11 |
Principais lesões macro e microscópicas em frangos de corte condenados por caquexia em abatedouro: contribuição ao diagnósticoBorges, Vívian Palmeira [UNESP] 10 April 2006 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:27:58Z (GMT). No. of bitstreams: 0
Previous issue date: 2006-04-10Bitstream added on 2014-06-13T18:32:19Z : No. of bitstreams: 1
borges_vp_me_jabo.pdf: 810273 bytes, checksum: 0704631ed3d05666adee30a0ec98e496 (MD5) / Universidade Estadual Paulista (UNESP) / A caquexia figura como uma das mais importantes causas de condenação total de frangos de corte durante a inspeção em abatedouros frigoríficos determinando grandes prejuízos ao setor avícola. Para melhor entender esta enfermidade foram estudados os aspectos macro e microscópicos de 400 aves caquéticas de um abatedouro frigorífico sob Inspeção Federal no Estado de Mato Grosso do Sul. Foram relatadas e catalogadas todas as lesões macro e microscópicas das aves caquéticas examinadas. Devido às diferentes alterações detectadas e aos diversos órgãos atingidos pôde-se concluir que as etiologias devem ser variadas. O fígado, sacos aéreos e pele foram os órgãos mais comumente comprometidos. O envolvimento do fígado, em vários graus e com lesões diferenciadas, em grande parcela dos casos induziu à percepção de que o comprometimento deste órgão - importante para a síntese protéica - está intimamente relacionado ao aparecimento de quadros de caquexia. A lesão de degeneração da cabeça femoral, embora não tenha sido uma alteração freqüentemente detectada têm correlação positiva com o aparecimento de casos de nefrite caseosa. O índice de aparecimento de lesões teciduais maior nos animais caquéticos que naqueles não caquéticos e o fato de que períodos curtos de privação alimentar não interferem no aparecimento de graus mais severos de caquexia são dados que corroboram para o entendimento de que esta é uma síndrome associada a enfermidades e não à fome. / Cachexia is one of the most important causes of carcass downgrading in poultry inspection and it determines serious losses to poultry industry. To better understand this syndrome, the macro and microscopic aspects of 400 cachetic carcasses were studied in a slaughterhouse under Federal inspection in Mato Grosso do Sul State. Each macro and microscopic lesion was reported and classified. Because of the several alterations in many viscera it was possible to conclude that there must be a plenty of etiologies. Liver, air sacs and skin were the most compromised organs. Hepatic involvement in different levels induce to the perception that this important organ in protein synthesis is close related to cachexia cases. Femoral head degeneration although not frequently identified showed a positive correlation to caseous nephritis. Ali the studied lesions were greater in cachetic animais when compared to non-caquetic broilers. This data associated to the fact that short periods of time of food deprivation do not interfere in severe cases of cachexia corroborate to the understanding that this is a syndrome related to diseases and not to hunger.
|
12 |
Principais lesões macro e microscópicas em frangos de corte condenados por caquexia em abatedouro : contribuição ao diagnóstico /Borges, Vívian Palmeira. January 2006 (has links)
Orientador: Oswaldo Durival Rossi Júnior / Banca: Antonio Carlos Alessi / Banca: Eurípedes Batista Guimarães / Resumo: A caquexia figura como uma das mais importantes causas de condenação total de frangos de corte durante a inspeção em abatedouros frigoríficos determinando grandes prejuízos ao setor avícola. Para melhor entender esta enfermidade foram estudados os aspectos macro e microscópicos de 400 aves caquéticas de um abatedouro frigorífico sob Inspeção Federal no Estado de Mato Grosso do Sul. Foram relatadas e catalogadas todas as lesões macro e microscópicas das aves caquéticas examinadas. Devido às diferentes alterações detectadas e aos diversos órgãos atingidos pôde-se concluir que as etiologias devem ser variadas. O fígado, sacos aéreos e pele foram os órgãos mais comumente comprometidos. O envolvimento do fígado, em vários graus e com lesões diferenciadas, em grande parcela dos casos induziu à percepção de que o comprometimento deste órgão - importante para a síntese protéica - está intimamente relacionado ao aparecimento de quadros de caquexia. A lesão de degeneração da cabeça femoral, embora não tenha sido uma alteração freqüentemente detectada têm correlação positiva com o aparecimento de casos de nefrite caseosa. O índice de aparecimento de lesões teciduais maior nos animais caquéticos que naqueles não caquéticos e o fato de que períodos curtos de privação alimentar não interferem no aparecimento de graus mais severos de caquexia são dados que corroboram para o entendimento de que esta é uma síndrome associada a enfermidades e não à fome. / Abstract: Cachexia is one of the most important causes of carcass downgrading in poultry inspection and it determines serious losses to poultry industry. To better understand this syndrome, the macro and microscopic aspects of 400 cachetic carcasses were studied in a slaughterhouse under Federal inspection in Mato Grosso do Sul State. Each macro and microscopic lesion was reported and classified. Because of the several alterations in many viscera it was possible to conclude that there must be a plenty of etiologies. Liver, air sacs and skin were the most compromised organs. Hepatic involvement in different levels induce to the perception that this important organ in protein synthesis is close related to cachexia cases. Femoral head degeneration although not frequently identified showed a positive correlation to caseous nephritis. Ali the studied lesions were greater in cachetic animais when compared to non-caquetic broilers. This data associated to the fact that short periods of time of food deprivation do not interfere in severe cases of cachexia corroborate to the understanding that this is a syndrome related to diseases and not to hunger. / Mestre
