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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Concentrados de alta fibra em dietas para a terminação de novilhas Nelore

Oliveira, Priscila Silva Neubern de [UNESP] 02 July 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:28:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-07-02Bitstream added on 2014-06-13T19:16:12Z : No. of bitstreams: 1 oliveira_psn_me_jabo.pdf: 143666 bytes, checksum: 8917daa47b0787a19d0ef98f6d336e3a (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O estudo foi conduzido para avaliar o efeito de duas proporções de concentrado, 70 e 80%, com duas fontes energéticas, milho e farelo de gérmen de milho, e volumoso à base de silagem de milho, sob o consumo de nutrientes, desempenho, características de carcaça, não componentes de carcaça e qualidade da carne de 28 novilhas Nelore confinadas, com aproximadamente 14 meses de idade e peso corporal médio de 200 kg, objetivando o abate. O delineamento experimental utilizado foi o inteiramente casualizado segundo esquema fatorial 2 x 2 ( 2 proporções de concentrado x 2 fontes energéticas) totalizando 4 tratamentos e 7 repetições, sendo as médias comparadas pelo teste de Tukey a 5%. Não houve interação da proporção de concentrado x fonte energética da dieta sobre o consumo de MS. Houve efeito significativo da interação proporção de concentrado x fonte energética da dieta para os consumos de proteína bruta (PB) e fibra em detergente neutro (FDN), sendo que a maior proporção de concentrado, associada ao milho, possibilitou maior consumo diário de PB (1,17 kg/dia) e FDN (4,05 kg/dia). Observou-se valor médio de consumo de fibra em detergente ácido superior para as dietas com 80% de concentrado, tanto para a dieta com milho quanto com farelo de gérmen de milho. Houve efeito significativo da fonte energética da dieta sobre o peso final dos animais, sendo que os animais alimentados com as dietas contendo milho apresentaram valor médio de peso final (326,14 kg) superior aos alimentados com as dietas contendo farelo de gérmen de milho (292,07 kg). A associação de altas proporções de concentrado, com milho como fonte energética, proporciona resultados satisfatórios de ganho em peso e desempenho de novilhas Nelore, já a substituição total do milho pelo farelo de gérmen de milho, associado à altas proporções de concentrado ricos em fibra... / The objective of this study was to evaluate the effect of two proportions of concentrate, 70 and 80%, with two energy sources, corn and corn germ meal, and roughage basis of corn silage on the intake of nutrients, performance, characteristics of a carcass, non components of carcass and meat quality of confined 28 Nellore heifers. The experimental design was a completely randomized design in factorial scheme 2 x 2 (2 proportions of concentrate x 2 energy sources) 4 replications and 7 treatments, and the averages has been compared by Tukey 5% test.. There was no interaction proportion of concentrate x energy source on the intake of dry matter. There was a significant effect of interaction proportion of concentrate x energy source intake for crude protein (CP) and neutral detergent fiber (NDF), suggesting that a higher proportion of concentrate, with the corn, allowed greater intake of CP (1.17 kg / day) and NDF (4,05 kg / day). It was observed average intake of acid detergent fiber than for diets with 80% concentrate, with both the diet with corn as the corn germ meal. There was a significant effect of dietary energy source on the final weight of animals, and the animals fed the diets with corn had average final weight (326.14 kg), above the fed with diets with corn germ meal (292.07 kg). The association of high proportions of concentrate with corn as an energy source, provided satisfactory results in performance of Nellore heifers, since the replacement of the corn germ meal, associated with high proportions of concentrate rich in fiber, not was recommended for young Nellore heifers. There was a significant effect the energy source of the diet on the weight of empty body, and the animals that received the diets with corn showed the average value of empty body weight (309.44 kg) than the diets of with corn germ meal (276.42 kg). The carcass yield, the thickness... (Complete abstract click electronic access below)
62

Efeitos das concentrações de progesterona, duração do proestro e diâmetro folicular sobre a taxa de concepção de novilhas Nelore submetidas à inseminação artificial após detecção do estro ou inseminadas em tempo fixo

