• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 13
  • 12
  • 8
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 2
  • Tagged with
  • 49
  • 49
  • 11
  • 8
  • 8
  • 7
  • 6
  • 6
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 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.
31

The Damara sheep : an appraisal of its reproductive performance and potential

Schoombee, Cornelius Johan Albertus 03 1900 (has links)
Digitized from microfiche to pdf. / Thesis (PhD(Agric) (Human and Animal Physiology))--University of Stellenbosch, 1998. / Please refer to full text.
32

Vyhodnocení reprodukce v chovu ovcí clun forest

KLEČÁKOVÁ, Martina January 2019 (has links)
The aim of the diploma thesis was to evaluate reproduction indicators (percentage of pregnancy, fertility, intensity, total rearing, reactivity, rearing of lambs born and total lamb mortality), their comparison over the years and the average in the Czech Republic. The influence of the age of the mother on fertility and the proportion of sheep according to the frequency of litters was also evaluated. Monitoring was carried out in breeding sheep clun forest (at 30 ewes) at Studnice farm from 2015 - 2018. In the monitored reproduction indicators, there was a statistically significant effect (P 0,01) only in the fertility of the herd in question for the period 2015 - 2018. This was caused by higher fertility differences in the first two years on average by 10% between selected breeding and average in the Czech Republic . For the past two years, fertility was on average 25% lower than the national average. When assessing the effect of maternal age on fertility, the highest fertility rates were in three-year-old (174%) and four-year-old sheep (168%). The effect on the highest fertility rates was the highest number of lambs born (about 2 lambs per sheep). Since the third year of age fertility has fallen until the fifth year. Then there was a slight increase (the number of born lambs in the sheep (1.5 lambs) increased) and the lowest fertility (133%) was found in seven-year-old and older sheep, when the number of lambs was also decreasing. Based on the above data on the effect of age on fertility, a statistically highly significant effect (P 0,01) was observed in the observed breeding for the years 2015 - 2018.
33

Emprego do sêmen criopreservado e capacitado in vitro na inseminação artificial intracervical superficial em ovinos.

Silva, Carlos Alberto Brigoni e January 2012 (has links)
A inseminação artificial intracervical superficial em ovinos é uma técnica simples, de baixo custo e eficiente no emprego do sêmen fresco. Por outro lado, particularidades do aparelho reprodutivo da fêmea ovina, a quantidade de células espermáticas que sobrevivem ao pós-congelamento bem como a capacitação precoce de espermatozóides durante o processo de criopreservação, impedem o emprego desta técnica com sêmen criopreservado, fazendo-se necessária a deposição intrauterina, com auxílio da laparoscopia. Desconhece-se a eficiência da inseminação artificial intracervical superficial em ovinos, empregando-se sêmen criopreservado e capacitado in vitro. O experimento foi realizado com objetivo de determinar as taxas de prenhez com o sêmen criopreservado e capacitado in vitro. Os animais foram divididos aleatoriamente em 5 grupos: sêmen fresco (SF); sêmen congelado cervical (SCC); sêmen congelado laparoscopia (SCL); sêmen congelado capacitado cervical (SCCC); e sêmen congelado capacitado laparoscopia (SCCL). Todas as fêmeas receberam doses inseminantes com concentração de 200x106 sptz. As inseminações ocorreram em um período de 52 a 60 horas após a retirada dos dispositivos de progesterona. Os diagnósticos de prenhez foram realizados com auxílio da ultrassonografia 30 dias após as inseminações. As taxas de prenhez observadas foram: No grupo SF 42,30% (11/26), SCC 23,07% (6/26), SCL 54,16% (13/24), SCCC 25,92% (7/27), SCCL 48,14% (13/27), não existindo diferença estatística entre os grupos experimentais. O experimento realizado mostrou que é possível obter prenhez, empregando sêmen criopreservado e capacitado in vitro, na inseminação artificial pela via cervical em ovinos. / The superficial intracervical insemination in sheep is a simple, low cost and efficient technique using fresh semen. Still, the particularities of the female tract, the amount of sperm cells wich survive and the early capacitation during the cryopreservation process, difficult the use of this technique with cryopreserved semen, maaing it's necessary to intrauterine with the aid of laparoscopy. It's unanown the efficiency of superficial intracervical insemination in ovine, using cryopreserved and in vitro capacitated semen. The experiment was carried out with the objective to determine the pregnancy rate of ewes inseminated with cryopreserved and in vitro capacitated semen. The females were randomly distributed among five experimental groups: fresh semen (SF), frozen semen cervical (SCC), frozen semen laparoscopy (SCL), frozen semen in vitro capacitated cervical (SCCC), frozen semen in vitro capacitated laparoscopy (SCCL). All females received dosis with 00x106sptz per insemination. The inseminations were performed from to 60 hours after the withdrawal of progesterone implants. The pregnancy diagnosis was conducted by ultrasongraphy 30 days after inseminations. The observed pregnancy rates was: SF ,30% (113 6), SCC 3,07% (63 6), SCL ,16% (133 ) SCCC %, SCCL 4,1 % (133 7). our experiment showed that in sheep it's viable the superficial cervical artificial insemination using cryopreserved and in vitro capacitated semen.
34