|
13 |
Influência do jejum alimentar, probióticos e antibiótico na população de enterobactérias, bactérias ácido lácticas, Bacillus e Salmonella sp. em cecos e papos de frangos de corte / Influence of feed withdrawal, probiotics and antibiotic on the enterobacteria, lactic acid bacteria, Salmonella and Bacillus populations in the crop and caeca of broiler chickensAline Brigato Abreu da Silva 19 October 2006 (has links)
No presente trabalho foram realizadas análises de enterobactérias e Salmonella em cecos e papos de frangos de corte criados sem reaproveitamento de cama e com baixa densidade, submetidos a períodos de jejum de 3, 6, 9, 12, 15 e 18 horas; também foram feitas análises das mesmas bactérias, incluindo esporos de Bacillus subtilis e bactérias ácido lácticas em papos e cecos de frangos de corte alimentados com probióticos (bactérias lácticas, Bokashi e esporos de B. subtilis) e antibiótico (bacitracina de zinco) nas rações. Não houve diferença significativa entre as populações de enterobactérias nos períodos de jejum analisados, e não foram isoladas cepas de Salmonella nos diferentes tratamentos. Houve diminuição significativa na população de enterobactérias nos cecos em relação ao grupo controle quando os frangos foram alimentados com bactérias ácido lácticas nas rações. Com Bokashi e antibiótico nas rações, a população de enterobactérias nos cecos foi maior que no grupo controle. Nos papos, não houve diferença significativa entre as populações de enterobactérias para os diferentes tratamentos, mas o tratamento com Bokashi foi o que obteve menor população das enterobactérias nesse habitat. As contagens de bactérias ácido lácticas e esporos de B. subtilis dos cecos e papos analisados não sofreram alteração significativa devido aos diferentes aditivos presentes nas rações, quando comparadas ao grupo controle. Novamente não foram isoladas cepas de Salmonella nos cecos e papos dos frangos analisados. A ausência de Salmonella pode ter explicação no modo de criação dos frangos, com baixa densidade (12 aves/m2) e sem reaproveitamento de cama, pois foi um resultado encontrado nas duas fases do trabalho. A diminuição de enterobactérias nos cecos por parte das bactérias ácido lácticas administradas na ração pode ter sido devido à exclusão competitiva, apesar da população dessas bactérias não ter aumentado significativamente neste habitat. O tratamento com administração de Bokashi obteve menor contagem de enterobactérias no papo possivelmente devido ao fato de ser um produto fermentado, com pH baixo, que poderia agir prontamente no papo. A administração de esporos de B. subtilis não surtiu efeito nas populações das bactérias analisadas nos cecos e papos dos frangos de corte. / This study analyzed the population of enterobacteria and Salmonella in the crop and caeca of broiler chickens submitted to 3, 6, 9, 12, 15 and 18 hours of feed withdrawal, and raised without reutilization of the litter, in low density. The same bacteria were analyzed, plus Bacillus subtilis spores and lactic acid bacteria, in the crop and caeca of broiler chickens fed rations with probiotics (lactic acid bacteria, Bokashi and B. subtilis spores) and antibiotic (zinc bacitracin). There were no significant differences between enterobacteria populations on the analyzed withdrawal periods, and Salmonella and antibiotic (zinc bacitracin). There were no significant differences between enterobacteria populations on the analyzed withdrawal periods, and B. subtilis spores populations from the caeca and crops of analyzed broiler chickens did not differ from the control group when the different additives were fed through the ration. Again there were no Salmonella isolates in the analyzed crop and caeca. The absence of Salmonella may have an explanation on the way that chickens were raised, with low density (12 birds/m2) and no litter reutilization, because this result was found on the two phases of the study. The lower caeca enterobacteria population found when the broilers were fed lactic acid bacteria may have been due to competitive exclusion, even though the lactic acid bacteria counting did not increase significantly in this habitat. Treatment with Bokashi administration had lower counting of enterobactérias in the crop, possibly due to the fact that Bokashi is a fermented product, with low pH, that could act readily in the crop. The administration of B. subtilis spores did not have any effect on the populations of the analyzed bacteria, in the crop and caeca of broiler chickens.
