RESUMEN

The objective of this study was to evaluate consumer habits as well as the sensory perception and characteristics of farm eggs produced in Los Ríos, Chile. Data were collected from an online survey of 197 respondents and a sensory evaluation carried out by 30 untrained panelists of 4 types of eggs (brown-shell and blue-shell eggs acquired from family farms, free-range eggs acquired from large, industrial systems, and white-shell cage eggs from industrial, cage systems.) To evaluate differences and preferences, data were analyzed in a GLM. In addition, sensory evaluation was analyzed using principal component analysis. In accordance with the survey, 99% of the participants eat eggs (P < 0.001), 58% eat 1 to 3 eggs/wk, and 84% declared to consume eggs at home (<0.0001). Surveyed participants reported that price and size are the determining factors (31%) when purchasing eggs. Among the physical characteristic for consumers, yolk color was the most important attribute rather than white color, egg appearance, texture, flavor, or odor. In the consumer acceptability test, farm eggs (either brown or blue shell) received the most favorable sensory evaluation by the panel and were preferred to both free-range and white-shell cage eggs. Yolk color was the most influential parameter in making this difference. Brown farm eggs were predominately selected for greatest general satisfaction by participants in both the sensory evaluation (P = 0.008) and in the survey (40%; P = 0.026). There were no differences between farm eggs (brown and blue shell, P > 0.05) in the evaluated parameters. There was a consequence in the information given from surveyed consumers and the sensory panel with the yolk color.

Asunto(s)

Crianza de Animales Domésticos , Pollos , Comportamiento del Consumidor , Huevos , Crianza de Animales Domésticos/estadística & datos numéricos , Animales , Chile , Huevos/normas , Huevos/estadística & datos numéricos , Granjas/estadística & datos numéricos , Femenino , Masculino , Sensación , Encuestas y Cuestionarios

RESUMEN

This study aimed to evaluate the effect of a pectin biofilm on the preservation of refrigerated and unrefrigerated eggs during 5 wk of storage based on egg weight loss, albumen height, Haugh unit (HU), and the yolk index (YI). A total of 1,200 nonfertile eggs from GLK Bankiva laying hens (40 wk of age), which were freshly laid and came from a single collection, were obtained from a model poultry rearing system (Planaltina, Federal District, Brazil) that meets all animal welfare criteria. The experimental outline was entirely randomized, with 20 treatments in a factorial scheme of 2 × 2 × 5, with 2 biofilm treatments (with and without) × 2 storage temperatures (refrigeration: 5°C and ambient: 25°C) × 5 storage periods (7, 14, 21, 28, and 35 d), with 12 repetitions per treatment. Starting from the third storage week, increased weight loss (%) was observed in noncoated eggs (4.46 ± 1.06; 5.61 ± 1.37; 6.93 ± 1.66%) compared with biofilm-coated eggs (3.57 ± 1.26; 4.74 ± 1.8; 6.05 ± 2.21%), respectively. The HU variation in the pectin-coated eggs (86.84-78.02) was smaller than that in the noncoated eggs (83.01-64.36) between the beginning (7 d) and the end (35 d) of the experimental period. Eggs with and without biofilm stored in the refrigerator presented average HU values of 91.26 ± 6.27 and 88.35 ± 6.96, respectively. In contrast, when kept at room temperature, eggs with the coating presented higher HU values (71.27 ± 10.78) than eggs without the coating (59.11 ± 15.97). Coated eggs (0.37 ± 0.16) showed higher YI values than noncoated eggs (0.35 ± 0.16). A pectin-based biofilm effectively maintained egg quality during the 35 d of storage.

