaning. These animals also had greater average daily gain and body condition at the beginning and at the end of the feeding treatments, and at the beginning of the breeding season. Those traits could be used as indicators for an early selection of heifers to be designated to breeding programs at 14/15 months of age. Herds with stabilized conception at two years of age require selection for greater sexual precocity and conception at 14/15 months of age, and not only have adequate body weight and condition at the time of breeding. Heifers that conceived at 14/15 months of age with forage allowance of 2,500 kg DM ha-1 present good development in tifton 85 pasture during the autumn months. Primiparous supplemented for 44 days prior to breeding had greater weight gain and conception, with shorter calving-to-conception interval and shorter interval between calving than those not supplemented, but still about thirty days longer than recommended to calving systems with higher productivity and reproductive efficiency.

Elucidating the factors that drive variation in the abundance and distribution of organisms is central to ecology. Variables that explain the spatial variation in the abundance of organisms primarily include environmental (e.g., temperature and precipitation) and biotic factors (e.g., competition, predation, and parasitism). An important mechanism influencing the spatial distribution of organisms, at least at small spatial scales, is habitat selection. Traditionally, habitat selection theory has assumed that animals select habitat based on their ability to acquire depletable resources within that habitat, especially food. Ectotherms, however, may instead select habitat based on their ability to process food within the habitat, given the strong dependence of body temperature (and performance) on environmental temperature in this group. The major objective of my thesis was to determine whether energy gain, habitat selection, and population density were driven primarily by food availability or by temperature in ectotherms. I used Sceloporus jarrovii lizards as a study species because these lizards occur at high densities and in similar habitat across a broad altitudinal range. In Chapter 1, I tested the prediction, central to the thermal coadaptation hypothesis, that juvenile lizards prefer body temperatures that maximize their net energy gain. I also tested whether lizards shifted their preferred body temperatures to correspond to the optimal temperature for different energetic states, as per Huey’s (1982) energetics model. In Chapter 2, I determined whether the home range size and density of lizards shifted in response to manipulations of food availability and/or thermal quality within a site. In Chapters 3 and 4, I determined whether mean body condition, individual growth rate, and population density were driven by food availability or thermal quality. In Chapter 3, I visited 32 study sites over a 1,550 m altitudinal range within a year; whereas in Chapter 4, I food-supplemented five out of 10 study sites where I performed mark-recapture over a period of three years. Overall, my thesis demonstrates that both food availability and thermal quality of the habitat drive energy gain, habitat selection, and population density. Juvenile S. jarrovii preferred body temperatures that maximized net energy gain, regardless of energetic state. Although they did not shift their preferred body temperature range depending on energetic state, the difference in the optimal temperature for net energy gain between states (0.4°C), may have been too small to warrant a change in behaviour. Within a site, S. jarrovii increased their home range size and occurred at higher densities as natural food availability increased, and decreased their home range size and occurred at lower densities as the thermal quality under the rocks increased. This suggests that S. jarrovii respond to food availability and thermal quality at different scales, selecting territories based on thermal quality and home ranges based on food availability. Over 32 sites, the abundance of S. jarrovii increased with food availability, whereas the mean body condition increased and the rate at which lizards attained their maximum body size decreased with elevation (at lower thermal quality). In the three-year study, mean body condition and individual growth rate decreased and population density increased with thermal quality, but the strength of the relationship depended on natural food availability. Overall, both food availability and thermal quality of the habitat drive energy gain, habitat selection, and population density; however, thermal quality is often the stronger driver. Thus, improvements to habitat selection models should incorporate habitat thermal quality to improve predictions on how ectotherms distribute themselves on a landscape.

