RESUMEN
Highly pathogenic avian influenza (HPAI) is continuously causing significant economic losses with massive poultry depopulations. Airborne transmission of HPAI was suspected, as initial bird mortalities were reported near air inlets of poultry houses. In addition, infected farms were distant, indicating that the viruses carried by dust particles might help the viruses travel for long distances in the environment. The objective of this study focused on simulating the airborne transmission of HPAI by using computational modeling to assess the risk of airborne and deposited avian influenza (AI) carried by poultry-litter dust particles. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) modeling was used in this study. Data from 168 infected cases in the Mid-Western area of U.S. were obtained from the Animal and Plant Health Inspection Service (APHIS) and Watt Poultry. The concentration simulation modeling was performed to estimate the airborne and deposited AI concentration carried by PM2.5 dust particles. Results showed that concentrations of airborne AI, deposited AI, and combined AI transmitted to other farms in a day were lower than the minimal infective dose for poultry. In most of the scenarios, the predicted probability of infection showed that Iowa-infected farms and turkey poultry houses had the highest infection probability. The findings may provide an understanding of the risk of airborne HPAI virus carried by dust particles and suggest the factors that influence long-distance airborne transmission.
Asunto(s)
Gripe Aviar , Enfermedades de las Aves de Corral , Animales , Polvo , Aerosoles y Gotitas Respiratorias , Pollos , Aves de Corral , Brotes de Enfermedades/veterinariaRESUMEN
Consumption of poultry meat has increased dramatically due to the relative price-competitiveness as compared to other meat products. The rapid growth and increased production efficiency of modern genetic strains is perceived to negatively impact the welfare of the animal. Hematological analyses such as acid-base balance provide a thorough evaluation of the welfare in both animals and humans. This study investigated the effects of feeder space availability on welfare of broilers grown to heavy weights using blood physiological variables. The study was a randomized complete block design. In each of the 2 trials, a total of 1,440 one-d-old Ross × Ross 708 chicks (straight-run) were obtained from a commercial hatchery. Chicks were equally and randomly allocated to 32 pens based on feeder space treatment. Treatments were 4 different feeder space allocations: 2.3 (Single feeder), 2.30, 4.60, and 6.90 cm/bird. To maintain uniform bird:feeder floor space, 3 feeders were installed in each pen, except for the single feeder pen. Blood samples (3 mL) were collected from the brachial wing vein of 3 birds per pen on d 27 and 55, which were then analyzed immediately for whole blood physiological variables. The remaining blood samples were centrifuged to collect plasma that was used for corticosterone and thyroid hormones analysis. Results show there was no effect of feeder space on most of the selected physiological variables, but age had significant effects on most of the examined variables. However, all observed changes were within physiological ranges. Plasma corticosterone and blood glucose were not affected by feeder space and age, indicating absence of physiological stress. The results are in broad agreement with those reported in the literature and on homeostatic variation of broilers grown to heavy weights. In conclusion, expanding feeder allowance does not enhance the welfare of broilers grown to heavy weights.
Asunto(s)
Crianza de Animales Domésticos , Pollos , Crianza de Animales Domésticos/métodos , Animales , Fenómenos Fisiológicos Sanguíneos , Pollos/fisiología , Estrés FisiológicoRESUMEN
Understanding broiler behaviours provides important implications for animal well-being and farm management. The objectives of this study were to classify specific broiler behaviours by analysing data from wearable accelerometers using two machine learning models, K-Nearest Neighbour (KNN) and Support Vector Machine (SVM). Lightweight triaxial accelerometers were used to record accelerations of nine 7-week-old broilers at a sampling frequency of 40 Hz. A total of 261.6-min data were labelled for four behaviours - walking, resting, feeding and drinking. Instantaneous motion features including magnitude area, vector magnitude, movement variation, energy, and entropy were extracted and stored in a dataset which was then segmented by one of the six window lengths (1, 3, 5, 7, 10 and 20 s) with 50% overlap between consecutive windows. The mean, variation, SD, minimum and maximum of each instantaneous motion feature and two-way correlations of acceleration data were calculated within each window, yielding a total of 43 statistic features for training and testing of machine learning models. Performance of the models was evaluated using pure behaviour datasets (single behaviour type per dataset) and continuous behaviour datasets (continuous recording that involved multiple behaviour types per dataset). For pure behaviour datasets, both KNN and SVM models showed high sensitivities in classifying broiler resting (87% and 85%, respectively) and walking (99% and 99%, respectively). The accuracies of SVM were higher than KNN in differentiating feeding (88% and 75%, respectively) and drinking (83% and 62%, respectively) behaviours. Sliding window with 1-s length yielded the best performance for classifying continuous behaviour datasets. The performance of classification model generally improved as more birds were included for training. In conclusion, classification of specific broiler behaviours can be achieved by recording bird triaxial accelerations and analysing acceleration data through machine learning. Performances of different machine learning models differ in classifying specific broiler behaviours.
