RESUMEN
Broiler chicks usually hatch in the hatchery without access to feed and water until placement at the farm. This can affect their health and welfare negatively. Therefore, alternative strategies have been developed, for instance providing chicks with early nutrition in the hatchery or hatching eggs directly on-farm. However, information on the physical and mental welfare of chicks hatched in these systems compared to conventionally hatched chicks is limited. The aim of this study was to investigate the effects of alternative hatching systems on the welfare of broiler chickens in early and later life. A system comparison was performed with chickens that hatched conventionally in a hatchery (HH), in a system which provided light, feed, and water in a hatcher (hatchery-fed, HF), or on-farm (on-farm hatched, OH, where feed and water were available and transport of day-old chicks from the hatchery to the farm was not necessary). Chickens were reared in 3 batches, in 12 floor pens per batch (approximately 1,155 animals per pen), with a total of 12 replicates per treatment. Animal-based welfare indicators were assessed following standard protocols: plumage cleanliness, footpad dermatitis (FPD), hock burn, skin lesions (all at day 21 and 35 of age), and gait score (day 35). Furthermore, a set of behavioral tests was carried out: novel environment (day 1 and 21), tonic immobility, novel object, and avoidance distance test (day 4 and 35). Plumage cleanliness, hock burn, and skin lesions were affected by age but not by hatching system, with older broilers scoring worse than younger ones (P < 0.05). An effect of hatching system was only found for FPD, with the highest prevalence in HH chickens, followed by HF and OH chickens (P < 0.05). All responses measured in the behavioral tests were affected by age but not by hatching system. In later life, chickens were significantly less fearful than during the first days of life. The results indicate that conventionally hatched chickens scored significantly worse for FPD, whereas, in general, hatching system seemed to have minor effects on other broiler welfare indicators.
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Crianza de Animales Domésticos , Bienestar del Animal , Pollos , Cigoto , Crianza de Animales Domésticos/métodos , Crianza de Animales Domésticos/normas , Animales , Métodos de Alimentación/normas , Estado Nutricional , Cigoto/crecimiento & desarrolloRESUMEN
This study was conducted to determine the effect of feeding frequency on growth performance, carcass traits, and apparent nutrient digestibility in geese from 28 to 70 D of age. In experiment 1, a total of 240 geese were distributed in a completely randomized design into 4 treatments and 6 replicates of 10 birds each. The treatments were free access to the feeder (ad libitum) and access to the feeder 3, 4, and 5 times daily. Geese fed 3 times daily had a lower (P < 0.05) BW, ADG, and ADFI and a higher (P = 0.064) feed conversion ratio (FCR) from 28 to 41 D of age compared with the other groups. Geese fed 4 times daily had a higher (P < 0.05) ADG and ADFI and a lower (P < 0.05) FCR from 42 to 55 D of age compared with ad libitum fed geese. Geese fed 3 times daily had a higher (P < 0.05) ADG from 56 to 69 D of age than geese fed ad libitum and 4 times daily. No differences (P > 0.05) in BW, ADFI, ADG, and FCR were observed between ad libitum and feeding frequency groups from 28 to 69 D of age. Carcass traits and gastrointestinal development were not affected (P > 0.05) by feeding frequency. In experiment 2, the apparent nutrient digestibility in geese from 71 to 77 D of age fed using different feeding frequencies was determined using the total fecal collection method. Feeding frequency did not affect (P > 0.05) the apparent digestibility of DM, CP, crude ash, calcium, phosphorous, or ether extract in geese. Our study demonstrates for the first time that compensatory growth can be gained by enhancing feed intake when a lower feeding frequency is imposed on geese. Both ad libitum feeding and fixed feeding frequency for 3 to 5 times daily are suitable for geese from 28 to 70 D of age to achieve optimum production.