Caracterização do crescimento folicular, ovulação e atividade lútea após tratamento com progestágenos de borregas pré-púberes Santa Inês portadores de gene FecGe

Toma, Claudia Monteiro Dias [UNESP] 17 December 2012 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:35:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-12-17Bitstream added on 2014-06-13T19:24:34Z : No. of bitstreams: 1 toma_cdm_dr_botfmvz.pdf: 1436243 bytes, checksum: 56562676bbc756d475dc2ab4b1cbcda5 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Visou-se caracterizar em borregas Santa Inês de 20-24 semanas de idade, o desenvolvimento final do trato reprodutivo, desencadeamento da puberdade, crescimento folicular, ovulação e atividade lútea após tratamento com progestágenos. Para tanto foram realizados 3 experimentos. No primeiro objetivou-se determinar os efeitos de estímulos subsequentes de progestágenos sobre o desenvolvimento uterino em borregas, Santa Inês independente da constatação da presença de gene de prolificidade. A condição impúbere das fêmeas foi detectada pela ausência de ciclicidade por meio de duas quantificações de progesterona pareadas com intervalo de sete dias. Posteriormente foram formados três grupos de 6 animais. O primeiro grupo (G1) foi submetido a um período de 12 dias de estímulos com progestágeno (1,5 mg de norgestomet/1/2 implante subcutâneo Crestar®), o segundo (G2) a dois períodos, com intervalo de 5 dias entre eles, de 12 dias de estímulos com progestágeno (1,5 mg de norgestomet/1/2 implante subcutâneo Crestar®) e o terceiro (G Controle) permaneceu como controle, não recebendo estímulo hormonal exógeno e mantido em isolamento social das fêmeas dos outros grupos. Em todos os animais (n=18) o desenvolvimento do trato reprodutivo e a resposta ovariana foram avaliados por meio da obtenção do diâmetro uterino médio, comprimento e largura do ovário e mensuração dos folículos ovarianos por exames ultrassonográficos seriados e laparoscopia em 3 momentos. Após os estímulos, um de 12 (G1) e dois de 12 dias (G2), as borregas tratadas apresentaram maior diâmetro médio uterino que aquelas do grupo controle, não se constatando diferença no maior diâmetro dos cornos uterinos entre os animais dos grupos tratados. O comprimento e largura do ovário e tamanho médio de folículos ovarianos... / The aim is the studied in Santa Inês lambs of 20-24 weeks of age, suffering gene FecGE, onset of puberty, follicular growth, ovulation and luteal activity after treatment with progesterone (CIDR®). For this purpose three experiments were performed. In the first the objective was to determinate the effects of subsequent stimulation of progestogens on uterine development in ewe lambs, regardless of the finding of gene prolificacy. The pré-puberal condition of females was detected by the absence of cyclicity by means of two measurements of progesterone paired with an interval of seven days. Subsequently three groups were formed of 6 animals. The first group (G1) was submitted for a period of 12 days with progestogen stimulus (1.5 mg norgestomet/1/2 subcutaneous implant Crestar®), second (G2) to two periods separated by 5 days, 12 days of stimulation with progestogen (1.5 mg subcutaneous implant norgestomet/1/2 Crestar®) and third (G control) was the control, receiving no exogenous hormone stimulation and kept in isolation from females of other social groups. In all animals (n = 18) the development of the reproductive tract and ovarian response were evaluated obtaining the average uterine diameter by serial ultrasound examinations and laparoscopy in 3 times. After the stimulation of 12 or 24 days, the treated lambs had higher uterine diameter than those in the control group, no difference was verified in diameter of the uterine horns between animals treated groups. The second experiment was carried out MOET (multiple ovulation and embryo transfer) of adult sheep carriers FecGE gene order to obtain ewe lambs carriers of the FecGE gene to compose Experiment III. Was monitored during this experiment body development, across weight, body condition score (BCS) and body mass index (BMI) of lambs during the growth... (Complete abstract click electronic access below)
35

