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1.
Br Poult Sci ; 60(4): 431-438, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31046430

RESUMEN

1. The study was conducted to investigate the effects of different dietary levels of an unsaturated or saturated fat source and the effects of different dietary energy levels in laying hen diets on the carotenoid content of the egg yolk. 2. Seventy-two ISA Brown laying hens aged 22 weeks old were allocated, for a 10 week period, to three treatments: control diet (HE group) with a 3.4% supplemented fat containing 2.1% soybean and 1.3% palm oil as fat sources and a ratio of unsaturated to saturated fatty acid (u/s) of 3.33; a lowered energy diet with 2.4% supplemented fat containing 1.4% soybean and 1.0% palm oil and u/s of 3.41 (LE+high u/s); a lowered energy diet with 2.4% supplemented fat containing 0.5% soybean and 1.9% palm oil and a u/s of 2.39 (LE+low u/s). A marigold plant extract supplement was used as a source of lutein. 3. Performance parameters (feed consumption, feed conversion, body weight), egg production rate and egg quality parameters were similar between treatments. Dietary fat digestibility at the middle of the study period was not different. Egg yolk total fat content was similar in all treatments at the middle and at the end of the study period. 4. Lutein, zeaxanthin, cis-lutein and total carotenoids content were significantly lower in eggs produced from the LE+low u/s group compared to those from the HE and the LE+high u/s groups (P < 0.01 for all parameters). 5. It was concluded that feeding laying hens with a diet containing 1% less supplemented fat and a lower u/s ratio compared to a control diet and to a diet with 1% less supplemented fat with a higher u/s ratio resulted in a significant reduction of carotenoid expression in the egg yolk at the end of experimental period. Performance and egg quality parameters were not affected by treatments.


Asunto(s)
Pollos/fisiología , Grasas de la Dieta/metabolismo , Yema de Huevo/química , Luteína/metabolismo , Zeaxantinas/metabolismo , Alimentación Animal/análisis , Animales , Carotenoides/metabolismo , Dieta/veterinaria , Grasas de la Dieta/administración & dosificación , Grasas de la Dieta/clasificación , Suplementos Dietéticos/análisis , Relación Dosis-Respuesta a Droga , Yema de Huevo/efectos de los fármacos , Femenino , Distribución Aleatoria
2.
Avian Pathol ; 47(6): 616-624, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30221537

RESUMEN

Heat stress is a physical environmental stressor, which can affect performance, health and welfare of poultry. The present study investigates the effect of cyclic acute heat stress as a predisposing factor for necrotic enteritis in broiler chicks in an experimental challenge model. Two hundred and forty broiler chicks were randomly allocated to four treatment groups, as follows: group A served as negative control (25°C), group B birds were subjected to cyclic acute heat stress (35°C), group C birds were challenged and group D birds were both subjected to heat stress and challenged. From each bird, the intestine, gizzard and liver were collected and scored for gross lesions. The intestinal digesta was collected for pH and viscosity determination. One caecum from each bird was taken for microbiological analysis. The statistical analysis and evaluation of data revealed that the heat stress in challenged birds showed a relative trend to increase the severity and the incidence of necrotic enteritis lesions, although it was not considered as statistically significant (Ρ = 0.077). Additionally, the heat stress induced necrotic enteritis outbreak in unchallenged birds; the challenge of birds as well as its combination with the heat stress affected significantly (Ρ ≤ 0.05) the pH and viscosity of intestinal digesta and the caecal Clostridium perfringens counts. The study provides evidence that cyclic acute heat stress is an environmental stressor, which can significantly affect necrotic enteritis and gut health, and thus should be taken into account in warmer areas of the world where poultry farming becomes a major industry.


