Resumo: O presente trabalho teve como objetivo estimar parâmetros genéticos e fenotípicos de peso corporal e características de carcaça de 3422 aves nascidas de 17 incubações e resultantes de cruzamento recíproco de uma linhagem de corte e outra de postura, mantidas pela Embrapa Suínos e Aves. As características estudadas foram: peso vivo (PV42), rendimento (RC), matéria seca (MS) e umidade da carcaça (UC) aos 42 dias e proteína bruta, extrato etéreo e cinzas, medidas na carcaça, em porcentagem da matéria natural (PBMN, EEMN e CZMN), da matéria seca (PBMS, EEMS e CZMS) e em gramas (PBG, EEG e CZG). Os componentes de variância foram estimados por máxima verossimilhança restrita, utilizando-se modelo animal uni e bicaracterística, considerando o efeito aleatório genético aditivo e o efeito fixo de grupo (animais de mesmo sexo, incubação e acasalamento). As estimativas de herdabilidade (h2) para PV42, RC, MS e UC foram, respectivamente, iguais a 0,31 ± 0,069, 0,20 ± 0,05, 0,33 ± 0,074 e 0,33 ± 0,074. Melhores estimativas de h2 para as características de qualidade de carcaça foram obtidas quando estas foram expressas em porcentagem da matéria seca (0,48 ± 0,093, 0,55 ± 0,099 e 0,36 ± 0,077, respectivamente para PBMS, EEMS e CZMS). O aumento no PV42 resulta em maior porcentagem de extrato etéreo e menor de proteína bruta e cinzas na carcaça, enquanto que a seleção para rendimento de carcaça pouco irá influenciar os constituintes desta. Correlações genéticas entre características medidas na carcaça em porcentagem da matéria seca indicaram que a seleção para proteína bruta poderia favorecer maiores proporções de cinzas e menores de gordura. / Abstract: The objective of this work was to estimate genetic and phenotypic parameters of body weight and carcass traits from 3422 chickens born of 17 hatches and originated of reciprocal crosses between a broiler and egg type strain, maintained by "Embrapa Suínos e Aves", in Concordia, SC. The traits studied were body weight (BW), carcass yield (CY), carcass dry matter (DM) and moisture (MC) of carcass at 42 days of age and protein, fat and ash, measured in carcass, in wet carcass percentage (PW, FW, and AW), in carcass dry matter percentage (PD, FD and AD) and in grams (PG, FG and AG). The variance components were estimated using a REML method, considering a single and bi-trait model that included random additive genetic effect and the fixed effect of group (animals from the same gender, hatch and cross mating procedure). The heritabilities estimates (h2) for BW, CY, DM, MC were, respectively, 0.31 ± 0.069, 0.20 ± 0.05, 0.33 ± 0.074 and 0.33 ± 0.074. Best h2 estimates of carcass composition traits were calculated when they were expressed in carcass dry matter percentage (0.48 ± 0.093, 0.55 ± 0.099 e 0.36 ± 0.077, respectively for PD, FD and AD). The increase of BW would result in amount in fat percentage and reduction in percentage of protein and ash carcass. The selection for carcass yield would have little influence on the carcass composition. Genetic correlations between traits measured in dry matter percentage carcass indicated that the selection for protein could favor increased ash and reduced fat percentage. / Orientador: Danísio Prado Munari / Coorientadora: Mônica Corrêa Ledur / Banca: João Ademir de Oliveira / Banca: Claudia Cristina Paro de Paz / Mestre