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Alimentación Animal , Crianza de Animales Domésticos , Digestión , Métodos de Alimentación , Gansos , Alimentación Animal/análisis , Crianza de Animales Domésticos/métodos , Animales , Constitución Corporal/fisiología , Dieta/veterinaria , Digestión/fisiología , Métodos de Alimentación/normas , Métodos de Alimentación/veterinaria , Gansos/crecimiento & desarrollo , Gansos/metabolismo , Nutrientes/metabolismo , Distribución AleatoriaRESUMEN
PURPOSE: We report findings from an institutional ethnography (IE) of nurses' work of feeding infants within an increasingly technical organization of NICUs. SAMPLE: Five primary informants; 18 secondary informants. DESIGN: The institutional ethnographic approach included field observations, interviews, and phone and e-mail conversations. Our analysis followed accounts of what actually happened within the textual organization of nurses' work. MAIN OUTCOME: Nurses' feeding practices are directed by protocols that arise within multiple documentation systems and clinical technologies. These systems produce barriers to nurses' efforts to skillfully feed infants. RESULTS: Prioritization of quality and safety perspectives can obscure and constrain the ordinary yet critical clinical reasoning neonatal nurses employ during feeding work. Clinical technologies that have been developed to improve safety can paradoxically disrupt the ability of nurses to respond in the moment to neonatal feeding cues. This finding provides nurses, leaders, and policymakers with insight into why policies and procedures may not be followed as expected.
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Actitud del Personal de Salud/etnología , Métodos de Alimentación/normas , Cuidado Intensivo Neonatal/normas , Enfermeras Neonatales/psicología , Seguridad del Paciente/normas , Guías de Práctica Clínica como Asunto , Adulto , Alberta , Antropología Cultural , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana EdadRESUMEN
OBJECTIVE: To examine maternal and newborn factors that influence non-medically indicated (NMI) formula supplementation of newborns in the hospital setting. DATA SOURCES: Electronic databases CINAHL and Ovid MEDLINE were searched for peer-reviewed articles published in English between January 1, 2000, and September 30, 2017. STUDY SELECTION: A total of 616 studies were returned from the search. After removal of duplicates, 558 studies remained, 531 of which were excluded based on factors of not being related to term newborns, not being published in a peer-reviewed journal, or study not completed in a hospital setting. Five studies were included that met the inclusion and exclusion criteria. DATA EXTRACTION: Data from the five studies were extracted and compiled into a summary table. DATA SYNTHESIS: Synthesis indicated that maternal ethnicity, educational level, and income influence the decision to provide NMI formula supplementation to newborns. First-time mothers and those with cesarean birth, no previous breastfeeding experience, female newborns, and large-for-gestational-age newborns were at greater risk for NMI formula supplementation. Neonates born at night are more likely to receive NMI formula supplementation, and NMI formula supplementation increases during the night hours and during the first 24 hours after birth. CONCLUSION: Identification of newborn/maternal risk factors, continuous breastfeeding support, and provision of consistent breastfeeding education to women are factors that influence NMI formula supplementation of newborns. With collaboration among hospital physicians, midwives, nurse practitioners, nurses, and lactation consultants to identify at-risk newborns, the goal of decreasing NMI formula supplementation of newborns in the hospital can be achieved.
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Lactancia Materna/métodos , Suplementos Dietéticos/normas , Métodos de Alimentación/normas , Fórmulas Infantiles/normas , Femenino , Humanos , Recién Nacido , Masculino , Factores de Tiempo , Carga de Trabajo/normasRESUMEN
Dietary guidelines provide advice on what to eat to different subsets of the population but often do not take into account the "how" to eat. Responsive feeding is a key dimension of responsive parenting involving reciprocity between the child and caregiver during the feeding process and is characterized by caregiver guidance and recognition of the child's cues of hunger and satiety. Evidence indicates that providing responsive feeding guidance to mothers on how to recognize and respond appropriately to children's hunger and satiety cues can lead to improved feeding practices and weight status and developmental outcomes among infants and young children. In addition, early and nurturing exposures to foods with different tastes and textures and positive role modelling help children to learn to eat healthy foods. The importance of improving caregiver's responsive feeding behaviours to ensure the adequate introduction of complementary foods is becoming increasing recognized, but responsive feeding principles have not been taken into account in a comprehensive way in the development of dietary guidelines. The incorporation of all responsive feeding principles into dietary guidelines has a strong potential to enhance their impact on early childhood development outcomes for infants and young children but will require adaptation to the different contexts across countries to ensure that they are culturally sensitive and grounded in a deep understanding of the types of foods and other resources available to diverse communities.