Martins, Thiago [UNESP] 30 November 2011 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:28:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-11-30Bitstream added on 2014-06-13T19:16:16Z : No. of bitstreams: 1 martins_t_me_botfmvz.pdf: 1373980 bytes, checksum: f2c744fca36213ab387227a01d3d9dc0 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Universidade Estadual Paulista (UNESP) / O objetivo desse estudo foi avaliar o efeito das concentrações de progesterona no desenvolvimento folicular e a influência do diâmetro folicular e duração do proestro na concepção de novilhas púberes inseminadas após detecção de cio ou submetidas à IATF. No exp.1, 723 novilhas foram sincronizadas com o protocolo: D0: benzoato de estradiol (BE, 2,0 mg, Estrogin®) + CIDR®; D7: dinoprost trometamina (PGF2a, 12,5 mg, Lutalyse ). As novilhas foram distribuídas aleatoriamente no dia 0 para inserção de CIDR® sem utilização prévia (CIDR1) ou utilizado previamente por 18 dias (CIDR3) e retirada no dia 7 ou dia 9 seguido de detecção de cio e inseminação 12h após o cio. No exp.2, 1083 novilhas foram sincronizadas de acordo com o exp1, entretanto todos dispositivos foram removidos no dia 9 e os animais foram inseminados 48 h (0,5 mg, i.m., ECP® no dia 9), 54 ou 72 h (100 μg, im., Fertagyl® no dia da IATF). No exp.3 474 novilhas foram distribuídas aleatoriamente para receberem: D-1: 2mg de BE no grupo 3; D0: 1 e 2 mg de BE respectivamente nos grupos 1 e 2. Todas novilhas foram sincronizadas com CIDR1, receberam 12,5 mg de PGF2a no dia 7 e 0,5 mg de ECP no dia 9. No grupo 2 foi aplicado 200 UI de eCG no dia 9. As novilhas foram inseminadas 48 horas após a remoção do dispositivo, perfazendo assim 3 grupos experimentais: grupo 1 (1 mg de BE no D0), grupo 2 (200 UI de eCG no D9) e grupo 3 (CIDR por 10 dias). Nos exp.1 e 2 o diâmetro do maior folículo (ØFD) e amostras de sangue (P4) foram obtidas em um subgrupo de animais no dia 7 e dia 9. No dia da IA e IATF foi feita avaliação do ØFD em um subgrupo de animais no exp.3 e em todos animais no exp1 e 2. Amostras de sangue para dosagem de P4 foram colhidas 7 dias após a IA ou IATF em um subgrupo de animais do exp.1 e em todos animais nos... / The aim of this trial was to evaluate the effect of progesterone concentration in follicular development and influence of follicular diameter and length of proestrus in the conception rate of pos pubertal heifers inseminated after detection of estrus or submitted to TAI. In exp.1, 723 heifers were synchronized with the protocol: D0: estradiol benzoate (EB, 2.0 mg, Estrogin®) + CIDR®; D7: dinoprost trometamina (PGF2a, 12.5 mg, Lutalyse ). The heifers were randomly assigned on D0 for inserting CIDR® without prior use (CIDR1) or previously used for 18 days (CIDR3) and were withdraw on day 7 or day 9 followed by heat detection and insemination 12 hours after estrus. In exp.2, 1083 heifers were synchronized according to exp1, however all devices were removed in day 9 and the animals were inseminated 48h (0.5 mg, i.m., ECP® on day 9), 54 ou 72 h (100 μg, im., Fertagyl® on day TAI). In exp.3, 474 heifers were randomly assigned to receive: D-1: 2 mg of EB in group 3; D0: 1 and 2 mg of EB respectively in groups 1 and 2. All heifers were synchronized with CIDR1, received 12.5 mg of PGF2a on day 7 and 0.5 mg of ECP on day 9. In the group 2 was administered 200 UI of eCG on day 9. The heifers were inseminated 48 hours after device removal, so three experimental groups were formed: group 1 (1 mg of EB on D0), group 2 (200 UI of eCG on D9) and group 3 (CIDR for 10 days). In the exp.1 and 2 the diameter of the largest follicle (ØFD) and sample of blood (P4) were obtained of subset of animals on day 7 and day 9. On days of AI and TAI the diameter of the largest follicle (ØFD) was measured in the subset of animals in the exp.3 and all animals in the exp.1 and exp.2. Blood samples for P4 assays were harvested seven days after AI or TAI in subset of animals the exp.1 and all heifers the exp.2 and exp.3. Pregnancy diagnosis was... (Complete abstract click electronic access below)
63