The objective of the present thesis was to study the effect of the selection for growth rate on the carcass and meat quality of line R, which is a line of rabbits selected for growth rate between the 4th and 9th week of age. This line is usually used in breeding schemes, where males from line R are mated with crossbreed females from two lines selected for litter size. When the line R was in the 7th generation of selection some embryos were recovered and vitrified. The selection of the line continued and the embryos were devitrified after some generations. The offspring of the rabbits obtained from the embryos formed the control group (Group C). This group was contemporary compared with the selected group (Group S), formed with rabbits from the present generation of selection. With groups S and C, two experiments were developed. The first experiment consisted in the study of the effect of selection for growth rate on the relative growth of offal, organs, tissues, carcass linear measurements and weight of several parts of the carcass. Group C was contemporary compared with Group S, formed with animals from the 18th generation of selection. A total of 313 animals from both groups and sexes were slaughtered at 4, 9, 13, 20, and 40 weeks old. Organs, tissues and retail cuts were weighed and several carcass linear measurements were recorded. Huxley's allometric equations relating the traits to liveweight by a parameter related to the scale (b) and an allometric coefficient (k) were fitted. Butterfield's quadratic equations relating the degree of maturity of the traits and the degree of maturity of the liveweight by an allometric coefficient (q) were also fitted. Values obtained for k and q coefficients led to similar patterns of growth in most of the traits studied. Full gastrointestinal tract and organs such as liver, kidneys, and thoracic viscera were early maturing (k<1 or q>1) whereas the chilled and reference carcass where late maturing (k>1 or q<1). The re / Pascual Amorós, MDLD. (2007). Effect of selection for growth rate on carcass composition and meat quality in rabbits [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/1938 / Palancia

No description available.

Master of Science / Department of Animal Sciences and Industry / James S. Drouillard / A trial was conducted replacing portions of steam-flaked corn with either dry-rolled corn or dried distiller’s grains with solubles to evaluate effects on performance, carcass characteristics, carcass composition, meat color stability, and meat sensory attributes. Seven hundred crossbred yearling heifers (302 ± 65 kg initial BW) were used in a randomized complete block experiment with a 2 x 2 factorial arrangement of treatments. All diets contained steam-flaked corn (SFC), and factors consisted of the levels of dry-rolled corn (DRC; 0 or 25%) and dried corn distiller’s grains with solubles (DDGS; 0 or 25%). Results revealed no interactions between DRC and DDGS in terms of effects on feedlot performance, and only minor interactive effects were observed for carcass characteristics and meat quality attributes. Feedlot performance and carcass characteristics were not affected by the addition of DRC or DDGS (P > 0.05). Carcass composition and meat quality attributes were measured to determine if fat content of carcasses was altered by feeding DDGS. Diet had no significant effects, as carcasses from the four treatments contained similar amounts of separable portions of muscle, adipose, and bone; and similar percentages of protein, moisture, and ether extract. Compositions of both adipose and muscle tissue were evaluated to assess differences in fatty acid profile. Minimal effects were noted on the fatty acid profiles of the muscle and adipose tissue from cattle fed DDGS or DRC. Feeding cattle DDGS decreased alpha tocopherol (vitamin E) content of meat (P < 0.05). Meat quality attributes were largely unaffected by addition of DRC or DDGS to the diet, as retail color display life, lipid oxidation, sensory attributes, and heterocyclic amine concentrations were not different among treatments. Overall, DRC or DDGS can replace portions of SFC without negatively altering feedlot performance, carcass characteristics, meat composition, or meat quality attributes.

