Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 5 uppsater.

Thesis (Ph. D.)--Michigan State University. Dept. of Animal Science, 2008. / Title from PDF t.p. (viewed on July 23, 2009) Includes bibliographical references. Also issued in print.

Thesis (Ph. D.)--University of Wisconsin, 1956. / Typescript (carbon copy). eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 66-74).

Thesis (M. Sc.)--University of Alberta, 2010. / Title from pdf file main screen (viewed on June 9, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Animal Science, Department of Agricultural, Food and Nutritional Science, University of Alberta. Includes bibliographical references.

Thesis (Ph. D.)--University of California, Riverside, 2010. / Includes abstract. Available via ProQuest Digital Dissertations. Title from first page of PDF file (viewed May 17, 2010). Includes bibliographical references. Also issued in print.

The need for a more reliable method to select beef heifers to retain as replacement dams has become a concern in the beef industry. Two polymorphisms described in leptin (LEP), p.Arg25Cys, and pro-melanin concentrating hormone (PMCH), g.-134A>T, have already been shown to improve carcass quality in beef cattle. This study was designed to evaluate any additional advantages of these polymorphisms in terms of heifer conception and calving success and lactational milk yield measured indirectly by their calves’ early ADG while they were primarily on lactation. A dominant effect of the dam’s PMCH T allele was observed on improved calf early ADGs in Simmental heifer dams, although not in Angus heifer dams. This effect could be useful in cow-calf operations where calves were suckling their dams for a longer period before sending the cow-calf pairs out to summer pasture. The dam LEP genotype did not show an effect on their calves’ ADG. This was assumed to be due to low body fat reserves of the heifer dams at the age of two years, allowing for only low levels of leptin. Even though heifer conception was not affected by their LEP and PMCH genotypes, it would be worth evaluating their rebreeding success in the presence of these SNPs in the future. The Integral Membrane Protein 2A (ITM2A) was hypothesized as a candidate gene for frame size in cattle. DNA fragments from 20 cattle, matching the predicted exons of the cattle ITM2A gene, were sequenced to determine whether genetic variation existed. However, the sequence obtained based on the predicted cattle ITM2A sequences appeared to be a pseudogene, rather than the actual cattle ITM2A gene, because exons 1, 2, 3 and 5 contained stop codons. Since frame size has been reported to be associated with the reproductive performance of beef dams and their calves’ growth characteristics, it would be useful to characterize this gene once an improved cattle genome assembly is available.