Desempenho reprodutivo de novilhas Nelore pré-púberes expostas à progesterona

Claro Junior, Izaias [UNESP] 12 August 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:28:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-08-12Bitstream added on 2014-06-13T18:34:32Z : No. of bitstreams: 1 clarojunior_i_me_botfmvz.pdf: 295153 bytes, checksum: c36ee0a1b86bf612b9001d23303be47c (MD5) / Universidade Estadual Paulista (UNESP) / O objetivo desse experimento foi avaliar o efeito de tratamentos com progesterona (P4) na indução de estro, concepção e prenhez em novilhas Nelore prépuberes. Novilhas Nelore (n = 935) com idade média de 24,0 ± 1,13 meses, peso de 298,0 ± 1,89 Kg e ECC 3,2 ± 0,26, foram submetidas a dois exames ultrassonográficos com intervalo de sete dias (d-19 e d-12) para determinar a presença ou ausência de CL, e aquelas com presença de CL em uma ou ambas avaliações foram consideradas púberes (Grupo PGF; n = 346). No dia -12 as novilhas consideradas pré-púberes foram divididas aleatoriamente para não receberem tratamento (Grupo CIDR0; n = 113), para receberem um dispositivo intravaginal novo contendo 1,9 g de P4 (Grupo CIDR1; n = 237), ou para receberem um dispositivo utilizado previamente por 27 dias (Grupo CIDR4; n = 239). No dia zero foi retirado o CIDR das novilhas dos tratamentos CIDR1 e CIDR4, e as novilhas do tratamento PGF receberam aplicação de prostaglandina F2 . Todas as novilhas foram submetidas à palpação retal para avaliação do escore uterino (EU) e amostras de sangue foram colhidas para dosagens de P4. O diâmetro do maior folículo (ØFOL) foi mensurado em todas as novilhas no dia zero. A partir do dia um (d1) todas as novilhas foram submetidas à observação de estro durante 45 dias e inseminadas seguindo o esquema: cio manhã / IA tarde do mesmo dia e cio tarde / IA no dia seguinte de manhã e depois foram expostas a touros por mais 45 dias de estação de monta (EM). As variáveis contínuas foram avaliadas pelo PROC GLM e as binomiais pelo PROC LOGISTIC do SAS. Nas novilhas prépúberes, houve influência (P < 0,05) do tratamento nas concentrações de P4 no dia 0 (CIDR0: 0,43 ± 0,16; CIDR1: 2,26 ± 0,11; CIDR4: 1,22 ± 0,11 ng/ml), ØFOL (CIDR0: 9,41 ± 0,24; CIDR1: 9,73 ± 0,17; CIDR4: 11,37 ± 0,16 mm), EU no dia... / The aim of this trial was to evaluate the effects of treatments with progesterone (P4) on the rates of induced estrus, conception and pregnancy in pre-pubertal Nelore heifers. Nelore heifers (n = 935) with 24.0 ± 1.13 months, body weight of 298.0 ± 1.89 Kg and body conditional score (BCS) of 3.2 ± 0.26 were submitted to two ultrasound examinations 7 d apart (d -19 and -12) to determine the presence or absence of CL, and those with presence of CL in at least one examination were considered pubertal (PGF; n = 346). On d -12, the pre-pubertal heifers were randomly assigned to receive no treatments (group CIDR0; n = 113), a new intravaginal insert containing 1.9 g of P4 (group CIDR1; n = 237) or a P4 insert used previously for 27 d (group CIDR4; n = 239). On d 0, heifers from treatments CIDR1 and CIDR4 had inserts removed, and heifers from treatment PGF received a prostaglandin F2 treatment. Also, heifers were rectally palpated for uterine score (US) evaluation, blood samples were taken for P4 analysis and follicular diameter (ØFOL) was measured in all heifers on d 0. Beginning on d 1, animals were observed for estrus and inseminated during 45 d [estrus morning / artificial insemination (AI) afternoon of same day and estrus afternoon / AI on next day morning] and further exposed to natural breeding from d 46 to 90 of breeding season (BS). Continuous variables were evaluated by PROC GLM and binomial variables by PROC LOGISTIC of SAS. In pre-pubertal heifers, there were effects of treatment (P < 0.05) on serum concentrations of P4 at d 0 (CIDR0: 0.43 ± 0.16; CIDR1: 2.26 ± 0.11; CIDR4: 1.22 ± 0.11 ng/mL), ØFOL (CIDR0: 9.41 ± 0.24; CIDR1: 9.73 ± 0.17; CIDR4: 11.37 ± 0.16 mm), US at d 0 (CIDR0: 1.46 ± 0.06; CIDR1: 1.86 ± 0.04; CIDR4: 2.20 ± 0.04), means days to show estrus (CIDR0: 4.45 ± 0.28; CIDR1: 3.52 ± 0.13; CIDR4: 3.19 ± 0.14 days), estrus detection rate in 7 d of BS... (Complete abstract click electronic access below)
64

