Made available in DSpace on 2016-05-02T13:55:02Z (GMT). No. of bitstreams: 1 Leandro Francisco Gofert- Dissertacao.pdf: 644155 bytes, checksum: c324806273039e5418f42b4f7ed29fa2 (MD5) Previous issue date: 2015-02-27 / To test a new follicular growth inducer on the increase of follicular growth, the rate of ovulation and pregnancy in cows submitted to fixed time artificial insemination (FTAI). Was associated with a GnRH analogue (gonadorelin, Fertagyl®, MSD, São Paulo, Brazil) diluted in 20% sodium hyaluronate solution. It was used 27 Nellore cows, lactating, body condition score (BCS) of 2.5 (range 1-5) in anoestrus (fol. <8 mm and absence of corpus luteum). On day 0 all cows received a progesterone device (Primer® - Tecnopec, São Paulo, Brazil) and 2 mg of estradiol benzoate (RIC-BE® - Tecnopec, São Paulo, Brazil). Eight days later were evaluated by ultrasound and divided into 3 groups, balancing groups by follicular condition, that day all animals had their devices removed and received 500 g of sodium Cloprostenol (Ciosin® - MSD, São Paulo, Brazil). In the G100 group was administered intramuscularly the priming solution of growth with 100 &#956;g of gonadorelin. In the G200 was applied to priming solution of growth with 200 &#956;g of gonadorelin. In the control group (CG) was applied 2 mL of saline solution. On day 9 the animals received 1 mg of estradiol benzoate as ovulation inducer. All animals were inseminated on day 10, 54 h after removal of the devices. In day 9 and 10 the animals were evaluated by ultrasound for follicular measurement, on day 19 for corpus luteum ID (ovulation rate) and day 44 for pregnancy diagnosis. Follicular diameter did not differ between groups at D0: 5.2 ± 1.16 mm vs. 5.8 ± 1.45 mm vs. 5.2 ± 1.55 mm; at D8: 7.3 ± 1.83 mm vs. 8.2 ± 1.67 mm vs. 7.4 ± 1.60 mm; in D9: 9.2 ± 1.69 mm vs. 9.6 ± 1.55 mm vs. 9.2 ± 1.18 mm, respectively, for G100, G200 and GC. Follicular growth between day 8 and 9 also did not differ between groups: 1.9 mm vs. 1.4 mm vs. 1.8 mm, for G100, G200 and GC respectively. The cows treated with GnRH, evaluated in the D10, had anticipation of ovulation in relation to GC: 100% vs. 77.8% vs. 0%, respectively, for G100, G200 and GC. The ovulation rate determined by the presence of CL in the D19 did not differ between the groups: 100% vs. 77.8% vs. 77.8% respectively for G100, G200 and GC, the diameters of corpora lutea did not differ, when evaluated in D19: 1.56 ± 0.24 mm vs. 1.68 ± 0.40 vs. 1.51 ± 0.30 mm, respectively, for G100, G200 and GC. The pregnancy rate was higher in GC than those treated: 33.4% vs. 0 vs. 0, respectively for GC, G100 and G200. The data suggest that the association between the GnRH analogue and hyaluronate 20% (at the doses tested) did not increase follicular growth or ovulation rate. Probably this association induced a premature LH surge, leading to early ovulation and harming the pregnancy rates of the treated animals. / Para testar um novo indutor de crescimento folicular sobre o aumento do crescimento folicular, a taxa de ovulação e prenhez em vacas submetidas à inseminação artificial em tempo fixo (IATF). Associou-se um análogo de GnRH (gonadorelina, Fertagyl®, MSD, São Paulo, Brasil) diluído em solução de hialuronato de sódio a 20%. Foram utilizadas 27 vacas Nelore, lactantes, com escore de condição corporal (ECC) de 2,5 (escala de 1 a 5), em anestro (fol. < 8 mm e ausência de corpo lúteo). No dia 0 todas as vacas receberam um dispositivo de progesterona (Primer® - Tecnopec, São Paulo, Brasil) e 2 mg de benzoato de estradiol (RIC-BE® - Tecnopec, São Paulo, Brasil). Oito dias depois foram avaliadas por ultrassom e divididas em 3 grupos, equilibrando-se os grupos pela condição folicular. Nesse dia todos os animais tiveram seus dispositivos removidos e receberam 500 µg de Cloprostenol sódico (Ciosin® - MSD, São Paulo, Brasil). No grupo G100 foi aplicada por via IM a solução indutora de crescimento com 100 µg de gonadorelina. No G200 foi aplicada a solução indutora de crescimento com 200 µg de gonadorelina. No grupo controle (GC) foi aplicado 2 ml de solução fisiológica. No dia 9 os animais receberam 1 mg de benzoato de estradiol como indutor de