|
14 |
Influence of a Phytogenic Feed Additive on Broiler Chicken Behavior and WelfareHayley Lynn Sutherland (16618575) 20 July 2023 (has links)
<p> Broiler chickens are routinely exposed to various conditions, such as heat stress and stocking density, which may negatively influence their welfare status. This study examined the influence of a commercially available proprietary phytogenic feed additive (Probiotech International, Inc.) on welfare measures, environmental measures, productivity, body temperature, and behavior of commercial broiler chickens. Two flocks (Trials 1 & 2) utilized a total of 1,650 Ross 708 broilers housed in two separate rooms with floor pens at Purdue University’s ASREC Poultry Unit. </p>
<p> Trial 1 birds (n = 750) were divided into 20 separate pens (5 pens/treatment): PHD: phytogenic supplementation and raised at standard industry stocking density (37 kg/m²), PLD: phytogenic supplementation and raised at a lowered stocking density (27 kg/m²), CHD: control diet and raised at standard industry stocking density, and CLD: control diet and raised at a lowered stocking density. Due to the aromatic properties of the phytogenic additive, PHD and PLD birds were housed in one room and CHD and CLD birds were housed in another room. The feed supplement was mixed in at an inclusion rate of 0.25 g/kg. Phytogenic supplementation began at 15 d, coinciding with feeding the grower diet, and continued until 42 d when the study concluded. Heat stress was applied to all birds from 30 to 32 d, where the peak temperature did not exceed 34.4ºC. Welfare measures (gait, footpad dermatitis, hock burn, and feather cleanliness) and litter quality were assessed at 27 d and 39 d. Ammonia concentrations were measured at 35 d and 39 d. Productivity (body weight, feed intake, and feed conversion ratio) was measured weekly. Body temperature via thermography of the eye surface was collected at 29, 32, and 34 d. Behavior data were collected at the following periods for 2 continuous days: 23-24 d (Period 1), 31-32 d (Period 2), and 36-37 d (Period 3). </p>
<p> Trial 2 birds (n = 900) were assigned to 25 separate pens (5 pens/treatment) with the same groups as Trial 1, with an additional group (MHD): control diet, housed in the same room as PHD and PLD birds, and raised at standard industry stocking density. Phytogenic supplementation was provided as in Trial 1. Heat stress was again applied to all treatments from 30 to 32 d, where the peak temperature did not exceed 31ºC. Welfare measures and litter quality were collected at 27 d and 38 d. Ammonia concentrations were measured at 27, 31, and 38 d. Productivity was measured from 15 d to 27 d (grower phase), and 27 d to 38 d (finisher phase). Body temperature via cloacal temperature recording occurred at 29, 31, and 33 d. </p>
<p> Welfare data and litter quality were analyzed using PROC LOGISTIC (SAS 9.4); productivity data were analyzed using PROC MIXED (SAS 9.4); behavior data were analyzed using PROC GLIMMIX (SAS 9.4); and eye surface temperature, cloacal temperature, and ammonia concentration were analyzed using a nested mixed model found in the afex package using R (version 4.2.1) and R Studio (R Foundation for Statistical Computing). All statistical differences were considered significant when P < 0.05. Results of Trial 1 indicated that phytogenic supplementation significantly influenced hock burn and feather cleanliness, body weight and feed conversion ratio, ammonia concentration, as well as Period 1 sitting, Period 2 drinking, preening, standing, and wing spreading, and Period 3 drinking, preening, sitting, standing, and walking behaviors. Results of Trial 2 indicated that diet had no effect on any measured parameter. The variation in results suggests that factors such as stocking density or management strategies influenced the measured parameters, rather than diet alone. More research is needed to understand the specific effects of phytogenic feed additives, social and environmental stressors and whether phytogenic feed additives can improve bird performance and welfare under longer heat stress periods.</p>