Asunto(s)

Pollos , Huevos , Conservación de Alimentos , Animales , Biopelículas , Brasil , Huevos/análisis , Huevos/normas , Femenino , Conservación de Alimentos/métodos , Conservación de Alimentos/normas , Pectinas/química , Refrigeración/veterinaria

RESUMEN

Curcumin is an herbal component with several biological properties, and we highlight here the thermal stability, antioxidant and anti-inflammatory activity. We determined whether curcumin supplementation in the diets of laying hens under cold stress and naturally infected with Escherichia coli would control infection, and would have positive effects on overall health, as well as egg production and quality. We allocated 36 chickens that had been naturally infected with E. coli into two groups, with six replicates and three chickens per repetition: control group and curcumin group (200 mg curcumin/kg). The experimental period lasted 42 days, and fecal, blood and egg samples were collected at 1, 21 and 42 days We found that feces and eggs had lower total bacterial counts, E. coli counts and total coliform counts in the curcumin group at 21 and 42 days. In fresh eggs, the brightness and yellow intensity (b+) were significantly higher in the curcumin group. In stored eggs, higher specific gravity, albumen height and lower yolk pH were observed in the curcumin group. Fresh eggs collected and stored on day 42 showed lower levels of lipid peroxidation in the curcumin group, while the total antioxidant capacity in the stored eggs was significantly higher in the curcumin group. The curcumin group showed lower total leukocyte counts as a result of lower numbers of neutrophils and lymphocytes, as well as lower levels of total protein, alkaline phosphatase and alanine aminotransferase. Lower serum lipoperoxidation at 42 days was observed in the curcumin group, probably because of the higher activity of glutathione peroxidase and glutathione transferase in other words, because of antioxidant stimulation. Taken together, our findings suggest that curcumin supplementation in laying hens under cold stress and with colibacillosis has positive effects on infection control because of antioxidant stimulation.

Asunto(s)

Antiinfecciosos/farmacología , Antiinflamatorios/farmacología , Antioxidantes/farmacología , Pollos/fisiología , Respuesta al Choque por Frío/efectos de los fármacos , Curcumina/farmacología , Aclimatación , Animales , Antiinfecciosos/administración & dosificación , Antiinflamatorios/administración & dosificación , Antioxidantes/administración & dosificación , Pollos/metabolismo , Frío , Curcumina/administración & dosificación , Suplementos Dietéticos , Huevos/microbiología , Huevos/normas , Escherichia coli/efectos de los fármacos , Escherichia coli/patogenicidad , Femenino , Peroxidación de Lípido/efectos de los fármacos , Linfocitos/efectos de los fármacos , Neutrófilos/efectos de los fármacos

RESUMEN

Abstract The present study investigated the influences of selected coatings (paraffin wax (PW), chitosan (CH), whey protein isolate (WPI), and soy protein isolate (SPI)) on the quality changes of hardboiled salted duck eggs when kept under ambient temperature (30±2 oC). At 5-day intervals for 15 days, samples were tested for color (L*, C*, and h˚), shell strength, weight loss, microbial analysis, water activity, moisture, pH, salt content, TBARS, and sensory analysis. L*, C* and h˚ gradually decreased in egg white, whereas C* and h˚ gradually increased in egg yolk. Shell strength gradually decreased in all cases, and weight loss similarly increased throughout the storage. PW and WPI coatings gave the best shell strengths and the least weight loss. The aw was not significantly different between the treatments. WPI and PW retained the most moisture. A slight decrease in pH was observed in all the samples (P ≥ 0.05). On the other hand, salt content gradually increased with storage time, and the WPI and SPI treatments gave < 2% salt accumulation. TBARS steadily increased throughout storage, and the WPI samples had the least lipid oxidation. TPC, mold, and yeast at the end of storage were the least with the WPI treatment. Both the storage period and coating material choice significantly influenced the sensory scores that declined throughout the storage. Overall, the WPI coating treatment gave the best results.