Experiments were conducted to assess effects of nursery feeding programs (using complex or simple diets, including or excluding antibiotics) on growth performance of barrows and gilts up to market weight (approximately 115 kg body weight), plasma levels of growth-related hormones, chemical body composition and carcass traits at market weight. Reducing nursery diet complexity decreased (P < 0.05) growth performance and plasma levels of triiodothyronine during the nursery period, but had no negative carry-over effects on growth performance or hormone plasma levels thereafter. Excluding antibiotics from nursery diets reduced nursery growth performance and plasma levels of insulin-like growth factor-1 and triiodothyronine but appeared to induce subsequent compensatory growth. In general, nursery feeding programs had no effect on body composition and carcass traits at market weight and no effect on wean-to-finish growth performance or carcass value at market weight. This represents an opportunity to improve profitability in commercial pork production. / Ontario Pork; The Ontario Ministry of Agriculture, Food and Rural Affairs; Canadian Agriculture and Agri-Food Swine Research Cluster

Resumo: O estresse por calor é considerado um dos fatores de maior impacto na criação de frangos de corte, já que exerce grande influência no desempenho e na qualidade da carcaça, bem como no perfil de expressão de genes relacionados ao crescimento e desenvolvimento animal. Assim, o presente trabalho objetivou verificar o efeito da temperatura e da restrição alimentar no desempenho, composição de carcaça e nos padrões de expressão de genes envolvidos na regulação do crescimento e desenvolvimento (GHR, IGF-I e IGF-IR), aos 21 e 42 dias de idade dos frangos de corte pela técnica de PCR quantitativo em tempo real. Os resultados evidenciaram que a restrição alimentar imposta pela exposição ao calor reduziu o desempenho e rendimento de peito e aumentou o rendimento de coxas+sobrecoxas. O estresse por calor e o consumo de ração alteraram o rendimento de asas, mas não influenciaram o rendimento de carcaça e de gordura abdominal. O calor aumentou o teor de extrato etéreo no peito e nas asas e diminuiu o de matéria mineral nas coxas+sobrecoxas. Independente da temperatura de criação, a restrição alimentar exerce um efeito negativo na expressão do gene do GHR no fígado das aves jovens, sem maiores reflexos na expressão do gene do IGF-I. O estresse térmico afeta a expressão dos genes hepáticos GHR e IGF-I somente nas aves adultas, as quais apresentam perfil inverso ao das aves restritas pelo "pair-feeding". A reação de amplificação do gene IGF-IR apresentou formação de produtos de amplificação inespecíficos, assim como formação de estruturas secundárias das moléculas dos iniciadores (dímeros e "hairpins"), o que impossibilitou a análise dos resultados / Abstract: Heat stress is considered one of greatest impact factors on broiler chicken production, once that it has great influence on the performance and carcass quality, as well as on the expression profile of genes related to growth and animal development. Thus, the present work had the objective of verifying the effect of temperature and food restriction on the performance, carcass composition and expression pattern of genes involved in the growth regulation and development (GHR, IGF-I and IGF-IR), at 21 and 42 days of age of the broilers using the PCR quantitative real-time technique. The results showed that the food restriction imposed by heat exposure, affected negatively the performance and breast yield and, positively, the tight and drumstick yield. The heat stress and feed intake altered the yield of wings, but did not affect carcass yield and abdominal fat. The heat increased both ether extract content in the breast and wings and reduced the mineral matter content in the tights and drumsticks. Independent of temperature, in the young bird's livers, food restriction endorses a negative effect on the GHR gene expression, without greatest reflects on IGF-I expression. Only on adult bird's, thermal stress affects the expression of GHR and IGF-I hepatic genes, that exhibit an inverse profile of restricted pair-feeding birds. The amplification reaction of IGF-IR gene showed both formation of nonspecific amplification products, as well as secondary structures of the primers of the molecules (dimerous and hairpins), precluding the analysis of results / Orientador: Renato Luís Furlan / Coorientador: Luiz Roberto Furlan / Banca: João Martins Pizauro Júnior / Banca: Poliana Fernanda Giachetto / Mestre