Estádio de maturidade sexual em novilhas da raça gir leiteiro com faixa etária de 11 a 29 meses de idade criadas em regime extensivo / Sexual maturity stage in zebu breed gir heifers between 11 to 29 mouths of age in extensive livestock

Lima, Diogo Vivacqua de 29 May 2009 (has links)
Made available in DSpace on 2015-03-26T14:02:17Z (GMT). No. of bitstreams: 1 texto completo.pdf: 585635 bytes, checksum: 505a39e4e39b0de0546abdf24356aa9e (MD5) Previous issue date: 2009-05-29 / The objective of this work was to evaluate the measurement development and the sexual maturity stage in Zebu Gir heifers in interval of 46 to 57 days, along 8 months. There were carried out 31 Zebu heifers (Bos indicus) with age between 11 to 29 months, in extensive livestock, management in grass Brachiaria decumbens paddocks and had free access to shade, water and mineral ad libitum. The follicular development was characteristic by presence or not of follicle by ultrasound. The measurement was done by characteristics as, girth height, bodily length, pillion length; distance between isquiun-isquiun; distance between iliun-iliun; rib depth, thoracic perimeter and bodily weight. The data were subjects to regression analysis by SAEG (2007). Only 4 female (4 / 31, 7,7%) showed by ultrasound the presence of luteum body, which means female puberty, but, there were linear growth to bodily development and for weight gain with mean 0,177kg. The heifers showed late when compeer to puberty and sexual maturity, where only 4 animals showed puberty until 29 months of age. The bodily weight of Zebu Gir seems more important than female ages to puberty arise and probably the bodily weight at last to be raised is ± 270 kg. / Objetivou-se verificar o desenvolvimento biométrico, e o estádio de maturidade sexual em novilhas da raça Gir em intervalos de 46 a 57 dias, durante 8 meses. Foram utilizadas 31 novilhas zebuínas (Bos taurus indicus) da raça Gir leiteiro, com idades variando entre 11 e 21 meses, criadas em regime extensivo, manejadas em piquetes com pastagem predominantemente de Brachiaria decumbens, água, sombra e sal mineral ad libitum. O desenvolvimento folicular foi caracterizado pela presença ou não de folículos por ultrassonografia. A biometria foi feita mensurando as características de altura de cernelha; comprimento corporal; comprimento de garupa; distância entre ísqueos; distância entre íleos; profundidade de costela, perímetro torácico, peso corporal. Os dados obtidos foram submetidos a analise descritiva e analise de regressão utilizando-se o SAEG (2007). Somente 4 fêmeas (4/31, 7,7%) apresentaram corpo lúteo pela avaliação ultrassonografica, indicando à puberdade dessas fêmeas, porém houve crescimento linear para desenvolvimento corporal e para ganho de peso diário com média de 0,177kg. As novilhas mostraram-se tardias com relação a puberdade e maturidade sexual, onde apenas 4 animais apresentaram a puberdade até os 29 meses de idade. O peso corporal na raça Gir leiteira parece ser mais importante que a idade da fêmea para o surgimento da puberdade e provavelmente o peso corporal mínimo a ser alcançado é de ± 270kg.
65