Asunto(s)

Huevos/normas , Almacenamiento de Alimentos/métodos , Conservación de Alimentos

RESUMEN

The aim of this study was to evaluate whether the addition of curcumin in the diet of commercial laying hens could have an anticoccidial action and improve egg quality. For this, 60 laying hens were divided into three groups: T0 (the control group); T30 and T50 (30 and 50 mg/kg of curcumin in the feed, respectively). Eggs recently laid were collected on days 14 and 21 of the experiment, and stored for 21 days. It was observed increased specific gravity and yolk index in stored eggs of the groups T30 and T50 compared to T0. The yolk color reduced in the eggs stored from groups T30 and T50 compared to T0. Moreover, TBARS levels were lower in fresh and stored eggs from groups T30 and T50. It was observed increased TAC levels in fresh eggs from groups T30 and T50 and in stored eggs from the group T50. The presence of curcumin was not detected by HPLC in the yolk and albumen. Seric levels of albumin and uric acid did not differ between groups, while seric levels of total proteins increased on day 21 on groups T30 and T50. Finally, it was observed a significant reduction on the number of oocysts in fecal samples on days 14 and 21 of T30 and T50 compared to T0. Based on these evidences, it is possible to conclude that the addition of curcumin in the diet of laying hens has an anticoccidial effect and improves egg quality.

Asunto(s)

Alimentación Animal , Pollos , Coccidiostáticos/administración & dosificación , Curcumina/administración & dosificación , Huevos/normas , Bienestar del Animal , Animales , Coccidiostáticos/farmacología , Curcumina/farmacología , Dieta , Yema de Huevo , Femenino , Óvulo

RESUMEN

An experiment was performed using 1,000 laying Japanese quails to assess the availability of two alternative dietary methionine sources. Treatment 01 = Basal Feed that is deficient in digestible methionine + cystine (Met + Cys). The other treatments were constituted by Met + Cys levels of 0.8, 1.60 and 2.40 g/kg, supplemented with DL-Methionine-99%, HMTBA-88% and HMTBA-84%, being 10 treatments in total. The following characteristics were studied: feed intake (g/bird/day), egg production (egg/day × 100), egg weight (g/egg), egg mass (g/egg), feed conversion per egg dozen (kg feed/dozen eggs), feed conversion per egg mass (kg feed/kg eggs), relative yolk weight (g/100 g of egg), relative albumen weight (g/100 g of egg), relative shell weight (g/100 g of egg), shell thickness (mm) and specific gravity (g/cm3 ). In general result comment, supplemental methionine sources must be included in the poultry diet. The different methionine sources affect the performance of quails, and the increase in the levels within each source improves the performance variables. Significant effect was observable on performance variables and egg quality variables, being that DLM-99% is superior to the other sources. The HMTBA-88% source is superior to the HMTBA-84% source for the same aforementioned variables. In conclusion, the bioefficacy values of the HMTBA-88% and HMTBA-84% sources compared to the DLM-99% source on an equimolar basis were 81 and 79%, respectively, for the performance variables, and 83 and 74 while the methionine sources were equivalent for the variables related to egg quality.

Asunto(s)

Coturnix/fisiología , Metionina/análogos & derivados , Metionina/farmacocinética , Animales , Huevos/normas , Femenino , Metionina/administración & dosificación , Oviposición

RESUMEN

In this review, we examine the variation in stable isotope signatures of the lighter elements (δ2H, δ13C, δ15N, δ18O, and δ34S) of tissues and excreta of domesticated animals, the factors affecting the isotopic composition of animal tissues, and whether stable isotopes may be used to differentiate organic and conventional modes of animal husbandry. The main factors affecting the δ13C signatures of livestock are the C3/C4 composition of the diet, the relative digestibility of the diet components, metabolic turnover, tissue and compound specificity, growth rate, and animal age. δ15N signatures of sheep and cattle products have been related mainly to diet signatures, which are quite variable among farms and between years. Although few data exist, a minor influence in δ15N signatures of animal products was attributed to N losses at the farm level, whereas stocking rate showed divergent findings. Correlations between mode of production and δ2H and δ18O have not been established, and only in one case of an animal product was δ34S a satisfactory marker for mode of production. While many data exist on diet-tissue isotopic discrimination values among domesticated animals, there is a paucity of data that allow a direct and statistically verifiable comparison of the differences in the isotopic signatures of organically and conventionally grown animal products. The few comparisons are confined to beef, milk, and egg yolk, with no data for swine or lamb products. δ13C appears to be the most promising isotopic marker to differentiate organic and conventional production systems when maize (C4) is present in the conventional animal diet. However, δ13C may be unsuitable under tropical conditions, where C4 grasses are abundant, and where grass-based husbandry is predominant in both conventional and organic systems. Presently, there is no universal analytical method that can be applied to differentiate organic and conventional animal products.