|
15 |
Physiological and Biochemical Aspects of Methionine Isomers and Precursors in BroilersZhang, Shuai 19 July 2016 (has links)
Methionine (Met) is an essential amino acid for animals and also the first limiting amino acid in a broiler diet. The dietary supplemental Met sources include the natural isoform L-methionine (L-Met), the synthetic form DL-methionine (DL-Met) and the synthetic Met precursor DL-2-hydroxy-4 (methylthio)-butanoic acid (DL-HMTBA). The objective of this dissertation was to determine the effect of different dietary Met source supplementation and Met deficiency on a series of physiological and biochemical aspects, including growth performance, global DNA methylation and methyltransferase activity, blood antioxidant profile (e.g., acute phase protein, leukocyte count), intestinal nutrient transporter gene expression, Met converting enzyme gene expression and activity, oxidative stress markers, and a potential pathway related to amino acid signaling. To achieve this goal, male Cobb-500 broilers were raised from day of hatch (d0) to d35 post-hatch and fed a diet deficient in methionine and cysteine (Met + Cys) (control) or the same diet supplemented with 0.22% DL-Met, 0.22% L-Met or 0.31% DL-HMTBA (to provide 0.22% DL-Met equivalent) to meet Met + Cys requirements. Tissues (liver, breast muscle, duodenum, jejunum and ileum) and blood samples were collected at various ages from d0 to d35 for analysis. Met supplementation significantly improved body weight gain and feed efficiency compared to the Met deficient group, but no differences were observed among DL-Met, L-Met and DL-HMTBA for growth performance parameters (P > 0.05). Met supplementation had no effect on red blood cell packed cell volume, white blood cell differential count, hepatic total DNA methylation, DNA methyltransferase and Met oxidase activity, and had limited effects on activation of p70S6K, a key amino acid signaling protein (P > 0.05). Although dietary Met sources did not change oxidative status of the treated chickens, both L-Met and DL-Met but not DL-HMTBA supplementation decreased the level of acute phase protein serum amyloid A compared to the control group (P > 0.05). The effect of Met supplementation on gene expression of nutrient transporters and Met converting enzymes were complex and dynamic. Most of the target genes demonstrated tissue- and development-dependent expression patterns, with few significant treatment effects observed. L-Met and DL-Met but not DL-HMTBA supplementation enhanced the neutral amino acid transporters ATB0,+ and B0AT gene expression in various small intestinal segments. All three Met sources increased monocarboxylic acid transporter (MCT1) gene expression in the jejunum. DL-HMTBA and L-Met fed chickens showed greater hepatic L-HMTBA oxidase (HAO1) gene expression. DL-Met increased glutamic-oxaloacetic transaminase 2 (GOT2) gene expression in the duodenum. An in vitro study with tissue explants, however, did not demonstrate a similar gene expression pattern as that in the in vivo study. Lastly, RNA sequencing results illustrated that Met deficiency could lead to many differentially expressed genes but different supplemental Met sources had no influence on hepatic gene expression profiles. In conclusion, as common dietary supplemental Met sources, L-Met, DL-Met and DL-HMTBA exhibited similarity in impacting intestinal amino acid/peptide/monocarboxylic acid transporter gene expression and Met converting enzyme activity. The regulatory roles of Met as an antioxidant and nutrient signaling in cell metabolism were not affected by different dietary supplemental Met sources. / Ph. D.