ovulação. Todos os animais foram inseminados no dia 10, 54 h após a retirada dos dispositivos. Nos dias 9 e 10 os animais foram avaliados por ultrassonografia para mensuração folicular, no dia 19 para identificação de corpo lúteo (taxa de ovulação) e no dia 44 para diagnóstico de gestação. O diâmetro folicular não diferiu entre os grupos no D0: 5,2±1,16 mm vs. 5,8±1,45 mm vs. 5,2±1,55 mm; no D8: 7,3±1,83 mm vs. 8,2±1,67 mm vs. 7,4±1,60 mm; no D9: 9,2±1,69 mm vs. 9,6±1,55 mm vs. 9,2±1,18 mm, respectivamente para G100, G200 e GC. O crescimento folicular entre o dia 8 e 9 também não diferiu entre os grupos: 1,9 mm vs. 1,4 mm vs. 1,8 mm, para G100, G200 e GC respectivamente. As vacas tratadas com GnRH, avaliadas no D10, tiveram antecipação da ovulação em relação ao GC: 100% vs. 77,8% vs. 0%, respectivamente para G100, G200 e GC. A taxa de ovulação avaliada pela presença de CL no D19 não diferiu entre os grupos: 100% vs. 77,8% vs. 77,8% respectivamente para G100, G200 e GC. Os diâmetros dos corpos lúteos também não diferiram quando avaliados no D19: 1,56±0,24 mm vs. 1,68±0,40 mm vs. 1,51±0,30 mm, respectivamente para G100, G200 e GC. A taxa de prenhez foi superior no GC em relação aos tratados: 33,4% vs. 0 vs. 0, respectivamente para GC, G100 e G200. Os dados sugerem que, a associação entre análogo de GnRH e hialuronato a 20% (nas doses testadas) não aumentou o crescimento folicular, nem a taxa de ovulação. Provavelmente essa associação induziu um pico precoce de LH, levando à ovulação antecipada e prejudicando as taxas de prenhez dos animais tratados.

Os minerais são de extrema importância no metabolismo geral e no desempenho produtivo e reprodutivo dos animais a campo. Atualmente no Rio Grande do Sul, há poucos relatos sobre o diagnóstico de deficiências de minerais através da análise de macro e microelementos em fluidos biológicos. As informações disponíveis limitam-se ao diagnóstico clínico de deficiências isoladas e à análise de elementos nas pastagens, que sugerem deficiências subclínicas de alguns elementos minerais. A região da Depressão Central é caracterizada pela produção extensiva em campo nativo com manejo precário da suplementação mineral. A incidência de baixos níveis de alguns elementos nas pastagens contribuiu para a escolha da região. Os objetivos do presente trabalho foram: (a) determinar o perfil mineral em quatro períodos importantes do ciclo produtivo de matrizes (monta, repasse de touros, final da gestação e inicio da lactação); (b) diagnosticar possíveis deficiências minerais em vacas de corte na região da Depressão Central mediante a dosagem dos seguintes indicadores no sangue: Pi, Ca, Cu, Zn, glutation peroxidase (Se) e tiroxina (I). Na saliva foram dosados Na e K. (c) correlacionar os indicadores com os teores de minerais na pastagem nativa. Para isso, foram obtidas amostras de sangue e saliva em 4 propriedades no município de Cachoeira do Sul totalizando 112 animais (28 por período). O perfil indicou deficiência marginal de P, Na, I e Se em todos os períodos. As médias de Cu e Zn estiveram dentro das referências enquanto que os de K na saliva mista estiveram elevados. O Ca sérico apresentou-se diminuído embora os teores nas pastagens estivessem elevados. Foi constatada baixa correlação entre os níveis de minerais no sangue/saliva e na pastagem de todos os elementos. Os períodos mais afetados foram o final da gestação e inicio da lactação indicando que essas categorias possuem maior necessidade fisiológica. / Minerals play an important role in the metabolism and in the production and reproductive performance of animal raised on extensive grassland. Presently, in the state of Rio Grande do Sul (southern Brazil) there is a lack of information on macro and micro elements mineral deficiency troughout the analysis of biological fluids. Information available in this field reports only individual cases of mineral deficiency and analysis of elements on pastures. The level of mineral found on pasture suggests the presence of non-clinical mineral deficiency of some elements in either some seasons of the year or on the different animal categories of the State herds. The Central Valley Region, the third most