Asunto(s)

Productos Lácteos/análisis , Huevos/análisis , Inspección de Alimentos/métodos , Calidad de los Alimentos , Alimentos Orgánicos/análisis , Carne/análisis , Modelos Químicos , Animales , Biomarcadores/análisis , Bovinos , Productos Lácteos/normas , Yema de Huevo/química , Huevos/normas , Etiquetado de Alimentos , Alimentos Orgánicos/normas , Humanos , Isótopos , Ganado , Carne/normas , Productos de la Carne/análisis , Productos de la Carne/normas , Leche/química , Leche/normas , Aves de Corral

RESUMEN

Os ovos são alimentos consumidos em grande escala pela população brasileira. É um alimento nutritivo e de baixo custo, o que viabiliza o seu consumo pela população de baixa renda. Existem legislações que regulamentam a rotulagem dos produtos de origem animal, incluindo os ovos. Os rótulos trazem as informações essenciais dos produtos para que o consumidor saiba o que está sendo adquirido. O objetivo deste trabalho foi avaliar a conformidade da rotulagem de 31 amostras, de 15 marcas diferentes, de ovos in natura comercializados no município do Rio de Janeiro - RJ perante as legislações vigentes. Somente um rótulo (3,22%) estava em conformidade com todas as legislações vigentes. Este resultado demonstra a falta de fiscalização dos rótulos dos ovos in natura comercializados no município do Rio de Janeiro - RJ e da falta de comprometimento das indústrias brasileiras com as informações fornecidas nos rótulos dos ovos. (AU)

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Eggs are food consumed on a large scale by the Brazilian population. It is a nutritious and inexpensive food, which enables its consumption by low-income population. There are laws which regulate the labeling of products of animal origin, including eggs. The labels bring the essential information of the products so that consumers know what is being purchased. The objective of this study was to evaluate the compliance of the labeling of 31 samples of 15 different brands of eggs in nature sold in the city of Rio de Janeiro - RJ according to the current legislation. Only one label (3.22%) was in compliance with all current laws. This result demonstrates the deficiency inspection of eggs labels in nature sold in the city of Rio de Janeiro - RJ and the absence of the Brazilian industries with the information provided on the eggs labels. (AU)

Asunto(s)

Huevos/normas , Etiquetado de Alimentos/normas , Información Nutricional , Alimentos de Origen Animal

RESUMEN

This study was carried out with the aim of evaluating the effects of mineral oil application on eggshells and the use of plastic packages with lids on the physical-chemical and microbiological quality and biogenic amine contents of eggs stored under refrigeration for up to 125 d. A total of 1,920 eggs from 46-wk-old Hyline W36 laying hens were randomly distributed into 4 groups soon after classification: (i) 480 eggs were stored in pulp carton tray packages; (ii) 480 eggs were stored in plastic packages with lids; (iii) 480 eggs were stored in carton packages after the application of mineral oil; and (iv) 480 eggs were stored in plastic packages with lids after the application of mineral oil. The internal quality was measured by Haugh units, by the counts of mesophilic and psychrotrophic microorganisms, by the most probable number of total and thermal-tolerant coliforms, by the counts of molds and yeasts, by the analysis of Salmonella spp. and Staphylococcus spp., and by the levels of biogenic amines in the egg yolk and albumen. The application of mineral oil to the eggshell resulted in higher Haugh unit values throughout storage, and the use of plastic packages altered the internal quality. The application of mineral oil and the use of packaging had no effects on the microbiological and biogenic amine results. Microbiological analyses showed the absence of Salmonella spp., Staphylococcus aureus, thermal-tolerant coliforms, and fungi. However, the highest counts of mesophilic (1.1 × 10(7) cfu/g) and psychrotrophic (6.7 × 10(7) cfu/g) microorganisms were recorded. The highest values of biogenic amines detected and quantified were putrescine (2.38 mg/kg) and cadaverine (7.27 mg/kg) in the egg yolk and putrescine (1.95 mg/kg), cadaverine (2.83 mg/kg), and phenylethylamine (2.57 mg/kg) in the albumen. Despite these results, the biogenic amine levels recorded were considered low and would not be harmful to consumer health.