Orientador: Hélio Takachi Okuda / Banca: Sony Dimas Bicudo / Banca: Edson Guilherme Vieira / Resumo: A sincronização do estro e a interrupção temporária do aleitamento visam antecipar o restabelecimento da atividade ovariana pós-parto. Este estudo teve por objetivo avaliar o efeito de um protocolo da sincronização do estro associado à interrupção temporária do aleitamento durante o período pós-parto em fêmeas primíparas da Raça Nelore (Bos taurus indicus). O lote (80 animais) recebeu os seguintes tratamentos: T1 - Testemunha / Controle (20 animais), T2 - Interrupção temporária do aleitamento (20 animais), T3 - Protocolo de sincronização de estro - Crestar (20 animais), T4 - Associação dos tratamentos T2 e T3 (20 animais). Os dados coletados foram: data do parto, sexo do bezerro, data do estro, avaliação reprodutiva (corpos lúteos, folículos, condição corporal, involução uterina, animais em anestro), pesos, escores, dosagem de progesterona, data de inseminação, data do implante, data da retirada do implante, resultado do diagnóstico de gestação. O peso médio, o escore corporal médio e o ganho de peso médio em T3 e T4 foram respectivamente 332,85 Kg, 340,83 Kg, , 4,5 e 4,0 e 0,10 Kg/cab/dia. A manifestação do estro em T3 e T4 foi respectivamente 21,05% e 55,55%. O Intervalo Parto - 1º Estro em T3, diferiu significativamente (Duncan p<0,05) em relação aos outros tratamentos. A taxa de gestação em T3 e T4 foi de 15,78 %. A taxa de gestação das vacas primíparas foi baixa. / Abstract: The syncronization of estrous and temporary interruption of suckling aim restablishment of the post-partum ovarian activity. The objective of this study was to evaluate the effect of the syncronization protocol associated with the temporary interruption of suckling during post-calving period in Nelore Breed primiparous females (Bos taurus indicus). The lot (80 animals) received the following treatments: Treatment 1 - Control (20 animals), Treatment 2 - Temporary Interruption of Suckling (20 animals), Treatment 3 - Syncronization Protocols - Crestar (20 animals), Treatment 4 - Association of treatment T3 and T4 (20 animals). The collected data were: calving date, calf sex, estrous date, reproductive evaluation (corpus luteum, follicles, body score condition, uterine involution, anestrous animals), progesterone dose, insemination date, implant date, implant removing date, pregnancy rate. The mean body weigth, the mean body condition score and mean weigth gain in T3 and T4 respectively were 332,85 Kg and 340,83 Kg, 4,5 and 4,0 e 0,10 Kg/cab/day. The estrous rate in T3 and T4 respectively were 21,05% and 55,55%. The calving - first estrous period in T4 was significanthy different (Duncan p<0,05) in relation to the other treatments. The pregnancy rate in T3 and T4 were 15,78%. The pregnancy rate of primiparous cows were lower. / Mestre

Made available in DSpace on 2014-06-11T19:27:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-04-24Bitstream added on 2014-06-13T20:36:09Z : No. of bitstreams: 1 meneghetti_m_me_botfmvz.pdf: 184024 bytes, checksum: b833a6860023243a1fd026c9cdb4eef2 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Universidade Estadual Paulista (UNESP) / O objetivo deste estudo foi avaliar o efeito do mês de parição na condição corporal (CC) no início de estação de monta e na resposta a dois protocolos de inseminação artificial em tempo fixo (IATF) em vacas primíparas de corte. No experimento I (exp. I) foi avaliado a alteração da CC pré e pós-parto em 87 novilhas Nelore e 68 u sangue Red Angus, inseminadas para parir de Setembro a Dezembro. A CC foi avaliada mensalmente no pré e pós-parto de Junho a Fevereiro. No exp. II as 155 vacas do exp. I foram sincronizadas entre 29 e 129 dias pós-parto (DPP), com o protocolo: remoção dos bezerros (RB) por 48 h antes do primeiro GnRH (100 mcg, Fertagyl®, INTERVET) e foi inserido dispositivo intravaginal de progesterona (CIDR®, Pfizer, 1,9 g). Após 6,5 dias, foi feita nova RB por 46h; o CIDR® foi removido; e foi aplicado prostaglandina 2 (PGF2 ) (25 mg, Lutalyse®, Pfizer). Entre 42 e 46h após a PGF2 as vacas receberam nova aplicação de GnRH e foram inseminadas. No exp. III, 538 primíparas de duas fazendas (60 Nelore e 123 u sangue Red Angus na fazenda 1 e 355 Nelore na fazenda 2), entre 33 e 104 DPP foram sincronizadas com o protocolo: inserção do CIDR® junto à de Benzoato de Estradiol (2,0 mg, Estrogin®, Farmavet), No dia 7 foi aplicado PGF2 (12,5 mg, Lutalyse®, Pfizer). No dia 9 foi retirado o CIDR®, foi feita RB e aplicado 0,5 mg de Cipionato de Estradiol (E.C.P.