Efeito da gordura protegida sobre a composição do leite, anestro pós-parto, resposta às infecções parasitárias e desempenho de cordeiros, em ovelhas da raça Bergamácia /

Stradiotto, Monalissa de Melo, 1980- January 2007 (has links)
Orientador: Edson Ramos de Siqueira / Banca: Lia de Alencar Coelho / Banca: Alessandro Francisco Talanine do Amarante / Resumo: No Brasil, muito pouco se conhece sobre o leite ovino, pois a maioria das raças brasileiras são especializadas para a produção de carne ou lã, mas é possível encontrar animais com aptidão leiteira. O presente trabalho teve o objetivo de avaliar o efeito da gordura protegida na composição do leite, duração do anestro pós-parto, resposta às infecções parasitárias e desempenho dos cordeiros, em ovelhas da raça Bergamácia. Utilizou-se 77 ovelhas distribuídas em 2 grupos por ordem de parição e idade, em dois tratamentos: dieta Controle (C): silagem de milho e concentrado; e dieta com Gordura Protegida (GP): a mesma de C e adição de gordura ruminalmente protegida (35 g/ovelha/dia) ao concentrado. As dietas foram isoenergéticas e isoprotéicas, contendo 70% NDT e 16% PB com base na matéria seca. Os cordeiros permaneceram com suas mães até 45 dias de idade, quando foram desmamados. As ovelhas, 48 horas pós-parto, foram ordenhadas mecanicamente uma vez ao dia, às 7h 00, com produção de leite mensurada diariamente pelo período de 60 dias. Amostras de leite foram coletadas semanalmente para análise da composição centesimal e teor de caseína. O tratamento GP apresentou maior produção de leite média diária após a desmama (0,531 vs 0,489 kg/cab/dia), entretanto, a produção de todo o período experimental não foi diferente entre os tratamentos (0,453 vs 0,468 kg/cab/dia, para C e GP, respectivamente). Não foram observadas diferenças entre tratamentos para os teores de gordura do leite até a 6ª semana de lactação, sendo verificadas apenas após a desmama. Ambos teores de alfa e beta caseínas apresentaram diferenças entre tratamentos (30,00 vs 18,50 Kda para alfa caseína e 32,48 vs 25,65 Kda para beta caseína, para os tratamentos C e GP respectivamente). O sistema de produção utilizado provavelmente foi uma variável importante nos resultados... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Little is known about sheep milk in Brazil because the majority of Brazilian breeds are for meat production or wool, but is possible to find some type milk animals. The present work aimed to evaluated the effect of protected fat on milk composition, time to estrus regress after lambing, gastrointestinal nematodes infections and lamb performance of Bergamasca ewes. It were used 77 ewes allocated in 2 homogenous groups by parity and age. Diet control (C): corn silage and concentrate; diet with protected fat (GP): same of C and protected fat added (35 g/ewe/day) to the concentrate. Diets were isoenergetic and isonitrogenous with 16% of CP and 70% of TDN on dry matter basis. In both groups, lambs were kept with their mothers in pasture during the day, being separated at night. After morning milking, lambs were returned to their mothers, being weaned at 45 days of age. Ewes from both groups were mechanically milked for 60 days. Treatment GP presented higher daily average milk productionafter lambs weaning (0.5351 vs 0.489 kg/head/d), horewer, average milk production of the whole period was not different (0.453 vs 0.468 kg/head/d for C and GP, respectively). There was no found difference between treatments for fat content milk until 6th week of lactation. Alfa e beta casein content has presented differences between treatment (30,00 vs 18,50 Kda for alfa casein and 32,48 vs 25,65 Kda for beta casein, for C e GP respectively). The production system used probably was an important variable in that results due to lamb presence during a moment in the day induced milk retention during ewe machine milking. / Mestre
36