Objetivo: Investigar a influência do posicionamento mãe/bebê e da pega do bebê nas freqüências de amamentação exclusiva e na ocorrência de traumas mamilares no primeiro mês de vida do bebê. Métodos: Estudo de coorte, contemporâneo, em que foram observadas mamadas de 211 pares mães/bebês sadios na maternidade e aos sete e 30 dias, no domicílio. Foram comparadas as freqüências de cinco itens desfavoráveis ao posicionamento mãe/bebê e três itens desfavoráveis à pega do bebê, bem como as médias do número de itens desfavoráveis, entre as duplas em amamentação exclusiva e as que haviam abandonado essa prática aos 7 e aos 30 dias. Compararam-se também as médias do número de itens desfavoráveis nas mulheres com e sem lesões mamilares na maternidade. Resultados: Não houve associação entre técnica de amamentação na maternidade e freqüência de amamentação exclusiva aos 7 e aos 30 dias. No entanto, aos 30 dias, as duplas em amamentação exclusiva apresentaram melhor posicionamento e pega. Os seguintes itens desfavoráveis foram mais freqüentes entre as duplas que já haviam abandonado a amamentação exclusiva: cabeça e tronco do bebê não alinhados (RR=1,5; IC95%=1,2-1,9), boca pouco aberta (RR=2,3; IC95%=1,3-4,2) e pega não assimétrica (RR=1,6; IC95%=1,3-1,9). Não houve diferença na qualidade da pega entre as mulheres que apresentaram ou não traumas mamilares na maternidade, porém as mulheres que apresentaram lesões nos mamilos mostraram melhor posicionamento na avaliação. Conclusões: A técnica de amamentação na maternidade não foi preditiva para a prática da amamentação exclusiva no primeiro mês. No entanto, aos 30 dias, ela mostrou associação com essa prática. / Objective: To investigate the influence of mother/baby's positioning and the baby's latch on the frequency of exclusive breastfeeding and on the occurrence of nipple traumas in the first month of the baby's life. Methods: Through a prospective cohort study, we observed breastfeeding sessions of 211 healthy mother/baby couples in rooming-in and at day 30 at home. We compared the frequencies of 5 items unfavorable to positioning of the couple and 3 items unfavorable to baby latch between the couples in exclusive breastfeeding and those who had abandoned this practice at days 7 and 30. We also compared the means of numbers of unfavorable items in women with and without nipple lesions in the maternity hospital. Results: No association between the breastfeeding technique in the maternity and the frequency of exclusive breastfeeding at days 7 and 30 was found. However, at day 30, the couples on exclusive breastfeeding presented better positioning and latch. The following unfavorable items were more frequent in the couples that had already abandoned exclusive breastfeeding: unaligned head and trunk of the baby (RR=1.5; IC 95%+1.2-1.9), mouth not opened enough (RR= 2.3; IC 95% = 1.3-4.2), and asymmetrical latch (RR=1.6; IC 95% =1.3-1.9). No difference was found on latch quality for the women with or without nipple traumas in the maternity, but the women with nipple lesions showed better positioning in the evaluation. Conclusions: In the maternity, the breastfeeding technique was not predictive of exclusive breastfeeding practice in the first month. However, at day 30, it showed an association with this practice.