Made available in DSpace on 2014-06-11T19:28:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-07-23Bitstream added on 2014-06-13T19:16:15Z : No. of bitstreams: 1 deantonio_j_me_jabo.pdf: 657213 bytes, checksum: 374031f1e29e0df005c8fe1ed5dc8c25 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O estresse por calor é considerado um dos fatores de maior impacto na criação de frangos de corte, já que exerce grande influência no desempenho e na qualidade da carcaça, bem como no perfil de expressão de genes relacionados ao crescimento e desenvolvimento animal. Assim, o presente trabalho objetivou verificar o efeito da temperatura e da restrição alimentar no desempenho, composição de carcaça e nos padrões de expressão de genes envolvidos na regulação do crescimento e desenvolvimento (GHR, IGF-I e IGF-IR), aos 21 e 42 dias de idade dos frangos de corte pela técnica de PCR quantitativo em tempo real. Os resultados evidenciaram que a restrição alimentar imposta pela exposição ao calor reduziu o desempenho e rendimento de peito e aumentou o rendimento de coxas+sobrecoxas. O estresse por calor e o consumo de ração alteraram o rendimento de asas, mas não influenciaram o rendimento de carcaça e de gordura abdominal. O calor aumentou o teor de extrato etéreo no peito e nas asas e diminuiu o de matéria mineral nas coxas+sobrecoxas. Independente da temperatura de criação, a restrição alimentar exerce um efeito negativo na expressão do gene do GHR no fígado das aves jovens, sem maiores reflexos na expressão do gene do IGF-I. O estresse térmico afeta a expressão dos genes hepáticos GHR e IGF-I somente nas aves adultas, as quais apresentam perfil inverso ao das aves restritas pelo “pair-feeding”. A reação de amplificação do gene IGF-IR apresentou formação de produtos de amplificação inespecíficos, assim como formação de estruturas secundárias das moléculas dos iniciadores (dímeros e “hairpins”), o que impossibilitou a análise dos resultados / Heat stress is considered one of greatest impact factors on broiler chicken production, once that it has great influence on the performance and carcass quality, as well as on the expression profile of genes related to growth and animal development. Thus, the present work had the objective of verifying the effect of temperature and food restriction on the performance, carcass composition and expression pattern of genes involved in the growth regulation and development (GHR, IGF-I and IGF-IR), at 21 and 42 days of age of the broilers using the PCR quantitative real-time technique. The results showed that the food restriction imposed by heat exposure, affected negatively the performance and breast yield and, positively, the tight and drumstick yield. The heat stress and feed intake altered the yield of wings, but did not affect carcass yield and abdominal fat. The heat increased both ether extract content in the breast and wings and reduced the mineral matter content in the tights and drumsticks. Independent of temperature, in the young bird’s livers, food restriction endorses a negative effect on the GHR gene expression, without greatest reflects on IGF-I expression. Only on adult bird’s, thermal stress affects the expression of GHR and IGF-I hepatic genes, that exhibit an inverse profile of restricted pair-feeding birds. The amplification reaction of IGF-IR gene showed both formation of nonspecific amplification products, as well as secondary structures of the primers of the molecules (dimerous and hairpins), precluding the analysis of results

Made available in DSpace on 2017-07-10T17:48:23Z (GMT). No. of bitstreams: 1 Leandro_Castilha.pdf: 563829 bytes, checksum: 6d297cffa932c5d373629232128d653e (MD5) Previous issue date: 2011-02-21 / Aiming to determine the digestible isoleucine requirement for female swines from 15 to 30 kg, two experiments were conducted, a performance one and a nitrogen balance. In the first experiment, 40 crossbreed female swines of high genetic potential and average performance were used, with 15.00 ± 0.52 kg initial weight, distributed in a randomized blocks design, consisting of five treatments (0.45, 0.52, 0.59, 0.66, 0.73% digestible isoleucine), four replicates and two animals. At the beginning and the end of the performance experiment one animal per experimental unit was bleed for determination of plasma urea. At the end of the experiment, the second animal of each experimental unit was slaughtered to