Caracterização do crescimento folicular, ovulação e atividade lútea após tratamento com progestágenos de borregas pré-púberes Santa Inês portadores de gene FecGe /

Toma, Claudia Monteiro Dias. January 2012 (has links)
Orientador: Sony Dimas Bicudo / Banca: Eunice Oba / Banca: Maria Denise Lopes / Banca: Daniel Bartoli Souza / Banca: Claudia Fernandes Barbosa / Resumo: Visou-se caracterizar em borregas Santa Inês de 20-24 semanas de idade, o desenvolvimento final do trato reprodutivo, desencadeamento da puberdade, crescimento folicular, ovulação e atividade lútea após tratamento com progestágenos. Para tanto foram realizados 3 experimentos. No primeiro objetivou-se determinar os efeitos de estímulos subsequentes de progestágenos sobre o desenvolvimento uterino em borregas, Santa Inês independente da constatação da presença de gene de prolificidade. A condição impúbere das fêmeas foi detectada pela ausência de ciclicidade por meio de duas quantificações de progesterona pareadas com intervalo de sete dias. Posteriormente foram formados três grupos de 6 animais. O primeiro grupo (G1) foi submetido a um período de 12 dias de estímulos com progestágeno (1,5 mg de norgestomet/1/2 implante subcutâneo Crestar®), o segundo (G2) a dois períodos, com intervalo de 5 dias entre eles, de 12 dias de estímulos com progestágeno (1,5 mg de norgestomet/1/2 implante subcutâneo Crestar®) e o terceiro (G Controle) permaneceu como controle, não recebendo estímulo hormonal exógeno e mantido em isolamento social das fêmeas dos outros grupos. Em todos os animais (n=18) o desenvolvimento do trato reprodutivo e a resposta ovariana foram avaliados por meio da obtenção do diâmetro uterino médio, comprimento e largura do ovário e mensuração dos folículos ovarianos por exames ultrassonográficos seriados e laparoscopia em 3 momentos. Após os estímulos, um de 12 (G1) e dois de 12 dias (G2), as borregas tratadas apresentaram maior diâmetro médio uterino que aquelas do grupo controle, não se constatando diferença no maior diâmetro dos cornos uterinos entre os animais dos grupos tratados. O comprimento e largura do ovário e tamanho médio de folículos ovarianos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim is the studied in Santa Inês lambs of 20-24 weeks of age, suffering gene FecGE, onset of puberty, follicular growth, ovulation and luteal activity after treatment with progesterone (CIDR®). For this purpose three experiments were performed. In the first the objective was to determinate the effects of subsequent stimulation of progestogens on uterine development in ewe lambs, regardless of the finding of gene prolificacy. The pré-puberal condition of females was detected by the absence of cyclicity by means of two measurements of progesterone paired with an interval of seven days. Subsequently three groups were formed of 6 animals. The first group (G1) was submitted for a period of 12 days with progestogen stimulus (1.5 mg norgestomet/1/2 subcutaneous implant Crestar®), second (G2) to two periods separated by 5 days, 12 days of stimulation with progestogen (1.5 mg subcutaneous implant norgestomet/1/2 Crestar®) and third (G control) was the control, receiving no exogenous hormone stimulation and kept in isolation from females of other social groups. In all animals (n = 18) the development of the reproductive tract and ovarian response were evaluated obtaining the average uterine diameter by serial ultrasound examinations and laparoscopy in 3 times. After the stimulation of 12 or 24 days, the treated lambs had higher uterine diameter than those in the control group, no difference was verified in diameter of the uterine horns between animals treated groups. The second experiment was carried out MOET (multiple ovulation and embryo transfer) of adult sheep carriers FecGE gene order to obtain ewe lambs carriers of the FecGE gene to compose Experiment III. Was monitored during this experiment body development, across weight, body condition score (BCS) and body mass index (BMI) of lambs during the growth... (Complete abstract click electronic access below) / Doutor
37

Emprego do sêmen criopreservado e capacitado in vitro na inseminação artificial intracervical superficial em ovinos.