Melhorar o peso dos leitões ao nascimento e consequentemente ao desmame é um os principais desafios da suinocultura moderna, uma vez que ao serem melhoradas para produzir uma quantidade maior de leitões ao nascimento, as matrizes hiperprolíficas acabaram desenvolvendo uma característica indesejável, que é a produção de leitegadas com maior desuniformidade, e um número elevado de leitões com baixo peso ao nascimento. O objetivo do presente estudo foi avaliar a variação do nível de fibra bruta na dieta fornecida dos 74 aos 114 dias de gestação, sobre a digestibilidade dos nutrientes e da energia na gestação, desempenho produtivo e respostas sanguíneas das fêmeas nos períodos de lactação e gestação. Foram utilizadas 33 porcas distribuídas em um delineamento experimental inteiramente casualizado. Os níveis de fibra bruta (FB) nos tratamentos (T) foram: 3,3%, 7,0% e 10,1%. Para aumentar o nível de fibra a quirera de arroz e o farelo de soja foram substituídos parcialmente por farelo de arroz desengordurado e casca de soja. O consumo diário de nutrientes e energia foi similar para todo o período de gestação estudado, diferindo apenas o volume de ração consumida, que para o período dos 74 aos 90 dias de gestação foi de 2,10, 2,21 e 2,40 kg/dia, e para 91 a 111 dias de 2,47, 2,65 e 2,85 kg/dia para T1, T2 e T3, respectivamente. Os dados foram submetidos à análise de variância pelo procedimento MIXED do SAS, e as médias comparadas pelo teste de Fisher (LSD). Análise de regressão foi realizada, utilizando-se a regressão linear ou quadrática conforme o melhor ajuste. Na gestação, o aumento de fibra da dieta proporcionou um decréscimo linear (P<0,05) na energia digestível (ED) e no coeficiente de digestibilidade aparente (CDA) (%) da matéria seca (MS), energia bruta (EB), proteína bruta (PB), carboidratos não fibrosos (CNF) e matéria orgânica (MO). Os níveis sanguíneos, na gestação, de proteína total e globulinas apresentaram um efeito quadrático (P<0,05) ao nível de fibra da dieta, já o colesterol apresentou um efeito linear crescente (P<0,05). Aos 105 dias de gestação e aos 4 dias de lactação os níveis de creatinina (P<0,05) foram maiores nas fêmeas que consumiram 10,1% de FB. O desempenho produtivo e reprodutivo das fêmeas na gestação e lactação, e o peso dos leitões ao nascimento não foram influenciados (P>0,05) pelos T, no entanto, o ganho médio diário das leitegadas apresentou um efeito linear crescente (P<0,05) com o aumento da FB da dieta. Concluindo, o aumento da fibra na dieta causou diminuição na digestibilidade dos nutrientes e energia, sem, contudo afetar o desempenho das matrizes na gestação, lactação e dos leitões ao parto. O uso da fibra na gestação melhorou o ganho de peso dos leitões na lactação. / Improving the weight of piglets at birth and consequently at weaning is one the key challenges of modern pig industry, since by being improved to produce greater amount of piglets at birth, hyperprolific matrices end up by developing an undesirable characteristic, which is the production of littermates with lack of uniformity and high number of piglets with low birth weight. The aim of this study was to evaluate the effect of the variation in crude fiber level in the diet provided at 74 to 114 days of gestation on the digestibility of nutrients and energy in pregnancy, production performance and blood responses of sows in periods of lactation and pregnancy. Thirty-three sows were distributed in a completely randomized design. Crude fiber levels (CF) in treatments (T) were 3.3%, 7.0% and 10.1%. To increase the fiber level, broken rice and soybean meal were partially replaced by defatted rice bran and soybean hulls. The daily intake of nutrients and energy was similar for the entire pregnancy period, differing only in the amount of diet consumed, and for the period from 74 to 90 days of pregnancy, levels were 2.10, 2.21 and 2.40 kg/day and from 91 to 111 days of 2.47, 2.65 and 2.85 kg/day for T1, T2 and T3, respectively. The data were submitted to analysis of variance using the SAS MIXED procedure, and means were compared using the Fisher test (LSD ). Regression analysis was performed using the linear or quadratic regression according better fit. During pregnancy, the increase in dietary fiber provided a linear decrease (P <0.05) in digestible energy (DE) and apparent digestibility coefficient (ADC) (%) of dry matter (DM), crude energy (CE), crude protein (CP), non-fiber carbohydrates (NFC) and organic matter (OM). Blood globulins and total protein levels in pregnancy showed a quadratic effect (P <0.05) to the dietary fiber level, but cholesterol showed an increasing linear effect (P <0.05). At 105 days of pregnancy and after 4 days of lactation, creatinine levels (P <0.05) were higher in females who consumed 10.1% CF. The productive and reproductive performance of females during pregnancy and lactation, and the weight of piglets at birth were not affected (P> 0.05) by T; however, the average daily gain of piglets showed a linear increase (P <0.05) with increasing CF in the diet. In conclusion, increasing fiber in the diet caused a decrease in the digestibility of nutrients and energy, without; however, affecting the performance of matrices during pregnancy, lactation and weight of piglets at birth. The use of fiber during pregnancy improved the weight gain of piglets during lactation.

