Two trials using Lupinus angustifolius cv. Uniharvest were conducted in the summer of 1978-1979 at Lincoln College, Canterbury. From the first trial, designed to measure dry matter accumulation and changing nutritive value of lupins with time, a maximum dry matter yield of just under 990 kg ha⁻¹ was obtained 150 days after sowing. Peak digestibility was 65.0 per cent and was recorded at 125 days after sowing. Protein concentration was highest in the young plant (28.75 per cent at 45 days after sowing) and declined after this, but highest total nitrogen yield coincided with peak dry matter accumulation. In the second trial, lupins at 60 and 100 plants m⁻² were grazed with weaned lambs at each of four successive stages of the plants' growth - pre-flower, primary flower, secondary flower and green pod (post-flower). Highest dry matter accumulation,at just under 1 000 g m⁻², occurred at the green pod stage, and peak protein concentration of 23.7 per cent at the pre-flower stage (lower density). Digestibility was highest at the pre-flower stage (higher density) and the metabolizable energy concentration was also highest in the pre-flower high density plots. Regrowth of lupins following grazing occurred in plots which had been grazed at the pre- and primary flower stage. Maximum total dry matter accumulation from the first grazing combined with the regrowth was 1 350 g m⁻². Digestibility, protein and metabolizable energy concentration of the regrowth was at acceptable levels for animal growth. From the results obtained, and those of other workers, both in New Zealand and overseas, it is suggested that lupins may have considerable potential as a high quality summer forage crop for grazing of young lambs.

L'activité humaine a des conséquences sur l'évolution de la société et de l'environnement. Dans notre cas nous nous intéressons aux particularités de l'élevage comme activité humaine dans le Nord de l'Uruguay, dans la région d'Arapey. Pour effectuer l'étude nous utilisons une approche systémique, où se combine une analyse narrative avec la simulation en utilisant des systèmes multi-agents. Sont décrites les principales caractéristiques de l'activité agricole, en incluant les évolutions sur le long terme. Nous démontrons ainsi comment l'agriculture et l'élevage ont permis le développement de sociétés stratifiées et comment ce processus s'est accéléré avec le temps. En particulier, nous montrons les interactions entre société, science et agriculture, en expliquant comment au cours du dernier siècle, des augmentations énormes de productivité ont été réalisées par l'industrialisation de l'agriculture, et cela grâce à l'utilisation de combustibles fossiles. L'élevage uruguayen est en permanente interaction avec ce qui se passe en dehors des frontières. La mondialisation de l'alimentation a vu le jour en même temps que la viande d'Uruguay était globalement distribuée, tout au long de la seconde moitié du 19ième siècle. La construction du modèle Arapey comprend trois étapes : i) identification de pratiques " significatives " au moyen d'une combinaison d'enquêtes, recherches et observations de terrain ii) modélisation du système à l'échelle des exploitations en privilégiant les pratiques qu'on a choisi d'étudier, et en utilisant le " Unified Modeling Language " (UML) et iii) évaluation des conséquences de ces pratiques sur l'évolution des exploitations et de la région, en utilisant la plate-forme Cormas pour réaliser les simulations à partir du modèle Arapey ainsi construit. Face à des situations de grande incertitude, une amélioration de l'action collective peut être obtenue par la mise en discussion des actions à prendre. Elle doit s'appuyer sur une grande participation des acteurs intéressés, ainsi que sur l'utilisation d'instruments permettant à la fois d'intégrer des connaissances d'origines diverses et d'explorer différentes scénarii en représentant différents points de vue, comme par exemple les systèmes multi-agents et/ou une famille de diagrammes. Une connaissance approfondie de la situation est une condition nécessaire pour que cette action puisse être significative, croyable et légitime. Les SMA en tant que " laboratoire virtuel " peuvent accélérer l'apprentissage en incorporant des variables qualitatives, ce qui augmente le coté réaliste du modèle et sa capacité à être un support effectif de prises de décisions.

