Orientador Francisco Leydson Formiga Feitosa / Coorientador: Paulo Sérgio Patto dos Santos / Banca: Alexandre Secorum Borges / Banca: Nereu Carlos Prestes / Resumo: O trabalho teve como objetivo determinar e avaliar o escore Apgar, os parâmetros vitais, os valores hemogasométricos, o proteinograma e a atividade de gamaglutamiltransferase (GGT) séricas de cordeiros oriundos de partos eutócicos e nascidos de cesarianas induzidas por diferentes protocolos anestésicos, ao nascimento, aos 15 minutos, e após uma, 24 e 48 horas de vida. Os animais foram divididos em três grupos, sendo o primeiro constituído por cordeiros nascidos de parto normal (NORMAL) e os outros dois de cesarianas, porém com dois protocolos anestésicos diferentes, ou seja, por anestesias inalatória (INAL) e total intravenosa (ATI), respectivamente. Os animais nascidos de parto normal apresentaram melhor vitalidade em relação aos nascidos de cesarianas. A frequência respiratória (FR), ao nascimento, foi significativamente menor nos animais nascidos de cesarianas (26 ± 25 mpm, INAL; 5 ± 5 mpm, ATI). Constatou?se tendência à diminuição nos valores de temperatura até os 15 minutos de vida em todos os grupos, prolongando?se, até os 60 minutos, nos animais pertencentes ao grupo ATI. Após o nascimento, tanto os cordeiros nascidos de parto normal quanto os nascidos de cesarianas, desenvolveram acidose respiratória. Os cordeiros recém?nascidos necessitaram de 24 horas de vida para estabilização do equilíbrio acidobásico. Ao nascimento, todos os neonatos tiveram valores mais baixos de proteína total, de gamaglobulina e da atividade sérica de GGT, com aumento significativo, às 24 horas de vida, para as três variáveis, com progressivo decréscimo às 48 horas / Abstract: The aim of this study was to evaluate vital parameters, vitality, the blood gas effect, serum variations of protein and gamma?glutamyltransferase activity of lambs born by normal delivery and by cesarean section, during 48 hours of life. The animals were divided into three groups. The first group was formed with lambs born by normal delivery (NORMAL) and the other two groups were formed with lambs, born by cesarean sections, but with two different anesthetic protocols, one used inhalation anesthesia (INAL) and the other total intravenous anesthesia (TIVA). Lambs in the NORMAL group obtained higher pontuation in Apgar score than cesarean section group. The respiratory rate at birth for the animals delivered by cesarean section (26 ± 25 bpm, INAL; 5 ± 5 bpm, TIVA) was significantly lower than for the ones of the normal delivery. A tendency for decreasing temperature values was verified until the 15 minutes in all groups, lasting until 60 minutes in animals in the TIVA group. Respiratory acidosis was observed in lambs born by normal delivery and by cesarean section after birth. The newborn lambs need 24 hours of life for acid base stabilization. At the moment of birth, all the newborns had lower values of all studied variable, with significant increase at 24 hours of life, followed by gradual decrease at 48 hours / Mestre

Orientador: Ana Carolina de Souza Chagas / Coorientador: Cintia Hiromi Okino / Banca: Maria Cristina de Sena Oliveira / Banca: Alessandro Francisco Talamini do Amarante / Resumo: Tendo em vista o impacto da infecção por Haemonchus contortus na ovinocultura, é crescente o número de estudos acerca da resistência a esse parasita, sendo essencial a compreensão dos mecanismos imunes diretamente relacionados. A resposta a infecções por helmintos é predominantemente de perfil Th2, embora o conjunto de mecanismos imunes que conferem resistência aos ovinos não sejam completamente elucidado. O presente estudo objetivou avaliar as respostas imunes locais (abomaso) associados à resistência à infecção por H. contortus em cordeiros Morada Nova, raça considerada resistente. Um rebanho composto por 287 ovinos foi fenotipado, por meio de contagens de ovos nas fezes, volume globular e peso corporal, após dois desafios parasitários com 4000 L3. Os 20 extremos de infecção (10 mais resistentes e 10 mais susceptíveis) foram submetidos a um terceiro desafio e abatidos sete dias após. Foram quantificados, por RT-qPCR, os níveis de expressão de 22 genes associados às respostas imunes, em abomaso e linfonodos abomasais. Além disso, eosinófilos e mastócitos foram quantificados, e os níveis de IgG e IgA no muco abomasal mensurados. Genes relacionados à resposta inata (TLR2 e CFI) foram superiormente expressos na região pilórica dos animais resistentes. Esses animais também apresentaram, na região fúndica, IL33 (promotor da polarização Th2) e MS4A2 (receptor de IgE) em níveis superiores aos verificados nos susceptíveis. Marcadores pró-infl... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Considering the impact of Haemonchus contortus infection on sheep breeding, there is an increasing number of studies addressing host resistance against to this parasite, and the understanding of directly related immune mechanisms is essential. The response to helminth infections is predominantly Th2- polarized, although the immune mechanisms that confer resistance to sheep are not fully elucidated. The present study aimed to evaluate the local immune responses (abomasum) associated with resistance to H. contortus infection in Morada Nova lambs, a breed considered resistant. A 287 sheep flock was phenotyped, by means of fecal egg counts, packed cell volume and body weight, after two parasitic challenges with 4000 L3. The 20 extremes of infection (10 most resistant and 10 most susceptible) were submitted to a third challenge and slaughtered seven days later. 22 immune-related genes were quantified (RT-qPCR) in abomasum and abomasal lymph nodes. In addition, abomasal eosinophils and mast cells were quantified, and IgG and IgA levels were measured (ELISA) in abomasal mucus. Genes related to innate response (TLR2 and CFI) were superiorly expressed in the pyloric region of the resistant animals. IL33 (Th2 polarization promoter) and MS4A2 (IgE receptor) were also at higher levels in this group. Proinflammatory cytokines (TNFα and IL1β) were superiorly expressed in the fundic region of the susceptible group, which also had IL4 (Th2 response) superiorly expressed in their abomasal lym... (Complete abstract click electronic access below) / Mestre

I studied the acquisition of foraging skills by lambs eating shrub or grass in three experiments. The general approach was to isolate those skills involved in prehending forage from those related to the acceptance of novel foods. Treatment lambs received 15 times more exposure to grass or shrub than did control lambs. Lambs were tested in 2.5 x 2.5 meter monocultures of shrub or grass 5 min/d, on two separate occasions. Height, bulk density and spatial arrangement of plant material were controlled during testing. In Experiment 1, I studied the acquisition of foraging skills by lambs on monocultures of shrubs. I found that inexperienced lambs ingested less forage per unit time than experienced lambs because they had less developed prehension skills. Lambs were more successful at plucking individual leaves than breaking twigs from branches or stripping 1 eaves. Lambs emphasized prehension patterns that were most successful. In Experiment 2, I explored the extent to which foraging skills gained on shrub or grass are specific to shrub or grass. Grass-experienced lambs were more successful at prehending and ingesting grass than were shrub experienced lambs. No statistical differences were observed between shrub- and grass-experienced lambs at prehending and ingesting shrub although numerical values were higher for shrub- than grass-experienced lambs. I hypothesize that a relationship exists between plant form, prehension pattern and foraging experience. In Experiment 3, I studied the degree to which lambs experienced with grass or shrub vary in their ability to prehend and ingest vegetative and flowering grass. Grass- and shrub-experienced lambs ingested more flowering than vegetative grass per unit time. Grass-experienced lambs were more efficient than shrub-experienced lambs at prehending and ingesting vegetative and flowering grass. Shrub-experienced lambs experienced more difficulty at prehending flowering compared to vegetative grass while grass-experienced lambs did not.

