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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Effects of time specific F-strain Mycoplasma gallisepticum inoculation overlays on pre-lay ts-11-strain Mycoplasma gallisepticum inoculation on performance, egg, blood, and visceral characteristics of commercial egg laying hens

Vance, Elizabeth Anne Middleton, January 2007 (has links)
Thesis (M.S.)--Mississippi State University. Department of Poultry Sciences. / Title from title screen. Includes bibliographical references.
22

Morphological and physiological changes in laying hens in various stages of non-feed withdrawal molt

McDonald, Ann Laster. January 2008 (has links)
Thesis (Ph.D.)--Mississippi State University. Department of Food Science, Nutrition, and Health Promotion. / Title from title screen. Includes bibliographical references.
23

Evaluation of guar meal as a source of prebiotic galactomannans for laying hens

Zhang, Cheng 01 November 2005 (has links)
Four experiments were conducted to evaluate guar meal as a source of prebiotic galactomannans for laying hens. In the 1st experiment, late phase laying hens were fed diets with 0, 5, 10% guar meal (GM) for 56 days or 15% GM for 28 days then switched to the 0% GM diet for the final 28 days. In the 2nd experiment, young pullets were fed guar germ (GG) or GM at 0, 2.5 or 5% for 20 weeks. In the 1st and 2nd experiments, egg production and feed consumption were not affected by feeding up to 5% guar by-products whereas feed efficiency was decreased by guar feeding. Feeding of GG or GM did not affect egg weight or shell quality, but decreased the egg yolk color and Haugh units. Guar increased absolute and relative liver weight, but did not affect the weights of the pancreas, spleen, or the incidence of fatty liver or liver hemorrhage. Feeding 10% GM depressed feed consumption and increased body weight loss. Feeding 15% GM severely depressed egg production followed by a recovery of production after returning to 0% GM feeding. In the 3rd and 4th experiments, late phase laying hens were induced to molt by feed withdrawal (FW) or feeding 15 or 20% GM with or without β-mannanase (Hemicell??). All hens except those fed 15% GM with enzyme obtained a complete cessation of lay in 10 days. Compared to FW birds, hens fed GM had lower body weight reduction and mortality, while hens fed 20% GM with enzyme had higher post-molt egg production. Salmonella enteritidis (SE) present in 6 organs (crop, liver, spleen, ovary, oviduct and cecum), and SE in cecal contents were significantly reduced by 20% GM feeding with and without enzyme. The results showed that GG or GM can be safely fed to laying hens up to 5% without adverse effects on performance. An alternative molting method employing 20% GM with or without β-mannanase is preferable to FW because GM feeding results in a complete molt and decreases mortality, as well as enhances the resistance to SE of molted hens.
24

Barley silage effects on poultry behaviour

Johannson, Sarah G. 28 April 2008
A series of trials were conducted to determine the effect of feeding barley silage to laying hens and broiler breeder pullets on performance, stress and behaviour. In the first study, two trials were conducted each with 20 hens and 2 roosters (n=176) randomly assigned to one of 8 community cages. The birds in 4 cages were provided with a nutritionally balanced soy/wheatbased laying hen diet ad libitum, whereas the birds in another 4 cages were given free access to barley silage in addition to the regular laying hen diet. In both trials, the control birds consumed more feed (P < 0.05) than the birds given barley silage. Birds fed barley silage had significantly decreased (P < 0.05) aggressive and feather pecking behaviours as well as time spent in their nest boxes at different ages. Time spent drinking, resting, preening and eating a large particle calcium source was similar between the two treatments. No treatment effects (P > 0.05) were found in regards to egg quality, egg production and bird weights at various ages; however yolk colour was darker by silage treatment in each trial. At the end of each trial, the feather score was improved in silage-fed birds compared to the control birds. It was concluded that feeding barley silage as a supplement to laying hens can improve their welfare without negatively affecting the egg production and egg quality. <p>A second study was conducted to determine the effect of feeding barley silage on body weight, stereotypic behaviour, stress and fear on broiler breeder pullets during the brooding and rearing periods. The 3 week old broiler breeder pullets (n=180) were randomly allocated into 12 straw litter floor pens having 15 birds per pen. The birds in 6 pens were provided with a nutritionally balanced corn/oat-soybean/canola meal-based broiler breeder diet at recommended restricted levels, whereas the birds in another 6 pens were given free access to barley silage in addition to a regular broiler breeder diet. Total DM intake was significantly higher (P < 0.05) for silage-fed birds compared to their control counterparts without affecting mean body weights. Dietary treatment had no significant effect on bird behaviour with the exception of object pecking behaviour which was reduced with silage feeding. Aggressive and gentle feather pecking behaviour was consistently numerically higher in the control birds than the silage-fed birds, although not significantly. Age affected many of the behaviours recorded in this study. Silage feeding had no significant effect on heterophil to lymphocyte ratios and tonic immobility values indicating that birds in both treatments were not very stressed or fearful. It was concluded that feeding barley silage to broiler breeder pullets has potential to aid in improving their welfare.
25