Anaemia, which is caused by iron deficiency, is a global nutritional disorder of utmost concern. It has been assumed that meat, which contains haem as well as non-haem iron, enhances non-haem iron absorption due to the presence of the “meat factor”. In the experiment reported here, 24 semi-anaemic, 3-week-old piglets were utilised as human nutrition models to assess the effects of dietary lactoferrin, meat and LSF (Low Molecular Weight Sarcoplasmic Fraction) on iron bioavailability during a 4-week feeding period. The parameters that were used as measurements of iron bioavailability were changes in haematological indices, haemoglobin iron repletion efficiency, intestinal morphology and mineral balances. Non-significant (p > 0.05) dietary effects were observed for growth performance and for all the haematological and some histological parameters (small intestine villi height, crypt depth and mucosal thickness). Haemoglobin iron repletion efficiency was highest for the control group and was not significantly different between the other 3 diets. The superiority of the control diet in this respect was not consistent with previous trials and can not be explained. Results suggested that increased retention of calcium, magnesium, phosphorous and manganese tended to inhibit iron absorption. However, the LSF and meat diets significantly (p = 0.003) increased the number of goblet cells/100 µm suggesting that mucin secretion was favoured by these two diets. Additionally, all immunological parameters were significantly (p < 0.05) improved by the LSF diet. As such, the LSF diet can be a potential immunobooster feed ingredient for weanling piglets. Overall, the level of LSF in the LSF diet was insufficient to exert a desirable enhancement of iron bioavailability and betterment of 3 iron status of the semi-anaemic piglets relative to the control group. However, the diet containing LSF was as effective as the meat diet with respect to these characteristics.

This thesis describes two approaches for studying of lipoprotein metabolism in sheep. The first approach involves the assay of lipoprotein lipase (LPL) activity to determine the role of lipoprotein-triacylglycerol fatty acids in fat deposition in sheep. This enzyme is the rate limiting enzyme in the hydrolysis of fatty acids from lipoprotein-triacylglycerol. The second approach was to characterize and quantify in vivo lipoprotein metabolism using iodinated very low density lipoprotein (¹²⁵I-VLDL) and low density lipoprotein (¹³¹I-LDL). Cross-bred lambs were divided into two treatment groups and either weaned early at 5 weeks of age or remained suckling. Lambs were slaughtered at 12 or 23 weeks at which time the body composition and adipose tissue LPL activity were determined. The differences in rearing led to differences in body composition. The suckled lambs were larger and fatter than weaned lambs. The increased fatness in the suckled lambs was associated with increased LPL activity (U/mg protein) in subcutaneous adipose tissue and was reflected in higher LPL activity in post-heparin plasma (PHP) taken 2 days prior to slaughter. The role of insulin in the regulation of LPL activity was investigated by either infusing a subset of the weaned and suckled lambs with insulin for 7 or 18 weeks or using the euglycemic clamp technique to study the effect of short insulin infusions. The long term infusion of insulin had no significant effect on PHP LPL or on adipose tissue LPL (U/g tissue). However, after infusing insulin for 6h at 6.3 mU.kg⁻·⁷⁵.h⁻¹ during the euglycemic clamps, a two fold increase in LPL activity in biopsied subcutaneous adipose tissue was observed. In the second approach, in vivo lipoprotein metabolism was investigated in 4 lambs using apolipoprotein B as a marker. Following the simultaneous injection of ¹²⁵I VLDL and ¹³¹I VLDL, the specific activities of apoB in VLDL, IDL and LDL fractions were determined. ApoB specific activity curves demonstrated that VLDL is metabolised to IDL and subsequently to LDL. The turnover of VLDL-B (3.45mg.d⁻¹.kg⁻¹) and LDL-B (4.8mg.d⁻¹.kg⁻¹) was calculated by fitting the VLDL-¹²⁵I-B and LDL-¹³¹I-B specific activity data to a mono-exponential equation. The metabolism of lipoproteins, inferred from the study of apoB, was shown to be similar in sheep to that reported in other animals although the amount of lipoprotein synthesised was low. A model to describe the kinetics of apoB metabolism in sheep was developed using SAAM. The proposed model features a three pool delipidation chain for VLDL, and subsystems containing two pools for IDL and LDL. IDL may be catabolised to LDL or cleared directly from the plasma. The developed model can now be used to compare the metabolism of lipoproteins in different physiological states and to design new experiments to study lipoprotein metabolism further.