Growth data were collected on 1848 Targhee and Targhee crossbred lambs from the Utah Agricultural Experiment Station flock at Cedar City for 1981 and 1982. The study objectives were to establish growth curves for seven lamb genotypes and examine within genotype growth differences among four grazing treatments (sheep alone, sheep and cattle mixed, both continuous and rotation). Body weights were measured at birth, and at mean ages of 56, 120, and 154 (weaning) days of age. Linear, quadratic, and cubic regressions of weight on age were used to establish growth curves. Among genotype comparisons of entire growth curves were impossible as non-linear components were significant. (p<.05). Thus, weights per weigh period and average daily gain between weigh periods were examined to determine differences. Rearing type, birth type, genotype, and pasture treatment were 50.9%, 22.7%, 12.4%, and 6.1%, respectively, of the total variance accounted for by the effects on weaning weights examined. Overall growth patterns were the same for all genotypes with the most rapid gains occurring between 56 and 120 days of age (combined mean .66 pounds). Suffolk-sired lambs from Suffolk-Targhee and Targhee-Finn-Targhee ewes were faster gaining (p<.05) than straight-bred Targhee lambs as well as those from Suffolk sires bred to finn-Targhee, Targhee-Suffokl-Targhee ewes. The second most rapid gains (combined mean .56 pounds) occurred between birth and 56 days. All crossbred lambs had higher average daily gains than Targhee lambs (p%lt;.05). The slowest rate of gain (mean .16 pounds) occurred int he 34 days prior to weaning. Not all differences in body weight among pastures can be attributed to grazing treatments as three genotypes exhibited a significant (p<.05) effect of pasture assignment on weight prior to treatment implementation. Despite initial weight imbalances, genotypes responded similarly to pasture treatments. Sheep rotation pastures had the lightest (p<.05) lambs for most genotypes exhibiting differences in grazing treatments at 120 days and in all genotypes at weaning. The fastest gains and heaviest lambs were in mixed species pastures. In sheep alone pastures, lamb performance was better in continuously grazed pastures than in the rotation pastures.

Importance of lamb marketings The production and marketing of lambs is important in Utah's economy. In 1956, Utah ranked fifth in the United States in lambs produced and saved, with 1,038,000 head produced and 840,000 marketed for consumption, table 1. Cash receipts from the lamb marketings during the year amounted to over 10 million dollars, and in addition, the state's economy benefited through revenues, employment, and raw materials which were provided by the lamb industry. Marketing decisions Lamb producers and handlers are faced with many decisions in marketing their lambs. They not only must decide when and where to sell, but the question of what method of transportation to use must be answered. In essence, the producer or handler can make direct ranch sale to slaughterers, lamb feeders, or speculators and can thereby pass on some of the decision making to the buyer; or he can sell through commission firms and competitive bidding at public livestock markets and retain the decision making himself. In the case of direct sale at the ranch, the buyer usually assumes the cost of marketing from that point until he relinquishes title. Generally, the buyer charges for this service by giving a lower price to the seller than would be received if the seller were to ship to the public livestock market.

Environmental contamination along roadways with lead from processed petroleum and automotive residues has been reported. Toxicity to the herbivores grazing these areas has not been well studied. Comparison of lead concentrations adjacent to roads in Kuwait and in Oregon, USA was studied. Soil samples were taken from three sites at three different distances from the highway (0, 3 and 10 meters) adjacent to King Fahad Highway in Kuwait and Interstate 5 (I-5), Highway 34 (H-34) and Highway 20 (H-20) in Oregon. Soil was analyzed for lead concentrations. The mean lead concentrations in soil samples along King Fahad Highway were significantly higher (p<0.05) than those along 1-5, H-34 and 14-20 in Oregon [4943.6 ppm (mg/kg) vs 129 ppm, 94.9 and 81.67 ppm respectively]. In a field trial animal toxicity studies were conducted on sheep grazing near roadway in Kuwait and also in a controlled barn studies. Fifty lambs ranging in age from 4 to 9 months and grazing on Kuwait pasture adjacent to the King Fahad Highway were tested for blood lead. Levels were determined by Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES). Blood lead levels of these lambs ranged from 0.05-1.00 ppm. Only 12% of the tested population exceeded the blood lead above 0.1 ppm (the high normal value). None demonstrated