Asunto(s)

Aminas Biogénicas/química , Huevos/análisis , Huevos/normas , Manipulación de Alimentos/métodos , Aceite Mineral , Animales , Pollos , Femenino , Factores de Tiempo

RESUMEN

The physicochemical and microbiological qualities of commercial eggs produced by layer hens of different ages (approximately 30 and 60 wk old) were submitted to storage under room temperature or refrigeration for 28 d. A total of 600 eggs were subjected to microbiological analyses of their inner contents and another 600 to a determination of Haugh units (HU) and bioactive amine content. A decrease in the quality of the inner contents of the eggs was observed during the experiment, mainly in the eggs from the 60-wk-old layers, which presented the worst HU values when stored at room temperature (P < 0.05). Microbiological analyses showed an absence of Salmonella spp., Staphylococcus aureus, and coliforms, either total or thermal-tolerant; however, low counts of other Staphylococcus species, Enterobacter spp., Pseudomonas spp., mesophilic aerobic bacteria, and fungi were also recorded. The chromatographic analysis of bioactive amines detected the presence of phenylethylamine in all albumens (38.0 mg/kg) and spermidine in the yolks (1.02 mg/kg). It was concluded that the age of the hens and the time and temperature of storage influenced the quality parameters of the eggs (P < 0.05). Furthermore, despite the low levels of microbial contamination found, phenylethylamine was detected in the albumen. It was not possible to establish index of quality of eggs using bioactive amines present in the yolk and albumen of eggs.

Asunto(s)

Aminas/química , Pollos/fisiología , Huevos/normas , Conservación de Alimentos/métodos , Almacenamiento de Alimentos/métodos , Envejecimiento , Animales , Huevos/análisis , Huevos/microbiología , Femenino , Refrigeración , Temperatura , Factores de Tiempo

RESUMEN

One approach to enhance the Crude Protein (CP) value of laying hens diets it is the use of enzymes. The objective of this experiment was to evaluate different CP levels and an enzyme blend (Avizyme; AZ) in laying hens diets on egg quality. Two hundred and eighty eight ISA Babcock B-300 hens were used. The diets were: (A) 18.8% CP, (B) 18.8% CP+AZ, (C) 16.6% CP, (D) 16.6% CP+AZ, (E) 16.0% CP and(F) 15.4% CP. Data were analyzed using analyses of variance for factorial designs (Diets A, B, C and D) and a complete randomized design (Diets C, E and F). CP or AZ had no effect on egg quality (p>0.05). Reduction of CP in laying hen diets tended (p<0.08) to increase feed intake (90.8, 93.6 and 96.5 g day(-1)) and feed conversion (p<0.05) (2.1, 2.2 and 2.3) for 16.6, 16.0 y 15.4% of CP, respectively. Reduction of CP in laying diets increased (p<0.05) albumen height (11.4, 11.9 y 11.9 mm). Significant (p<0.05) reductions of feed intake (96.2 vs 89.9 g day(-1)) and feed conversion (2.1 versus 2.0) in diets supplemented AZ were observed. Significant (p<0.05) interactions of PC and AZ on feed intake and feed conversion were found. The reduction of CP in the diets did not affect egg quality, but has an effect on feed intake and feed conversion. Avizyme supplementation reduced feed intake and improve feed efficiency in high CP diets.