Asunto(s)
Conducta Animal , Pollos , Acelerometría/veterinaria , Animales , Aprendizaje Automático , Máquina de Vectores de SoporteRESUMEN
Stretching behavior is one of the broiler comfort behaviors that could be used for animal welfare assessment. However, there is currently no methodology for automatic monitoring of stretching behavior under representative production practices. The objectives of this study were to (1) develop a faster region-based convolutional neural network (faster R-CNN) stretching behavior detector for broiler stretching behavior detection, (2) evaluate broiler stretching behaviors under stocking densities (SDs) of 27 (27SD), 29 (29SD), 33 (33SD), and 39â¯kg/m2 (39SD) and at weeks 4 and 5 of bird ages, and (3) examine the temporal and spatial distribution of broiler stretching behaviors. The results show that the precision, recall, specificity, and accuracy were over 86% on broiler stretching detection across all SDs and bird ages using the faster R-CNN stretching behavior detector. Broilers spent 230-533â¯sec stretching every day and showed more stretching behaviors under the 29SD, 33SD, and 39SD in week 4 and under the 29SD and 33SD in week 5, as compared to other SDs. They performed less stretching in a couple of hours after light ON and before light OFF but preferred to stretch in areas with less traffic and disturbance, that is, along the fences and away from the inspection aisle. It is concluded that the stretching behavior detector had acceptable performance in detecting broiler stretching, thus being a useful tool for broiler stretching detection. Broiler stretching behavior is affected by SD and bird age and shows temporal and spatial variations.
Asunto(s)
Pollos , Redes Neurales de la Computación , Bienestar del Animal , AnimalesRESUMEN
Effects of light sources, photoperiods, and strains on growth performance, carcass characteristics, and health indices of broilers grown to heavy weights (>3 kg) were evaluated. The experimental design was a 4 × 2 × 2 factorial treatments consisting of 4 light sources [incandescent (ICD, standard), compact fluorescent light, neutral light emitting diode (Neutral-LED), and cool poultry specific LED (Cool-poultry specific (PS)-LED)], 2 photoperiods (regular/intermittent [2L:2D], and short [8L:16D]), and 2 strains (A, B). In each trial, chicks of 2 different strains from different commercial hatcheries were equally and randomly distributed into 16 environmentally controlled rooms at 1 D of age. Each room was randomly assigned one of 16 treatments from day 1 to 56 D of age. Feed and water were provided ad libitum. Birds were provided a 4 phase-feeding program (starter, grower, finisher, withdrawal). Birds and feed were weighed on 1, 14, 28, 42, and 56 D of age for growth performance. On day 56, a total of 20 (10 males and 10 females) birds from each room were processed to determine weights and yields. The BW, BW gain, live weight, and carcass weight of birds reared under PS-LED were higher (P < 0.05) in comparison with birds reared under ICD, but feed intake, feed conversion ratio, mortality, and carcass characteristics were not affected by treatments. Also, broilers subjected to the short/non-intermittent photoperiod had the lowest (P < 0.05) growth performance and carcass characteristics compared with values obtained for regular/intermittent photoperiods. In addition, strain was significant (P < 0.05) for most of the examined variables. Feed conversion, fat, tender, and yield were not affected by treatments. There was no effect of photoperiod, light sources, or their interactions on mortality. This study shows positive impacts on alternative light sources when compared to ICD along with regular/intermittent photoperiod in commercial poultry facilities rearing the 2 strains used in this study, thereby reducing energy costs and optimizing production efficiency without compromising the welfare of broilers grown to heavy weights.
Asunto(s)
Crianza de Animales Domésticos/métodos , Pollos/fisiología , Luz , Fotoperiodo , Animales , Pollos/genética , Pollos/crecimiento & desarrollo , Femenino , Masculino , Carne/análisis , Distribución AleatoriaRESUMEN
Radio frequency identification (RFID) technology offers a real-time solution to monitor behavioral responses of individual animals to various stimuli, which provides crucial implications on farm management and animal well-being. The objectives of this study were to (1) develop and describe an ultra-high frequency radio frequency identification (UHF-RFID) system for continuously monitoring feeding and drinking behaviors of individual broilers in group settings; and (2) validate the performance of the UHF-RFID system against video analysis in determining the instantaneous bird number (IBN) and time spent (TS) at feeder and drinker. The UHF-RFID system consisted of cable-tie tags, antennas, a reader and a data acquisition (DAQ) system. The antennas generated electromagnetic fields where tags were detected and registered by the DAQ system. Electromagnetic fields of the antennas were modified to cover areas of concern (i.e. tube feeders and nipple drinkers) through a series of system evaluations and customizations including tag sensitivity test, power adjustment, radio wave shielding, and assessment of interference by add-ons (e.g. plastic wraps for protecting antennas and an empty carton box for zoning out broilers) and feed/feeder. System validation was performed in two experimental rooms, each with 60 tagged broilers. The results showed that the max reading distances of tags with an identical manufacturer's specification were markedly different, indicating large variations in sensitivity among the tags. Desired electromagnetic fields could be achieved by adjusting the power supplied to antennas and by partially shielding antennas with customized stainless steel sheets. The protection materials and fully loaded feeder had little effect on electromagnetic fields of the antennas. The accuracies of the UHF-RFID system for determining IBN and TS were, respectively, 92.5±4.2% and 99.0±1.2% by the feeder antennas and 94.7±4.2% and 93.7±6.9% by the drinker antennas. It is concluded that the UHF-RIFD system can accurately detect and record feeding and drinking behaviors of individual broilers in group settings and thus is a useful tool for investigating impacts of resource allocations and management practices on these behaviors.