any clinical signs of lead toxicosis. In addition, a controlled feeding trial was conducted with sheep ingesting similar concentrations of lead as were found along the roadways. These sheep were observed for clinical, gross and histopathological changes. Using the intensive lamb production system common in Kuwait, twenty five lambs ranging in age from 2-10 months were orally fed 0, 2, 4, 8 and 16 mg lead acetate/kg body weight/day in a controlled study. Blood lead levels were tested in these lambs at time zero, week two, and then at monthly intervals until the 14th week. All lambs were slaughtered and necropsied with select tissues analyzed for lead concentrations. Levels of lead in the blood were directly related to the daily administrated lead acetate (P<0.05). Neither gender, age nor breed of the sire had any affect on blood lead levels except for the 14th week where blood lead levels of the young lambs significantly exceeded (P<0.05) those in the older lambs with mean values of 0.54 and 0.34 ppm respectively. In general, lead levels in all the tested tissues were directly related to the amount of the daily oral administration of lead acetate. Differences between the tissue levels of lead in the experimental and control lambs (N=25) were statistically significant (P<0.05) in liver, bone and kidney but were not significant in trachea, testis, brain, diaphragm, ovary, lung, muscle, rumen, aorta, spleen, tongue, eye, intestine, heart and esophagus. Lead accumulation was the highest in bone at the lower ingested lead concentrations, but was the highest in the kidney at higher lead dosages. Lead values were significantly greater (P<0.05) in the livers of female lambs compared to those of the male. Bone, liver and kidney of the young lambs had significantly higher (P<0.05) levels of lead than older lambs with means of 19.24, 7.31 and 54.54 compared to 6.34, 3.59 and 21.31 ppm respectively. Gross lesions were not found in any of the 25 necropsied lambs. Histopathological changes of intranuclear inclusion bodies were found in 100% of the kidneys in lambs administered 8 mg/Kg/day and above and in 50% of the livers of the lambs administered the same dosages. Thirty three per cent of lambs administered 2 and 4 mg/kg/day had intranuclear inclusion bodies in their kidney but not in the liver. The controls had no inclusion bodies in any of these matching tissues. No clinical signs of lead toxicosis were observed in any lambs during the 14 weeks of the experiment. The same lamb population was used to compare blood lead levels and the growth performance of lambs (feed intake, weight gain and feed conversion) in relation to different dosages of lead acetate. Although there was a tendency for lambs ingesting the two higher lead doses to eat less feed, gain less weight; and have a lower feed conversion ratio, these differences were not statistically significant (P>0.05). The conclusion of these studies reveal some concern. Levels of lead as found near the highways of Kuwait were high enough to cause elevated tissue lead concentrations, particularly in liver and kidney, of lambs grazing adjacent to these highways. These levels cause tissue abnormalities in lambs and could be hazardous to human health eating the internal organs of these lambs. / Graduation date: 2000

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Lamb mortality remains a significant welfare and economic issue for sheep production. Two significant causes of mortality are dystocia and low lamb vigour; both requiring high levels of human care to ensure lamb survival. Genetic solutions to reduce lamb mortality and its main causes (dystocia and low vigour lambs) are desirable, with at least two possible solutions available: (i) use of suitable breeds or strains and (ii) intrabreed selection. Approach (i) requires the existence of breed/strain differences in the desired traits and approach (ii) needs sufficient intrabreed genetic variance. Reproductive and behavioural traits are, however, difficult to quantify and measure on farm. On dedicated research farms, lamb vigour has been measured using latencies to perform specific behaviours (e.g. standing and sucking) but this methodology is difficult to transfer to a commercial setting - timed behavioural traits are not as easy to measure on farm when compared with categorical indicator traits. Therefore, proxy methods (categorical scoring systems) are needed to measure behaviour traits in a manner that allows for collection of sufficient data to enable genetic analysis. The main purpose of this thesis was to develop such proxy methods, to estimate the heritability of lamb traits, and thus to investigate whether it is possible to improve the welfare of lambs through selection of parents with superior vigour and lambing ease characteristics. Scoring systems were developed for quantifying neonatal lamb fitness and behaviour