determine carcass composition and organ weights. In the second experiment, 20 castrated crossbred pigs were used, averaging 22.26 ± 1.79 kg of initial weight, distributed individually in metabolism cages in a randomized blocks design, consisting of five treatments (0.45, 0.52, 0.59, 0.66, 0.73% digestible isoleucine) and four replications. In the first experiment, there was quadratic effect (P<0,05) of digestible isoleucine levels over the daily feed intake, with estimation of best feed intake at level 0,704%. There was quadratic effect (P<0,05) of digestible isoleucine levels over efficiency of isoleucine utilization for weight gain, with increase until 0.506% of digestible isoleucine. In the second experiment, only N intake (g/kg BW0,75/day) was influenced (P<0,05) by digestible isoleucine levels, with linear increase on N intake values as digestible isoleucine levels were increased in the rations. The level of 0.506% digestible isoleucine, for female swines from 15 to 30 kg, provided the best efficiency of isoleucine utilization for weight gain, which digestible isoleucine:lysine relation was 0,51. The daily requirement of digestible isoleucine was 4,94 g/day, providing 1,56g of digestible isoleucine/Mcal of metabolizable energy / Com o objetivo de determinar a exigência de isoleucina digestível para fêmeas suínas dos 15 aos 30 kg, foram realizados dois experimentos, um ensaio de desempenho e um balanço do nitrogênio. No primeiro experimento, foram utilizadas 40 fêmeas suínas, mestiças, de alto potencial genético e desempenho médio, com peso vivo inicial de 15,00 ± 0,52kg, distribuídas em um delineamento experimental de blocos ao acaso, constituído de cinco tratamentos (0,45; 0,52; 0,59; 0,66; 0,73% de isoleucina digestível), quatro repetições e dois animais por unidade experimental. No início e no final do experimento, foi realizada a coleta de sangue de um animal por unidade experimental, para determinação da ureia do plasma. Ao final do experimento, o segundo animal de cada unidade experimental foi abatido, para a determinação da composição de carcaça e peso de órgãos. No segundo experimento, foram utilizados 20 suínos, mestiços, machos castrados, com peso vivo inicial de 22,26 ± 1,79kg, distribuídos individualmente em gaiolas de metabolismo, em um delineamento experimental de blocos ao acaso, constituído de cinco tratamentos (0,45; 0,52; 0,59; 0,66; 0,73% de isoleucina digestível) e quatro repetições. No primeiro experimento, houve efeito quadrático (P<0,05) dos níveis de isoleucina digestível sobre o consumo diário de ração, com estimativas de melhor consumo para o nível de 0,704%. Obteve-se efeito quadrático (P<0,05) dos níveis de isoleucina digestível sobre a eficiência de utilização de isoleucina para ganho de peso, com aumento até o nível 0,506%. No segundo experimento, foi observada diferença linear (P<0,05) apenas para o nitrogênio ingerido (g/kg PV0,75/dia), em que o modelo linear apresentou aumento nos valores de N ingerido à medida que aumentaram os níveis de isoleucina digestível nas rações. O nível de 0,506% de isoleucina digestível, para fêmeas suínas dos 15 aos 30 kg, proporcionou a melhor eficiência de utilização de isoleucina para ganho de peso, conferindo uma relação isoleucina:lisina digestível de 0,51. A exigência diária de isoleucina digestível foi de 4,94 g/dia, proporcionando 1,56g de isoleucina digestível/Mcal de energia metabolizável

Heat stress (HS) induced changes in energy metabolism, proteolysis, lipogenesis, and oxidative balance have meat quality ramifications for livestock. However, several knowledge gaps exist in understanding heat stressed finishing pig physiology and pork quality characteristics and how dietary zinc may ameliorate undesirable outcomes. Research was completed to determine zinc supplementation effects on carcass composition, meat quality, and oxidative stability of fresh and processed pork from pigs subjected to a chronic, cyclic heat stress using a 2×2×2 factorial arrangement of treatments with main effects of environment (HS vs. thermoneutral; TN), added zinc level (50 vs. 130 mg kg^-1 available zinc), and zinc source (inorganic vs. organic). Commercial crossbred mixed-sex pigs (initially 72.0 kg) were group-housed under either TN (18.9-16.7°C) or cycling HS conditions with chronic diurnal heat (30-29°C/26-27°C for 12h:12h) on days 24-71 with acute heat waves (32-33°C/29-30°C for 12h:12h) on days 21-24, 42-45, and 63-65. One representative pig (<i>n</i>=80) per pen was slaughtered