Asunto(s)
Pollos/microbiología , Infecciones por Clostridium/veterinaria , Enteritis/veterinaria , Respuesta al Choque Térmico , Enfermedades de las Aves de Corral/epidemiología , Animales , Causalidad , Ciego/microbiología , Ciego/patología , Infecciones por Clostridium/epidemiología , Infecciones por Clostridium/microbiología , Infecciones por Clostridium/patología , Clostridium perfringens/aislamiento & purificación , Modelos Animales de Enfermedad , Enteritis/epidemiología , Enteritis/microbiología , Enteritis/patología , Molleja de las Aves/microbiología , Molleja de las Aves/patología , Calor/efectos adversos , Hígado/microbiología , Hígado/patología , Necrosis/patología , Necrosis/veterinaria , Enfermedades de las Aves de Corral/microbiología , Enfermedades de las Aves de Corral/patología , Distribución Aleatoria
3.
Br Poult Sci ; 59(2): 232-239, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29293022

RESUMEN

1. The study aimed to investigate the effect of lysolecithin supplementation in low-energy diets on growth, nutrient digestibility and intestinal mucosa characteristics of broilers. 2. A total of 800 one-d-old Ross 308 broiler chickens were assigned to 4 dietary treatments consisting of 10 replicates of 20 broilers each. Broilers were fed with 4 different diets: (i) HE: positive control group broilers received a diet with unaltered energy; (ii) LE: negative control group broilers received a diet with lower energy of about 0.27 MJ/kg; (iii) LElys500: broilers received a diet similar to LE supplemented with 500 g/tn lysolecithin product (Lysoforte Booster DryTM); and (iv) LElys300: broilers received a diet similar to LE supplemented with 300 g/tn lysolecithin product. The experimental period was 42 d. 3. Body weight gain in treatments HE was higher than LE during the overall experimental period, while LElys500 and LElys300 had intermediate values. Feed conversion ratio was lower in HE and LElys500 than LE group, while the LElys300 had intermediate values. Fat digestibility was improved in both LElys 500 and LElys300 compared to the HE group. Apparent metabolisable energy (AMEn) was higher in HE, LElys500 and LElys300 than LE. Ileum viscosity at 42 d was also affected, being higher in LE group compared to HE. At 28 d mucosal thickness was lower both in LElys500 and LElys300 compared to HE and LE, while no difference occurred between treatment proliferation patterns of duodenal epithelial cells. 4. These findings indicated that lysolecithin supplementation at 500 g/tn of feed in low-energy diets maintained broiler performance. Supplementation of reformulated low-energy diets induced an increase in digesta viscosity. Lysolecithin supplementation resulted in variable alterations in the duodenum mucosal morphology.


Asunto(s)
Pollos/fisiología , Digestión/efectos de los fármacos , Metabolismo Energético , Mucosa Intestinal/efectos de los fármacos , Intestinos/efectos de los fármacos , Lisofosfatidilcolinas/metabolismo , Alimentación Animal/análisis , Fenómenos Fisiológicos Nutricionales de los Animales/efectos de los fármacos , Animales , Pollos/crecimiento & desarrollo , Dieta/veterinaria , Suplementos Dietéticos/análisis , Mucosa Intestinal/fisiología , Intestinos/química , Lisofosfatidilcolinas/administración & dosificación , Viscosidad
4.
J Appl Microbiol ; 120(4): 1033-40, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26725456

RESUMEN

AIMS: The objective of this study was twofold: (i) to examine the effect of early-posthatch dietary inclusion of the clay mineral palygorskite on laying pullets' growth and (ii) to determine the potential effects of the latter diet on caecal microbial communities. METHODS AND RESULTS: Four hundred and thirty-two female, 1-day-old Hyline Brown chickens were equally and randomly allocated to two dietary treatment groups; control and palygorskite (0 and 0·5% palygorskite respectively). They were reared in floor pens for 18 weeks. Feed intake, feed conversion ratio, body weight gain and uniformity were assessed. At the end of the rearing period, 53 birds per group were transferred to laying cages without any changes in their respective dietary treatments. At onset of lay, eight birds from each group were euthanized and their caeca were obtained for analysis. Culture-independent and sequencing-based methods were used to analyse caecal microbial composition. CONCLUSIONS: Palygorskite dietary supplementation increased the uniformity of the relative group at the end of the rearing period. Pullets that received palygorskite had different and more homogeneous caecal microbial profiles at onset of lay when compared to controls. Moreover, in the caeca of the former pullets a more favourable microbiota was evident; it comprised largely of bacteria that are major degraders of resistant polysaccharides and efficient in butyrate production. SIGNIFICANCE AND IMPACT OF THE STUDY: The novelty of this study lies to the beneficial effect of palygorskite (a clay mineral) to pullets growth and health, likely through modulation of the gut microbiota.