Asunto(s)

Alimentación Animal/normas , Pollos/fisiología , Dieta/métodos , Proteínas en la Dieta/administración & dosificación , Huevos/normas , Enzimas/administración & dosificación , Animales , Pollos/metabolismo , Proteínas en la Dieta/metabolismo , Suplementos Dietéticos , Ingestión de Alimentos , Enzimas/metabolismo , Femenino

RESUMEN

Chelonians have been exploited since ancient times for their meat, eggs, fat, and offal, among other things. Among these animals, there is Scorpion mud turtle (Kinosternon scorpioides) which is an omnivorous turtle with semiaquatic habits and is widely consumed in Brazil. The aim of this study was to evaluate the influence of different feeding management systems on the reproductive performance of captive-bred Scorpion mud turtles, including egg quality and chemical composition. Study animals included 15 males and 48 females, divided into three groups. Animals were fed with either a commercial diet or a commercial diet supplemented with one of two different mixes (wet diet). All animals were fed at 1 % BW/day divided on Mondays, Wednesdays, and Fridays. Treatments were as follows: TR = 100 % fish food (22 % CP); TRM1 = 70 % fish food + 30 % mix 1 (bovine offal and fish); TRM2 = 70 % fish food + 30 % mix 2 (bovine offal, fish, and shrimp). Samples were collected during 7 months, and eggs were identified, weighed, measured, and frozen for later analysis. Statistical analyses, including ANOVA, were performed using the program SAEG 9.0. Measurements taken from the nests were compared using the Tukey's test (P < 0.05). The different diets were associated with differential egg-laying performance and eggshell thickness. Animals fed with wet diets containing protein of animal origin displayed the best performance. Furthermore, nests with fewer eggs contained eggs of better external quality (e.g., greater length, width, and eggshell thickness). Finally, animals fed with only commercial feed produced eggs with lower saturated fatty acid content.

Asunto(s)

Acuicultura/métodos , Tortugas/fisiología , Alimentación Animal/análisis , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Brasil , Dieta , Suplementos Dietéticos/análisis , Huevos/normas , Femenino , Masculino , Óvulo/química , Distribución Aleatoria , Reproducción

RESUMEN

The aim of this experiment was to study the suitability of the outdoor system for Rhode Island Red hens under the tropical conditions of southern Mexico. Twelve floor pens, each containing four birds, were divided randomly into two groups. The first group was raised indoors only, while each of the second group replicates had access to an outdoor area with natural-grown vegetation from 0800 to 1700 hours daily. Both groups fed ad libitum on a commercial layers diet. The results revealed no differences in body weight between treatments. The outdoor group recorded significantly higher egg laying rate (86.90 vs. 78.05 %), higher egg mass (50.66 vs. 45.30 g egg/hen/day), and higher feed intake (103.70 vs. 97.67 g/day) versus the indoor group. The outdoor group had eggs with darker yellow yolks (9.46 vs. 5.46), lower yolk, and higher albumen proportions (P < 0.05) versus the indoor group. The crop content of the outdoor hens consisted of 86.55 % concentrated feed, 6.30 % plant material, 2.27 % grit stones, 1.69 % snails and oyster shells, 1.25 % seeds, 0.95 % farm wastes, and 0.99 % insects, worms, and larvae. Of the outdoor hens, 43.1 % was observed to be in the range at each scanning time. The outdoor system in the tropics had beneficial effects on Rhode Island Red hen performance, and the hens utilized the outdoor area effectively and obtained various feed items.

Asunto(s)

Alimentación Animal/análisis , Crianza de Animales Domésticos , Pollos/fisiología , Huevos/normas , Contenido Digestivo/química , Reproducción , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Buche de las Aves/química , Dieta/veterinaria , Femenino , México , Distribución Aleatoria