Silva, Carlos Alberto Brigoni e January 2012 (has links)
A inseminação artificial intracervical superficial em ovinos é uma técnica simples, de baixo custo e eficiente no emprego do sêmen fresco. Por outro lado, particularidades do aparelho reprodutivo da fêmea ovina, a quantidade de células espermáticas que sobrevivem ao pós-congelamento bem como a capacitação precoce de espermatozóides durante o processo de criopreservação, impedem o emprego desta técnica com sêmen criopreservado, fazendo-se necessária a deposição intrauterina, com auxílio da laparoscopia. Desconhece-se a eficiência da inseminação artificial intracervical superficial em ovinos, empregando-se sêmen criopreservado e capacitado in vitro. O experimento foi realizado com objetivo de determinar as taxas de prenhez com o sêmen criopreservado e capacitado in vitro. Os animais foram divididos aleatoriamente em 5 grupos: sêmen fresco (SF); sêmen congelado cervical (SCC); sêmen congelado laparoscopia (SCL); sêmen congelado capacitado cervical (SCCC); e sêmen congelado capacitado laparoscopia (SCCL). Todas as fêmeas receberam doses inseminantes com concentração de 200x106 sptz. As inseminações ocorreram em um período de 52 a 60 horas após a retirada dos dispositivos de progesterona. Os diagnósticos de prenhez foram realizados com auxílio da ultrassonografia 30 dias após as inseminações. As taxas de prenhez observadas foram: No grupo SF 42,30% (11/26), SCC 23,07% (6/26), SCL 54,16% (13/24), SCCC 25,92% (7/27), SCCL 48,14% (13/27), não existindo diferença estatística entre os grupos experimentais. O experimento realizado mostrou que é possível obter prenhez, empregando sêmen criopreservado e capacitado in vitro, na inseminação artificial pela via cervical em ovinos. / The superficial intracervical insemination in sheep is a simple, low cost and efficient technique using fresh semen. Still, the particularities of the female tract, the amount of sperm cells wich survive and the early capacitation during the cryopreservation process, difficult the use of this technique with cryopreserved semen, maaing it's necessary to intrauterine with the aid of laparoscopy. It's unanown the efficiency of superficial intracervical insemination in ovine, using cryopreserved and in vitro capacitated semen. The experiment was carried out with the objective to determine the pregnancy rate of ewes inseminated with cryopreserved and in vitro capacitated semen. The females were randomly distributed among five experimental groups: fresh semen (SF), frozen semen cervical (SCC), frozen semen laparoscopy (SCL), frozen semen in vitro capacitated cervical (SCCC), frozen semen in vitro capacitated laparoscopy (SCCL). All females received dosis with 00x106sptz per insemination. The inseminations were performed from to 60 hours after the withdrawal of progesterone implants. The pregnancy diagnosis was conducted by ultrasongraphy 30 days after inseminations. The observed pregnancy rates was: SF ,30% (113 6), SCC 3,07% (63 6), SCL ,16% (133 ) SCCC %, SCCL 4,1 % (133 7). our experiment showed that in sheep it's viable the superficial cervical artificial insemination using cryopreserved and in vitro capacitated semen.
38

Emprego do sêmen criopreservado e capacitado in vitro na inseminação artificial intracervical superficial em ovinos.