Asunto(s)
Pollos/fisiología , Conducta de Ingestión de Líquido , Conducta Alimentaria , Monitoreo Fisiológico/veterinaria , Dispositivo de Identificación por Radiofrecuencia/métodos , AnimalesRESUMEN
Replacing outdated incandescent light sources provides the opportunity to modify lighting systems according to the needs of different species and according to their spectral sensitivity. Providing a lighting environment geared towards poultry vision may improve bird welfare and blood physiological homeostasis. The influence of two LED light sources (red-supplemented vs. un-supplemented) adjusted to either human spectral sensitivity (lux) or poultry spectral sensitivity (CLUX) was investigated on selected blood physiological variables of male broilers. A total of 960 1-d-old male chicks were randomly distributed into 16 environmentally controlled rooms (60 chicks/room). Birds were provided a diet formulated to meet NRC recommendations with feed and water provided ad libitum. The treatments consisted of two LED light sources (red-supplemented (RS) vs. un-supplemented (WL)) adjusted to either human spectral sensitivity (CIE) or poultry spectral sensitivity (CLUX) arranged in a 2 × 2 factorial. Blood samples were collected from the brachial wing vein of six birds per room on d 21, 28, 42, and 56, which were then analyzed immediately for whole blood physiological variables. Blood plasma samples were analyzed for corticosterone. In comparison to broilers reared under RS, broilers reared under WL had lower levels of pO2, SaO2, angap, and Osmo, which were within physiological ranges. Also, birds reared under CIE had lower levels of Na+, which were also within the physiological range. In addition, blood glucose and plasma corticosterone concentrations were not affected by treatments, suggesting an absence of physiological stress. In conclusion, it is suggested that minor differences in lighting programs such as lighting source should not be expected to compromise broilers welfare, but rather is primarily an economic decision driven by capital and operation costs.
Asunto(s)
Crianza de Animales Domésticos/métodos , Pollos/sangre , Luz , Iluminación/métodos , Animales , Análisis Químico de la Sangre/veterinaria , Pollos/fisiología , Vivienda para Animales , Masculino , Distribución Aleatoria , Especificidad de la EspecieRESUMEN
We evaluated the influence of light sources and photoperiod on blood physiological variables in four trials. In each trial, 720 1-d-old Ross × Ross 708 chicks were randomly distributed into 12 environmentally controlled rooms (30 males/30 females/room). The experimental design was a 4 × 3 factorial treatments consisting of four light sources [incandescent (ICD, standard), compact fluorescent, neutral light emitting diode, and cool poultry-specific-filtered LED] and three photoperiods [long/continuous (23L:1D), regular/intermittent (2L:2D), and short/non-intermittent (8L:16D)] from d8-d56 at 50% relative humidity. Birds were fed the same diet, while feed and water were provided ad libitum. Blood samples were collected from the brachial wing vein on d 14, 28, 42, and 56 of age and analyzed immediately. Light sources had significant (P ≤ 0.05) effects on body weight (BW), and some of the selected blood physiological indices except Hb, Hct, Ca2+ angap, glucose, and corticosterone. Also, the photoperiods had significant (P ≤ 0.05) effects on BW and most of the selected blood physiological indices except HCO3-, angap, glucose, corticosterone, and T4. However, all these changes were still within the normal acid-base homeostasis and physiological ranges of this species. Acid-base regulation during the short photoperiod exposure had not deteriorated despite higher pCO2 that consequently decreased blood pH, due to a respiratory acidosis. Plasma corticosterone and glucose concentrations were not affected by treatments, suggesting an absence of physiological stress. It was concluded that the three LED light bulbs evaluated could be suitable for replacement of ICD along with the regular/intermittent photoperiod. Commercial poultry facilities can thereby reduce energy costs and optimize production efficiency without compromising the welfare of broilers grown to heavy weights (>3 kg).