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Señales (Psicología) , Dieta Saludable , Métodos de Alimentación/normas , Cuidado del Lactante/normas , Fenómenos Fisiológicos Nutricionales del Lactante/normas , Responsabilidad Parental , Adulto , Humanos , Hambre , Lactante , Política Nutricional , Respuesta de SaciedadRESUMEN
BACKGROUND: Children with congenital heart disease are at high risk for malnutrition. Standardisation of feeding protocols has shown promise in decreasing some of this risk. With little standardisation between institutions' feeding protocols and no understanding of protocol adherence, it is important to analyse the efficacy of individual aspects of the protocols. METHODS: Adherence to and deviation from a feeding protocol in high-risk congenital heart disease patients between December 2015 and March 2017 were analysed. Associations between adherence to and deviation from the protocol and clinical outcomes were also assessed. The primary outcome was change in weight-for-age z score between time intervals. RESULTS: Increased adherence to and decreased deviation from individual instructions of a feeding protocol improves patients change in weight-for-age z score between birth and hospital discharge (p = 0.031). Secondary outcomes such as markers of clinical severity and nutritional delivery were not statistically different between groups with high or low adherence or deviation rates. CONCLUSIONS: High-risk feeding protocol adherence and fewer deviations are associated with weight gain independent of their influence on nutritional delivery and caloric intake. Future studies assessing the efficacy of feeding protocols should include the measures of adherence and deviations that are not merely limited to caloric delivery and illness severity.
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Procedimientos Quirúrgicos Cardíacos , Métodos de Alimentación/normas , Adhesión a Directriz , Apoyo Nutricional/normas , Aumento de Peso , Femenino , Cardiopatías Congénitas/cirugía , Humanos , Recién Nacido , Tiempo de Internación , Modelos Lineales , Masculino , Desnutrición/prevención & control , Alta del Paciente , Estudios ProspectivosRESUMEN
The global population is aging, and with this demographic shift, the incidence and prevalence of dementia are expected to increase. According to the World Health Organization, an estimated 50 million people are living with dementia worldwide, and this number is expected to triple to 150 million by 2050. Dementia initially affects the brain, eventually affecting the entire body culminating in death, commonly from the complications and comorbidities. People with dementia often experience eating difficulties in addition to a severe decline in cognitive, verbal, and functional abilities secondary to gradual neurodegenerative process, leading to weight loss, malnutrition, and dehydration. When eating difficulties and weight loss occur, health care providers and families often feel obligated to decide to either continue the oral feeding or opt for feeding tube placement. Primary care clinicians, both nurse practitioners and physicians, are presented with challenges when facilitating the decision regarding the feeding options in patients with advanced dementia. This narrative review aims at evaluating the impact of enteral nutrition versus oral feeding by comparing the rates of survival and adverse events in older adults with advanced dementia. It also highlights the best approaches to optimizing nutrition for this frail population.
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Demencia/dietoterapia , Nutrición Enteral/normas , Métodos de Alimentación/normas , Toma de Decisiones , Nutrición Enteral/estadística & datos numéricos , Métodos de Alimentación/estadística & datos numéricos , Humanos , Oportunidad RelativaRESUMEN
BACKGROUND: The timely establishment of enteral feeds and a reduction in the number of feeding interruptions are key to achieving optimal nutrition in premature infants. Nutritional guidelines vary widely regarding feeding regimens and there is not a widely accepted consensus on the optimal feeding interval. PURPOSE: To critically examine the evidence to determine whether there is a relationship to feeding intervals and feeding outcomes in premature infants. METHODS: A systematic review of the literature in the following databases: PubMed, CINAHL, Embase and the Cochrane Library. The search strategy used the terms infant premature, low birth weight, enteral feeding, feed tolerance and feed intervals. RESULTS: Search results yielded 10 studies involving 1269 infants (birth weight ≤1750 g). No significant differences in feed intolerance, growth, or incidence of necrotizing enterocolitis were observed. Evidence suggests that infants fed at 2 hourly intervals reached full feeds faster than at 3 hourly intervals, had fewer days on parenteral nutrition, and fewer days in which feedings were withheld. Decrease in the volume of gastric residuals and feeding interruptions were observed in the infants fed at 3 hourly intervals than those who were continuously fed. IMPLICATIONS FOR PRACTICE: Reducing the feed interval from 3 to 2 hourly increases nurse workload, yet may improve feeding outcomes by reducing the time to achieve full enteral feeding. IMPLICATIONS FOR RESEARCH: Studies varied greatly in the definition and management of feeding intolerance and in how outcomes were measured, analyzed, and reported. The term "intermittent" is used widely but can refer to a 2 or 3 hourly interval.