RESUMEN

This study aimed to evaluate the potential of Moringa oleifera fresh leaves (MOL) as feed supplement on the performance and egg quality of Rhode Island Red (RIR) hens under the tropical conditions of Yucatan, Mexico. Forty-eight RIR hens were allocated in 12 floor pen replicates each with four birds. Thereafter, the replicates were divided into three groups which were corresponded to ad libitum feed (control), ad libitum feed supplemented with MOL T1 (AL + MOL) and restricted feed amount (20% lower than control) with MOL T2 (RCD + MOL), respectively. T1 (AL + MOL) had higher egg laying rate (71.4% versus 66.6%), higher daily egg mass production (45.4 versus 41.9 g/day), lower feed intake (121.3 versus 127.5 g/day) and better feed conversion ratio (2.8 versus 3.2 g feed:g egg) versus control. T2 / (RCD + MOL) had lower values of body weight, egg laying rate, egg weight and egg mass, and recorded better feed conversion ratio than the control group. The control group recorded a higher percentage of pecked eggs versus T1 and T2 (6.5% versus 1.2% and 2.0 %). Similar intake of MOL (3.1 and 3.4 g DM/day) was recorded in T1 (AL + MOL) and T2 (RCD + MOL). Yolk color was improved significantly in T1 (AL + MOL) than both control and T2 (RCD + MOL), while T2 (RCD + MOL) had eggs with lower yolk and higher albumen percentages than the other two ad libitum groups. The results suggest that MOL could be used successfully as sustainable tropical feed resource for RIR hens.

Asunto(s)

Crianza de Animales Domésticos , Pollos/fisiología , Suplementos Dietéticos/análisis , Huevos/normas , Moringa oleifera/química , Alimentación Animal/análisis , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Dieta/veterinaria , Femenino , México , Hojas de la Planta/química , Distribución Aleatoria

RESUMEN

It has been hypothesized that zinc (Zn) levels beyond those that are nutritionally required may favor the utilization of dietary lysine, and consequently reduce the level of its inclusion into the diet. Therefore, the possible effects of interaction between chelated Zn and the level of lysine (Lys) on egg production and egg quality of laying hens were evaluated. In total, 720 ISA Brown layer hens aged 24 to 36 wk (early phase) and 48 to 60 wk (late phase) were allotted in a completely randomized factorial design that used 3 Zn and 5 Lys levels (6 replications, 8 birds/replication). All birds aged 37 to 47 wk (between early and late phases) were fed a standard diet and maintained under the same experimental design. The Zn levels used were 137, 309, and 655 mg/kg; and the Lys levels were 0.560, 0.612, 0.677, 0.749, and 0.851%. The optimal levels of Lys digestibility were based on laboratory analyses with regard to the weighted average relationship between 83.5% digestibility and the total Lys from principal ingredients. There was no effect of interaction found between the dietary levels of Zn and Lys for most of the variables studied; however, each had an independent effect on the variables. An increase in Zn from 137 to 655 mg/kg had no significant effect (P > 0.05) on the performance of hens in both phases; however, it showed a significant effect on egg quality (P < 0.01), principally on mineral composition. Increased Zn resulted in decreased shell weight, percentage of ash, yolk ash deposition, and total ash deposition. On the other hand, an increase in Lys from 0.560 to 0.851% significantly affected (P < 0.002) several performance parameters and the chemical composition of the eggs, including feed intake, feed conversion efficiency, BW gain, egg weight, and production. In conclusion, there was no interaction found between Zn and Lys, but higher dietary levels of chelated Zn reduced bird performance and egg quality parameters, whereas higher Lys levels could be beneficial to bird performance and egg quality.

Asunto(s)

Alimentación Animal/análisis , Pollos , Dieta/veterinaria , Suplementos Dietéticos , Lisina/farmacología , Zinc/farmacología , Animales , Huevos/normas , Femenino , Oviposición/efectos de los fármacos , Zinc/química

RESUMEN

The objective of this study was to investigate the possibility of using bioactive amines as an index of quality of fresh and stored eggs. Large white eggs from 24-wk-old Dekalb layers were randomly distributed in 3 groups: (i) 10 freshly laid eggs, (ii) 60 eggs stored at 25 +/- 1 degrees C and 60% RH for 30 d, and (iii) 50 eggs stored at 6 +/- 1 degrees C and 60% RH for 50 d. The eggs were weighed and the internal quality was evaluated by Haugh units (HU), pH of albumen, total solids, total volatile bases, and bioactive amines in the albumen and yolk. The fresh eggs had, on average, 56.85 g, 98.55 HU, albumen pH of 8.02, total solids of 12.17 g/100 g in the albumen and 52.43 g/100 g in the yolk, and absence of volatile bases. None of the 10 amines investigated were detected in the albumen; however, the yolk contained 0.37 mg/kg of spermidine. Throughout storage, there was a significant decrease in the weight of the egg and HU and a significant increase in the pH and in the total solids of the albumen. The decrease in HU and the increase in the total solids of the albumen were faster at 25 +/- 1 degrees C compared with 6 +/- 1 degrees C. At 50 and 30 d of storage at 6 +/- 1 and 25 +/- 1 degrees C, respectively, significant levels of total volatile bases were detected. The levels of spermidine in the yolk increased significantly at the 40th and 15th days of storage at 6 +/- 1 and 25 +/- 1 degrees C, respectively. At these storage times, the presence of putrescine and agmatine was also detected. Therefore, the presence of other amines besides spermidine or spermidine levels higher than 1.0 mg/kg in the yolk could be used as an index of quality of fresh eggs and throughout storage.