Barley silage effects on poultry behaviour

Johannson, Sarah G. 28 April 2008 (has links)
A series of trials were conducted to determine the effect of feeding barley silage to laying hens and broiler breeder pullets on performance, stress and behaviour. In the first study, two trials were conducted each with 20 hens and 2 roosters (n=176) randomly assigned to one of 8 community cages. The birds in 4 cages were provided with a nutritionally balanced soy/wheatbased laying hen diet ad libitum, whereas the birds in another 4 cages were given free access to barley silage in addition to the regular laying hen diet. In both trials, the control birds consumed more feed (P < 0.05) than the birds given barley silage. Birds fed barley silage had significantly decreased (P < 0.05) aggressive and feather pecking behaviours as well as time spent in their nest boxes at different ages. Time spent drinking, resting, preening and eating a large particle calcium source was similar between the two treatments. No treatment effects (P > 0.05) were found in regards to egg quality, egg production and bird weights at various ages; however yolk colour was darker by silage treatment in each trial. At the end of each trial, the feather score was improved in silage-fed birds compared to the control birds. It was concluded that feeding barley silage as a supplement to laying hens can improve their welfare without negatively affecting the egg production and egg quality. <p>A second study was conducted to determine the effect of feeding barley silage on body weight, stereotypic behaviour, stress and fear on broiler breeder pullets during the brooding and rearing periods. The 3 week old broiler breeder pullets (n=180) were randomly allocated into 12 straw litter floor pens having 15 birds per pen. The birds in 6 pens were provided with a nutritionally balanced corn/oat-soybean/canola meal-based broiler breeder diet at recommended restricted levels, whereas the birds in another 6 pens were given free access to barley silage in addition to a regular broiler breeder diet. Total DM intake was significantly higher (P < 0.05) for silage-fed birds compared to their control counterparts without affecting mean body weights. Dietary treatment had no significant effect on bird behaviour with the exception of object pecking behaviour which was reduced with silage feeding. Aggressive and gentle feather pecking behaviour was consistently numerically higher in the control birds than the silage-fed birds, although not significantly. Age affected many of the behaviours recorded in this study. Silage feeding had no significant effect on heterophil to lymphocyte ratios and tonic immobility values indicating that birds in both treatments were not very stressed or fearful. It was concluded that feeding barley silage to broiler breeder pullets has potential to aid in improving their welfare.
26

Evaluation of guar meal as a source of prebiotic galactomannans for laying hens

Zhang, Cheng 01 November 2005 (has links)
Four experiments were conducted to evaluate guar meal as a source of prebiotic galactomannans for laying hens. In the 1st experiment, late phase laying hens were fed diets with 0, 5, 10% guar meal (GM) for 56 days or 15% GM for 28 days then switched to the 0% GM diet for the final 28 days. In the 2nd experiment, young pullets were fed guar germ (GG) or GM at 0, 2.5 or 5% for 20 weeks. In the 1st and 2nd experiments, egg production and feed consumption were not affected by feeding up to 5% guar by-products whereas feed efficiency was decreased by guar feeding. Feeding of GG or GM did not affect egg weight or shell quality, but decreased the egg yolk color and Haugh units. Guar increased absolute and relative liver weight, but did not affect the weights of the pancreas, spleen, or the incidence of fatty liver or liver hemorrhage. Feeding 10% GM depressed feed consumption and increased body weight loss. Feeding 15% GM severely depressed egg production followed by a recovery of production after returning to 0% GM feeding. In the 3rd and 4th experiments, late phase laying hens were induced to molt by feed withdrawal (FW) or feeding 15 or 20% GM with or without &#946;-mannanase (Hemicell??). All hens except those fed 15% GM with enzyme obtained a complete cessation of lay in 10 days. Compared to FW birds, hens fed GM had lower body weight reduction and mortality, while hens fed 20% GM with enzyme had higher post-molt egg production. Salmonella enteritidis (SE) present in 6 organs (crop, liver, spleen, ovary, oviduct and cecum), and SE in cecal contents were significantly reduced by 20% GM feeding with and without enzyme. The results showed that GG or GM can be safely fed to laying hens up to 5% without adverse effects on performance. An alternative molting method employing 20% GM with or without &#946;-mannanase is preferable to FW because GM feeding results in a complete molt and decreases mortality, as well as enhances the resistance to SE of molted hens.
27