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Métodos de Alimentación/normas , Salud del Lactante/normas , Recien Nacido Prematuro/crecimiento & desarrollo , Cuidado Intensivo Neonatal/normas , Estado Nutricional/fisiología , Nutrición Parenteral/normas , Guías de Práctica Clínica como Asunto , Educación Continua en Enfermería , Femenino , Humanos , Recién Nacido , Masculino , Factores de TiempoRESUMEN
The aim of the present study was to evaluate empirically confusion matrices in device validation. We compared the confusion matrix method to linear regression and error indices in the validation of a device measuring feeding behaviour of dairy cattle. In addition, we studied how to extract additional information on classification errors with confusion probabilities. The data consisted of 12â¯h behaviour measurements from five dairy cows; feeding and other behaviour were detected simultaneously with a device and from video recordings. The resulting 216 000 pairs of classifications were used to construct confusion matrices and calculate performance measures. In addition, hourly durations of each behaviour were calculated and the accuracy of measurements was evaluated with linear regression and error indices. All three validation methods agreed when the behaviour was detected very accurately or inaccurately. Otherwise, in the intermediate cases, the confusion matrix method and error indices produced relatively concordant results, but the linear regression method often disagreed with them. Our study supports the use of confusion matrix analysis in validation since it is robust to any data distribution and type of relationship, it makes a stringent evaluation of validity, and it offers extra information on the type and sources of errors.
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Bovinos/fisiología , Conducta Alimentaria/fisiología , Métodos de Alimentación/normas , Modelos Estadísticos , Monitoreo Fisiológico/instrumentación , Animales , Métodos de Alimentación/instrumentación , Femenino , Probabilidad , Reproducibilidad de los Resultados , Estudios de Validación como Asunto , Grabación en VideoRESUMEN
Growing evidence supporting the health benefits of human milk, particularly in the preterm population, has led to rising demand for donor human milk in NICUs and pediatric hospitals. There are no previous reports describing the use of unpasteurized shared human milk (USHM) in the hospital setting, but the use of USHM solicited from community donors through social networks appears to be common. Many pediatric hospitals permit inpatients to receive breast milk that has been screened and pasteurized by a human milk banking organization and will provide pasteurized donor human milk (PDHM) only to infants who are preterm or have specific medical conditions. These policies are designed to minimize potential adverse effects from improperly handled or screened donor milk and to target patients who would experience the greatest benefit in health outcomes with donor milk use. We explore the ethical and health implications of 2 cases of medically complex infants who did not meet criteria in our tertiary care hospital for the use of PDHM from a regulated human milk bank and were incidentally found to be using USHM. These cases raise questions about how best to balance the ethical principles of beneficence, nonmaleficence, justice, and patient autonomy in the provision of PDHM, a limited resource. Health care staff should ask about USHM use to provide adequate counseling about the risks and benefits of various feeding options in the context of an infant's medical condition.