Silva, Carlos Alberto Brigoni e January 2012 (has links)
A inseminação artificial intracervical superficial em ovinos é uma técnica simples, de baixo custo e eficiente no emprego do sêmen fresco. Por outro lado, particularidades do aparelho reprodutivo da fêmea ovina, a quantidade de células espermáticas que sobrevivem ao pós-congelamento bem como a capacitação precoce de espermatozóides durante o processo de criopreservação, impedem o emprego desta técnica com sêmen criopreservado, fazendo-se necessária a deposição intrauterina, com auxílio da laparoscopia. Desconhece-se a eficiência da inseminação artificial intracervical superficial em ovinos, empregando-se sêmen criopreservado e capacitado in vitro. O experimento foi realizado com objetivo de determinar as taxas de prenhez com o sêmen criopreservado e capacitado in vitro. Os animais foram divididos aleatoriamente em 5 grupos: sêmen fresco (SF); sêmen congelado cervical (SCC); sêmen congelado laparoscopia (SCL); sêmen congelado capacitado cervical (SCCC); e sêmen congelado capacitado laparoscopia (SCCL). Todas as fêmeas receberam doses inseminantes com concentração de 200x106 sptz. As inseminações ocorreram em um período de 52 a 60 horas após a retirada dos dispositivos de progesterona. Os diagnósticos de prenhez foram realizados com auxílio da ultrassonografia 30 dias após as inseminações. As taxas de prenhez observadas foram: No grupo SF 42,30% (11/26), SCC 23,07% (6/26), SCL 54,16% (13/24), SCCC 25,92% (7/27), SCCL 48,14% (13/27), não existindo diferença estatística entre os grupos experimentais. O experimento realizado mostrou que é possível obter prenhez, empregando sêmen criopreservado e capacitado in vitro, na inseminação artificial pela via cervical em ovinos. / The superficial intracervical insemination in sheep is a simple, low cost and efficient technique using fresh semen. Still, the particularities of the female tract, the amount of sperm cells wich survive and the early capacitation during the cryopreservation process, difficult the use of this technique with cryopreserved semen, maaing it's necessary to intrauterine with the aid of laparoscopy. It's unanown the efficiency of superficial intracervical insemination in ovine, using cryopreserved and in vitro capacitated semen. The experiment was carried out with the objective to determine the pregnancy rate of ewes inseminated with cryopreserved and in vitro capacitated semen. The females were randomly distributed among five experimental groups: fresh semen (SF), frozen semen cervical (SCC), frozen semen laparoscopy (SCL), frozen semen in vitro capacitated cervical (SCCC), frozen semen in vitro capacitated laparoscopy (SCCL). All females received dosis with 00x106sptz per insemination. The inseminations were performed from to 60 hours after the withdrawal of progesterone implants. The pregnancy diagnosis was conducted by ultrasongraphy 30 days after inseminations. The observed pregnancy rates was: SF ,30% (113 6), SCC 3,07% (63 6), SCL ,16% (133 ) SCCC %, SCCL 4,1 % (133 7). our experiment showed that in sheep it's viable the superficial cervical artificial insemination using cryopreserved and in vitro capacitated semen.
39

The effects of dietary molybdenum and sulfur on serum copper concentrations, growth and reproductive function in lambs

Robinson, Julie A. January 1991 (has links)
Feeds often contain molybdenum (Mo) and sulfur (S) in excess of recommended allowances for adequate copper (Cu) absorption by ruminant livestock. Two randomized-block experiments were conducted using lambs given a cereal-based diet (90% of dry matter (DM) intake), containing 8 mg Cu, 0.7 mg Mo and 2.1g S per kg DM, that was either unsupplemented or supplemented with ammonium molybdate or sodium sulfate alone or in combination, to determine the effects of Mo, S and Mo+S on growth, hematology, serum Cu and Mo concentrations and reproductive function. Short term intake (4 weeks) by rams, aged 18 and 20 weeks, of 26 mg Mo alone or in combination with 2g S per kg DM, had no effect on growth, hematology or the concentration of total Cu in serum (TCu). However, supplemented groups had lower (P<0.05) concentrations of serum Cu soluble in trichloroacetic acid (TCA-Cu), but the group given Mo+S had the highest (P<0.05) concentration of serum residual Cu (RCu). Luteinizing hormone (LH) peak amplitude was affected by age*diet interaction (P<0.05), because of high amplitude LH peaks in the serum of lambs, aged 24 wks, given Mo alone. Testosterone serum secretory profiles did not differ among diet groups, but testosterone peak frequency was higher (P<0.05) for older ram lambs. Long term intake (32-39 wks) by ewe, ram and wether lambs (gonadal influence) of 12 mg Mo, or 2g S alone or combined per kg DM also had no effect on hematology or TCu. Food intake and liver weights were higher (P<0.05), but TCA-Cu was lower (P<0.05) for groups given S. Serum concentrations of total Mo (TMo) were higher (P<0.05) for Mo-supplemented groups, but RCu was highest only for the Mo+S group. Growth was affected by Mo*S*gonadal influence*time interaction (P<0.05); until autumn, the body weight of Mo-supplemented groups were higher than those of ram and wether lambs given Mo+S. Ovarian or testicular functions were delayed more severely for Mo- than Mo+S-supplemented groups. Mean concentrations of LH were affected by Mo*S*gonadal influence*time interaction (P<0.05); the mean LH values of Mo-supplemented ram and ewe lambs were higher than the Mo+S-supplemented group, whereas a reverse trend was observed for wether lambs. The amplitude of LH peaks was affected by Mo*S*gonadal influence*time interaction (P<0.05); for ram lambs, LH peak amplitude was higher for Mo than Mo+S-supplemented groups, whereas for wether and ewe lambs the reverse trend was noted. Mean concentrations of serum Cortisol and Cortisol peak amplitude were affected by Mo*S interaction (P<0.05); the mean Cortisol concentration and peak amplitude for the Mo-supplemented group were higher than those for the Mo+S-supplemented group. The frequency of LH and Cortisol peaks did not differ (P>0.10) among diet groups. In conclusion, Mo supplementation of cereal-based diets containing a high concentration of Cu did not adversely affect lamb growth. However, the effect of high dietary Mo on reproductive function appears to depend on the dietary level of S and the induction of high serum RCu (thiomolybdate). Further investigations on the effects of Mo and thiomolybdate on endocrine function may provide a nutritional basis for improving reproductive efficiency in ruminants. / Land and Food Systems, Faculty of / Graduate
40