®, Pfizer). A IATF foi realizada 46 a 52 h após a retirada do CIDR®. A taxa de sincronização foi avaliada (exceto na fazenda 2 do exp. III) por dois exames de ultra-som (Aloka SSD-500, 5,0 MHz) e determinada pela presença e ausência de folículo dominante na IATF e 48 h após. O diagnóstico de gestação foi feito por ultra-som 28 dias após a IATF. A análise estatística do exp. I foi feita no PROC MIXED e dos exp. II e III no PROC LOGISTIC do SAS... / The aim of this study was to evaluate the calving date effect on body condition score (BCS) at the beginning of breeding season and on the response to a two timed artificial insemination (TAI) protocols in first-calf beef heifers. In experiment I (exp. I) was evaluated the BCS change pre and post-partum. Eighty seven Nelore heifers and 68 u blood Red Angus were inseminated to calve from September to December. The BCS were monthly measured from June to February, during the pre and post-partum of these animals. In exp. II, the cows from exp. I were TAI when they were between 29 and 129 days post-partum (DPP) with the protocol: calf removal (CR) for 48 h before the first GnRH (100 mcg, Fertagyl®, INTERVET) and an insertion of an intravaginal progesterone device (1.9 g, CIDR®, Pfizer). After 6,5 days a new CR was performed, the CIDR® was removed and was injected prostaglandin F2? (PGF2?) (25 mg, Lutalyse®, Pfizer). Between 42 and 46 h after PGF2? was injected a new GnRH and cows were TAI. In exp. III, 538 primiparous cows from two herds (60 Nelore and 123 u blood Red Angus from farm 1 and 355 Nelore from farm 2), between 33 and 104 DPP were synchronized with the protocol: day 0, insertion of a CIDR® and a injection of 2.0 mg of estradiol benzoate (Estrogin®, Farmavet), on day 7 was injected PgF2? (12.5 mg, Lutalyse®, Pfizer), in the CIDR® withdraw (Day 9) was injected estradiol cipionate (0.5 mg, E.C.P.®, Pfizer) and a CR was done, the TAI was preformed 46 to 52 hours after the device withdraw. In the TAI moment and 48 hours later a ultrasound scan (Aloka SSD-500, 5.0 MHz) was performed to determine the ovulation rate (except in the farm 2 of exp. 3). The pregnancy diagnosis was made by ultrasound 28 days after the TAI. The statistic analysis in exp. I was performed with PROC MIXED and in exp.II and III with PROC LOGISTIC from SAS... (Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:28:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-12Bitstream added on 2014-06-13T18:34:31Z : No. of bitstreams: 1 biluca_df_me_botfmvz.pdf: 232011 bytes, checksum: 5f66e2b253e27ff8acb7ace15eb4f40e (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Universidade Estadual Paulista (UNESP) / O objetivo deste estudo foi avaliar o efeito da suplementação com monensina, em vacas nelore paridas a pasto, em anestro, nas concentrações plasmáticas de AGNE, IGF-1, no diâmetro de maior folículo e na capacidade de resposta desse folículo a um estímulo ovulatório hormonal (GnRH). Nesse estudo foram usadas 302 vacas (123 primíparas e 179 multíparas) que foram divididas em dois tratamentos, proporcionalmente, onde o lote controle recebeu apenas suplementação mineral e o lote tratado recebeu suplementação monensina (110mg/vaca/dia). Os tratamentos se iniciaram 30 dias pré-parto, onde avaliou-se o ECC pré-parto, até 90 dias pós-parto. Todas as vacas, em média aos 54 dias pós-parto, receberam um estímulo hormonal ovulatório (administração de 50 mcg de GnRH), foram avaliadas para o escore de condição corporal (escala de 1 a 5), colhido sangue para análise de IGF-1 e AGNE e foram avaliadas para o do diâmetro folicular através de ultra-sonografia (US). Após 7 dias nova US foi realizada para verificar a taxa de ovulação. As variáveis foram submetidas à análise de variância pelo GLM do SAS. O ECC pós-parto foi maior (p<0,01) em vacas tratadas com monensina (3,11) que vacas controle (3,00); além disso, vacas tratadas não perderam ECC no período periparto enquanto vacas controle perderam 0,19 pontos. Vacas suplementadas com monensina (883,9 mmol/l) tiveram concentração plasmática de AGNE menor (p<0,01) que vacas controle (1013,8 mmol/l), caracterizando, junto com a ECC, menor mobilização de reservas. Já a concentração plasmática de IGF-1 foi maior (p<0,01) nas vacas tratadas (118,5 ng/ml) que vacas controle (85,1 ng/ml). Primíparas (118,0 ng/ml) apresentaram IGF-1 maior (p<0,01) que multíparas (84,8 ng/ml). Vacas tratadas (10,07mm) apresentaram folículo maior que vacas controle (9,58mm) e multíparas (10,35mm) maior que primíparas (9,30mm)... / The objective of this trial was to evaluate the effects of monensin supplementation in suckled anestrous Nellore cows on IGF-1 and NEFA concentrations, follicular