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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.
1

Evaluation of the relationship between hair coat shedding ability, apparent forage digestibility, and mineral status in Angus cattle

Loftin, Margaret P 12 May 2023 (has links) (PDF)
The objective of this study was to evaluate the relationship between hair coat shedding ability, apparent forage digestibility, and mineral status in Angus cattle. Fecal samples were collected on fall calving Angus cows for one week in March, May, and July from 2019-2022. Liver and plasma samples were collected in March and July each year. Fecal samples were analyzed for DM, ash, NDF, and ADF while liver and plasma were analyzed for mineral concentration. Data were analyzed using MIXED procedure of SAS with significance declared at P0.05. Interactions were detected for DM, NDF, ADF, and liver Fe concentration. The model included MFS, month, and MFS by month interaction for each response variable. Interpretation of results showed no clear trends or associations between hair coat shedding ability, apparent forage digestibility, and mineral status, but further investigation is needed to understand cow performance due to relationships between genes and environment.
2

HAIR COAT AND STEROIDAL IMPLANT EFFECTS ON STEERS GRAZING NDOPHYTE-INFECTED TALL FESCUE DURING THE SUMMER

McClanahan, Linda Kay 01 January 2007 (has links)
Sixty steers were grazed on toxic tall fescue for 104 days to determine the effects of hair coats and steroidal ear implants on physiological measurements. Steers were stratified by body weight and hair coat color for assignment to six, 3.0-ha pastures of 'Kentucky 31' tall fescue. Main plot treatments of either ten clipped or ten unclipped steers were randomly assigned to pastures. Five steers in each pasture were implanted with Synovex-S (200 mg progesterone-20 mg estradiol) and five were implanted with Compudose (25 mg estradiol) as sub-plot treatments. Hair growth rate averaged 0.29 mm/day. Sweating rate declined (P andlt; 0.001) over the grazing period and was higher (Pandlt; 0.10) with the estradiol implant. Rectal temperatures were lower (P andlt; 0.05) in clipped cattle (39.3 vs. 39.5??C) when the highest ambient temperature (33??C) of the study was recorded. At high environmental temperatures, percentage of steers actively grazing was negatively correlated (P andlt; 0.10) with ambient temperature. Winter hair coat retention, continuous hair growth, and reduced sweating caused impaired thermoregulation and thus decreased grazing frequency resulting in poor animal performance.
3

Effect of dietary polyunsaturated fatty acid and related nutrients on plasma lipids, and skin and hair coat condition in canines

Hester, Shaleah Lynnae 15 November 2004 (has links)
A study was performed to investigate the effect of diet modifications on skin and hair coat condition in canines. The study included 24 normal adult dogs fed a baseline diet (Ol'Roy[trademark]), during an acclimation period of 12 wk (Phase I). Nine female Beagles and 15 male Hound mix-breed dogs were used. For the next 12 wk (Phase II) the dogs were divided into three groups and fed one of three specially formulated diets. They contained similar ingredients and had similar nutrient profiles except for the following differences: Diet A contained lower but adequate amounts of dietary zinc and linoleic acid than diet B. Diet C was similar to B with respect to zinc and linoleic acid but contained more α-linolenic acid. An evaluation panel conducted skin and hair coat condition scoring on wk 0, 4, 7, and 12 (Phase I) and wk 14, 16, 19, and 24 (Phase II). The panel evaluated the dogs for glossiness, softness, scale, greasiness, and overall condition. Transepidermal water loss (TEWL) and skin hydration (HYDR) assessments were determined on wk 3, 7, and 11 (Phase I) and wk 11, 12, 15, 19, and 23 (Phase II) using a Tewameter[trademark] and Corneometer[trademark] respectively. Blood samples were collected on d 0, 5, 8, 16, 28, 56, and 84. Profiles of plasma phospholipid fatty acids were determined at each collection period. Serum zinc concentrations were analyzed on wk 12, 14, and 24. The hypothesis was that a diet containing increased LA, ALA, and zinc concentrations (diet C) would show improvements of skin and hair coat condition in dogs compared to the other diets. All three test diets caused significant improvements compared to Ol'Roy[trademark]. Diet B caused more improvement than diet A in both subjective and objective assessments of skin and hair coat. Based on mean values diet B is better to be fed to dogs that need to improve skin hydration and diet C should be fed to dogs that need to decrease TEWL. Diet C not only led to improvements in skin and hair coat condition, but also provided additional benefit by producing less pro-inflammatory conditions in the skin.
4

PERFORMANCE AND PHYSIOLOGY OF YEARLING STEERS GRAZING TOXIC TALL FESCUE AS INFLUENCED BY CONCENTRATE FEEDING AND STEROIDAL IMPLANTS