Crescimento dos tecidos muscular e adiposo e qualidade da carne de novilhas de diferentes grupos genéticos no modelo biológico superprecoce /

Rodrigues, Erico. January 2007 (has links)
Resumo: O objetivo deste trabalho foi avaliar o crescimento de femeas bovinas de diferentes grupos geneticos no sistema intensivo de producao de carne superprecoce, analisando caracteristicas de desempenho como peso vivo (PV), ganho de peso medio diario (GPMD) e crescimento dos tecido muscular e adiposo atraves de avaliacao da area de olho de lombo (AOL) e espessura de gordura subcutanea (EGS) do musculo Longissimus dorsi e espessura de gordura subcutanea da garupa (EGG) do musculo Biceps femoris com imagens coletadas por ultra-som em tempo real nos animais vivos no inicio e fim do experimento. Foram utilizadas 42 femeas de 4 grupos geneticos sendo: 12 . Canchim x . Nelore (. CN), 12 . Canchim x . Nelore (. CN), 10 Simbrasil . Simental X . Nelore ( SIMB) e 10 Three-cross . Simental x . Nelore x . Angus (TC) desmamadas aos 210 dias de idade e peso vivo medio de 247,4 }16,5kg provenientes de creep-feeding durante a fase de cria, e confinadas por aproximadamente 132 }14 dias. Os animais foram abatidos, sendo o criterio de abate peso final de 350kg/PV e 5mm de gordura subcutanea. Os animais do grupo Three-cross apresentaram area de olho de lombo final e final ajustada para 100kg/PV inferiores aos demais grupos, porem apresentaram pesos finais superiores aos demais grupos com um tempo intermediario de confinamento e este grupo tambem apresentou os melhores ganhos de peso medio diario (GPMD) 1,07kg/dia (P<0,05). Nao houve diferenca significativa para area de olho de lombo inicial, espessura de gordura subcutanea (EGS) e para espessura de gordura subcutanea da garupa (EGG). Ajustando-se os valores de (EGG) e (AOL) para o menor numero de dias de confinamento onde os animais Three-cross e Simbrasil foram superiores (P<0,05) para (EGG F 114), e Simbrasil superior (P<0,05) para (AOL F 114). / Abstract: The objective of this study was to evaluate the growth of young heifers of different genetic groups in an intensive meat production system. It was used 42 animals of 4 different genetics groups: 12 . Canchim x . Nellore (. CN), 12 . Canchim x . Nellore (. CN), 10 Simbrasil . Simental X . Nellore (SIMB) and 10 Three way cross . Simmental x . Nellore x . Angus (TC). The animals received creep feeding supplementation and were weaned at 210 days of age with 247,4 }16,48kg. It was analyzed the characteristics of body weight (BWG), average daily gain (ADG), muscular and fat tissues growth. Real time ultrasound evaluation was used to measure ribeye area (RBA, Longissimus dorsi muscle), back fat thickness and P8 (Top rump, Biceps femoris) fat thickness. The feeding period was 132 (}14) days in feedlot system while daily gain was measured every 28 days. The animals were slaughtered with the final weight of 350 kg and 5mm of back fat thickness. The Three way cross heifers had smaller final and adjusted at 100 kg/PV ribeye area compared with the others groups. This group also had a greater final body weight, better average daily gain (GPMD), 1,07 kg/day (P<0,05) and an intermediate days of feeding. There was no significant differences for initial ribeye area (AOL), back fat thickness (EGS) and P8 (EGG), but when the values were adjusted for days of feeding, greater values (P<0,05) (EGG F 114) and (P<0,05) (AOL F 114), respectively. / Orientador: Mário de Beni Arrigoni / Coorientador: André Mendes Jorge / Banca: Roberto de Oliveira Roça / Banca: Rafael da Costa Cervieri / Mestre
66