diameter and GnRH ovulatory response. In this trial were used 302 cows (123 primiparous and 179 multiparous) divided in two treatments. The control group received only mineral supplementation and the treated group received monensin supplementation (110 mg/cow/day). The treatments began 30 days prepartum to 90 days postpartum. All cows, at average of 54 days postpartum, received hormonal ovulatory stimulation (50 mcg GnRH), BCS were evaluated (1 to 5 scale), blood samples were collected to IGF-1 and NEFA analysis and follicular diameter was measured by ultrasound (US). Seven days later ovulation rate was evaluated. Cows that received monensin had higher postpartum BCS (3.11) and lost less BCS at peripartum than control cows (3.00). Treated cows had lower (P<0.01) NEFA plasmatic concentration (883.9 mmol/l) than control cows (101.8 mmo/l), which associated with BCS suggests less reserve mobilization. IGF-1 plasmatic concentration was higher in treated cows (11.5 ng/ml) than control cows (85.1 ng/ml). Primiparous (118.0 ng/ml) had higher IGF-1 than multiparous (84.8 ng/ml). Treated cows had higher follicular diameter (10.07mm) than control cows (9,58mm) and multiparous (10.35mm) higher than primiparous (9.30mm). The hormonal ovulatory stimulation (GnRH) response is follicle diameter dependent and treated cows had higher response (35.9%) than control cows (31.5%). Monensin supplementation is a good strategy to improve energy status due to decrease in BCS loss and reduction of NEFA concentration. Monensin supplementation also increased IGF-1 plasmatic concentration, follicular diameter and hormonal (GnRH) ovulatory response.

Made available in DSpace on 2014-06-11T19:29:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2002-03-18Bitstream added on 2014-06-13T19:38:55Z : No. of bitstreams: 1 moraes_tt_me_ilha.pdf: 118193 bytes, checksum: 381cadf1263c24dace3cfe7601d90d6d (MD5) / A sincronização do estro e a interrupção temporária do aleitamento visam antecipar o restabelecimento da atividade ovariana pós-parto. Este estudo teve por objetivo avaliar o efeito de um protocolo da sincronização do estro associado à interrupção temporária do aleitamento durante o período pós-parto em fêmeas primíparas da Raça Nelore (Bos taurus indicus). O lote (80 animais) recebeu os seguintes tratamentos: T1 - Testemunha / Controle (20 animais), T2 - Interrupção temporária do aleitamento (20 animais), T3 - Protocolo de sincronização de estro - Crestar (20 animais), T4 – Associação dos tratamentos T2 e T3 (20 animais). Os dados coletados foram: data do parto, sexo do bezerro, data do estro, avaliação reprodutiva (corpos lúteos, folículos, condição corporal, involução uterina, animais em anestro), pesos, escores, dosagem de progesterona, data de inseminação, data do implante, data da retirada do implante, resultado do diagnóstico de gestação. O peso médio, o escore corporal médio e o ganho de peso médio em T3 e T4 foram respectivamente 332,85 Kg, 340,83 Kg, , 4,5 e 4,0 e 0,10 Kg/cab/dia. A manifestação do estro em T3 e T4 foi respectivamente 21,05% e 55,55%. O Intervalo Parto - 1º Estro em T3, diferiu significativamente (Duncan p<0,05) em relação aos outros tratamentos. A taxa de gestação em T3 e T4 foi de 15,78 %. A taxa de gestação das vacas primíparas foi baixa. / The syncronization of estrous and temporary interruption of suckling aim restablishment of the post-partum ovarian activity. The objective of this study was to evaluate the effect of the syncronization protocol associated with the temporary interruption of suckling during post-calving period in Nelore Breed primiparous females (Bos taurus indicus). The lot (80 animals) received the following treatments: Treatment 1 - Control (20 animals), Treatment 2 – Temporary Interruption of Suckling (20 animals), Treatment 3 – Syncronization Protocols - Crestar (20 animals), Treatment 4 - Association of treatment T3 and T4 (20 animals). The collected data were: calving date, calf sex, estrous date, reproductive evaluation (corpus luteum, follicles, body score condition, uterine involution, anestrous animals), progesterone dose, insemination date, implant date, implant removing date, pregnancy rate. The mean body weigth, the mean body condition score and mean weigth gain in T3 and T4 respectively were 332,85 Kg and 340,83 Kg, 4,5 and 4,0 e 0,10 Kg/cab/day. The estrous rate in T3 and T4 respectively were 21,05% and 55,55%. The calving - first estrous period in T4 was significanthy different (Duncan p<0,05) in relation to the other treatments. The pregnancy rate in T3 and T4 were 15,78%. The pregnancy rate of primiparous cows were lower.