Important physiological changes occur during lactation to allow for nourishment of the offspring. Specific neuronal groups within the arcuate nucleus of the hypothalamus influence prolactin (PRL) secretion, metabolism and fertility during lactation. Our overall goal was to identify gene expression changes in the arcuate nucleus during lactation and examine the roles of PRL and ovarian hormones in regulating expression of select genes. We evaluated transcriptome changes in the arcuate nucleus during lactation using RNA-sequencing. Thirty-seven differentially expressed genes, including neuropeptides, signaling molecules, receptors and enzymes, were identified between suckled and pup-deprived groups. Selected genes were evaluated by qRT-PCR in ovary-intact and ovariectomized lactating models, which included non-lactating, suckled and 24hr pup-deprived lactating groups. The mRNA expression of tyrosine hydroxylase (Th), kisspeptin (Kiss1), and neurokinin B (Tac3) was decreased, whereas mRNA expression of proenkephalin (Penk), parathyroid hormone 2 receptor (Pth2r), insulin-like growth factor binding protein 3 (Igfbp3), membrane progesterone receptor beta (Paqr8), suppressor of cytokine signaling 2 (Socs2) and cytokine-inducible SH2 domain-containing protein (Cish) was increased in suckled lactating rats. In 24hr pup-deprived dams, mRNA expression of Pth2r, Igfbp3, Paqr8, Socs2 and Cish was decreased and Th was increased, as compared to suckled rats. The mRNA expression of Kiss1 and Tac3 was increased and Penk was decreased after 72hr, but not 24hr, pup deprivation suggesting gene expression of these neuropeptides is slow to return to non-lactating levels after removing the suckling stimulus. Tyrosine hydroxylase (TH) protein and enkephalin (ENK) peptide expression was examined by immunohistochemistry. Lactating rats had increased ENK in the median eminence and decreased TH in the median eminence and arcuate nucleus as compared to virgin ovariectomized rats. ENK co-localization with TH in the arcuate nucleus was more predominant in lactating rats. Penk, Igfbp3, Pth2r, Cish, and Socs2 mRNA expression was decreased after 72hr bromocriptine treatment in suckled rats, suggesting that these genes are PRL-regulated. In contrast, gene expression of Th, Tac3 and Kiss1 were increased and Paqr8 was decreased with 72hr pup-deprivation, but expression of these genes, were not altered with bromocriptine treatment, indicating that these genes are regulated by a non-PRL component of the suckling stimulus. The mRNA expression of Kiss1, Socs2 and Igfbp3 was increased and Penk was decreased in ovariectomized as compared to ovary intact lactating rats, suggesting that ovarian hormones influence the expression of these genes during lactation. Our data show gene expression changes in the arcuate nucleus that may contribute to increased PRL secretion (Th, Penk and Pth2r), decreased PRL receptor signaling (Cis and Socs2), reduced fertility (Kiss1 and Tac3), increased metabolism (Igfbp3) and support a role for progesterone membrane actions (Paqr8). The expression of some genes appeared to be selectively regulated by ovarian hormone input and/or PRL feedback.