The cost of lamb mortality caused by cold exposure has been estimated at approximately 40 million dollars per year. This value is probably conservative as it does not include the cost due to the reduction in productivity in hypothermic lambs that manage to survive or the cost of reduced selection potential incurred by fewer lambs surviving until selection. The objectives of this research was to investigate whether sire-line variation exists in neonatal lamb cold tolerance and whether polymorphism in the β₃ adrenergic receptor gene can be used as a genetic marker for lamb cold tolerance and lean muscle growth. The influence of the climate, birthweight, age of dam at lambing, gender and birth rank on neonatal lamb cold tolerance was also analysed. Neonatal lamb mortality due to cold exposure was analysed in four field trials that used neonatal lamb morality from cold exposure as a predictor of neonatal lamb cold tolerance. Sire-line variation in neonatal lamb morality was observed in all trials, though it appeared that this effect was largely mediated through sire-line variation in lamb birth weight. Variation in lamb birth weight between birth rank classed was also found to be responsible for the influence of birth rank on neonatal lamb mortality due to cold exposure. The age of dam at lambing and the lamb gender was not observed to influence neonatal lamb mortality due to cold exposure. The sires from the cold tolerance study and the progeny of the lean muscle growth study were genotyped for the β₃ adrenergic receptor locus. Other studies have found evidence that a major gene exists in the catecholamine stimulation of brown adipose thermogenesis and evidence that the β₃-AR gene is a likely candidate. However, this hypothesis and the hypothesis that polymorphism in the β₃-AR gene is also linked to lean muscle growth in lambs was not confirmed in this study. So while it appears that the results were confounded by experimental design, there is evidence that influence of polymorphism in the ovine β₃ AR gene on neonatal lamb mortality and/or lean muscle growth is not sufficient to be considered a major gene effect. The implications of this experiment on the sheep industry and sheep farmers in general are huge. While completely eliminating lamb deaths due to inadequate cold tolerance is impossible, this study shows that large gains in lamb survival could be possible through selective breeding.

This work aimed to evaluate the utilization of different grazing intensity on the productive and structural characteristics of pasture and on the ingestive behaviour and performance of sheep in continuous grazing. The treatment were different herbage masses (HM) in Italian ryegrass (Lolium multiflorum Lam.) pasture: LHM: 1000-1200 kg/ha of dry matter (DM); IHM: 1400-1600 kg/ha DM; HHM: 1800-2000 kg/ha DM. The experimental design was the randomly complete, with three treatments and two area replicates. The data were submitted at the regression analysis in function of HM observed in the experimental units: 1136.8, 1190.9, 1359.2, 1375, 1556 e 1739.1 kg/ha DM. The values of leaf lamina mass, pseudostem mass, forage allowance, leaf lamina allowance, sward height, pseudostem height, leaf lamina depth and average daily gain increased linearly with increase of HM (P<0.10). Quadratic effect (P<0.10) in herbage production, herbage losses and herbage disappearance were observed. The stocking rate (kg/ha of live weight and hoggets/ha) and bite rate decreased linearly with increase of HM (P<0.10). No HM effects (P>0.10) on the tiller population density, herbage daily accumulation rate, percentage of pasture utilization, herbage intake, grazing time, ruminating time, idle time, number of daily bite, bite mass, body condition score gain, live weight gain per area and conversion efficiency of forage in live weight were observed. Herbage mass varying among 1136.8 a 1739.1 hg/ha DM in Italian ryegrass pasture affect the herbage production and herbage losses, without influence in the percentage of pasture utilization, weight gain per area and conversion efficiency of forage in animal product. The main factor determining individual performance of animals is the leaf lamina layer depth / O objetivo deste trabalho foi avaliar a utilização de diferentes intensidades de pastejo sobre as características produtivas e estruturais da pastagem e sobre o comportamento ingestivo e desempenho de ovinos em pastejo contínuo. Os tratamentos foram diferentes massas de forragem (MF) em pastagem de azevém anual (Lolium multiflorum Lam.): MFB: 1000-1200 kg/ha de matéria seca (MS); MFI: 1400-1600 kg/ha MS; MFA: 1800-2000 kg/ha MS. O delineamento