Asunto(s)
Pollos/crecimiento & desarrollo , Dieta/veterinaria , Suplementos Dietéticos , Compuestos de Magnesio/farmacología , Compuestos de Silicona/farmacología , Animales , Pollos/microbiología , Femenino , Microbiota/efectos de los fármacos
5.
Avian Pathol ; 44(6): 430-5, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26642742

RESUMEN

Cold stress is a physical environmental stressor with significant effect on the poultry industry. The aim of the present study was to investigate the effect of cold stress as a predisposing factor for necrotic enteritis in broiler chicks. The experimental challenge model included an oral inoculation with 10-fold dose of attenuated anticoccidial vaccine and multiple oral inoculations with a specific strain of Clostridium perfringens. Birds were either challenged or not as described above, and either exposed or not to repeated cold stress (15°C for 12 h/day for 4 days). From each bird, intestinal gross lesions were scored and intestinal digesta pH and viscosity were measured. C. perfringens was counted in the caecum. The statistical analysis and evaluation of the experimental data revealed that the cold stress in challenged birds significantly increased the incidence and the severity of necrotic enteritis lesions (Ρ ≤ 0.05), while causing no lesions in unchallenged birds. Moreover, the cold stress caused a significant increase (Ρ ≤ 0.05) in the pH and C. perfringens counts in the caeca. The study provides evidence that cold stress increased the susceptibility to necrotic enteritis in a subclinical experimental model and thus should be regarded as a physical environmental stressor that could significantly affect the welfare, health and intestinal ecosystem of broiler chicks.


Asunto(s)
Infecciones por Clostridium/veterinaria , Clostridium perfringens/patogenicidad , Enteritis/veterinaria , Enfermedades de las Aves de Corral/microbiología , Animales , Ciego/microbiología , Pollos , Infecciones por Clostridium/microbiología , Frío , Modelos Animales de Enfermedad , Enteritis/microbiología , Intestinos/microbiología , Necrosis/veterinaria , Estrés Fisiológico
6.
Avian Pathol ; 44(2): 59-66, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25563065

RESUMEN

Stocking density is a management factor which has critical implications for the poultry industry. The aim of the present study was to investigate the effect of high stocking density as a predisposing factor in an experimental model of necrotic enteritis in broiler chicks. The experimental challenge model included an oral inoculation with 10-fold dose of attenuated anticoccidial vaccine and multiple oral inoculations with a specific strain of Clostridium perfringens. Two hundred and forty as hatched day-old broiler chicks were randomly allocated to four treatment groups according to the following experimental design: group N, with normal stocking density (15 birds/m(2)) and no challenge; group D, with high stocking density (30 birds/m(2)) and no challenge; group P, with normal stocking density and positive challenge; and group DP, with high stocking density and positive challenge. From each bird, the intestine, gizzard and liver were collected and scored for gross lesions. The intestinal digesta was collected for pH and viscosity determination. One caecum from each bird was taken for microbiological analysis. The statistical analysis and evaluation of the experimental data revealed significant interaction effects between "stocking density" and "challenge", regarding gross lesion scores in intestine and liver, pH values in jejunum, ileum and caeca as well as C. perfringens counts in the caeca (P ≤ 0.05). High stocking density in challenged birds increased the gross lesion score in the intestine (P ≤ 0.05), contrary to unchallenged birds. It can be concluded that high stocking density affects unfavourably the welfare and gut health of broiler chicks, predisposes to necrotic enteritis in a subclinical experimental model and increases further its importance as a management factor for the poultry industry.