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Métodos de Alimentación , Inocuidad de los Alimentos/métodos , Trastornos de la Nutrición del Lactante , Enfermedades del Recién Nacido/terapia , Leche Humana , Pasteurización , Selección de Donante/ética , Selección de Donante/organización & administración , Selección de Donante/normas , Métodos de Alimentación/efectos adversos , Métodos de Alimentación/ética , Métodos de Alimentación/normas , Femenino , Humanos , Lactante , Alimentos Infantiles/efectos adversos , Alimentos Infantiles/análisis , Alimentos Infantiles/normas , Trastornos de la Nutrición del Lactante/etiología , Trastornos de la Nutrición del Lactante/prevención & control , Recién Nacido , Enfermedades del Recién Nacido/diagnóstico , Recien Nacido Prematuro/fisiología , Bancos de Leche Humana , Evaluación de Necesidades , Pasteurización/métodos , Pasteurización/normas , Medición de Riesgo , Red SocialRESUMEN
OBJECTIVE: A systematic review (2005) of observational studies has reported 87% reduction in the incidence of necrotizing enterocolitis (NEC) after introducing standardized feeding regimen (SFR) in preterm infants. Considering the many new studies in this field since 2005 and the continued health burden of NEC, we aimed to systematically review the incidence of NEC in preterm infants 'before' vs 'after' implementing a SFR. STUDY DESIGN: PubMed, EMBASE, CINAHL and E-abstracts from the Pediatric Academic Society meetings and other pediatric and neonatal conference proceedings were searched in May 2016. Observational studies reporting incidence of NEC before and after implementing a SFR were included. Relevant data were extracted independently by two reviewers. Meta-analysis was conducted using random effects model (REM) and results rechecked with fixed effects model. RESULTS: Pooled results from 15 observational studies (N=18 160) using REM showed that SFR significantly reduced the incidence of NEC (risk ratio 0.22; 95% confidence interval 0.13 to 0.36; P<0.00001; I2=74%). The results remained significant after comparing studies in two epochs (1978 to 2003 vs 2004 to 2016). CONCLUSION: SFR continues to be an important tool in prevention of NEC in preterm infants.
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Enterocolitis Necrotizante/prevención & control , Métodos de Alimentación/normas , Enfermedades del Prematuro/prevención & control , Recien Nacido Prematuro , Enterocolitis Necrotizante/epidemiología , Humanos , Fórmulas Infantiles , Fenómenos Fisiológicos Nutricionales del Lactante , Recién Nacido , Intubación Gastrointestinal , Leche Humana , Estudios Observacionales como AsuntoRESUMEN
Objective To provide preliminary descriptive data on caregiver and child weight status, parenting styles, feeding styles, and feeding practices of a small American Indian sample. Methods Participants included a subsample of American Indian caregivers (n = 23) identified from a larger study that was conducted in five states. Using previously validated instruments, means, standard deviations, and ranges for general parenting styles, feeding styles, and feeding practices were explored. Results In general, most caregivers reported healthy feeding practices. Most caregivers scored higher on responsive compared to restrictive or permissive in general parenting. Of the sample, 12 caregivers (52.2 %) were classified in the indulgent feeding style category, 5 caregivers (21.7 %) were classified as authoritative, 5 (21.7 %) uninvolved, and 1 (4.3 %) authoritarian. Conclusions More investigations are needed to explore questions raised by this study about using common tools that measure childhood obesity with American Indian families.
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Desarrollo Infantil , Métodos de Alimentación/normas , Indígenas Norteamericanos/psicología , Responsabilidad Parental/psicología , Adulto , Índice de Masa Corporal , California/epidemiología , Cuidadores/psicología , Cuidadores/normas , Cuidadores/estadística & datos numéricos , Preescolar , Métodos de Alimentación/estadística & datos numéricos , Femenino , Humanos , Indígenas Norteamericanos/estadística & datos numéricos , Nevada/epidemiología , New Jersey/epidemiología , Obesidad/dietoterapia , Obesidad/epidemiología , Obesidad/prevención & control , Oklahoma/epidemiología , Sobrepeso/dietoterapia , Sobrepeso/epidemiología , Sobrepeso/prevención & control , Relaciones Padres-Hijo , Encuestas y CuestionariosRESUMEN
n/a.