experimental foi inteiramente casualizado com três tratamentos e duas repetições de área. Os dados foram submetidos à análise de regressão em função das MF observadas nas unidades experimentais: 1136,8, 1190,9, 1359,2, 1375, 1556 e 1739,1 kg/ha MS. Os valores de massa de lâminas foliares e de pseudocolmo, oferta de forragem e de lâminas foliares, altura de dossel e de pseudocolmo, profundidade de lâminas foliares e ganho médio diário aumentaram linearmente com aumento da MF (P<0,10). Houve efeito quadrático (P<0,10) para produção, perdas e desaparecimento de forragem. A carga animal (kg/ha PV), taxa de lotação (borregas/ha) e taxa de bocadas diminuíram linearmente com o aumento da MF (P<0,10). Não houve efeito das MF avaliadas (P>0,10) na densidade populacional de perfilhos, taxa de acumulação diária de forragem, porcentagem de utilização da pastagem, consumo de forragem, tempos de pastejo, ruminação e ócio, número diário de bocadas, massa de bocado, ganho de condição corporal, ganho de peso vivo por área e eficiência de conversão de forragem em peso vivo. Massas de forragem variando de 1136,8 a 1739,1 kg/ha MS em pastagem de azevém afetam a produção e perdas de forragem, sem influenciar a porcentagem de utilização da pastagem, o ganho de peso vivo por área e a eficiência de transformação da forragem em produto animal. O principal fator determinante do desempenho individual dos animais é a profundidade da camada de lâminas foliares

Made available in DSpace on 2014-12-17T15:34:43Z (GMT). No. of bitstreams: 1 JoaoVEN_DISSERT.pdf: 2633777 bytes, checksum: a59b41665f97067cdafb895c7d67745c (MD5) Previous issue date: 2012-02-16 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / He aim of this study was to evaluate the structural characters, herbage accumulation, nutritive value and performance of sheep in different tropical pastures. The treatments were two cultivars and two of the genera Panicum Brachiaria pastures under intermittent stocking and variable stocking rate, in the rainy season. We evaluated the masses and the components of herbage pre grazing in two layers, and after grazing. Chemical analyzes were made of the stems and leaf blades pre grazing in two layers. We used 48 male sheep and whole for the assessment of individual weight gain and area, and anestrous females to adjust the stocking rate. In the cv. Massai showed the highest herbage mass, leaf blades and dead material, and the largest volume density and leaf blade: stem pre grazing. There was no difference among cultivars for the percentage of leaf blade (PLB) in both strata, but the higher the PLB was higher than the bottom. The highest percentage of dead material (PDM) was observed in cvs. Massai and Marandu in the two strata. In cvs. Massai and Piat? were observed lower levels of crude protein in stem and leaf. In stratum 0-25 cm lower nutritional value was observed in the stem in the leaf blades did not grant the nutritional value among the strata. Herbage mass, leaf blade, PLB and proportion of stem in the residue of the Massai pastures were higher than cv. Aruana. There was no difference for efficiencies in harvest leaf and stem between the cultivars. The cv. Massai got the higher accumulation of leaf per cycle per day. Animals kept in grass swards Aruana had the highest average daily gain. The higher stocking rates and earnings per area were observed in grass swards and Marandu Massai. The cultivars are suitable for sheep meat production in the rainy season / O objetivo deste estudo foi avaliar os caracteres estruturais, o ac?mulo de forragem, o valor nutritivo e o desempenho de ovinos em diferentes pastagens tropicais. Os tratamentos constitu?ram em duas cultivares dos g?neros Panicum e duas de Brachiaria, manejadas sob lota??o intermitente e taxa de lota??o vari?vel, na ?poca das ?guas. Foram avaliadas as massas e os componentes da forragem no pr? pastejo em dois estratos, e no p?s pastejo. Foram feitas an?lises bromatol?gicas dos colmos e das l?minas foliares no pr? pastejo em dois estratos. Utilizou-se 48 ovinos machos e inteiros para a avalia??o do ganho de peso individual e por ?rea, al?m de f?meas em anestro para ajuste na taxa de lota??o. Na cv. Massai foram observadas as maiores massa de forragem, de l?minas foliares e de material morto, al?m da maior densidade volum?trica e rela??o l?mina foliar:colmo no pr? pastejo. N?o houve diferen?a entre as cultivares para o percentual de l?minas foliares (PLF) em ambos os estratos, por?m o PLF no superior foi maior que no inferior. O maior percentual de material morto (PMM) foi observado nas cvs. Massai e Marandu nos dois estratos. Nas cvs. Massai e Piat? foram observados os