Asunto(s)

Aminas/química , Pollos/fisiología , Huevos/análisis , Huevos/normas , Animales , Femenino , Conservación de Alimentos , Temperatura , Factores de Tiempo

RESUMEN

1. Eggs from wild and captive populations of Greater Rhea (Rhea americana) were studied to determine their physical and chemical characteristics. 2. Significant differences were found among populations in almost all chemical parameters studied, whereas within physical parameters only shell weight (as a proportion of the entire egg) and density showed differences. 3. Eggs from wild populations had the highest protein and linolenic acid and the lowest total lipid contents, while cholesterol levels of these eggs and of those from the largest captive area were the lowest.

Asunto(s)

Huevos/análisis , Reiformes/fisiología , Animales , Animales Domésticos , Animales Salvajes , Colesterol/análisis , Proteínas del Huevo/análisis , Cáscara de Huevo/química , Huevos/normas , Lípidos/análisis

RESUMEN

Feed restriction was implemented in a factorial design (2x4) when pullets were at either 5 or 10% egg production. Periods of feed restriction were for 0, 3, 4, or 5 d. Two trials each using 672 Hy-line W-77 White Leghorn Hens 19 wk of age were identified and randomly assigned to 16, 2x3 m pens at a density of 7 birds per square meter. Data recorded were days at sexual maturity, egg production, mortality, feed consumption, feed conversion, egg weight, body weight gain, and body weight uniformity. Hens placed on feed restriction reached sexual maturity 3 to 5 d later (P < 0.05) than the unrestricted birds. No significant main effects or interactions were found for egg production, feed consumption, feed conversion, mortality, egg weight, body weight gain, or body weight uniformity for the initial 15 wk or the entire egg production period. These results suggest that early egg size was not increased with the practice of early feed restriction nor did short- or long-term laying performance improve.

Asunto(s)

Pollos/fisiología , Huevos/normas , Privación de Alimentos/fisiología , Oviposición/fisiología , Animales , Femenino

RESUMEN

The present experiment evaluated the effect of four levels of ascorbic acid (0, 100, 250, and 500 ppm) and two levels of calcium (3.0 and 3.5%) on the productivity and eggshell quality of molted Single Comb White Leghorn hens, housed four per 30.5 cm wide x 45.7 cm deep cage. The 4 x 2 factorial treatment combinations were randomly assigned to eight blocks of cages. Egg production increased (P < .06) an average of 5% for the levels of 250 and 500 ppm ascorbic acid. No differences were observed for feed consumption, egg weight, and shell thickness for the different levels of ascorbic acid or calcium in the diet. An increase (P < .01) was observed for specific gravity, as the levels of ascorbic acid increased. Increasing the level of calcium from 3.0 to 3.5% increased (P < .01) specific gravity from 1.073 to 1.075. Shell weight increased (P < .01) with the higher levels of ascorbic acid (250 and 500 ppm). No interactions were observed between the levels of ascorbic acid and calcium. Results suggest that supplementing ascorbic acid to molted laying hens can be beneficial to egg production and eggshell quality.

Asunto(s)

Alimentación Animal , Ácido Ascórbico/farmacología , Calcio/farmacología , Cáscara de Huevo/efectos de los fármacos , Oviposición , Animales , Pollos , Huevos/normas , Femenino