Asunto(s)
Crianza de Animales Domésticos/métodos , Pollos , Aglomeración , Enteritis/veterinaria , Necrosis/veterinaria , Enfermedades de las Aves de Corral/epidemiología , Enfermedades de las Aves de Corral/microbiología , Análisis de Varianza , Animales , Vacunas Bacterianas/farmacología , Causalidad , Clostridium perfringens/patogenicidad , Enteritis/epidemiología , Concentración de Iones de Hidrógeno , Intestinos/patología , Hígado/patología , Necrosis/epidemiología , Necrosis/microbiología
7.
Avian Pathol ; 43(2): 139-45, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24498863

RESUMEN

The objective of this study was to investigate the effect of feed restriction on the intestinal ecosystem and on the pathogenesis of experimental necrotic enteritis in broiler chicks. To induce subclinical necrotic enteritis, an experimental challenge model using a specific diet formulation, Gumboro vaccination, oral inoculation of broilers with a 10-fold dose of attenuated anticoccidial vaccine and multiple oral inoculations with a specific strain of Clostridium perfringens was adopted. Two hundred and forty 1-day-old Cobb 500 broilers were randomly allocated to four groups: feed restricted, challenged, both feed restricted and challenged, and negative control. At 21, 22, 23 and 24 days of age, the intestines, gizzard and liver were collected from 15 birds in each group and scored for gross lesions. The intestinal digesta was collected for pH and viscosity determination. One caecum from each bird was taken for microbiological analysis. The application of feed restriction in birds challenged with C. perfringens reduced the necrotic enteritis lesion score significantly (P ≤ 0.05) and feed restriction significantly reduced (P ≤ 0.05) pH in the small intestine, the viscosity of the jejunum digesta as well as the C. perfringens counts in the caeca compared with the controls. In conclusion, feed restriction of broilers has a positive effect on the intestinal ecosystem and a significant protective effect against necrotic enteritis in the subclinical experimental model.


Asunto(s)
Pollos/microbiología , Infecciones por Clostridium/veterinaria , Clostridium perfringens/aislamiento & purificación , Enteritis/veterinaria , Enfermedades de las Aves de Corral/prevención & control , Alimentación Animal , Animales , Peso Corporal , Infecciones por Clostridium/microbiología , Infecciones por Clostridium/prevención & control , Enteritis/microbiología , Enteritis/prevención & control , Privación de Alimentos , Molleja de las Aves/patología , Concentración de Iones de Hidrógeno , Intestinos/patología , Hígado/patología , Necrosis/veterinaria , Enfermedades de las Aves de Corral/microbiología , Distribución Aleatoria
8.
Avian Pathol ; 42(2): 163-70, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23581444

RESUMEN

The objective of the present study was to investigate the effect of an attenuated anticoccidial vaccination on the intestinal ecosystem and on the pathogenesis of experimental necrotic enteritis (NE) in broiler chickens. Two hundred and forty 1-day-old Cobb 500 broiler chickens were randomly allocated to four treatment groups according to the following experimental design: control Group N; Group PN, where birds were vaccinated with anticoccidial vaccine; Group M, where birds were challenged with Clostridium perfringens and with Eimeria maxima; and Group PM, where birds were both vaccinated and challenged. From each bird, the intestine, gizzard and liver were scored for gross NE lesions. Intestinal digesta were collected for pH and viscosity determination. Samples from the gastrointestinal tract and liver were taken for microbiological analysis. Evaluation of the experimental data revealed that Group M had significantly higher overall mean NE intestinal lesions compared with Group PM. Viscosity values of jejunum digesta as well as pH values of the duodenum, jejunum and ileum digesta in Group M were significantly lower compared with Group PM. C. perfringens counts in the caeca of Group PM were significantly lower compared with Group M. The milder decrease of pH and viscosity values of intestinal content and the reduction of C. perfringens counts in the caeca in challenged and vaccinated birds may explain the lower score of NE gross intestinal lesions and may suggest a positive effect on intestinal ecosystem and a significant protective effect of attenuated anticoccidial vaccination against NE in a subclinical experimental model.