menores teores de prote?na bruta no colmo e na l?mina foliar. No estrato de 0 25 cm foi observado menor valor nutritivo no colmo, nas l?minas foliares o valor nutritivo n?o deferiu entre os estratos. A massa de forragem, de l?mina foliar, PLF e propor??o de colmo no res?duo dos pastos de Massai foram superiores aos da cv. Aruana. N?o houve diferen?a para as efici?ncias na colheita de l?mina foliar e colmo entre as cultivares estudadas. A cv. Massai obteve os maiores ac?mulos de l?mina foliar por ciclo e por dia. Os animais mantidos em pastos de capim Aruana obtiveram os maiores ganhos m?dios di?rios. As maiores taxas de lota??o e ganhos por ?rea foram observadas nos pastos de capim Massai e Marandu. As cultivares testadas s?o adequadas a produ??o de carne ovina na ?poca das ?guas

Inicialmente, foram analisados dados peso-idade do nascimento até 100 meses de idade, de vacas de quatro grupos genéticos (G): Nelore (NEL), ½Canchim + ½Nelore (CN), ½Angus + ½Nelore (AN) e ½Simental + ½Nelore (SN), pertencentes a Embrapa Pecuária Sudeste, São Carlos. Os animais considerados neste estudo nasceram de 1998 a 2001 (Ano), na primavera e outono (EP), e foram criados em sistema de produção intensiva, recebendo três níveis de suplementação pós-desmama (M): 0, 1,5; 3,0 kg/animal/dia de concentrado. O objetivo neste estudo foi comparar diferentes modelos não-lineares para estimar o crescimento, e avaliar a influência de efeitos de ambiente e grupo genético sobre os parâmetros estimados. Os modelos não-lineares: Brody, Gompertz, Logístico, Von Bertalanffy e Richards foram ajustados por mínimos quadrados ordinários e ponderados, considerando a variância normal e ponderada pelo inverso dos pesos em diferentes períodos. Foi usado o procedimento NLIN do SAS. Os modelos Brody e Von Bertalanffy convergiram para todos os G, havendo, entretanto, leve superioridade do Brody ponderado. Na comparação do ajuste dos modelos considerando o uso do inverso da variância os modelos mostraram-se mais adequado. As estimativas dos parâmetros peso assintótico (A) e taxa de maturidade (k) do modelo de Brody ponderado foram analisadas por meio de modelo que, além do efeito médio global, incluiu os efeitos de G, M, EP e as interações entre estes efeitos. Houve diferenças significativas das curvas de crescimento médias para os G. Na análise individual dos parâmetros A e k estimados através do modelo Brody ponderado, verificou-se que A foi influenciado (P<0,05) por G e EP e k foi influenciado (P<0,05) por M, fornecidos aos animais durante quatro meses após desmama. Melhorias no manejo alimentar resultaram em menor variação na forma das curvas de crescimentos e em altas taxas de maturidade. Na segunda parte, verificou-se a qualidade do modelo Brody, ponderado pelo inverso das variâncias dos pesos, quanto ao ajuste peso-idade como também a influência das estimativas do peso à maturidade (A) e da taxa de maturidade (k) sobre características produtivas das vacas NEL, CN, AN e SN. Foram organizados 10 grupos contemporâneos (GC), com concatenação dos efeitos Ano-EP-M para cada G. Utilizando-se um modelo misto com efeitos de G e GC, foi incluído, alternadamente covariáveis linear e quadrática de A e k, na análise das características produtivas: peso à desmama dos bezerros (PD); número (ND8) e kg (KD8) de bezerros desmamados em até 8 anos de permanência da vaca no rebanho; relação PD/peso da vaca ao parto (PD_PVP); relação PD/peso da vaca à desmama do bezerro (PD_PVD); relação PD/unidade metabólica da vaca (PV0,75) à desmama do bezerro (PDW). Houve diferença significativa (P<0,05) da curva de crescimento entre os grupos genéticos (G) e também entre os grupos de contemporâneos (GC) dentro de G. Verificou-se que estas características foram, em geral, influenciadas (P<0,01) tanto pelos efeitos linear e quadrático de A quanto pelos efeitos linear e quadrático de k. / Initially, were analyzed weight-age data from birth to 100 months of age from cows of four genetic groups (G): Nellore (NEL), ½Nellore + ½Canchim (CN), ½Angus +½Nellore (AN) and ½Simmental + ½Nellore (SN), of a experiment carried out at Embrapa Southeast Cattle Research Center, State of São Paulo, Brazil. The animals considered in this study were born from 1998 to 2001 (Year) in spring and fall (EP), and were managed in intensive production system and submitted to three of levels of supplementation post-weaning (M): 0, 1.5 and 3.0 kg/animal/day of concentrate. The objective of this study was to compare different nonlinear models to fitted growth curves, of beef cattle females, and to evaluate of environmental and genetic group effects on the estimated parameters. The nonlinear models: Brody, Gompertz, Logistic, Von Bertalanffy and Richards were fitted by ordinary least squares and weighted by the inverse of the variances of the weights in different periods. It was used the NLIN procedure of SAS. The parameters asymptotic weight (A) and maturing rate (k) obtained from model of Brody were analyzed by a mixed linear model that, besides the overall mean effect, included the effects of G, M, EP, and the interactions among these effects. The Brody and Von Bertalanffy models converged for all genetic groups, although slight superiority of the weighted Brody. Comparing the goodness of fit of these models, the use of the inverse of variances showed more efficient than the adjust of the models considering normal variances. Individual analysis of A and k estimated the model weighted Brody, the A parameter was influenced (P <0.05) by genetic group and season of birth and k was influenced (P <0 05) for levels of supplementation to the animals. Improvements in feeding supplementation resulted in less variation in the shape of growth curves and rates of maturity. In the second part of the work, it was evaluated the goodness of the Brody model, weighted by the inverse variance weights, in the adjust of weight-age data, and also analyzed the influence of the maturity weight (A) and maturing rate (k) estimates for traits cows productivity. Were organized 10 contemporary groups (CG) with concatenation of effects Year- EP-M for each G. Considering a mixed model with effects of G and CG (10 contemporaneous groups organized by concatenation Year-EP-M effects), linear and quadratic covariate effects of A and k, were added, alternately, for the analysis of the following traits: weaning weight of calve (WW), number (NW8) and kg (KW8) of calves weaned over 8 years of the cow in the herd; WW/weight of the cow at calving (WW_WC); WW/cow weight at weaning of calf (WW_WWC); and WW/metabolic unit of the cow (PV0,75) at weaning of the calf (MW). There was significant difference (P<0.05) of the growth curve among the genetic groups and also among contemporary groups within G. It was found that the production traits were, in general, influenced (P<0.01) by both linear and quadratic effects of A and k.

<p>  </p> <p>Heat stress affects breeder ducks raised in North America and other parts of the world, but the effects of such stress on the progenies is not known. Therefore, the objectives of this study were to investigate: 1) The objectives of this thesis were to first investigate the effect of heat stress or exposure to exogenous glucocorticoid (GC) on fertility, production performance, egg biochemistry, egg quality, and welfare of breeder Pekin ducks. 2) the effects of maternal GC on phenotypic plasticity and behavior of the F1 generation. Three studies were carried out to investigate these objectives.</p> <p>The first experiment was conducted to test the hypothesis that chronic treatment with low levels of either corticosterone or cortisol would alter heterophil to lymphocyte ratio (HLR) and immune organ morphometrics. Further, we wanted to determine if chronic treatment with either GC would elicit an increase in cortisol levels in egg albumen. To test our hypotheses, we implanted silastic capsules subcutaneously under the skin of the neck of adult ducks (n = 5/sex/dose) using propofol anesthesia. Capsules contained corticosterone, cortisol, or empty capsules as controls. Over the course of 2 weeks, blood serum, blood smears, body weights, and egg quality data were collected. After 2 weeks, ducks were euthanized using pentobarbital (FatalPlus, 396 mg/ml/kg) and body weight, weights of spleens, livers, and the number of active follicles were recorded. Blood smears were analyzed for HLR by a lab unaware of the treatment groups. Albumen GC levels were assessed using mass spectrometry. Data were analyzed using a 2- or 3-way ANOVA as appropriate and <em>post hoc </em>with Fishers protected least squares difference (PLSD). There were no treatment effects on egg quality measures or body weight. Corticosterone treatment did elicit an increase in serum corticosterone (p < 0.05), but not cortisol levels, compared to controls in both sexes. Both cortisol and corticosterone treatments increased (p < 0.05) serum levels of cortisol compared to controls. Relative spleen weights were higher (p < 0.05) in hens following corticosterone but not cortisol treatment. No other organs showed any differences among the treatment groups. Both GCs elicited an increase (p < 0.001) in HLR in hens at all time-points over the 2-week treatment period compared to controls. Cortisol, not corticosterone, elicited an increase in HLR for drakes (p < 0.05) compared to controls at day 1 after implants. Chronic treatment with cortisol, but not corticosterone, elicited an increase (p < 0.01) in egg albumen cortisol levels compared to other groups. Corticosterone was not detected in any albumen samples.