Carter, Jessica Meagan 01 January 2008 (has links)
Fescue toxicosis can produce negative effects on animal weight gain and physiology. Sixty-four steers were grazed on endophyte-infected (E+) KY-31 tall fescue for 77 days in 2007 and sixty steers grazed for 86 days in 2008 to evaluate interactions with implantation of steroidal implants and concentrate feeding on performance and physiology of yearling steers. Steers were stratified by body weight for assignment to six, 3.0-ha toxic tall fescue pastures. The main plot treatment of with or without pelleted soybean hulls (SBH) were randomly assigned to pastures. Pelleted SBH were group-fed to provide daily consumptions of 2.3 kg/steer/d (as fed). Sub-plot treatments of with or without ear implantation with steroid hormone (200 mg progesterone--20 mg estradiol were assigned to groups of five or six steers within each pasture. Average daily gain in the experiment showed an additive effect of feeding SBH and implanting (P
5

Efeito das características do pelame e da taxa de sudação sobre parâmetros reprodutivos em vacas da raça Braford /

Bertipaglia, Elaine Cristina Abaker. January 2007 (has links)
Resumo: O objetivo deste estudo foi avaliar os efeitos das características do pelame e da taxa de sudação (TS) sobre o desempenho reprodutivo de vacas da raça Braford e estimar as herdabilidades e correlações genéticas destas características. Dados da TS, espessura da capa (E), refletância da superfície da capa (R), comprimento dos pêlos (C), diâmetro dos pêlos (D) e número de pêlos por unidade de área (N) foram observados. Ainda, foram avaliadas as seguintes variáveis da reprodução: intervalo de partos (IEP); dias para o parto (DPP); idade ao primeiro parto (IPP); taxa de detecção de cio (Dcio); taxa de gestação para a primeira inseminação (G1IA) e taxa de gestação para a estação de monta (GEM). Os dados de desempenho reprodutivo referem-se aos partos dos anos de 2003 e 2004. Foram avaliadas as inseminações referentes às gestações da estação de monta do período de outubro de 2003 a janeiro de 2004. Durante este período, foram observadas temperatura máxima do ar (Ta), pressão parcial de vapor (Pv) e carga térmica radiante (CTR). As variáveis contínuas (todas as características do pelame, TS, IEP, DPP e IPP) foram analisadas pelo método dos quadrados mínimos. Os seguintes efeitos fixos foram considerados no modelo de todas as características do pelame: pais; grupos de contemporâneos; mês da observação; genótipo e idade. O pai da vaca foi importante para todas as características do pelame, exceto para N. Grupos de contemporâneos afetou todas as variáveis, o mês afetou a variação do C e da R. O genótipo foi importante para C, D e R e a idade afetou R. Na análise da TS foram considerados: grupos de contemporâneos; pais; genótipo; E; C; D; N; R; hora da observação; idade; Ta; Pv e CTR. Todos os fatores meteorológicos e grupos de contemporâneos foram significativos...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study deals with the effects of hair coat characteristics and sweating rate on reproduction of Braford cows and estimation of heritabilities and genetic correlations of these traits. Data on hair length (L), coat thickness (T), hair diameter (D), number of hairs per unit area (N), coat reflectance (R) and sweating rate (SR) were recorded. In addition, calving interval (CI); days to calving (DC); age at first calving (AFC); Estrous detection rate (EDR); conception rate at first insemination (CR1AI) and conception rate at breeding season (CBS) were evaluated. The continuous data were analyzed by least squares methods; considering the following fixed effects on the model for hair coat traits: sires and contemporary groups; month; genotype and age. The effect of sire was important for all hair coat traits, except for N; contemporary groups affected all hair coat traits; the effect of sampling month was important for L and R; genotype affected L, D and R; age was important only for R. The model of SR considered the following fixed effects: contemporary groups; sires; genotype; T, L, D, N, R; time of day, age, air temperature (Ta), partial vapour pressure (Pv) and radiant heat load (RHL). All the meteorological factors and contemporary groups were significant on SR. Age at calving, genotype, sire, R, T, L, N, D and SR were considered as fixed effects on analyses of CI. For the analyses of DC were considered: R, T, L, N, D, SR, genotype, age and sire. Age, genotype and SR were significant on CI and DC. Age at first calving of heifers born from January to March (AFC1) and from July to October (AFC2) were analyzed. Only sire was significant on AFC1; sire, E and D affected the variation of AFC2. The binary traits EDR; CR1AI and CBS were analyzed by logistic regression models...(Complete abstract, acess undermentioned eletronic address) / Orientador: Roberto Gomes da Silva / Coorientador: César Roberto Esper / Banca: Vera Fernanda Martins H. de Lima / Banca: Danísio Prado Munari / Banca: Josineudson Augusto II de Vasconcelos Silva / Banca: Evaldo Antonio Lencioni Titto / Doutor
6