traits. Detailed historical behaviour data were analysed to develop criteria for three scores: birth assistance (BA), lamb vigour (LV) and sucking assistance (SA). These scoring systems were then validated in a separate flock by simultaneously recording scores and the latency to perform certain landmark behaviours. The results obtained indicated that the scoring systems developed were a practical, reliable and sensitive indicator of lamb fitness traits. To determine whether neonatal lamb vigour traits were heritable, scores from the scoring systems previously developed and validated were recorded in an experimental flock of pure-bred Texel sheep for the purpose of estimating genetics parameters for each trait. Results indicated that heritabilities for all traits range from low-moderate, BA 0.43 (s.e. 0.063), LV 0.15 (s.e. 0.059), SA (0.27 (s.e. 0.045), suggesting there is sufficient variation present within this Texel sub-population to allow for selection for improved neonatal fitness traits. Thus far, we have determined that neonatal traits are heritable and can be measured using proxy scoring systems. The next step was to establish whether the proxy scores developed were feasible, in a commercial setting, for the mass data collection needed for estimation of genetic parameters and to determine the relationship between neonatal traits and later production traits, with the aim of integrating this data into breeding programmes. A total of 11,092 lambs with complete neonatal records, from 290 flocks belonging to the Industrial Partner, the Suffolk Sheep Society (UK), were analysed to report the genetic variance present within the UK population of registered pure-bred Suffolk sheep. The results from this analysis show that heritabilities were moderate for BA, 0.26 (s.e. 0.03), LV, 0.40 (s.e. 0.04) and SA, 0.32 (s.e. 0.03) with genetic correlations between neonatal traits all moderate to high and positive. This demonstrates that neonatal fitness traits can have heritabilities comparable to those of production traits. The analysis also shows that neonatal survival traits of birth assistance and sucking assistance are moderately heritable, when treated as a lamb trait rather than a sire or ewe trait, indicating the selection should target the lambs in order to successfully, and efficiently, improve survival. A possible alternative method for improving dystocia and lamb vigour would be to introgress genes for improved lambing ease and lamb vigour from the New Zealand strain of Suffolk sheep into the British Suffolk strains. However, there has been no published record of how much ‘NZ genetics’ would improve (or compare to) British Suffolk’s under standard UK management practises. Therefore, the objectives of this study were to examine possible differences in neonatal behavioural traits (birth assistance, lamb vigour and sucking assistance) between NZ and UK Suffolks when used as terminal sires on commercial cross-bred ewes. Thus, neonatal scores from cross-bred lambs sired by rams from one of the three main Suffolk strains currently used in the UK were compared. The analysis indicated there was no significant effect of sire strain on any of the neonatal traits, and that individual sire variation was greater than the variation between the strains. In conclusion, the work contained within this thesis shows that neonatal lamb behaviour traits can be measured accurately and easily using well-realised and biologically relevant scoring systems. Furthermore, these scoring systems are a feasible and practical method of measuring neonatal lamb vigour which may be used to evaluate management systems and to improve selection criteria for neonatal traits.

Two studies were conducted to compare nitrogen (N) and glutamate metabolism in Polypay and percentage White Dorper lambs.First, a two-phase digestion/N metabolism trial was conducted with 18 wether lambs of three genetic types: Polypay (PP), 1/2 White Dorper 1/2 Polypay (1/2 D), and 3/4 White Dorper 1/4 Polypay (3/4 D). Six lambs of each genetic type were fed a high roughage diet (HR; Phase 1) or high concentrate diet (HC; Phase 2). DM and N digestion was higher for 1/2 D than PP or 3/4 D fed HC. N retention was highest for 1/2 D regardless of diet.The second study analyzed the effect of genetic type on glutamate transporter and metabolizing enzyme expression in liver, kidney, longissimus dorsi muscle (LD muscle), and subcutaneous fat (Sub Q Fat) tissue of 18 wether lambs of three genetic types: PP, 1/2 D, and 15 /16 White Dorper 1/16 Polypay (15 /16 D). Tissue samples were analyzed for protein and mRNA content of GS, GDH, ALT, EAAC1, and GLT-1. Glutamate transport and metabolism capacity was lowest for the heavier muscled 15 /16 D lambs.The results suggest genetic type has an effect on N metabolism due to differential expression of glutamate transporters and metabolizing enzymes.