Asunto(s)
Crianza de Animales Domésticos/métodos , Peso Corporal , Pollos/fisiología , Luz , Iluminación/métodos , Fotoperiodo , Animales , Análisis Químico de la Sangre/veterinaria , Fenómenos Fisiológicos Sanguíneos , Pollos/sangre , Pollos/crecimiento & desarrollo , Femenino , Masculino , Distribución AleatoriaRESUMEN
Effects of light sources and photoperiod on growth performance, carcass characteristics and health indices of broilers were investigated in 4 trials. In each trial, 720 1-day-old Ross × Ross 708 chicks were randomly distributed into 12 environmentally controlled rooms (30 males/30 females/room). The experimental design was a 4 × 3 factorial treatments consisted of 4 light sources [incandescent (ICD, standard), compact fluorescent (CFL), neutral light-emitting diode (Neutral-LED), and cool poultry-specific filtered LED (Cool-PSF-LED)] and 3 photoperiods [long/continuous (23L:1D), regular/intermittent (2L:2D), and short/non-intermittent (8L:16D)] from d8-d56. Birds were fed the same diet, while feed and water were provided ad libitum. Birds and feed were weighed on 1, 14, 28, 42, and 56 d of age for growth performance. Mortality was recorded daily and feed conversion was adjusted for mortality. Immune response was determined on d 28 to 35, whereas other welfare indices were performed on d 42, 43, and 49. At 56 d of age, 10 male and 10 female birds from each room were randomly selected and processed to determine weights and yields. The BW, BW gain, live weight, and carcass weights and yields of birds reared under Cool-PSF-LED were increased (P ≤ 0.05) in comparison to birds reared under ICD, but FI, FCR, and mortality were not affected. Moreover, broilers subjected to the short/non-intermittent photoperiod had the lowest (P ≤ 0.05) BW, BW gain, FI, live weight, carcass weight, and pectoralis major and minor weights compared to other 2 photoperiods. There was no effect of treatments on some carcass characteristics. There was no effect of treatments on welfare indices, suggesting that the light sources evaluated did not compromise welfare of heavy broilers. It was concluded that the 3 light sources evaluated in this study may be suitable for replacement of ICD light source along with regular/intermittent photoperiod instead of long/continuous photoperiod in poultry facilities to save energy utilization, thereby reducing the total cost of production.
Asunto(s)
Pollos/fisiología , Iluminación/métodos , Fotoperiodo , Crianza de Animales Domésticos/métodos , Animales , Peso Corporal , Pollos/crecimiento & desarrollo , Dieta/veterinaria , Femenino , Vivienda para Animales , Masculino , Distribución AleatoriaRESUMEN
Heat stress has a significant impact on all livestock and poultry species causing economic losses and animal well-being concerns. Providing shade is one heat-abatement strategy that has been studied for years. Material selected to provide shade for animals greatly influences the overall stress reduction provided by shade. A study was conducted to quantify both the environment and animal response, when cattle had no shade access during summertime exposure or were given access to shade provided by three different materials. A total of 32 Black Angus heifers were assigned to one of the four treatment pens according to weight (eight animals per pen). Each pen was assigned a shade treatment: No Shade, Snow Fence, 60% Aluminet Shade Cloth and 100% Shade Cloth. In the shaded treatment pens, the shade structure covered ~40% of the pen (7.5 m2/animal). Animals were moved to a different treatment every 2 weeks in a 4×4 Latin square design to ensure each treatment was applied to each group of animals. Both environmental parameters and physiological responses were measured during the experiment. Environmental parameters included dry-bulb temperature, relative humidity, wind speed, black globe temperature (BGT), solar radiation (SR) and feedlot surface temperature. Animal response measurements included manual respiration rate (RRm), electronic respiration rate (RRe), vaginal temperature (body temperature (BT)), complete blood count (CBC) and plasma cortisol. The environmental data demonstrated changes proportional to the quality of shade offered. However, the animal responses did not follow this same trend. Some of the data suggest that any amount of shade was beneficial to the animals. However, Snow Fence may not offer adequate protection to reduce BT. For some of the parameters (BT, CBC and cortisol), 60% Aluminet and 100% Shade Cloth offers similar protection. The 60% Aluminet lowered RRe the most during extreme conditions. When considering all parameters, environmental and physiological, 60% Aluminet Shade Cloth offered reductions of BGT, SR, feedlot surface temperature and the best (or equal to the best) overall protection for the animals (RRe, RRm, BT, blood parameters).