Salmoneliozės rizikos analizė Klaipėdos apskrities paukštynuose / Analyses of Salmonellosis hazard in poultry farms in Klaipeda County

Straukienė, Renata 19 April 2007 (has links)
The research of the Master thesis was carried out in 2005/2006 years in the Laboratory of the State Food and Veterinary Service of Klaipeda County, state and private poultry farms in Klaipeda County and in the Department of Infectious Diseases of the Lithuanian Veterinary Academy. The data was analysed applying the descriptive statistical analysis method. The Master thesis consists of 48 written pages, 7 tables, 10 figures and 56 references. The study aimed at analysing the Salmonellosis hazard in the poultry farms in Klaipeda County and preparing the plans for Salmonellosis prevention. The goals: to collect the data for epidemiological analysis; to analyse the hazards of Salmonellosis in poultry farms in Klaipeda County; to prepare the plans for Salmonellosis prevention. Bacteriological analyses were carried out according to Food and Feed Microbiology LST EN ISO 6579 standards; the horizontal method for the detection of Salmonella spp. (ISO 6579:2002) was applied. The commercial kits were used to identify Salmonella spp. In a year 2005, 15660 poultry keepers were registrated in Klaipeda County, with the total of 817960 birds, 797974 of which were hens. In 2005 there were analysed 1524 samples for Salmonellosis. About 40.4 % of the analysed samples were pooled samples of chicks 1 to 4 d old, in which the majority of pooled samples constituted the samples from boxes, bedding, faeces (282 samples). The pooled samples in the layer hens group amounted to 24.6 % of the total... [to full text]
28

The impact of daylength on turkey productivity, health and behaviour

2015 July 1900 (has links)
The impact of graded levels of daylength on the productivity, health and behaviour of hens and toms was studied in two experiments to 18 wk of age. Daylength treatments (trt) were 14 (14L), 17 (17L), 20 (20L) and 23 (23L) h and were started at 10 d of age. Turkeys (720 hens and 480 toms) were randomly allocated to 8 rooms (2 rooms per lighting trt) with six pens (3 hen and 3 tom) per room in each experiment. Body weight (BW) and feed consumption (FC) were assessed throughout the trial and feed efficiency (G:F; g of gain/g of feed) calculated from BW and FC values. Birds were checked daily for mortality and culls, and affected birds sent for necropsy. Bird well-being was evaluated by gait score (GS), the incidence of foot pad dermatitis (FPD), breast buttons and blisters, ocular size and pressure, and tom behavioural observations. Data were analyzed using SAS 9.3 based on a completely randomized design nested within four daylengths. Regression analysis established relationships between response criteria and daylength. Differences were considered significant at P≤0.05 and trends noted at P≤0.10. At 21 and 42 d, body weight increased linearly with daylength, but by 84 d tom weights decreased in a quadratic fashion and hen weights were unaffected by daylength. At 126 d, both male and female weights decreased linearly with increasing daylength, with the magnitude of the response gender dependent. Feed consumption corresponded to body weight changes, increasing for d 10-21 and 21-42, and decreasing for d 63-84, 84-105, and 105-126 with increasing daylength. Feed efficiency (G:F) was not affected by daylength for 10-84, 10-105 and 10-126 d periods. The incidence of mortality and culling was not affected by daylength for the 10-84 d period, but increased in a quadratic manner with increasing daylength for the 10-105 and 10-126 d periods. The incidence of skeletal disorders (valgus-varus and rotated tibia), injurious pecking and pendulous crops (females only) increased linearly with increasing daylength. Average GS increased linearly with daylength at 11 and 17 wk for both hens and toms, but the effect was larger in toms. Daylength did not affect FPD, but more lesions and more severe scores were found for hens than toms. The presence of breast buttons and blisters increased linearly with daylength (11 wk) with the effect on blisters predominately seen in toms. Eye weight increased and corneal diameter decreased linearly with increasing daylength at 12 and 18 wk. Dorso-ventral and media-lateral diameter, and anterior to posterior depth exhibited a quadratic relationship with the highest values seen for the 23L trt. Ocular pressure was not affected by daylength. Over 24 h of behavioural observation (both photo- and scotoperiod), resting increased, and walking, and environmental and feather pecking decreased with increasing daylength. During the photoperiod, inactive resting increased and feeding, drinking, standing, walking, preening, and environmental and feather pecking behaviours decreased as daylength increased. To conclude, daylength affects the growth and feed intake of turkeys in an age and gender specific manner, and mortality and culling increase with longer daylength. Health and welfare parameters are also affected by daylength with 23L demonstrating poorest overall bird well-being.
29