important social and economically of the State cattle industry, is characterised by extensive production on natural pasture, with quite poor mineral supplementation. The low mineral level found on pastures in this area, detected by previous works, suggest further investigation. The main aims of this work were: (a) to detect possible mineral deficiency in beef cows by determining Pi, Ca, Cu, Zn, Se (gluthathion peroxidase) and I (T4) in blood and Na and K in saliva; (b) to check the possible relationships with the mineral level on pasture; (c) to detect the mineral profile on four different periods of the productive circle (IA, clean up bulls, end of gestation period and beginning of lactation). A total of seven blood and saliva samples were collected from each of four herds of Cachoeira do Sul county on four different periods. The results showed marginal deficiencies of Pi, Na, I and Se in all periods of the year. Mean values of Cu and Zn were among normal levels but the K level was above the reference level. The Ca serum level was always bellow normal and could be related to the low protein ingestion and high Mg pasture level. Finally, only a low relationship was found between mineral level on blood/saliva and pasture levels. Most critical periods were end of gestation and beginning of lactation, suggesting a relationship with the physiological need of those periods.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The aim of this study was to develop a timed artificial insemination system (TAI) in suckled beef cows. For this, in 227 cows 60-80 days postpartum, received estradiol benzoate (5mg) and a vaginal device containing 250mg of medroxyprogesterone acetate (MAP; day 0). On day six, prostaglandin analogous (125μg), eCG (400IU) was administered and calves were removed for 88h. The device was removed on day seven (BioRep group) or on day eight (TAI group) and the cows of both groups received GnRH (100μg; day 9) 48h or 24h after device withdrawal, respectively. Experiment I: the follicular growth was daily monitored, from day 6 to day 9 (36h after GnRH), in 14 cows. The average of dominant follicle size on day nine was 11.1±0.99mm (BioRep, n=7) and 11.5±0.65mm (TAI, n=7) and all animals ovulated. Experiment II: in the BioRep group (n=106), the cows was observed for estrus behavior after withdrawal the device, twice a day during 48h and inseminated at 12h after detection; In the TAI group (n=107), the devices were withdrawn on day eight and after 24h these cows and those from the BioRep group, which were not stand in estrus, received 100μg of GnRH and TAI 16h later. The pregnancy rates were 57.6% (BioRep) and 52.3% (TAI). The time of MAP exposure and the period from MAP to GnRH did not affect the follicular dynamic and pregnancy rates. Furthermore, the treatment for eight days allows an efficient TAI system in suckled beef cows. / O objetivo deste estudo foi desenvolver um protocolo de inseminação artificial com tempo fixo (IATF) em vacas de corte amamentando, avaliando o intervalo entre a retirada do progestágeno e a aplicação de GnRH sobre a dinâmica folicular e a prenhez. Para isto, 227 vacas 60-80 dias pós-parto receberam benzoato de estradiol (5mg) e um pessário vaginal de acetato de medroxiprogesterona (250mg MAP; dia 0). No dia seis, cloprostenol sódico (125μg), gonadotrofina coriônica eqüina (400UI) e desmame temporário (88h). O MAP foi retirado no dia sete (Grupo BioRep) ou no dia oito (Grupo IATF) e, 48h ou 24h após os animais receberam GnRH (100μg; dia 9), respectivamente. No experimento I, o monitoramento das estruturas ovarianas de 14 vacas foi realizado a cada 24h, desde o dia seis até 36h após a aplicação de GnRH em ambos os grupos. O tamanho médio do folículo dominante no dia nove foi de 11,1±0,99mm (BioRep n=7) e 11,5±0,65mm (IATF n=7) e todos os animais ovularam. No experimento II, no grupo BioRep (n=106), após a retirada do MAP, as fêmeas foram inseminadas com detecção de estro durante 48 horas. O restante dos animais do grupo BioRep e todos do grupo IATF (n=107) receberam 100μg de GnRH (dia 9) e, após 16h, IATF. Os índices de prenhez foram de 57,6% (BioRep) e de 52,3% (IATF). O intervalo de 24h entre a retirada do MAP, mantido por 8 dias, e a aplicação de GnRH não interfere na dinâmica folicular e prenhez, viabilizando inseminar vacas de corte amamentando sem observação de estro.