Asunto(s)
Pollos , Coccidiosis/veterinaria , Eimeria/inmunología , Gastroenteritis/veterinaria , Enfermedades de las Aves de Corral/prevención & control , Enfermedades de las Aves de Corral/parasitología , Vacunas Antiprotozoos/farmacología , Animales , Clostridium perfringens , Coccidiosis/patología , Coccidiosis/prevención & control , Gastroenteritis/patología , Gastroenteritis/prevención & control , Molleja de las Aves/microbiología , Molleja de las Aves/parasitología , Molleja de las Aves/patología , Concentración de Iones de Hidrógeno , Intestinos/efectos de los fármacos , Intestinos/microbiología , Intestinos/parasitología , Intestinos/patología , Hígado/microbiología , Hígado/parasitología , Hígado/patología , Enfermedades de las Aves de Corral/microbiología , Enfermedades de las Aves de Corral/patología , Estadísticas no Paramétricas , Viscosidad
9.
Animal ; 4(10): 1628-33, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22445114

RESUMEN

This simulation study investigated the farm-level economic benefits of a genetic improvement scheme using artificial insemination (AI) with fresh ram semen in dairy sheep of the Chios breed in Greece. Data were collected from 67 farms associated with the Chios Sheep Breeders' Cooperative 'Macedonia', describing the percentage of ewes that would be artificially inseminated in the flock, pregnancy rate, annual ram costs that could be saved using AI rather than natural mating, expected improvement in milk production, annual costs of semen and feed, milk price and number of years of AI usage. The study considered 77 760 possible scenarios in a 3 × 4 × 4 × 3 × 3 × 3 × 4 × 15 factorial arrangement. Analysis of variance was used to investigate the effect of each factor on farm profitability. All factors considered were statistically significant (P < 0.001), but their effect varied. The number of years using AI had the greatest effect on profitability and farmers should become aware that using AI is a long-term investment. Semen price, pregnancy rate and improvement in milk production also had substantial effects. The price of milk and feed had a considerably lower effect on profitability, as did the annual cost of maintaining rams that would be replaced by AI. A positive annual and cumulative return was achieved in the model within the first 6 years. The cost of semen was estimated at 8€ to 10€ per dose for the first 5 years. Where the annual improvement in milk production was 1% of annual phenotypic mean (e.g. 3.0 kg) profitability of the scheme was improved greatly.

11.
Meat Sci ; 82(3): 317-23, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20416724

RESUMEN

The effect of dietary protein and gastrointestinal nematode (GIN) parasitism on growth and meat quality of growing kids was assessed using sixty (60) kids in three groups (n=20); A: control, B: regularly treated with ALBENDAZOLE(®) and C: supplemented with dietary protein. The kids grazed in a pasture contaminated with L3 larvae of GIN. Growth and condition score were assessed at 21-day intervals. After 86days all kids were slaughtered. Carcasses were assessed for conformation, fatness, ultimate pH and other meat quality characteristics. Parasitic challenge was assessed by means of faecal egg counts (FEC), pasture larvae and adult nematodes in the GI tract of kids at slaughter. Groups C and B had higher growth rates and body condition score and produced significantly heavier (P<0.05) carcasses with better (P<0.01) conformation and fatness when compared to those of group A. Total unsaturated and monounsaturated fatty acids were higher (P<0.05) in fat tissue of groups B and C. Group A had the highest FEC and group C had the lowest (P<0.05) FEC. The parasitic challenge of L3 on pasture reached its highest point at 42days and there were significant (P<0.01) differences between the numbers of Teladorsagia spp., Trichostrongylus spp., Haemonchus contortus, Oesophagostomum spp. and Chabertia spp. found in the GI tract of kids between the three groups; group A had the highest numbers. Overall, the results showed that the increased protein content in the diet of growing kids grazing on a pasture contaminated with L3 nematode larvae resulted in the production of acceptable carcasses.