</p> <p>The goal of our second experiment was to test the hypothesis that heat stress (HS) would alter welfare, egg quality, and morphometrics of breeder ducks. Furthermore, we wanted to test if HS would increase cortisol levels in egg albumen due to recent exciting findings that cortisol, not corticosterone, is isolated in egg albumen. To test our hypothesis, adult Pekin ducks were randomly assigned to two different rooms at 85% lay with 60 hens and 20 drakes per room. Baseline data including body weight, body condition scores (BCS) (such as footpad quality, eyes, nostrils, feather cleanliness, and feather quality scores), and egg production/quality were collected the week preceding heat treatment. Ducks were subjected to cyclic HS of 350C for 10h/day and to 29.50C for the remaining 14h/day for 3 weeks while the control room was maintained at 220C. Eggs were collected daily, and body weights were taken on days 0 and 21 relative to the onset of heat treatment. BCS were collected weekly. Eggs were collected weekly for quality assessment and albumen glucocorticoid (GCs) levels assessment using mass spectrometry. One week before the exposure to HS, 10 hens and 5 drakes were euthanized and the same number again after 3 weeks of HS or control exposures using pentobarbital and birds necropsied. Body weight, weights of the liver, spleen, and the number of maturing follicles were recorded. Data analyses were done by 2- or 3-way ANOVA as appropriate with a Tukey-Kramer post hoc test. BCS were analyzed using a chi-squared test. A p value ≤ 0.05 was considered significant. Circulating levels of corticosterone were significantly (p < 0.01) elevated at week 1 only in the HS hens while there was no significant difference in the circulating levels of corticosterone in drakes compared to the controls. The circulating levels of cortisol increased significantly at week 1 (p < 0.05), week 2 (p < 0.05), and week 3 (p < 0.01) in the hens and at week 2 and 3 only (p < 0.05) in the drakes compared to the controls. Feather quality scores (p < 0.01), feather cleanliness scores (p < 0.001) and footpad quality scores (p < 0.05) increased significantly in the HS group compared to controls, higher BCS indicate a decline in welfare. HS elicited a significant (p < 0.001) decrease in egg production at weeks 1 and 3 and a descriptive decrease in the number of fertile eggs upon candling at 10 days of incubation, numeric decrease hatchability and increase in the number of dead embryos in the HS group after the incubation period. Hens in the HS group showed a significantly decreased BW (p < 0.001), and number of ovarian follicles (p < 0.05) compared to controls. Shell weight decreased significantly at week 1 (p < 0.05) compared to controls. Yolk weight decreased significantly at week 3 (p < 0.01) compared to controls. HS elicited a significant increase in albumen cortisol levels at week 1 (p < 0.05) and week 3 (p < 0.05).</p> <p>The third experiment was conducted to determine if parental exposure to heat stress would impair performance, hypothalamic pituitary adrenal (HPA) axis response, welfare, or behavior of their offspring. To achieve these goals, we treated adult drakes and hens at peak lay to heat stress or control temperature for 3 weeks and incubated eggs collected from the last 3 days of the experiment. A total of 76 ducklings were placed into pens from each parental treatment group: control (CON-F1) and heat stress (HS-F1) and raised as grow-out ducks. Weekly data for body weights, body condition scores (BCS), and novel object test (NOT) were collected weekly. At 3 weeks of age, ducks (n = 6 per treatment group) were subjected to adrenocorticotropic hormone (ACTH) (ACTH/cosyntropin, 0.0625 mg/kg) challenge or vehicle as control. Blood samples were collected from the metatarsal vein into serum-separator tubes at 0, 1, 2, 3, and 4 hours relative to treatment for the determination of serum glucocorticoids. Blood smears were also produced from these same samples to determine heterophil to lymphocyte ratios (HLR). All injected birds were euthanized with pentobarbital on the second day relative to ACTH administration, spleen and bursa were removed and weighed immediately. Duck level analyses were completed using 1-, or 2 -way ANOVA as appropriate. BCS were analyzed using a chi-squared test. We observed that HS-F1 had a lower hatch weight (p < 0.05) compared to CON-F1. However, growth rates during the 5-week grow-out period were not significantly different between the two flocks. NOT (N = 4) analyses showed that the HS-F1 had a greater fear response (P< 0.001) compared to CON-F1. Similarly, an ACTH stimulation test showed that the HS-F1 ducks had significantly heightened corticosterone and HLR responses compared to CON-F1 ducks (p < 0.05). The HS-F1 showed altered baseline and ACTH-stimulated levels of cortisol compared to controls.