|
16 |
Dietary macronutrient composition and exogenous neuropeptide Y affect feed intake in brioler chicksNelson, Laura Ashley 11 June 2014 (has links)
Understanding the central nervous systems role in appetite regulation is crucial to cure the obesity epidemic, which is more prevalent than any disease in the United States. Central appetite regulators, known as neuropeptides, are pivotal in understanding appetite regulation. Neuropeptide Y (NPY), a 36 amino acid peptide, plays a major role in regulating the hunger signals from the brain. In all vertebrates studied, it is a strong orexigenic neurotransmitter located throughout multiple nuclei of the hypothalamus. Peripheral hormones associated with hunger are able to activate NPY neurons in the arcuate nucleus, which leads to a cascade of events that activate orexigenic neurons throughout the hypothalamus. Although extensive research has gone into understanding the role of NPY in appetite regulation, the effects of macronutrient composition of diets on NPY function have not been elucidated in non-mammalian species.
This research investigates how food intake is affected by dietary macronutrient composition in broiler type chickens that are fed three varying macronutrient diets: high carbohydrate (22% CP, 3000kcal/kg) a broiler starter diet, high fat (60% ME from lard), high protein 30%CP). All diets were formulated to be isocaloric. When chicks are fed the high fat diet central NPY administration has a greater effect on feed intake compared to both the basal and high protein diet. Regardless of what diet the chick is fed from hatch, if they are switched to one of the other two diets post central administration of NPY the high fat diet stimulated feed intake for the longest duration. Although, NPY had the strongest orexigenic effect on chicks fed the high fat diet, in a choice diet situation broiler chicks chose the high protein diet, independent of central NPY administration. / Master of Science
|
17 |
IMPACT OF INDIGESTIBLE PROTEIN ON BROILER CHICKENS AND PIGSJung Yeol Sung (19195414) 23 July 2024 (has links)
<p dir="ltr">Impact of indigestible protein on broiler chickens and pigs</p>
|
18 |
Assessment of iron bioavailability and protein quality of new fortified blended foods in broiler chickensFiorentino, Nicole Marie January 1900 (has links)
Master of Science / Department of Food, Nutrition, Dietetics, and Health / Brian L. Lindshield / Fortified-blended foods (FBFs), grain-legume porridges (most commonly corn and soy), are frequently used for food aid purposes. Sorghum and cowpea have been suggested as alternative FBF commodities because they are drought-tolerant, grown locally in food aid receiving countries, and are not genetically modified.
The objective of this thesis was to determine the protein quality and iron bioavailability of newly formulated, extruded FBFs in broiler chickens, which have been suggested as a good model for assessing iron bioavailability. Five FBFs were formulated to contain whey or soy protein to compare protein quality, sugar, oil, and an improved micronutrient premix. These included three white sorghum-cowpea FBFs; two were extruded with either whey protein concentrate (WSC) or soy protein isolate (WSC+SPI) added, one was non-extruded (N-WSC). Two others were white sorghum-soy (WSS) and corn-soy (CSB14) FBFs. Two additional white-sorghum cowpea FBFs were reformulated and “over-processed” to contain no sugar, less whey (O-WSC) or soy protein (O-WSC+SPI), and less oil, thus producing a less expensive FBF. Two studies were performed using prepared (Prep) or dry (Dry) FBFs, along with the United States Agency for International Development (USAID) corn and soy blend FBF, CSB+, fed to chickens for 3 and 2 weeks, respectively; food intake, body weights, hemoglobin, and hepatic iron were assessed.
In the Prep study, new FBFs significantly increased caloric and protein efficiency compared to CSB+, despite similar food intake and body weight gain. In the Dry study, CSB+ significantly decreased food intake and caloric efficiency, with the exception of O-WSC+SPI, and nonsignificantly reduced body weight gain and protein efficiency compared to new FBFs. CSB+ significantly reduced hepatic iron content compared to all FBFs in the Dry study, and was nonsignificantly decreased compared to new FBFs in the Prep study.