12.
Res Vet Sci ; 85(3): 622-4, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18455207

RESUMEN

A case of a myxoma virus strain in vaccinated and non-vaccinated rabbits is described, and genetic identification of that strain was performed in this study. In two commercial farms being 150km apart, myxomatosis has been occurred after the import of animals from a common supplier. The disease was manifested firstly in the existing non-immune population of does and fatteners, and later in all vaccinated animals, being 2-3 months immune at the time of first symptoms. Morbidity was almost 100% with nasal discharge, listlessness, fever, eyelid swelling, eye and nasal purulent discharge, papules in the ears, facial oedema, and swelling of the anagenital region, with result always the death of the animals. Examination by PCR had shown the presence of a 492-bp specific product in all the symptomatic animals tested from both farms, having 100% nucleotide sequence identity with the homologous region of the myxoma virus Lausanne strain. The simultaneous occurrence of myxomatosis in the vaccinated and non-vaccinated rabbits of both farms, suggests that the supplier was possibly the source of a viral isolate with increased virulence.


Asunto(s)
Myxoma virus/inmunología , Myxoma virus/patogenicidad , Infecciones por Poxviridae/veterinaria , Infecciones Tumorales por Virus/veterinaria , Vacunas Virales , Animales , Cartilla de ADN , Brotes de Enfermedades/veterinaria , Ojo/virología , Grecia/epidemiología , Myxoma virus/genética , Reacción en Cadena de la Polimerasa , Infecciones por Poxviridae/inmunología , Conejos , Infecciones Tumorales por Virus/inmunología
13.
Br J Nutr ; 99(3): 520-30, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17761008

RESUMEN

The inclusion of insoluble NSP (iNSP) in weaner pig diets has been reported to decrease post-weaning colibacillosis (PWC). Conversely, soluble NSP (sNSP) have been shown to exacerbate PWC. The present study investigated the effect of NSP solubility and inclusion level on the health and performance of newly weaned pigs challenged with enterotoxigenic Escherichia coli (ETEC), using NSP sources known not to affect digesta viscosity, in a 2 x 2 x 2 factorial combination of NSP solubility (iNSP v. sNSP), inclusion level (low (L; 50 g/kg) v. high (H; 150 g/kg)) and ETEC challenge (infected v. sham). Infection had no effect on pig health, but reduced performance to a larger extent in pigs on the L diets compared with those on the H diets. The inclusion of sNSP significantly decreased the occurrence of diarrhoea (P < 0.001) and improved gut health, as indicated by a lower caecal digesta pH (P = 0.008) and increased (P = 0.002) Lactobacillus:coliform ratio, when compared with the iNSP diet on day 14 post-weaning. There was no effect of NSP solubility on ETEC shedding, digesta viscosity or pig performance. Pigs on the H diets had fewer cases of diarrhoea and shed fewer ETEC than those on the L diets. Increasing NSP inclusion significantly increased colonic Lactobacillus:coliform ratio, volatile fatty acid concentration and caecal digesta viscosity, but decreased performance. These results suggest that sNSP per se are not detrimental to pig health and that increasing the concentration of NSP in weaner diets that do not increase digesta viscosity may have a beneficial effect on gut health and protect against PWC.


Asunto(s)
Fibras de la Dieta/administración & dosificación , Escherichia coli Enterotoxigénica/aislamiento & purificación , Infecciones por Escherichia coli/veterinaria , Polisacáridos/administración & dosificación , Enfermedades de los Porcinos/prevención & control , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Colon/crecimiento & desarrollo , Dieta , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/prevención & control , Ácidos Grasos Volátiles/análisis , Heces/microbiología , Femenino , Contenido Digestivo/microbiología , Concentración de Iones de Hidrógeno , Lactobacillus/aislamiento & purificación , Masculino , Tamaño de los Órganos , Solubilidad , Sus scrofa , Enfermedades de los Porcinos/microbiología , Viscosidad
14.
Animal ; 2(6): 825-33, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22443661

