Kilogram Of Eggs Research Articles

Assessment of four different dietary amino acid profiles recommended for ISA Brown layer hens: A validation study

The current feeding study was designed to validate the two dietary essential amino acid profiles (EAAP) established based on linear broken-line (LBL) and quadratic broken-line (QBL) models, in a previous study, against Evonik (AMINOHen) and breeder recommendations for ISA Brown layers for peak production (PP, 20 to 44 weeks of age), and post peak production (post PP, 44 to 75 weeks of age). The EAAP based on LBL models on average had 19.5% and 26.0% lower digestible AA (Lys, Met + Cys, Thr, Trp, Ile and Val), than the EAAP based on QBL models for PP and post PP, respectively. The EAAP based on AMINOHen and breeder recommendation had lower digestible AA than QBL, and higher EAAP than LBL models for both production phases. At 20 weeks of age, 224 ISA Brown layer hens were weighed and randomly allocated to individual battery cages. Each of the four diets was replicated 8 times with 7 birds per replicate. Egg production was recorded daily, and egg weights were measured at the end of each week. Feed consumption was measured at the end of each period. The egg production rate was not significantly affected by the diets and remained at around 98.0% (PP) and 95.0% (post PP) (P > 0.05). Birds fed diets based on LBL recommendation consistently laid smaller eggs, resulting in a lower egg mass (59.8 vs. 62.0 g egg/hen per day during PP, and 60.3 vs. 63.0 g egg/hen per day during post PP; P < 0.05). Diets had no significant effect on feed intake and body weight (P > 0.05). The highest feed conversion ratio (FCR) during PP (P = 0.067) and post PP (P < 0.05) was recorded for the birds offered diets based on LBL recommendation. In conclusion, all four EAAP tested in this study support an above average egg production rate. However, the EAAP based on LBL models may potentially decrease the input feed cost per kilogram of eggs but are not set to optimise FCR and maximise egg mass.

HEDONIC PRICE OF FREE-RANGE EGGS IN COSTA RICA

Eggs are a highly consumed animal product in Costa Rica. It is grown in different production systems and differentiation attributes, although there is little information about consumption and consumer preferences for grazing production. This study aimed to determine the effect of free-grazing on the price per kilogram of eggs paid by the consumer in Costa Rica. The results show a positive effect of 19.77% on price of eggs produced in free-grazing systems, but preference for other attributes such as nutritional fortification, egg size and brand names were also determined. Incorporating free-range technologies to replace caged poultry production can contribute to animal welfare and balance with nature, and producers can opt for differentiated prices in local markets.

Production Efficiency of Poultry Small-Scale Laying Hen in Indonesia

Competitiveness of layer business was determined by the level of efficiency, which was influenced by the level of technology adoption, production costs, and economy of scale. This study was carried out from April to July aim to analyse the performance of small-scale layer poultry farming. The study site was in the layer production centre, namely in Payakumbuh West Sumatera, Blitar East Java and Sidrap South Sulawesi. Primary data were collected through interviews with 50 farmers and 12 poultry shops at all study sites. Analysis of the efficiency level is using DEA (Data Envelopment Analysis) software and business feasibility using financial analysis. The following were the main research findings: (1) the development of layer farming technology had not been responded well by farmers so that the production level and mortality of chickens were still below standard; (2) relatively, the level of layer poultry farming efficiency in Sidrap and Payakumbuh was better than in Blitar with a value closer to one, where the inefficiency was due to the use of excessive inputs; and (3) small-scale layer poultry farming was financially feasible, where the determining factors were feed and eggs price. The study recommended the need to add both technical service staff from poultry shops and local agricultural extension workers. Feed costs should be reduced by IDR 1,000 in Blitar and IDR 57 di Sidrap per kilogram of eggs produced per period. In addition, an accurate and better allocation of corn for feed was needed to optimise the ratio of feed and egg price optimal.