Os minerais são de extrema importância no metabolismo geral e no desempenho produtivo e reprodutivo dos animais a campo. Atualmente no Rio Grande do Sul, há poucos relatos sobre o diagnóstico de deficiências de minerais através da análise de macro e microelementos em fluidos biológicos. As informações disponíveis limitam-se ao diagnóstico clínico de deficiências isoladas e à análise de elementos nas pastagens, que sugerem deficiências subclínicas de alguns elementos minerais. A região da Depressão Central é caracterizada pela produção extensiva em campo nativo com manejo precário da suplementação mineral. A incidência de baixos níveis de alguns elementos nas pastagens contribuiu para a escolha da região. Os objetivos do presente trabalho foram: (a) determinar o perfil mineral em quatro períodos importantes do ciclo produtivo de matrizes (monta, repasse de touros, final da gestação e inicio da lactação); (b) diagnosticar possíveis deficiências minerais em vacas de corte na região da Depressão Central mediante a dosagem dos seguintes indicadores no sangue: Pi, Ca, Cu, Zn, glutation peroxidase (Se) e tiroxina (I). Na saliva foram dosados Na e K. (c) correlacionar os indicadores com os teores de minerais na pastagem nativa. Para isso, foram obtidas amostras de sangue e saliva em 4 propriedades no município de Cachoeira do Sul totalizando 112 animais (28 por período). O perfil indicou deficiência marginal de P, Na, I e Se em todos os períodos. As médias de Cu e Zn estiveram dentro das referências enquanto que os de K na saliva mista estiveram elevados. O Ca sérico apresentou-se diminuído embora os teores nas pastagens estivessem elevados. Foi constatada baixa correlação entre os níveis de minerais no sangue/saliva e na pastagem de todos os elementos. Os períodos mais afetados foram o final da gestação e inicio da lactação indicando que essas categorias possuem maior necessidade fisiológica. / Minerals play an important role in the metabolism and in the production and reproductive performance of animal raised on extensive grassland. Presently, in the state of Rio Grande do Sul (southern Brazil) there is a lack of information on macro and micro elements mineral deficiency troughout the analysis of biological fluids. Information available in this field reports only individual cases of mineral deficiency and analysis of elements on pastures. The level of mineral found on pasture suggests the presence of non-clinical mineral deficiency of some elements in either some seasons of the year or on the different animal categories of the State herds. The Central Valley Region, the third most important social and economically of the State cattle industry, is characterised by extensive production on natural pasture, with quite poor mineral supplementation. The low mineral level found on pastures in this area, detected by previous works, suggest further investigation. The main aims of this work were: (a) to detect possible mineral deficiency in beef cows by determining Pi, Ca, Cu, Zn, Se (gluthathion peroxidase) and I (T4) in blood and Na and K in saliva; (b) to check the possible relationships with the mineral level on pasture; (c) to detect the mineral profile on four different periods of the productive circle (IA, clean up bulls, end of gestation period and beginning of lactation). A total of seven blood and saliva samples were collected from each of four herds of Cachoeira do Sul county on four different periods. The results showed marginal deficiencies of Pi, Na, I and Se in all periods of the year. Mean values of Cu and Zn were among normal levels but the K level was above the reference level. The Ca serum level was always bellow normal and could be related to the low protein ingestion and high Mg pasture level. Finally, only a low relationship was found between mineral level on blood/saliva and pasture levels. Most critical periods were end of gestation and beginning of lactation, suggesting a relationship with the physiological need of those periods.