Asunto(s)
Enfermedades de los Bovinos/prevención & control , Bovinos/fisiología , Trastornos de Estrés por Calor/veterinaria , Animales , Temperatura Corporal , Peso Corporal , Enfermedades de los Bovinos/fisiopatología , Femenino , Trastornos de Estrés por Calor/fisiopatología , Trastornos de Estrés por Calor/prevención & control , Calor , Frecuencia Respiratoria , Estrés Fisiológico , Luz SolarRESUMEN
This study investigated the effects of light sources and light intensity on growth performance, carcass characteristics, and welfare indices of heavy broilers (>3.0 kg) in 4 trials with 2 replications per trial. A total of 960 one-day-old Ross×Ross 708 chicks (30 males/30 females/room) were randomly distributed into 16 environmentally controlled rooms at 50% RH. A 4×2 factorial treatment structure evaluated 4 light sources (incandescent [ICD, standard], compact fluorescent [CFL], neutral light emitting diode [Neutral-LED], and cool poultry specific filtered LED [Cool-PSF-LED]) and 2 levels (5 lx, 20 lx) of light intensities. Each of the 4 light sources was paired with one of the 2 light intensities. Birds were fed the same diet with a 4-phase feeding program (starter, grower, finisher, and withdrawal). Feed and water were provided ad libitum. Birds and feed were weighed on one, 14, 21, 28, 42, and 56 d of age for growth performance. All mortality was recorded daily and feed conversion was adjusted for mortality. Immune response was determined on d 28 to d 35, whereas other welfare indices were performed on d 42 and 49, respectively. At d 56 of each trial, 20 (10 males and 10 females) birds from each room were processed to determine weights and yields. The BW, BW gain, live weight, and carcass weights of birds reared under Cool-PSF-LED were different (P≤0.05) in comparison to birds reared under ICD. However, FI, FCR, and mortality were not affected by treatments. There was no effect of treatments on fat or breast and tender weights and yields. In addition, there was no effect of treatments on ocular development, immune response, and other welfare indices, suggesting that the light sources evaluated did not compromise welfare of heavy broilers. It was concluded that the 3 light sources evaluated in this study may be suitable for replacement of ICD light source in poultry facilities to reduce energy cost and optimize production efficiency.
Asunto(s)
Crianza de Animales Domésticos/normas , Bienestar del Animal , Pollos/fisiología , Luz , Iluminación , Animales , Pollos/crecimiento & desarrollo , Pollos/inmunología , Femenino , Masculino , Distribución AleatoriaRESUMEN
Vaccines are utilized within the poultry industry to minimize disease-associated losses and spray vaccination is a commonly utilized means for the mass application of poultry vaccines. During this process, vaccine-laden particles are deposited upon target areas (e.g., eyes, nares, and oral cavity) resulting in the direct internalization of the vaccine. However, particles are also deposited on nontarget areas such as the exterior of the subject and its surrounding environment. To better determine the fate of particles deposited upon nontarget areas and the impact of deposition site on the efficiency of vaccine application, a live bacterial poultry vaccine (AviPro(®) MG F) was applied via spray using a spray cabinet with a slotted partition allowing for head-only, body-only, and whole-bird spray application. At 11 wk age, Hy-Line(®) W-36 pullets (n = 280) were allocated equally among 7 treatments including: nonvaccinated controls, pullets spray-vaccinated at the manufacturer's recommended dose (1X) in a site-specific manner (head-only, body-only, and whole-bird), pullets spray-vaccinated at 5X the recommended level (body-only), pullets vaccinated by manual eye-drop application (1X), and pullets eye-drop vaccinated at a level approximating that achieved during the spray vaccination process (1/700X). At 6 to 7 wk postvaccination, vaccination efficiency was assessed via serological-based assays [serum plate agglutination (SPA) and ELISA] and the detection of vaccine-derived in vivo populations. Results indicate an additive contribution of the vaccine deposited on the body to the overall vaccination efficiency of this live bacterial live poultry vaccine.
Asunto(s)
Vacunas Bacterianas/inmunología , Pollos , Infecciones por Mycoplasma/veterinaria , Enfermedades de las Aves de Corral/prevención & control , Vacunación/veterinaria , Animales , Vacunas Bacterianas/administración & dosificación , Femenino , Infecciones por Mycoplasma/prevención & control , Mycoplasma gallisepticumRESUMEN
Light-emitting diode (LED) lighting is being used in the poultry industry to reduce energy usage in broiler production facilities. However, limited data are available comparing efficacy of different spectral distribution of LED bulbs on blood physiological variables of broilers grown to heavy weights (>3 kg). The present study evaluated the effects of color temperature (Kelvin) of LED bulbs on blood physiological variables of heavy broilers in 2 trials with 4 replicates/trial. The study was a randomized complete block design. Four light treatments consisted of 3 LED light bulbs [2,700 K, (Warm-LED); 5,000 K, (Cool-LED-#1); 5,000 K, (Cool-LED-#2)] and incandescent light (ICD, standard) from 1 to 56 d age. A total of 960 1-day-old Ross × Ross 708 chicks (30 males/room 30 females/room) were equally and randomly distributed among 16 environmentally controlled rooms at 50% RH. Each of the 4 treatments was represented by 4 rooms. Feed and water were provided ad libitum. All treatment groups were provided the same diet. Venous blood samples were collected on d 21, 28, 42, and 56 for immediate analysis of selected physiological variables and plasma collection. In comparison with ICD, Cool-LED-#1 had greater (P < 0.05) effects on pH, partial pressure of CO2(pCO2), partial pressure of O2(pO2), saturated O2(sO2), and Kâº. However, all these acid-base changes remained within the normal venous acid-base homeostasis and physiological ranges. In addition, no effect of treatments was observed on HCO(3)(-), hematocrit (Hct), hemoglobin (Hb), Naâº, Ca²âº, Clâ», mean corpuscular hemoglobin concentration (McHc), osmolality, and anion gap. Moreover, blood glucose concentrations were not affected by treatments. This study shows that the 3 LED light bulbs evaluated in this study may be suitable for replacement of ICD light sources in commercial poultry facilities to reduce energy cost and optimize production efficiency without inducing physiological stress on broilers grown to heavy weights.