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Peso al Nacer , Desarrollo Infantil , Métodos de Alimentación , Fenómenos Fisiológicos Nutricionales del Lactante , Recién Nacido de Bajo Peso/crecimiento & desarrollo , Recien Nacido Prematuro/crecimiento & desarrollo , Estado Nutricional , Aumento de Peso , Factores de Edad , Métodos de Alimentación/normas , Edad Gestacional , Adhesión a Directriz , Humanos , Recién Nacido , Política NutricionalRESUMEN
Phytoseiid mites are commonly used as biological control agents of mite and small insect pests. To facilitate the production of phytoseiids, alternative food sources have been evaluated. The aim of this study was to evaluate the suitability of different food sources for the rearing of the phytoseiids Amblyseius tamatavensis Blommers, Euseius concordis (Chant) and Neoseiulus anonymus (Chant and Baker). This study evaluated the levels of oviposition of these predators when fed with 15 Astigmatina (Sarcoptiformes) mite species, one species of a bacteriophagous nematode, and pollen from five plant species. The highest oviposition rates of A. tamatavensis were obtained when fed on the mites Thyreophagus cracentiseta Barbosa, OConnor & Moraes and Aleuroglyphus ovatus (Troupeau) (2.6 and 2.1 eggs/female/day, respectively). The five highest oviposition levels of E. concordis occurred when the food source was pollen, especially of Ricinus communis L. (1.7 eggs/female/day). The evaluated oviposition levels of N. anonymus were at most 0.5 eggs/female/day on all food sources. The construction of life tables of A. tamatavensis and E. concordis with the two most favorable food sources showed that in both cases the values of rm were higher when the predator was fed with T. cracentiseta and R. communis, respectively. The possible use of pollen of Elaeis guineensis L. should be further evaluated, given the acceptance of this type of pollen by E. concordis and the ease of obtaining large amounts of this pollen in areas where this crop is grown.
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Alimentación Animal/análisis , Dieta , Métodos de Alimentación/normas , Ácaros/fisiología , Oviposición , Control Biológico de Vectores/métodos , Animales , Brasil , Ácaros/crecimiento & desarrollo , Especificidad de la EspecieRESUMEN
INTRODUCTION: Several studies have been done on infant feeding practices but few have focused on twins. The aim of this study was to compare the complementary feeding practices between mothers with twins and mothers with singletons. METHODS: Mother-infant pairs (50 mother-twin pairs and 50 mother-singleton pairs) with children aged 6 to 23 months were recruited from two public health clinics and communities in Tema and Ashaiman. Information was collected on the background characteristics of the mothers. Recumbent length and weight of the children were measured. Dietary information on the infants was collected using 24 hour recall. The differences between two groups were tested using independent t-student test for continuous variables and chi-square test for categorical variables. RESULTS: The minimum dietary diversity (4+ food groups) was met by only 32% of the twins and 40% of the singletons, and 28% of the twins and 38% of the singletons met the requirement for minimum acceptable diet (minimum dietary diversity and the minimum meal frequency). Minimum meal frequency was met by 78% of the twins and 76% of the singletons. There were no significant differences between the two groups of infants. Prevalence of undernutrition was not significantly different among the two groups (twins versus singletons: underweight-26% versus 24%, stunting-20% versus 24% and wasting-14% versus 10%. CONCLUSION: Complementary feeding practices were suboptimal in both groups of mothers requiring interventions to improve infant feeding practices.
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Conducta Alimentaria , Métodos de Alimentación/normas , Trastornos de la Nutrición del Lactante/epidemiología , Fenómenos Fisiológicos Nutricionales del Lactante/normas , Estudios Transversales , Femenino , Ghana/epidemiología , Humanos , Lactante , Masculino , Madres , Necesidades Nutricionales , Gemelos , Adulto JovenRESUMEN
The objective of our study was to explain the variability of average daily weight gain (ADWG) due to gastrointestinal nematode (GIN) infection for 291 non treated first grazing season (FGS) heifers, from 12 independent groups in the western part of France, by combining parasitological and clinical indicators at individual level and grazing management indicators at group level. Parasitological indicators were faecal egg count (FEC), anti Ostertagia ostertagi antibody level (Ostertagia ODR), and pepsinogen level. Clinical indicators were diarrhea score (DISCO) and breech soiling score (BSS). At group level, grazing management practice (GMP), based on three variables (supplementation, month of turnout, grazing season duration), was clustered into three categories reflecting low, medium or high exposure (EXP) to GIN. Depending on the groups, turnout was from mid-March to early July and housing was from mid-October to late November, with a FGS duration ranging from 4 to 8.4 months. At turnout, the mean age of heifers was 8 months (range: 6-16 months) and they weighed between 175 and 268kg. In each GMP category, FEC significantly decreased between the mid-season and the housing, while Ostertagia ODR and pepsinogen level increased gradually throughout the grazing season. In contrast, clinical indicators did not show any seasonal variation. In a multivariate linear model, 22% of the ADWG variability was significantly explained by two individual indicators (Ostertagia ODR: 12.6%, DISCO: 4.8%) and by the group indicator (GMP category: 4.8%). ADWG losses due to GIN exposure (Ostertagia ODR) were estimated up to 39kg per heifer for the overall grazing season. For groups within the low EXP category the difference between animals with low (<697g/day) or high (>697g/day) ADWG was explained by the clinical indicator DISCO. In contrast, for groups within the medium and high EXP categories this difference was explained by a parasitological indicator (Ostertagia ODR). This study highlighted the value of combining both grazing management (group level) and parasitological (individual level) indicators to assess the impact of GIN on ADWG of FGS heifers. As a result, this combination might allow a better discrimination of animals or groups that may be in need of treatment in a targeting selective treatment approach.