Os minerais são de extrema importância no metabolismo geral e no desempenho produtivo e reprodutivo dos animais a campo. Atualmente no Rio Grande do Sul, há poucos relatos sobre o diagnóstico de deficiências de minerais através da análise de macro e microelementos em fluidos biológicos. As informações disponíveis limitam-se ao diagnóstico clínico de deficiências isoladas e à análise de elementos nas pastagens, que sugerem deficiências subclínicas de alguns elementos minerais. A região da Depressão Central é caracterizada pela produção extensiva em campo nativo com manejo precário da suplementação mineral. A incidência de baixos níveis de alguns elementos nas pastagens contribuiu para a escolha da região. Os objetivos do presente trabalho foram: (a) determinar o perfil mineral em quatro períodos importantes do ciclo produtivo de matrizes (monta, repasse de touros, final da gestação e inicio da lactação); (b) diagnosticar possíveis deficiências minerais em vacas de corte na região da Depressão Central mediante a dosagem dos seguintes indicadores no sangue: Pi, Ca, Cu, Zn, glutation peroxidase (Se) e tiroxina (I). Na saliva foram dosados Na e K. (c) correlacionar os indicadores com os teores de minerais na pastagem nativa. Para isso, foram obtidas amostras de sangue e saliva em 4 propriedades no município de Cachoeira do Sul totalizando 112 animais (28 por período). O perfil indicou deficiência marginal de P, Na, I e Se em todos os períodos. As médias de Cu e Zn estiveram dentro das referências enquanto que os de K na saliva mista estiveram elevados. O Ca sérico apresentou-se diminuído embora os teores nas pastagens estivessem elevados. Foi constatada baixa correlação entre os níveis de minerais no sangue/saliva e na pastagem de todos os elementos. Os períodos mais afetados foram o final da gestação e inicio da lactação indicando que essas categorias possuem maior necessidade fisiológica. / Minerals play an important role in the metabolism and in the production and reproductive performance of animal raised on extensive grassland. Presently, in the state of Rio Grande do Sul (southern Brazil) there is a lack of information on macro and micro elements mineral deficiency troughout the analysis of biological fluids. Information available in this field reports only individual cases of mineral deficiency and analysis of elements on pastures. The level of mineral found on pasture suggests the presence of non-clinical mineral deficiency of some elements in either some seasons of the year or on the different animal categories of the State herds. The Central Valley Region, the third most important social and economically of the State cattle industry, is characterised by extensive production on natural pasture, with quite poor mineral supplementation. The low mineral level found on pastures in this area, detected by previous works, suggest further investigation. The main aims of this work were: (a) to detect possible mineral deficiency in beef cows by determining Pi, Ca, Cu, Zn, Se (gluthathion peroxidase) and I (T4) in blood and Na and K in saliva; (b) to check the possible relationships with the mineral level on pasture; (c) to detect the mineral profile on four different periods of the productive circle (IA, clean up bulls, end of gestation period and beginning of lactation). A total of seven blood and saliva samples were collected from each of four herds of Cachoeira do Sul county on four different periods. The results showed marginal deficiencies of Pi, Na, I and Se in all periods of the year. Mean values of Cu and Zn were among normal levels but the K level was above the reference level. The Ca serum level was always bellow normal and could be related to the low protein ingestion and high Mg pasture level. Finally, only a low relationship was found between mineral level on blood/saliva and pasture levels. Most critical periods were end of gestation and beginning of lactation, suggesting a relationship with the physiological need of those periods.