In conclusion, sorghum and cowpea FBFs performed similarly to corn and soy FBFs, suggesting these commodities are suitable replacements for corn and soy. Soy protein isolate (WSC+SPI) was an effective alternative to whey protein concentrate (WSC), suggesting SPI can be a less expensive protein supplement in FBFs. Surprisingly, non-extruded sorghum and cowpea (N-WSC) was equally efficacious to extruded WSC. However, N-WSC did not meet viscosity requirements and is not precooked, which limits its viability as an FBF. O-WSC+SPI resulted in poorer outcomes compared to other FBFs, which suggests the protein quality of cowpea may be inferior and the inclusion of whey protein is needed in this formulation, as O-WSC with whey performed similarly to other FBFs. Overall, new FBFs, with the exception of O-WSC+SPI, resulted in improved food efficiency and hepatic iron outcomes compared to CSB+, suggesting they are of higher nutritional quality. However, further research is needed to refine and identify the best FBF formulations.
|
19 |
EFFECT OF EXOGENOUS ENZYMES ON APPARENT METABOLIZABLE ENERGY VALUE OF BARLEY IN SWINE AND BROILER CHICKENSBryson, Brian L. 01 January 2018 (has links)
The objective of this thesis was to evaluate the effect of exogenous enzyme supplementation, phytase and xylanase-glucanase, on AME value of barley in poultry and swine. In the first study, 280 broilers were assigned 1 of 8 treatments. Barley inclusion in the diet resulted in decreased (P < 0.05) performance. There was a treatment × phytase × xylanase-glucanase interaction for dry matter retention with birds fed the corn-SBM-barley diet supplemented with phytase and xylanase-glucanase having higher (P < 0.05) DM retention compared to birds fed corn-SBM-based diet with only xylanase-glucanase supplementation. AME and AMEn of corn-SBM-based diets were greater (P < 0.05) than the corn-SBM-barley-based diets. Energy metabolizability and AMEn of barley significantly increased with xylanase-glucanase supplementation. In the second study, 24 pigs (12 pigs/phase) were assigned to 1 of 4 treatments with xylanase-glucanase and phytase. After a 7-d adaption period, urine and feces were quantitatively collected for 5 d. DE of the barley-based diet supplemented with xylanase-glucanase (3,578 kcal/kg) and phytase and xylanase-glucanase in combination (3,617 kcal/kg) were significantly different. Compared to control diets, exogenous enzymes either significantly improved or had a tendency to improve AME and AMEn value of barley in broilers, but not in growing pigs.
|
20 |
Attempt to develop treatments based on bacteria-enzyme combination to reduce broiler contamination by two main human bacterial food-born enteric pathogensVandeplas, Sabrina 10 September 2010 (has links)
Broiler flocks become frequently asymptomatically contaminated by the enteric bacteria Salmonella sp. and Campylobacter sp. which are human pathogens. Among the strategies developed at farm level to reduce the incidence of these pathogens, some lactic acid bacteria have been shown to be interesting because of their antimicrobial activity and their stimulatory properties on the immune system of poultry. The aim of this thesis was to select bacteria with antagonistic activity against Salmonella or Campylobacter, and to improve their inhibitory effect by the combination with enzymes of polysaccharidase type. The first step of the thesis was an epidemiological study carried out in the Walloon region in order to determine the contamination way of broilers by Campylobacter in free range production. Results showed that the major way of contamination is the open-air range to which the animals have access during the rearing period. A preventive treatment of the open-air range and the straw litter with an antagonistic strain in combination with an enzyme seems thus to be suitable in this case. The second step of the work aimed at the selection of a xylanase for using as a dietary additive in combination with an antagonistic bacterial strain against Salmonella. Four xylanases were studied in vivo for their effect on growth performances of broiler chickens. Diet supplementation with enzyme led to an increased final body weight and daily weight gain (P < 0.05), without difference according to the bacterial or fungal origin of the xylanase. The Belfeed B1100MP xylanase, which is commercialized in he Walloon region, was selected in order to develop a probiotic-xylanase feed additive. The purpose of the third part was to select a bacterial strain with antagonistic activity against Campylobacter for applying on open-air range and broiler litter. An in vitro screening of 12 lactic acid bacteria was realised using a co-culture assay with a growth medium based on straw and dehydrated poultry excreta, supplemented with different cellulase concentrations. Lactobacillus pentosus and Enterococcus faecium showed inhibitory effect against Campylobacter without enzyme which was intensified by cellulose from 200 ppm. Finally, the effect of dietary supplementation with a L. plantarum strain combined with the Belfeed B1100MP (PE treatment) on growth performance, microflora, and faecal Salmonella Typhimurium concentrations, was studied with experimentally infected broiler chickens. The PE diet allowed to partially overcome the negative effects associated with the infection on growth performance and microflora, and to significantly reduce faecal Salmonella concentration.
|
Page generated in 0.0482 seconds