</p> <p>In conclusion, GC elicit differential effects and although corticosterone has been stated to be the predominant GC in avian species, cortisol may provide critical information to further understand and improve welfare. HS decreased performance, fertility, and productivity of breeder ducks. In addition, HS and exogenous GC elicited a selective deposition of cortisol, not corticosterone, in the egg albumen. The maternal cortisol deposited in eggs alter the hypothalamic-pituitary adrenal (HPA) axis and behavioral responses of the F1 generation. This suggests that maternal hormones can alter the phenotypic plasticity of the offspring and can be used to produce offspring that have better adaptation to the rising temperatures as a result of climate change. Finally, the measure of cortisol in egg albumen can be used as a non-invasive marker of stress.</p>

Inledningen förklarar förändring av livsmedelsproduktionen och att industrin kan ha potentiella etiska dilemman för jämlikheten. Att den industriella djurproduktionen kan ha förstärkt spridningen av Covid19 och att industrier ofta placeras i områden med låg socioekonomi. Bakgrunden förklarar att ett jämlikt samhälle har fördelar för alla. Samt hur Folkhälsomyndigheten arbetar med jämlikhet genom målet om en god och jämlik hälsa. Därefter beskrivs tidigare forskning, begrepp och teorier. Syftet med studien var att analyseraom den industriella djurproduktionen var etiskt försvarbar. Detta utfördes genom att analysera om industrin har potentiella risker för jämlikheten. Metoden var en kvalitativ innehållsanalys. Urval var tio rapporter från privata- och statliga organisationer. Analysen i denna studie utgick från begreppet jämlikhet som kopplades till målet om en god och jämlik hälsa och de politiska folkhälsomålområdena. Vidare användes två normativa teorier, konsekvensetik och deontologisk/plikt- och rättighetsetik. Resultatet visar på att den industriella djurproduktionen kan ha potentiella risker. Riskerna framkom inom kategorierna; arbete, miljö och sjukdom. De potentiella riskerna sågs inom majoriteten av folkhälsopolitiska målområdena. Dessa risker kan påverka alla människor, dock visar resultatet att de som redan var utsatta var i högre risk för ohälsa och att dessa risker kan vara orättvisa, onödiga och undvikbara. Slutsatsen är att industrin kan ha potentiella direkta- och indirekta jämlikhetsbarriärer för en god och jämlik hälsa inom flera av de folkhälsopolitiska målområdena. De potentiella riskerna som framkommit i denna studie, analyserat från valda teorier, indikerar att IDP inte är etiskt försvarbar. / The introduction explains the change in food production and potential ethical dilemmas for equality. That the industrial animal production may have increased the spread of Covid19 and that industries are located in areas with low socioeconomic status. The background explains that equal society has benefits for everyone. And how the Public Health Agency works with equality through the goal of good and equal health. It then describes previous research, as well as concepts and theories. The purpose of the study was to analyse whether the industrial animal production was ethically defensible. The method was a qualitative content analysis. Selections were ten reports from private and government organizations. The analysis in this study was based on the concept of equality, which was linked to the goal of good and equal health and the political public health goal areas. Furthermore, two normative theories were used, consequential ethics and deontological/duty and rights ethics. The result shows that industrial animal production can have potential risks within the categories: work, environment, and illness. These risks can affect all people, the results show that those who were already exposed were at higher risk of ill health and that these risks can be unfair, unnecessary, and avoidable. The conclusion is that the industry can have potential direct and indirect equality barriers for good and equal health within several of the public health policy target areas. The potential risks identified in this study, analysed from selected theories, indicate that the industry is not ethically defensible.