Estudos mostram uma grande associação entre alterações nutricionais, hormonais ou ambientais durante períodos críticos da vida, como a gestação e lactação, e o surgimento de doenças crônicas na vida adulta tais como obesidade, diabetes e doenças cardiovasculares, decorrentes de alterações fisio-adaptativas do organismo. Esse fenômeno biológico é denominado programação metabólica. No presente trabalho, avaliamos a resposta parasitológica e histopatológica, durante a fase aguda da infecção, em camundongos adultos infectados com Schistosoma mansoni no modelo de programação pela desnutrição materna na lactação. Ao nascimento da ninhada, as lactantes foram divididas em: (C) controle - livre acesso a ração normal com 23% de proteína; (RP) restrição protéica - livre acesso a dieta com 8% de proteína; (RC) restrição calórica - acesso restrito à ração controle, cuja quantidade foi calculada de acordo com a ingestão do grupo RP. A restrição alimentar foi mantida até o final da lactação. Pós-desmame, todos os filhotes tiveram livre acesso à ração. A infecção das proles de 60 dias de idade foi por via transcutânea com 50 cercárias (cepa BH). O sacrifício ocorreu após 9 semanas de infecção (120 dias de vida). Avaliamos ingestão alimentar, peso e composição corporais, massa tecidual, hormônios séricos, além de morfometria, concentração de colágeno e a resposta inflamatória celular dos granulomas hepáticos. Nos vermes adultos recuperados avaliamos a infectividade e a morfologia do sistema reprodutor e tegumento. No estudo parasitológico foi avaliado o número de ovos eliminados nas fezes e o percentual de estágios evolutivos (oograma). A desnutrição materna pós-natal programou a prole RP para menor ganho de peso e hipofagia e a prole RC para sobrepeso e hiperfagia. O período pré-patente foi mais longo (45 dias) em ambas as proles programadas. Aos 55 dias de infecção com S mansoni, o grupo RP apresentou maior número de ovos nas fezes. Este grupo apresentou maior número de ovos totais nas porções intestinais e fezes, assim como aumento de ovos em todos os estágios evolutivos. Observamos que os vermes machos e fêmeas obtidos das proles RC e RP apresentaram alterações no sistema reprodutor e na estrutura do tegumento. O grupo RP infectado apresentou maior grau de lesão hepática provocada pelo número aumentado de áreas alteradas pelo estágio pré-granulomatoso classificado por exsudativo, menor capacidade de produção de colágeno e maior manifestação inflamatória, caracterizando uma deficiência na modulação do processo inflamatório. Já o grupo RC mostrou menor número de granulomas hepáticos, maior produção de colágeno e vários hepatócitos binucleados, portanto, apresentando melhores condições para modular a resposta inflamatória e melhor capacidade de regeneração hepática diante da presença de lesão, apresentando uma relação parasito-hospedeiro mais equilibrada. O conjunto dos nossos achados sugere que a desnutrição neonatal programou o estado metabólico do hospedeiro repercutindo na evolução da esquistossomose, onde o grupo RC apresentou maior habilidade na modulação da resposta inflamatória e o grupo RP exibiu fragilidades nesta complexa, mas fascinante, relação parasito-hospedeiro. Assim, a programação pela desnutrição materna na lactação afeta a evolução da esquistossomose murina experimental. / Studies have shown a strong association between nutritional, hormonal or environmental changes during critical periods of life, as pregnancy and lactation, and chronic diseases in adult life such as obesity, diabetes and cardiovascular disease, due to body physiological adaptive changes. This biological phenomenon is called metabolic programming. In the present study, we evaluated parasitological behavior and histopathological response during the acute phase of infection in adult mice infected with Schistosoma mansoni in the programming model by maternal malnutrition during lactation. At birth, mothers were divided into: (C) control - free access to normal diet with 23% protein, (PR) protein restriction - free access to diet with 8% protein, (CR) caloric restriction - restricted access to C diet, the amount was calculated according to the PR group intake. Malnutrition was maintained until the end of lactation. Post-weaning, all pups had free access to food. At 60 days-old, offspring was infected percutaneous with 50 cercariae (BH strain). Offspring were killed after 9 weeks of infection (120 days). We evaluated food intake, body weight and body composition, tissue mass, serum hormones, and morphometry, collagen concentration and cellular inflammatory response of the liver granulomas. In adult worms recovered, we analysed infectivity and the morphology of the reproductive system and tegument. The parasitological parameters were assayed by the number of eggs in the stool and the percent of evolutive stages (oogram pattern). Postnatal maternal malnutrition programs PR offspring for lower weight gain and hypophagia and CR offspring for overweight and hyperphagia. The prepatent period was longer (45 days) in both programmed offspring. At 55 days of infection with S. mansoni, PR group had higher number of eggs in the feces. This group had higher number of eggs in feces and intestinal parts as well as higher eggs in all stages of development. We found that male and female worms obtained from the PR and CR offspring showed changes in the reproductive system and structure of the tegument. PR-infected group showed a higher degree of liver damage caused by the increased number of areas altered by the pre-granulomatous exudative sorted by lower capacity to produce more collagen and inflammatory manifestations, indicating a deficiency in the modulation of the inflammatory process. Since CR-infected group showed lower liver granulomas, increased production of collagen and several binucleate hepatocytes, thus providing better conditions to modulate the inflammatory response and increased power of liver regeneration in the presence of injury, presenting a host-parasite relationship more balanced. Taken together, our findings suggest that neonatal malnutrition programs the metabolic state of the host with the consequent evolution of schistosomiasis, where CR group showed higher ability in modulating the inflammatory response and the PR group exhibited weaknesses in this complex, but fascinating, host-parasite relationship. Thus, the programming by malnutrition during lactation affects the development of experimental murine schistosomiasis.