Effects of Mycotoxin Contaminated Diets on Immunosuppression or Interference with Other Physiological Parameters in Commercial-Strain Laying Chicks, Pullets or Hens

Iselt, Stephanie Mae 03 October 2013 (has links)
The principal objective of this investigation was to evaluate the effects of mycotoxin contaminated diets (deoxynivalenol (DON)), aflatoxin B1 (AFB1), and fumonisin (FUM)), with or without the use of a commercially available deactivating compound (DC), in young pullets and replacement laying hens on performance, reproductive, serological, and histopathological parameters. In trial 1, experimental treatments consisted of control, low toxin (1 µg DON/g + 1 µg AFB1/g), and high toxin (2 µg DON/g + 2 µg AFB1/g) diets. Pullets fed the high toxin diet had reduced (P<0.05) body weights compared to control and low toxin diets at d 14, 35, 49, 56, and 63. At d 21 and 28, there was a significant interaction observed between mycotoxin and DC inclusion in body weights. Following necropsies (d 35 and 65), relative liver weights and histopathological liver tissue damage were increased (P<0.05) in pullets fed high toxin diets when compared to control and low toxin diets. Relative kidney weights were increased (P<0.05) due to high toxin diet at d 65. Expected negative effects of toxin administration on titer development were not observed. The only interaction observed between mycotoxin administration and DC inclusion in trial 1 was on body weights. In trial 2, experimental treatments consisted of control, DON (9 µg/g) challenge, AFB1 (2 µg/g) + FUM (54 µg/g) challenge, and a mixed challenge (6 µg DON/g, 1 µg AFB1/g, and 27 µg FUM/g). All mycotoxin diets fed to hens negatively influenced (P<0.05) feed efficiency for the trial period spanning weeks 6 through 10 when compared to control diets. Egg production was not affected (P>0.05) by all mycotoxin diets weeks 6 through 10. Relative weights of the liver and kidney were increased (P<0.05) by AFB1+FUM challenge weeks 4 and 9 compared to control diet. The data reported in this study demonstrate that dietary DON and / or AFB1+FUM influence some performance, reproductive, histopathological, and egg quality traits, but by and large, replacement layer pullets seem to be relatively resistant to the mycotoxins evaluated in this trial at the described levels of administration.
30

Stickstoffdynamik im Umfeld einer Legehennenhaltung

Lippmann, Jens 27 September 2011 (has links) (PDF)
Das Ziel kontinuierlicher Messungen über zwei Jahre war die Bewertung der Stickstoffdepositionen und Ammoniakimmissionen einer Bodenhaltung (Voliere) mit Auslauf für 20.000 Hennen auf das Umfeld. Untersucht wurden weiterhin die Staub- und Geruchskonzentrationen in Stall- und Abluft. Die untersuchte Bodenhaltung emittiert im Jahr 41 g Ammoniak je Tierplatz. Die Vergleiche 14-tägiger Messdatenreihen zeigen, dass Emissionsmessungen an Tierhaltungen in möglichst langen Zeitfenstern und mindestens viermal jährlich durchzuführen sind. Die Immissionswerte für Ammoniak sind 40 m vom Stall am höchsten und erreichen nach ca. 350 m wieder das Hintergrundniveau am Standort. Unter Abzug der nicht dem Stall zuzurechnenden Hintergrundkonzentrationen verursacht der Stall im Nahbereich (40 m) eine Stickstoffdeposition von 18 kg/ha. Ab 230 m Distanz werden nur noch ca. 3 kg/ha deponiert. Die mittlere Tageskonzentration der Staubgehalte im Abluftstrom wurde in Abhängigkeit vom Außenklima zwischen 1,2 und 9,0 mg/m³ ermittelt. Der Anteil von PM-10 und PM-2.5 am Gesamtstaub betrug 80 bzw. 30 %. Für Gesamtstaub wurde ein Emissionsfaktor von 145,4 g/Tpl. zur Berechnung der Jahresemissionen ermittelt. Die in den Außenklimabereichen ermittelten Geruchsstoffkonzentrationen (Geruchsschwelle) im Abluftstrom liegen zwischen 25 und 115 GE/m³. Die mittleren Referenzwerte der Außenluft liegen bei 19 GE.

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