O experimento foi conduzido com o objetivo de avaliar o desempenho corporal e reprodutivo de 120 novilhas de corte de um rebanho comercial Braford do desmame ao fim do período reprodutivo aos 14/15 meses de idade, quando submetidas a três sistemas alimentares: pastagem de aveia preta (Avena strigosa Schreb.) e azevém (Lolium multiflorum Lam.) (AV+AZ), pastagem de aveia e azevém mais 1% do peso corporal de farelo de trigo (FT), pastagem de aveia e azevém mais 1% de peso corporal de farelo de trigo e 200ml/cabeça/dia de glicerina bruta (FTG) e da prenhez das novilhas aos 14/15 meses de idade ao fim da prenhez quando primíparas aos 24/25 meses de idade, quando submetidas a dois sistemas alimentares: pastagem de azevém (Lolium multiflorum Lam.) por 22 dias pós-parto e mais 22 dias em pastagem natural (PSS), pastagem de azevém por 22 pós-parto recebendo 1% de peso corporal de farelo de trigo e por mais 22 dias em pastagem natural (PCS). O delineamento experimental foi o inteiramente ao acaso, com medidas repetidas no tempo. Sem limitações na oferta forrageira, as suplementações não afetaram a taxa de prenhez, mas determinaram maior concepção nos primeiros 21 dias da temporada Novilhas prenhes, independentes dos tratamentos, têm melhores características fenotípicas de conformação, precocidade, musculatura e tamanho já ao desmame, têm maiores ganhos de peso e condição corporal até o início e ao fim dos tratamentos alimentares e início da temporada reprodutiva, o que permite uma seleção prévia, à idades menores, das bezerras a serem postas em sistemas para prenhez aos 14/15 meses de idade. Rebanhos com prenhez estabilizada aos dois anos de idade necessitam de seleção para maior precocidade sexual e prenhez aos 14/15 meses de idade, não somente ter pesos e condições corporais. Novilhas prenhas aos 14/15 meses de idade têm bom desenvolvimento em pastagem de tifton 85 nos meses de outono com a oferta de 2.500kg de MS/ha. Primíparas suplementadas por 44 dias no pré-serviço têm significativo maior ganho de peso, maior prenhez, com menores intervalo parto-concepção e intervalo entre partos do que as não suplementadas, porém ainda cerca de trinta dias a mais do que o recomendado em sistemas de cria de maior produtividade e eficiência. / This study aimed to evaluate the body development and reproductive performance of 120 Braford heifers from a commercial beef herd from the weaning to first breeding at 14/15 months of age, when submitted to three different feeding systems: black oat (Avena strigosa Schreb.) and Italian ryegrass (Lolium multiflorum Lam.) pastures (AV+AZ), black oat and Italian ryegrass plus supplementation with wheat bran at 1% of the body weight (FT), and black oat and Italian ryegrass plus supplementation with wheat bran at 1% of the body weight plus 200 mL head-1 day-1 of crude glycerol (FTG). We also evaluated the reproductive performance of primiparous cows first bred with 14/15 months of age at their second calving, when submitted to two feeding systems prior to the second breeding season: Italian ryegrass pasture for 22 days postpartum following another 22 days in natural pasture (PSS), and Italian ryegrass pasture for 22 days postpartum receiving 1% of the body weight of wheat bran, following another 22 days in natural pasture (PCS). Treatments were arranged in a completely randomized design with repeated measures in time. Without limitations on herbage allowance from the pasture, supplementation did not affect the pregnancy rate, but increased conception on the first 21 days of the breeding season Heifers that conceived, regardless of the treatments, had better phenotypic characteristics of body conformation, precocity, musculature and frame size at weaning. These animals also had greater average daily gain and body condition at the beginning and at the end of the feeding treatments, and at the beginning of the breeding season. Those traits could be used as indicators for an early selection of heifers to be designated to breeding programs at 14/15 months of age. Herds with stabilized conception at two years of age require selection for greater sexual precocity and conception at 14/15 months of age, and not only have adequate body weight and condition at the time of breeding. Heifers that conceived at 14/15 months of age with forage allowance of 2,500 kg DM ha-1 present good development in tifton 85 pasture during the autumn months. Primiparous supplemented for 44 days prior to breeding had greater weight gain and conception, with shorter calving-to-conception interval and shorter interval between calving than those not supplemented, but still about thirty days longer than recommended to calving systems with higher productivity and reproductive efficiency.