RESUMEN

An experiment was conducted to investigate the effects of post-weaning dietary protein supply and weaning age on the performance of pigs in the absence of in-feed antimicrobial growth promoters (AGP) when artificially challenged with enterotoxigenic Escherichia coli (ETEC), a pathogen associated with post-weaning colibacillosis (PWC). The experiment consisted of a complete 2 × 2 × 2 factorial combination of two weaning ages (4 v. 6 week), two levels of dietary protein (H, 230 g CP/kg v. L, 130 g CP/kg) and challenge with ETEC (+ v. -). An additional four treatments were added to test for the effects of protein source (DSMP, dried skimmed milk powder v. SOYA, soybean meal) and AGP inclusion (yes v. no) on challenged pigs of both weaning ages. At weaning (day 0), pigs were assigned to one of the experimental treatments for 2 weeks. On day 14 post-weaning, the same standard grower ration was fed to all animals until 10 weeks of age. On day 3 post weaning, challenged pigs were administered per os with 109 cfu ETEC. The ETEC challenge had a detrimental short-term effect on performance, decreasing average daily gain (ADG) (days 3 to 6; P = 0.014) in both 4- and 6-week weaned animals. Compared with their non-infected counterparts, challenged 4-week weaned pigs on the H diet demonstrated a larger decrease in ADG immediately post infection than those on the L diet, -42% and -25%, respectively (P = 0.088). This effect was smaller in the 6-week weaned pigs, -26% and -19% for the H and L diets, respectively. Pigs fed SOYA had lower (P < 0.001) daily intake and ADG (day 0 to 14) than those fed DSMP, with 6-week weaned pigs being affected to a greater extent than 4-week weaned pigs. In the absence of AGP, increasing weaning age and decreasing dietary protein level, especially in earlier weaned pigs, may help to minimise the effects of PWC on performance, particularly in sub-optimal environments.

15.
Animal ; 2(6): 834-42, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22443662

RESUMEN

Weaning is often associated with post-weaning colibacillosis (PWC), caused by enterotoxigenic Escherichia coli (ETEC). The objective was to investigate the effects of manipulating dietary protein supply and increasing weaning age on enteric health and ETEC shedding of newly weaned pigs exposed to an experimental ETEC challenge. The experiment consisted of a complete 2 × 2 × 2 factorial combination of weaning age (4 v. 6 weeks), dietary protein content (H, 230 g crude protein (CP)/kg v. L, 130 g CP/kg) and experimental ETEC challenge (+ v. -); all foods were free from in-feed antimicrobial growth promoters (AGP). An additional four treatments were added to allow the effect of protein source (DSMP, dried skimmed milk powder v. SOYA, soybean meal) and AGP inclusion (yes v. no) to be investigated in challenged pigs of both weaning ages. On day 3 post-weaning challenged pigs were administered per os with 109 cfu ETEC O149. A subset of pigs was euthanased on days 0 and 6 post weaning to assess enteric health and small intestine morphology. Both weaning age and dietary protein content affected the consequences of ETEC challenge. ETEC excretion persisted longer in the 4-week-weaned pigs than those weaned at 6 weeks. Although not significant, the numbers of ETEC shed in the faeces post infection (days 4 to 14) were higher on the H than L diet, especially in the 4-week-weaned pigs (P = 0.093). Lowering CP level led to significantly firmer faeces post challenge (days 3 to 6) and decreased colonic digesta pH. Protein level had no effect on small intestine villous heights or crypt depths. There was no significant effect of protein source on ETEC excretion or enteric health. Results suggest that increasing weaning age and decreasing the level of dietary protein, especially in earlier weaned pigs, may help to maintain enteric health and minimise the effects of PWC.