Efeito das características do pelame e da taxa de sudação sobre parâmetros reprodutivos em vacas da raça Braford

Bertipaglia, Elaine Cristina Abaker [UNESP] 23 February 2007 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:35:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-02-23Bitstream added on 2014-06-13T20:26:14Z : No. of bitstreams: 1 bertipaglia_eca_dr_jabo.pdf: 1381681 bytes, checksum: 745ba23720e8cec6ab76449426629614 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo deste estudo foi avaliar os efeitos das características do pelame e da taxa de sudação (TS) sobre o desempenho reprodutivo de vacas da raça Braford e estimar as herdabilidades e correlações genéticas destas características. Dados da TS, espessura da capa (E), refletância da superfície da capa (R), comprimento dos pêlos (C), diâmetro dos pêlos (D) e número de pêlos por unidade de área (N) foram observados. Ainda, foram avaliadas as seguintes variáveis da reprodução: intervalo de partos (IEP); dias para o parto (DPP); idade ao primeiro parto (IPP); taxa de detecção de cio (Dcio); taxa de gestação para a primeira inseminação (G1IA) e taxa de gestação para a estação de monta (GEM). Os dados de desempenho reprodutivo referem-se aos partos dos anos de 2003 e 2004. Foram avaliadas as inseminações referentes às gestações da estação de monta do período de outubro de 2003 a janeiro de 2004. Durante este período, foram observadas temperatura máxima do ar (Ta), pressão parcial de vapor (Pv) e carga térmica radiante (CTR). As variáveis contínuas (todas as características do pelame, TS, IEP, DPP e IPP) foram analisadas pelo método dos quadrados mínimos. Os seguintes efeitos fixos foram considerados no modelo de todas as características do pelame: pais; grupos de contemporâneos; mês da observação; genótipo e idade. O pai da vaca foi importante para todas as características do pelame, exceto para N. Grupos de contemporâneos afetou todas as variáveis, o mês afetou a variação do C e da R. O genótipo foi importante para C, D e R e a idade afetou R. Na análise da TS foram considerados: grupos de contemporâneos; pais; genótipo; E; C; D; N; R; hora da observação; idade; Ta; Pv e CTR. Todos os fatores meteorológicos e grupos de contemporâneos foram significativos... / This study deals with the effects of hair coat characteristics and sweating rate on reproduction of Braford cows and estimation of heritabilities and genetic correlations of these traits. Data on hair length (L), coat thickness (T), hair diameter (D), number of hairs per unit area (N), coat reflectance (R) and sweating rate (SR) were recorded. In addition, calving interval (CI); days to calving (DC); age at first calving (AFC); Estrous detection rate (EDR); conception rate at first insemination (CR1AI) and conception rate at breeding season (CBS) were evaluated. The continuous data were analyzed by least squares methods; considering the following fixed effects on the model for hair coat traits: sires and contemporary groups; month; genotype and age. The effect of sire was important for all hair coat traits, except for N; contemporary groups affected all hair coat traits; the effect of sampling month was important for L and R; genotype affected L, D and R; age was important only for R. The model of SR considered the following fixed effects: contemporary groups; sires; genotype; T, L, D, N, R; time of day, age, air temperature (Ta), partial vapour pressure (Pv) and radiant heat load (RHL). All the meteorological factors and contemporary groups were significant on SR. Age at calving, genotype, sire, R, T, L, N, D and SR were considered as fixed effects on analyses of CI. For the analyses of DC were considered: R, T, L, N, D, SR, genotype, age and sire. Age, genotype and SR were significant on CI and DC. Age at first calving of heifers born from January to March (AFC1) and from July to October (AFC2) were analyzed. Only sire was significant on AFC1; sire, E and D affected the variation of AFC2. The binary traits EDR; CR1AI and CBS were analyzed by logistic regression models...(Complete abstract, acess undermentioned eletronic address)
7

Parâmetros fisiológicos e tricológicos na avaliação do conforto térmico em bovinos de corte / Morpho-physiological responses in genetic groups of cattle with heat adaptation of different degrees