Asunto(s)
Peso Corporal , Pollos/sangre , Iluminación/instrumentación , Animales , Bicarbonatos/sangre , Pollos/crecimiento & desarrollo , Color , Femenino , Vivienda para Animales , Concentración de Iones de Hidrógeno , MasculinoRESUMEN
Limited data are available for comparing light-emitting diode (LED) bulbs that are currently available in commercial broiler production facilities. We evaluated the effects of color temperatures (kelvin) of LED bulbs on growth performance, carcass characteristics, and ocular development indices of broilers grown to heavy weights (>3.0 kg). The experiment had a randomized complete block design. Four treatments consisted of 3 LED light bulbs (2,700 [warm LED]; 5,000 [cool LED 1]; and 5,000 K [cool LED 2]) and incandescent light (2,010 K [ICD], standard) from day zero to 56 d of age. A total of 960 Ross×Ross 708 day-old chicks were equally and randomly distributed into 16 environmentally controlled rooms at 50% RH (30 males and 30 females/room). Thus, each of the 4 treatments was represented by 4 rooms (4 replicates) per trial. Feed and water were provided ad libitum. All birds were fed the same diet. Ocular specimens were collected on d 42 for development and histopathologic examination. Blood samples were collected on d 21, 28, 42, and 56 to determine plasma corticosterone. On d 56, twenty birds from each room (10 males and 10 females) were processed to determine weights and yields. The BW and BW gain (BWG), live weight, and carcass weights of birds reared under cool LED 1 were different in comparison to birds reared under ICD (P<0.05). However, feed intake (FI), feed conversion ratio (FCR), and mortality were not affected by treatments. The treatments did not affect fat, breast and tender weights, and yields. In addition, ocular development indices and plasma corticosterone concentrations were not affected by treatments, suggesting the LED light bulbs we evaluated did not compromise the welfare of the birds. It was concluded that cool LED 1 may be a better potential replacement light source in comparison to ICD on performance, but it may be equal when compared to other LED light sources examined in this study.
Asunto(s)
Crianza de Animales Domésticos/métodos , Pollos/fisiología , Luz , Animales , Pollos/crecimiento & desarrollo , Color , Ojo/crecimiento & desarrollo , Femenino , Iluminación , Masculino , Distribución Aleatoria , Aumento de PesoRESUMEN
Effects of genetic strain and light intensity on growth performance and carcass characteristics of broilers grown to heavy weights were investigated. The experimental design was a randomized complete block design. Treatment structure was a 2 × 5 factorial arrangement with the main factors being strain (Ross × Ross 308, Ross × Ross 708) and light intensity (25, 10, 5, 2.5, and 0.2 lx) with trial as replicates. In each of the 5 trials, chicks of 2 different strains of the same commercial hatchery were equally and randomly distributed into 10 environmentally controlled rooms (5 rooms/strain) at 1 d of age at 50% RH. Each room was randomly assigned 1 of 5 light intensities from 22 to 56 d of age. Feed and water were provided ad libitum. Birds and feed were weighed on 0, 14, 28, 42, and 56 d of age for growth performance. Humoral immune response was determined on d 28, whereas ocular and blood samples were performed on d 42 and 55, respectively. On d 56, 20 (10 males and 10 females) birds/strain from each room were processed to determine weights and yields. Genetic strain was significant (P ≤ 0.05) for most of the examined variables, where Ross × Ross 308 had better growth performance and meat yield in comparison with Ross × Ross 708. Although, there was no main effect of light intensity on growth performance and meat yield, results indicated that birds under 10 and 5 lx intensities showed slightly better growth performance and meat yield compared with birds under 25, 2.5, and 0.2 lx in both strains. There was no effect of strain and light intensity on ocular indices, immune response, plasma corticosterone levels, and mortality. This study shows the positive influence on profits to commercial poultry facilities that are using a low lighting environment to reduce energy cost, optimize feed conversion, and maximize production without compromising the welfare of the broilers.