There is little evidence that the productivity of New Zealand beef herds has improved over time. Data from the NZ Meat and Wool Board’s Economic Service (2006) suggest that the average national calving percentage has declined over the last two decades. During the same period cattle carcass weights have increased but so too has the average cow live-weight which has resulted in increased maintenance costs of the cow herds. It is unclear whether production efficiency in the industry has improved or declined over time. The aim of this research was to develop means of improving productivity in commercial beef herds through practical methods of performance recording. The objectives were firstly to establish current management practices in commercial herds and secondly to develop an objective system for cow selection and culling which would have practical application in commercial herds. Beef management survey Ninety two commercial beef producers with more than 100 breeding cows from the greater Canterbury region of New Zealand were surveyed. Pasture control was the main reason given for owning a beef herd. Size and conformation were the main selection criteria for choosing replacement heifers and bulls. Over 80% of herds retained their own heifers as replacements and >60% mated yearling heifers to first calve at two years of age. Fertility was poor in the surveyed herds. In-calf rates at pregnancy testing averaged 88% for maiden heifers, 92% for rising second calvers and 93% for mixed age (m.a.) cows. There was no significant difference between in-calf rates of maiden heifers mated to first calve at two or three years of age; nor was there any significant difference between the re-breeding success of the two groups. Heifers mated at least one week earlier than m.a. cows, achieved a re-breeding success 4.7% greater (P<.01) than those mated at the same time. Reasons for cows not weaning a calf included wet dry (9.3% of pregnant cows wintered), pregnancy tested not-in-calf (7.4%) and dam death (2.6%). Only 87.9% of pregnant females wintered weaned a calf (89.4% of m.a. cows and 84.9% of heifers). Reasons why cows exited the herds included diagnosed empty (37.2% of all exits), involuntary culls (25.4%), sold wet dry (16.2%), deaths (13.1%) and poor calf production (5.1%). Vaccination was infrequent with clostridial vaccines the most common in m.a. cows (15.2%) and in calves (40.7%); vaccination against Leptospirosis was much less common. Very few of the surveyed farms used any system of performance recording; as a result there was very little performance-based selection or culling practiced. Evaluation of alternative measures of cow productivity Data from four performance recording beef herds were used to compare alternative measures of cow productivity with the industry standard which is calf weaning weight adjusted for sex (SOC) and age of calf and age of dam (AOD), i.e. the “200 day weight.” None of the alternative measures evaluated required knowledge of calving date and all were relatively easily obtainable in extensively managed beef herds. The assessment of cows was based not on their estimated breeding values but instead on their most probable producing ability which, as the sum of all of the permanent, repeatable aspects of the calf-rearing ability of the cow, explains considerably more of the variance of weaning weight than does breeding value alone. SOC and AOD-adjusted marking weight, weaning weight and average daily gain (ADG) between marking and weaning were the traits mostly highly correlated with the 200d wt of calves (r = 0.68, 0.90 and 0.74. respectively). An Extensively- Grazed-Cow-Weaning-Index of these three indicator traits was found to be more highly correlated than any of the individual traits on their own (r = 0.94). Index weights for the three indicator traits were calculated within each herd and then those within-herd index weights were regressed on readily obtainable herd descriptive variables to obtain a regression equation that could predict index weights for any herd. When the model was applied to data from two additional herd years not included in the original model, the EGCW Index was highly correlated with the 200d weights (r>0.90). Performance-based culling of previously unselected commercial beef herds based on the EGCW Index will result in improved productivity due to the moderately high repeatability of calf weaning weight. Objective data from extensively grazed commercial herds will also make possible the use of commercial herd data in genetic evaluations of herd sires.