The effect of blood urea nitrogen on reproductive performance of beef heifers on different levels of nitrogen supplementation

Tshuma, Takula January 2013 (has links)
Ruminants have a unique ability to acquire protein from non-protein nitrogen (NPN) sources, and to recycle nitrogen back into the rumen, instead of excreting all of it via the urine, faeces and milk. However, a high concentration of blood urea nitrogen (BUN) has a negative influence on conception. Additionally, a high dietary nitrogen intake poses a challenge to the environment in the form of ammonia emissions, eutrophication and bad odours. This calls for strategies to reduce the environmental impact of livestock production. Variation exists in the ability of cattle to recirculate nitrogen between as well as within cattle breeds. The purpose of this study was to investigate the effects of BUN concentration on reproductive performance in beef heifers under different management systems in South Africa. Serum samples from 369 Bonsmara heifers were taken in November and December 2010 to determine the BUN concentrations prior to the onset of the breeding season. Heifers were from five herds with different levels of protein supplementation during the weeks before the commencement of the breeding season. Body mass, age, body condition score (BCS) and reproductive tract score (RTS) were recorded at the same time as BUN concentration. Trans-rectal ultrasound and/or-palpation was performed four to eight weeks after the three-month breeding season to detect and estimate the stage of pregnancy. Days to pregnancy (DTP) was defined as the number of days from the start of the breeding season until a heifer was successfully mated. Logistic regression and Cox proportional hazards survival analysis were performed to estimate the effect of BUN concentration on subsequent pregnancy and DTP respectively, while stratifying by herd and adjusting for potential confounders. The correlations between BUN concentration, BCS and RTS were estimated using Spearman’s rho. Pearson correlations were used for the normally distributed variables of age and body mass. BUN concentration was not a significant predictor of pregnancy status but was a significant (P = 0.007) and independent predictor of DTP in heavily and some moderately supplemented herds. As BUN concentration increased, DTP also increased [hazard ratio (HR) = 0.827; 95% CI: 0.721 – 0.949; P = 0.007], while the chance of becoming pregnant decreased, although this was not statistically significant [odds ratio (OR) = 0.882; 95% CI: 0.772 – 1.007; P = 0.063]. Bonsmara heifers with higher BUN concentration, which suggests a better ability to recirculate nitrogen, might be at a disadvantage when the production system includes high levels of RDP supplementation because of this negative impact on reproductive performance. It is proposed that production systems be adapted to avoid selection against animals with an improved ability to recirculate nitrogen. / Dissertation (MMedVet)--University of Pretoria, 2013. / gm2014 / Production Animal Studies / Unrestricted
67