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Enfermedades de los Bovinos/sangre , Enfermedades de los Bovinos/fisiopatología , Métodos de Alimentación/veterinaria , Infecciones por Nematodos/veterinaria , Aumento de Peso/fisiología , Crianza de Animales Domésticos/normas , Animales , Anticuerpos Antihelmínticos/sangre , Bovinos , Métodos de Alimentación/normas , Femenino , Francia , Nematodos , Infecciones por Nematodos/sangre , Infecciones por Nematodos/fisiopatología , Ostertagia , Ostertagiasis/sangre , Ostertagiasis/fisiopatología , Ostertagiasis/veterinaria , Pepsinógeno A/sangre , Estaciones del AñoRESUMEN
Growth of farmed, wild and F1 hybrid Atlantic salmon parr Salmo salar was investigated under three contrasting feeding regimes in order to understand how varying levels of food availability affects relative growth. Treatments consisted of standard hatchery feeding (ad libitum), access to feed for 4 h every day, and access to feed for 24 h on three alternate days weekly. Mortality was low in all treatments, and food availability had no effect on survival of all groups. The offspring of farmed S. salar significantly outgrew the wild S. salar, while hybrids displayed intermediate growth. Furthermore, the relative growth differences between the farmed and wild S. salar did not change across feeding treatments, indicating a similar plasticity in response to feed availability. Although undertaken in a hatchery setting, these results suggest that food availability may not be the sole driver behind the observed reduced growth differences found between farmed and wild fishes under natural conditions.
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Conducta Alimentaria/fisiología , Métodos de Alimentación/normas , Salmo salar/crecimiento & desarrollo , Animales , Animales Salvajes/anatomía & histología , Animales Salvajes/crecimiento & desarrollo , Tamaño Corporal , Explotaciones Pesqueras , Salmo salar/anatomía & histologíaRESUMEN
Increased freshwater growth of juvenile steelhead Oncorhynchus mykiss improved survival to smolt and adult stages, thus prompting an examination of factors affecting growth during critical periods that influenced survival through subsequent life stages. For three tributaries with contrasting thermal regimes, a bioenergetics model was used to evaluate how feeding rate and energy density of prey influenced seasonal growth and stage-specific survival of juvenile O. mykiss. Sensitivity analysis examined target levels for feeding rate and energy density of prey during the growing season that improved survival to the smolt and adult stages in each tributary. Simulated daily growth was greatest during warmer months (1 July to 30 September), whereas substantial body mass was lost during cooler months (1 December to 31 March). Incremental increases in annual feeding rate or energy density of prey during summer broadened the temperature range at which faster growth occurred and increased the growth of the average juvenile to match those that survived to smolt and adult stages. Survival to later life stages could be improved by increasing feeding rate or energy density of the diet during summer months, when warmer water temperatures accommodated increased growth potential. Higher growth during the summer period in each tributary could improve resiliency during subsequent colder periods that lead to metabolic stress and weight loss. As growth and corresponding survival rates in fresh water are altered by shifting abiotic regimes, it will be increasingly important for fisheries managers to better understand the mechanisms affecting growth limitations in rearing habitats and what measures might maintain or improve growth conditions and survival.