on day 64. The HS pigs were lighter bodyweight (<i>P</i>=0.039), yielded lighter carcasses (<i>P</i>=0.011), less last rib backfat (<i>P</i>=0.032), tended to have smaller loin eye area (<i>P</i>=0.062) but similar percent lean in belly center slices (<i>P</i>>0.10). Compared to TN, HS carcasses had higher 24-h pH (<i>P</i>=0.001) and decreased drip loss (<i>P</i>=0.034). Shifts in individual fatty acid profile of sausage product derived from HS carcasses were observed but were of insufficient magnitude to affect iodine value. Initially, sausage from HS carcasses tended (day 0, <i>P</i>=0.071) to have less thiobarbituric acid reactive substances than TN but over a 10-day simulated retail display, no treatment induced lipid oxidation differences (<i>P</i>>0.05) were observed in either sausage or displayed loin chops. Consistent treatment differences in CIE L*a*b* of products throughout the 10-day display were not observed. The relationships between physiological changes in pigs receiving supplemental zinc and their body and ambient temperatures were also investigated. A representative gilt (<i>n</i>=96) was selected for thermal monitoring from each pen of the 2×2×2 treatments plus 4 additional treatments representing 2 intermediate levels of Zn in both environments. Core body temperatures (T_core) during the day 42-45 acute heat wave were continuously recorded via indwelling vaginal thermometers and infrared thermal imaging was used to measure skin temperatures at 12-hour intervals. From a 64-gilt subset of the 2×2×2 treatments, jejunum and ileum samples were collected on day 64 for analysis of villus height, crypt depth, and jejunal gene expression of heat shock proteins (27, 70, 90), occludin, and mucin (MUC2). The HS model induced thermoregulatory changes and increases in T_core (<i>P</i><0.05). Day 42-45 ambient temperature was negatively correlated with expression of HSP-27 (r=-0.42, <i>P</i>=0.047), HSP-90 (r=-0.49, <i>P</i>=0.014), and occludin (r=-0.69, <i>P</i><0.001) in HS pigs. For the organic Zn supplemented pigs, ambient temperature was positively correlated with expression of HSP-27 (r=0.42, <i>P</i>=0.034) and MUC2 (r=0.45, <i>P</i>=0.017) and negatively correlated with villus height in jejunum (r=-0.42, <i>P</i>=0.027) and ileum (r=-0.38, <i>P</i>=0.048). Thermal Circulation Index (measure of heat dissipation) of HS pigs was negatively correlated with their ileum villus height (r=-0.51, <i>P</i>=0.015) and positively correlated with HSP-70 expression (r=0.46, <i>P</i>=0.041). The T_core lacked correlation with most variables. This research demonstrates cyclic HS affects carcass composition and quality but does not appear to reduce display shelf-life of pork as indicated by lack of differences in lipid oxidation and color stability. In this HS model, zinc level or source imparted negligible benefits and thermal correlations with gut integrity characteristics existed for organic zinc supplemented and HS pigs. The degree of heat dissipation by heat stressed pigs appeared to be associated with classic HS damage and intestinal responses which may be useful indicators of HS in the grow-finish pig. Another agricultural challenge is maintaining higher education programming which establishes a successful career trajectory for agricultural students amid generational shifts in attitudes and background experiences. Undergraduates studying Animal Science and/or Agricultural Economics were surveyed to understand their perception of how collegiate curricular, co-curricular, and extracurricular experiences (coursework, club participation, relevant work experience, international experience, advising/mentoring, college life, and professional networking) contribute to their anticipated career success. A best-worst scaling experiment was used to force respondents (<i>n</i>=487) to make unbiased tradeoffs between the collegiate experience attributes. Responses were then related back to additional demographical and experience/perception characteristics of respondents. Students indicated relevant work experience was overwhelmingly the most critical of the 7 factors (57% preference share), followed by professional networking (19%), and coursework (14%). Students solely in a pre-veterinary Animal Science curriculum represented a distinct category of students regarding their beliefs and experiences. Further research is needed to investigate possible disconnects between student perceptions and reality in higher education and agricultural careers.