Beef replacement heifer decision tool

Sachse, John January 1900 (has links)
Master of Agribusiness / Department of Agricultural Economics / Dustin L. Pendell / Sachse Family Angus is both a commercial and registered Angus cow-calf operation in Northeast Kansas and has been in operation since 1935. The end goal in mind is to provide quality female breeding seedstock to other beef producers with the hopes of improving their herds. Successful selection and development of beef replacement heifers have major long term effects on stayability in any herd and can even have a positive impact on the whole herd. The objective of this study is to create a decision tool to determine best heifer selection strategies. Specifically, taking a look at the cost of heifer development under a range of scenarios as it applies to more traditional heifer development. The depth of literature addressing the issue of buying or raising replacement heifers is vast, providing various degrees of analysis to help a producer make the best informed decision. Some economists would argue that no single aspect of beef production management is as complicated, or has such an economic impact as cow culling and replacement heifer decisions (Melton, 1980). Procedures and methods were created to analyze whether a producer should raise or develop their own replacement heifers. One method used in creating a decision tool is an enterprise budget. Enterprise budgeting is the systematic determination and listing of expected outputs, revenues, and costs due to the production processes required to produce one unit of an enterprise for a specified time period. To take this one step further, it is assumed a producer makes choices with respect to the combinations of productive factors and products. Partial budgets include an analysis of net returns from small changes or refinement to a ranch. It focuses on parts that change while building upon an enterprise budget. In essence, it fine tunes current operations while holding all else constant. The benefits of partial budgeting take a look at what will be the new or added revenue if a change is implemented on the ranch and what costs will be reduced or eliminated if taken place. What will be the new or added costs and what revenues will be reduced if a change takes place are also things to keep in mind. Therefore, the result will show a producer the net benefit of the change. In turn, Sachse Family Angus will use this information to build their registered and commercial replacement heifers either by developing their own or purchasing from other breeders. Overtime, this decision will be critical as it will impact their herd for years to come. In conclusion, maintaining a good sound, high functioning beef cow herd means selecting and developing quality replacement heifers to retain in the herd each year. An estimated 20% of heifers born each year at Sachse Family Angus are kept as replacement heifers. When managing home raised heifers or purchased heifers, maintaining costs and keeping them in check is crucial because they represent a large up-front investment. The bottom line of this research is to give the managers at Sachse Family Angus and other operations across the country a decision tool that can be used to analyze their current resources and the resources it will take to develop their own heifers successfully and in the most cost effective way or help them analyze if purchasing their heifers makes the most financial sense.
68

The Effects of Estrus on Dry Matter Intake and Feeding Behavior in Beef Heifers of Divergent Sizes

Underdahl, Sarah Rose January 2020 (has links)
The biological process of estrus in cattle is known to initiate behavioral responses as a result of fluctuations in hormones, which may alter time budgeted for feeding. The current study aimed to quantify these variations that may exist in feed intake and behaviors in the days pre and post estrus. For this study, 517 estrous cycles in crossbred beef heifers of divergent sizes were used to analyze the impact of estrus behavior on feeding behavior with or without the presence of a bull. There were few differences in estrus behavior among heifers of divergent sizes, however the presence of a bull influenced all estrus activity parameters. Our findings indicate that feed intake and behaviors were sharply decreased on the day of estrus, but returned to baseline levels the following day. Thus, decreases in feed intake and behavior may serve as an additional tool indicating the onset of estrus.
69

Effects of Forced Exercise on Fertility, Parturition, Mammary Edema, Feed Consumption, and Milk Production in Two-Year-Old Holstein Dairy Heifers

Barker, Brent O. 01 May 1976 (has links)
Forty-two springer Holstein heifers were grouped in threes by sire, body weight, and due date. One of each group served as a control (no exercise). One of each group was exercised at 5.5 kilometers per hour for 1.6 kilometers per day, 5 days per week beginning 4 weeks before expected calving date . The third member of each group was exercised the same as the second member, but exercise was continued for 10 days after calving. Exercise was in a circular lane with a motor driven gate. Prepartum exercise increased ease of parturition and reduced the length of time from calving to release of the placenta. Exercise resulted in smaller uterine horn diameters at 42 days postpartum, but had no significant effect on measures of fertility such as days open or services per conception . Exercise did not appear to reduce severity of udder edema, but edema was first noticeable in control heifers. Milk production for the first 50 days after calving showed no affect from prepartum exercise, but continuing exercise after calving reduced milk production 2.4 kg per day (P< .05). Grain was fed according to production, hence grain consumption was also significantly lower for the postpartum exercise group. Hay consumption for the prepartum exercise group was significantly lower than for controls. Prepartum exercise significantly increased feed utilization efficiency as compared to postpartum exercise.
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Influence of plane of nutrition, growth hormone and growth factors on mammary gland development and function

Lacasse, Pierre January 1993 (has links)
No description available.

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