Mastelaro, Ariadne Pegoraro 29 February 2016 (has links)
Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2016-08-04T15:04:10Z No. of bitstreams: 2 Dissertação - Ariadne Pegoraro Mastelaro - 2016.pdf: 2581761 bytes, checksum: 8c68947f1595f8beb96f79d632dd1236 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-08-05T14:11:39Z (GMT) No. of bitstreams: 2 Dissertação - Ariadne Pegoraro Mastelaro - 2016.pdf: 2581761 bytes, checksum: 8c68947f1595f8beb96f79d632dd1236 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-08-05T14:11:39Z (GMT). No. of bitstreams: 2 Dissertação - Ariadne Pegoraro Mastelaro - 2016.pdf: 2581761 bytes, checksum: 8c68947f1595f8beb96f79d632dd1236 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-02-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This study aimed to evaluate the physiological responses and morphological characteristics of cattle belonging to four different genetic groups with different degrees of heat adaptability, raised in pastures in the Center - West of Brazil. The experiment was conducted in two experimental periods (March and August 2015), at São Carlos Farm, Três Lagoas (MS). 54 calves recently weaned from four genetic groups were used, 14 Nellore, 14 Senepol, 12 ½ Angus x ½ Nelore and 14 ¼ Brahman ¼Nelore x 2/4 Senepol, with age, in the beginning of the experiment, five seven months. The average weight of the animals was 197.0 kg (Nelore), 169 kg (Senepol), 235 kg (½ Angus x ½ Nellore) and 233 kg (¼ Brahman x ¼ Nellore x 2/4 Senepol). The experimental design was completely randomized, with four treatments (breeds), where repetitions are the animals within each genetic group. They measured the temperature (rectal, superficial skin and superficial hair coat), heart rate, respiratory rate and surface skin temperature, surface temperature of fur and sweat rate. Moreover, it was determined some morphologic characteristics of the dorsal region. To characterize the environment, there were collected dry bulb temperature, black globe temperature, dew point temperature, wind speed and relative humidity, the sun and the shade, to determine the following thermal comfort indexes: index temperature and humidity, globe temperature and humidity index, and radiation heat load. Among the adaptive features, only those relating to the present differences between the experimental groups (p <0.05), and the genetic group ½ Angus x ½ Nellore showed the highest values of length, diameter, number of hair, density medium and thickness of the hair coat cover in both evaluation periods (March and August). For physiological variables, there was no statistical difference between the experimental groups (p> 0.05), a fact that was also found in the evaluated periods (p <0.05). It follows, therefore, that the choice of breeds with characteristics consistent with the breeding environment is an important factor in the production system efficiency / Objetivou-se avaliar as respostas fisiológicas e características morfológicas de bovinos pertencentes a quatros diferentes grupos genéticos, com diferentes graus de adaptabilidade ao calor, criados em pastagens no Centro – Oeste brasileiro. O experimento foi realizado em dois períodos experimentais (março e agosto de 2015), na Fazenda São Carlos, município de Três Lagoas (MS). Foram utilizadas 54 bezerras recém-desmamadas, provenientes de quatro grupos genéticos, sendo 14 Nelore, 14 Senepol, 12 ½ Angus x ½ Nelore e 14 ¼ Brahman x ¼ Nelore x 2/4 Senepol, com idade, ao início do experimento, de cinco a sete meses. O peso vivo médio inicial dos animais foi de 197,0 kg (Nelore), 169 kg (Senepol), 235 kg (½ Angus x ½ Nelore), e 233 kg (¼ Brahman x ¼ Nelore x 2/4 Senepol). O delineamento experimental foi inteiramente casualizado, com quatro tratamentos (raças), em que as repetições são os animais dentro de cada grupamento genético. Foram mensuradas a temperatura (retal, superficial da pele e superficial de pelame), frequência cardíaca, frequência respiratória e taxa de sudação. Além disso, foram determinadas algumas características morfológicas do pelo na região dorsal. Para caracterização do ambiente, foram coletadas a temperatura de bulbo seco, temperatura de globo negro, temperatura de ponto de orvalho, velocidade do vento e umidade relativa do ar, ao sol e à sombra, para a determinação dos seguintes índices de conforto térmico: índice de temperatura e umidade, índice de temperatura de globo e umidade, e carga térmica de radiação. Entre as características adaptativas, apenas as que se referem ao pelo apresentaram diferenças entre os grupamentos genéticos (p<0,05), sendo que o grupo genético ½ Angus x ½ Nelore apresentou os maiores valores de comprimento, diâmetro, número de pelos, densidade média e espessura da capa de pelame, em ambos os períodos avaliados (março e agosto). Para as variáveis fisiológicas, não houve diferença estatística entre os grupamentos genéticos (p>0,05), fato que também se verificou nos períodos avaliados (p<0,05). Conclui-se, assim, que a escolha de raças com características compatíveis com o ambiente criatório é fator importante na eficiência do sistema de produção.

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