16.
Meat Sci ; 76(4): 779-86, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22061258

RESUMEN

The effect of dietary protein and gastrointestinal (GI) parasitism on growth and meat quality of lambs was assessed using 60 animals. The lambs were randomly allocated to one of three treatment groups (n=20): group A, which served as control, group B that was regularly treated with albendazole and group C, which was given supplementary feeding with dietary protein. The three groups of lambs grazed into a pasture (Lolium perenne), which was contaminated with L(3) larvae of GI nematodes. Lamb growth and condition score were assessed at 21-day intervals. After 126 days grazing all lambs were slaughtered and their carcasses were assessed for conformation and fatness and their ultimate pH was measured. Four carcasses from each group were randomly selected for meat quality measurements including physical analysis as well as colour, moisture, total fat, protein content and fatty acid composition. Parasitic challenge was assessed by means of faecal egg counts of lambs, pasture larvae and numbers of adult nematodes in the GI tract of lambs at slaughter. Growth rate of group B was higher (P<0.01) than that of group A and resulted in significantly (P<0.01) heavier carcasses. The produced carcasses had similar fatness, but differed significantly (P<0.05), in their conformation; carcasses of group C scored higher than either those of group B or group A, respectively. There was a significant difference in the colour attributes (L(∗)) with group A being significantly lighter (P<0.05) and in pH (P<0.01); Group B had the highest values. Carcasses of group C had the highest (P<0.05) amounts of intermuscular fat compared to those of group B and A, respectively. The proportion of C16:1n-7 and C18:2n-6 was higher (P<0.05) in subcutaneous fat tissue whereas the proportion of C18:0 was higher (P<0.05) in muscle tissue. In conclusion, the present results showed that the increased protein content in the diet of growing lambs, grazing on a pasture infected with GI nematode larvae, resulted in the production of acceptable carcasses.

17.
Meat Sci ; 72(4): 688-96, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22061881

RESUMEN

The effect of meat appearance on consumers' preferences for pork chops was assessed using images manipulated for appearance characteristics. Data were collected from 412 consumers in Greece and Cyprus. Consumers were asked for their preference for pork chops from a book of computer-modified images and then completed a questionnaire of socio-demographic information, including eating and purchasing behaviour. Consumers under the age of 35 years showed preferences for dark red, lean pork, while consumers aged 35 years and older preferred either dark or light red pork. Gender appeared to be an important selection factor as men showed an increased preference for dark red pork while women preferred the light red. Consumers who stated that they like pork for its taste (91%) preferred either dark or light red pork chops while those who like pork for reasons other than taste preferred dark red, lean pork. Urban consumers preferred light red, fatty pork chops while the rural consumers preferred the dark red pork chops.

18.
Meat Sci ; 60(4): 379-87, 2002 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22063641

RESUMEN

The eating quality of lamb meat of three indigenous Greek dairy breeds of sheep, reared under different nutritional management conditions, was assessed by Taste Panel Tests (TPT). Lean samples from the leg joints of 69 lamb carcasses of the Boutsko (B), Serres (S) and Karagouniko (K) breed were used. For the first TPT, 24 lambs (four males and four females of each breed) were reared in individual pens on a concentrate ration fed ad libitum. For the second TPT, 27 individual penned male lambs were fed on Lucerne hay ad libitum and on three different levels of concentrate: High (H), Medium, (M) and Low (L). For the third TPT, 18 male lambs were used; initially the groups were fed indoors for 63 days on three different levels of concentrate (H, M and L) together with ad libitum Lucerne hay, and subsequently finished on irrigated, sown pasture. For TPT 1, leg joints were obtained from lambs that had been slaughtered at 30, 45, 60 or 90% of mature weight (PMW) for each breed. For TPT 2, lambs were slaughtered at 23, 28 or 33 kg target slaughter live weights (TSLW), common for all breeds. For TPT 3, lambs were slaughtered at 48 or 55% of PMW for each breed. Panellists assessed warm, roasted lean samples of leg joints and rated Flavour, Juiciness, Tenderness and Overall Acceptability. In TPT 1, degree of maturity significantly affected Flavour, Tenderness and Overall Acceptability whereas sex affected only Flavour. In TPT 2, breed and concentrate level significantly affected the quality characteristics, but concentrate level had no significant effect in TPT 3. Effects associated with slaughter weight were significant for most characteristics in all TPT, with decreasing acceptability for older/heavier lambs. Significant interactions were found between breed and the other factors in TPT 2 and TPT 3 for most quality characteristics. Results from these studies suggest changing traditional production systems may enhance the eating quality of lamb meat.

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