The relationship between pelvic dimensions and linear body measurements in dorper sheep

Van Rooyen, Ignatius Martin January 2012 (has links)
Thesis (M. Tech. Agriculture) -- Central University of Technology, Free state, 2012 / Low lifetime rearing success and high perinatal mortality have been associated with small pelvic areas of ewes. Ewes with small pelvic areas are more prone to experience dystocia during parturition and high perinatal mortality. It would thus make sense to include pelvic area as criterion in selecting breeding animals (rams) in an attempt to assure bigger pelvic areas in the female progeny as the heritability of pelvic area ranges between 50-60%. The aims of this study were to develop two instruments to accurately measure the pelvic area and rump slope in small stock, to investigate the hindquarter dimensions and to quantify the relationship between a number of easy to measure external body measurements and pelvic dimensions of Dorper sheep. The pelvic meter developed was pre-tested on 90 sheep prior to slaughtering at an abattoir and shortly after slaughter. The correlation between the pre- and post- slaughter measurements was highly significant (P <0.05; r = 0.85). In this study 272 Dorper and White Dorper rams (5-7 months of age) participating in the Northern Cape Veldram project and 332 young Dorper and White Dorper ewes (±12 months of age) from three different breeders were measured. The inside pelvic area was measured trans-rectally. The rams’ pelvic areas were measured five times transrectally, at 40 days intervals between the ages of 223 ± 41 and 385 ± 41 days of age. The height of the pelvis was obtained by measuring the distance between the dorsal pubic tubercle on the floor of the pelvis and the sacrum (spinal column) on the top. The width of the pelvis was measured as the widest distance, between the right and the left shafts of the ilium bones. The pelvic area was calculated using the π (PH/2)*(PW/2) formula. Other linear body measurements (body height, shoulder height, chest depth, forequarter width, hindquarter width, rump length) as well as body weight were taken. The rams’ rump slope was measured in degrees with an instrument that was developed for this purpose, and the ewes’ rump slope was visually scored on a scale from 1-5 with one being very flat and five being very droopy. The overall mean pelvic area of ewes 35.44 ± 4.89 cm2 and those of the rams 28.22 ± 3.21 cm2 differed with 7.22 cm2. Stud ewes recorded significantly larger (P <0.05) pelvic areas (37.38 ± 4.3 cm2) than commercial ewes (33.92 ± 3.77cm2). Results indicated that there are no significant correlations between pelvic dimensions and other body measurements considered in this study, indicating the need to measure pelvic area directly. Both the pelvic meter and rump slope meter, specially developed for this study, proved to be accurate and relatively practical to use in Dorper sheep.

Page generated in 0.0944 seconds