Asunto(s)
Crianza de Animales Domésticos/métodos , Pollos/fisiología , Iluminación , Carne/análisis , Animales , Análisis Químico de la Sangre/veterinaria , Pollos/clasificación , Pollos/genética , Pollos/crecimiento & desarrollo , Pollos/inmunología , Ojo/crecimiento & desarrollo , Ojo/efectos de la radiación , Femenino , Inmunidad Humoral/efectos de la radiación , Masculino , Carne/efectos de la radiación , Fenómenos Fisiológicos Oculares/efectos de la radiación , Distribución AleatoriaRESUMEN
Eggshell color can greatly influence visual appeal of table eggs, and within the United States, table eggs are normally sorted and marked according to eggshell color to maximize consumer appeal. Recently, table egg producers have noted increased incidence of "off-color" or tinted (TT) eggs derived from white egg laying breeder hens. Therefore, the objectives of this study were to determine the production characteristics and resultant eggshell color of laying hens hatched from different colored eggs. Hy-Line W36 eggs were obtained from a commercial breeder operation and eggshell color was assessed with a colorimeter to separate eggs into groups of tinted (TT) and nontinted (NT) eggs before incubation. Treatment groups were placed into separate hatching trays. At hatching, chicks from each treatment group were individually wing-banded. Pullets were randomly allocated into cages according to treatment groups at 18 wk. Birds were placed into individual cages, with 5 consecutive cages representing a treatment replicate. Each treatment was replicated 24 times for a total of 120 birds per treatment and fed a nutritionally complete layer diet. Production performance was evaluated from 18 to 34 wk of age. Average weekly egg production was calculated. Feed intake, egg weights, egg mass, feed conversion ratio, and egg color were analyzed every 2 wk. Birds were weighed every 4 wk until completion of the study. Birds hatched from TT eggs had significantly increased BW throughout the experimental period. Hen-day egg production was significantly different when compared with the NT treatment at 19 and 20 wk of age. Eggshell color was also found to be significantly different for the NT and TT groups with TT eggs being significantly further from true white. Selection of progeny based on eggshell color may be a criterion for selecting white egg layers as layers hatched from TT eggs resulted in more off-color eggs, which may affect consumer acceptance for buying white table eggs.
Asunto(s)
Pollos/fisiología , Cáscara de Huevo/fisiología , Pigmentación , Animales , Peso Corporal , Pollos/crecimiento & desarrollo , Color , Colorimetría/veterinaria , Femenino , Distribución AleatoriaRESUMEN
The effects of genetic strain, light intensity, and their interaction were examined on blood physiological variables of broilers maintained in environmentally controlled rooms in each of 5 trials. The study consisted of a 2 × 5 factorial arranged in a randomized complete block design with 10 treatments of 2 strains (Ross × Ross 308 and 708) and exposure to 5 light intensities (25, 10, 5, 2.5, and 0.2 lx) with chicks equally and randomly distributed at 1 d of age. The 5 light intensities were randomly assigned from 22 to 56 d of age. Feed and water were provided ad libitum. Venous blood samples were collected on d 21 (base line), 28, 42, and 56 of age. Main effects indicate that Ross × Ross 308 significantly (P ≤ 0.05) increased BW, partial pressure of CO2, Ca(2+), Na(+), Cl(-), and thyroxine, along with significantly (P ≤ 0.05) reduced pH level, partial pressure of O2, HCO3(-), and triiodothyronine in comparison with Ross × Ross 708. No main effect of light intensity was observed on all examined variables. In addition, no significant main effects were observed for strain, light intensity, or their interaction on saturated O2, hematocrit, hemoglobin, K(+), mean corpuscular hemoglobin concentration, glucose, osmolality, and anion gap. Physiologically, although Ross × Ross 308 had a significantly increased BW in comparison with Ross × Ross 708, Ross × Ross 708 showed a significant (P ≤ 0.05) increase in partial pressure of O2 and triiodothyronine along with lower blood partial pressure of CO2 and thyroxine. The results of this study supplement current knowledge of physiological response to differing lighting levels and may be used to establish the normal blood values for commercial broilers grown to heavy weights. Plasma corticosterone was not affected by either treatments or strain, indicating that the treatments did not induce physiological stress in broilers.
Asunto(s)
Equilibrio Ácido-Base/efectos de la radiación , Crianza de Animales Domésticos/métodos , Pollos/fisiología , Electrólitos/efectos de la radiación , Iluminación , Animales , Análisis de los Gases de la Sangre/veterinaria , Pollos/sangre , Pollos/genética , Electrólitos/metabolismo , Femenino , Masculino , Distribución Aleatoria , Estrés Fisiológico/efectos de la radiaciónRESUMEN
Corn distillers dried grains with solubles (DDGS) are now being further processed to remove corn oil, which may be used as a dietary energy source for poultry. The objectives of this study were to compare the effects of a poultry fat (PF) and a new DDGS-derived corn oil blend (CO) on live performance and carcass characteristics of 49-d-old broilers. Four corn-soybean meal based diets were formulated with differing blends of PF and CO. All diets contained the same percentage of total fat, but differed in the fat source. One diet had the sole source of fat as PF (100:0% PF:CO) and was then replaced with 25% CO, 75% CO, and a 100% replacement of CO. Each of the diets was fed in a 3-phase feeding program to 6 replicate pens. At day of hatch, Ross × Ross 708 broilers were randomly allocated to 24 pens composed of 42 birds of equal sex. On d 49, 10 birds from each pen were processed, and carcass, abdominal fat pad, and breast muscle components were determined. There were no significant differences in live performance for the starter phase (0-18 d). For the grower phase (19-35 d), birds fed 75:25% PF:CO significantly (P ≤ 0.05) increased BW, BW gain, and decreased feed conversion compared with the control (100:0% PF:CO). Birds fed 0:100% PF:CO also observed similar improvements in BW, BW gain, and feed conversion during the grower phase. There were no significant differences for the finisher phase (36-48 d). On d 49, live weights for birds fed the 0:100% PF:CO diets were significantly lower compared with other treatments. A trend for lower carcass and breast weights and increased abdominal fat was also observed for birds fed the 0:100% PF:CO. The addition of CO led to significant improvements in pellet durability for grower and finisher pellets. The results of this study indicate that DDGS-derived CO can be used to partially replace PF in broiler diets without any detrimental effects.
Asunto(s)
Alimentación Animal/análisis , Pollos/fisiología , Aceite de Maíz/metabolismo , Grasas de la Dieta/metabolismo , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Composición Corporal , Pollos/genética , Pollos/crecimiento & desarrollo , Aceite de Maíz/administración & dosificación , Dieta/veterinaria , Grasas de la Dieta/administración & dosificación , Suplementos Dietéticos , Grano Comestible/química , Femenino , Masculino , Distribución AleatoriaRESUMEN
The effects of photoperiod, light intensity, and their interaction on blood acid-base balance, metabolites, and electrolytes in broiler chickens under environmentally controlled conditions were examined in 2 trials. A 3 × 3 factorial experiment in a randomized complete block design was used in this study. In each trial, all treatment groups were provided 23L:1D with 20 lx of intensity from placement to 7 d, and then subjected to the treatments. The 9 treatments consisted of 3 photoperiods [long/continuous (23L:1D) from d 8 to 56, regular/intermittent (2L:2D), and short/nonintermittent (8L:16D) from d 8 to 48 and 23L:1D from d 49 to 56, respectively] and exposure to 3 light intensities (10, 5.0, and 0.5 lx) from d 8 through d 56 at 50% RH. Feed and water were provided ad libitum. Venous blood samples were collected on d 7, 14, 28, 42, and 56. Main effects indicated that short/nonintermittent photoperiod significantly (P < 0.05) reduced BW, pH, partial pressure of O2, saturated O2, Na(+), K(+), Ca(2+), Cl(-), osmolality, triiodothyronine (T3), and total protein along with significantly (P < 0.05) elevated partial pressure of CO2, hematocrit, hemoglobin, and lactate concentrations. In addition, there were no effects of photoperiod on HCO3(-), glucose, anion gap, and thyroxine (T4). Plasma corticosterone was not affected by photoperiod, light intensity, or their interaction. There was no effect of light intensity on most of the blood variables examined. Acid-base regulation during photoperiod and light intensity exposure did not deteriorate despite a lower pH and higher partial pressure of CO2 with normal HCO3(-). These results indicate that continuous exposure of broiler chickens to varying light intensities had a minor effect on blood physiological variables, whereas the short photoperiod markedly affected most blood physiological variables without inducing physiological stress in broilers.
Asunto(s)
Pollos/fisiología , Electrólitos/sangre , Fotoperiodo , Aumento de Peso , Equilibrio Ácido-Base , Animales , Análisis Químico de la Sangre/veterinaria , Pollos/anatomía & histología , Pollos/sangre , Femenino , Luz , Masculino , Distribución AleatoriaRESUMEN
Two simultaneous trials were conducted using a commercially available, live, F strain Mycoplasma gallisepticum (FMG) vaccine (trial 1) or 2 inocula of layer complex-derived MG strains (LCD-MG; trial 2). In each of the 2 trials, 4 commercial turkeys were housed in each of 2 adjoining pens immediately adjacent to air inlets. The turkeys (8/trial) were inoculated in the right eye with either a 1× dose of FMG (trial 1) or with 0.02 mL of 1 of 2 actively growing LCD-MG inocula (4 turkeys/inoculum; trial 2). In each of the 2 trials, one pen housing 4 inoculated turkeys was maintained without the addition of other poultry, whereas 16 MG-free broilers and 4 MG-free layers were added to the other pen of 4 inoculated turkeys. Within each of the trials and at increasing intervals, either 4 layers (3 pens) or 4 turkeys (3 pens) were placed down-airstream from the inoculated pens. The distance of the first pen from the inoculated turkeys was separated by the width of one pen that was empty. Succeeding down-airstream pens were situated such that the empty distance (absence of any poultry) between pens that contained poultry doubled from one pen to the next such that the final pen that contained poultry had 4 empty pens between it and the next up-airstream pen that also contained poultry. At 106 d postinoculation, all poultry were bled, swabbed for MG from the choanal cleft, and then euthanized and necropsied. No commingled poultry in trial 1 (FMG), whether inoculated (turkeys) or commingled (layers and broilers), died during the course of the trial, and 5 of the 8 FMG-vaccinated turkeys exhibited serological but not cultural evidence of mycoplasmosis. In trial 2 (LCD-MG), 2 commingled broilers died and no inoculated turkeys exhibited either serological or cultural evidence of mycoplasmosis. In both trials, no poultry housed down-airstream from the inoculated poultry showed evidence of clinical signs of mycocplasmosis and none showed either serological or cultural evidence of mycoplasmosis.