Evaluación de dos aceites acidulados de soya en la producción y calidad de huevo en gallinas Bovans

En la alimentación de gallinas en postura se utiliza el aceite crudo de soya (ACS), pero debido a que éste compite con la alimentación humana su precio es alto, por lo cual se evaluaron dos aceites acidulados de soya (AAS), los cuales son más económicos. El objetivo del estudio fue evaluar el efecto de los AAS en la producción de gallinas Bovans, calidad de huevo, composición lipídica y costo de un kilo de huevo. Se determinó la energía metabolizable (EM) y composición de lípidos de los acidulados. Se utilizaron 240 gallinas en seis tratamientos, con cinco repeticiones, con ocho gallinas cada una. En las dietas se incluyeron ACS y dos acidulados (AAST y AASY), a dos niveles (2% y 4%). Las variables productivas fueron alimento consumido, porcentaje de postura, peso del huevo, masa del huevo, conversión alimenticia; en calidad de huevo se midió altura de albumina, unidades Haugh (UH), color de yema y grosor de cascarón. Se determinó la composición lipídica del huevo y su costo. Al sustituir el ACS por los AAS no se afectó la producción de las aves (P&gt;0.05). En calidad de huevo, los AAS mejoraron las UH (P&lt;0.05); la concentración de ácidos grasos del huevo se modificó según la composición del aceite en la dieta de las gallinas (P&lt;0.05), mientras que el nivel de aceite influyó en el contenido de algunos ácidos grasos. Finalmente los AAS disminuyeron el costo de un kilo de huevo (P&lt;0.05) en comparación del ACS.

Níveis de sódio na ração de poedeiras semipesadas após o pico de postura criadas em clima quente

The objective of this study was to estimate the sodium (Na) requirements of semi-heavy laying hens reared in a hot climate after peak lay. A total of 120 Hisex Brown hens, 48 weeks of age, were used. The birds were allocated in a completely randomized design consisting of five treatments, six replicates and four animals per experimental unit. The experimental diets were formulated with corn and soybean meal and the treatments consisted of five levels of sodium (0.12, 0.17, 0.22, 0.27 and 0.32%) derived from common salt. The following parameters were evaluated: feed intake (g), egg production (%), egg weight (g), egg mass (g), feed conversion (kg) per kilogram of eggs and per dozen eggs, specific gravity (g/cm 3 ), shell thickness (mm), egg components including egg yolk (g and %), albumin (g and %) and shell (g and %), viability (%), and variation in body weight (g) of the birds. There was no effect (P>0.05) of sodium levels on egg yolk weight (g) or albumin percentage. A decreasing linear effect (P<0.01) was observed for feed intake, which decreased with increasing sodium level in the diet. A quadratic effect (P<0.05) was found for egg production, egg weight, feed conversion per kilogram of eggs and dozen eggs, albumin and shell weight, specific gravity, shell thickness, and percentage of shell and egg yolk. A sodium level higher than 0.27% negatively influenced egg components and zootechnical performance of the birds. The inclusion of 0.20% sodium in the diet after peak lay is recommended for semi-heavy laying hens reared in a hot climate to increase egg quality and productive performance.

Glycerin and lecithin inclusion in diets for brown egg-laying hens: Effects on egg production and nutrient digestibility

The effects of the inclusion of raw glycerin (GLYC) and lecithin in the diet on egg production, egg quality and total tract apparent retention (TTAR) of dietary components was studied in brown egg-laying hens from 23 to 51 wk of age. The experimental design was completely randomized with six diets combined as a 2×3 factorial with two levels of GLYC (0 vs. 70g/kg) and three animal fat to lecithin ratios (40:0, 20:20 and 0:40g/kg). Each treatment was replicated eight times and the experimental unit was a cage with ten hens. Production was recorded by replicate every 28-d period and cumulatively. For the entire experiment, the inclusion of GLYC in the diet hindered feed conversion ratio per kilogram of eggs (2.071 vs. 2.039; P<0.05) but did not affect any of the other production or egg quality traits studied. The replacement of animal fat by lecithin (40:0, 20:20 and 0:40g/kg) increased egg weight (60.1, 60.7 and 61.8g, respectively; P<0.001) and egg mass production (56.8, 57.5 and 58.8g/d, respectively; P<0.01) and improved yolk color as measured by the DSM color fan (9.2, 9.2 and 9.5, respectively; P<0.001) and feed conversion ratio per kilogram of eggs (2.072, 2.068 and 2.027, respectively; P<0.05). Feed intake, egg production and body weight gain, however, were not affected. The inclusion of GLYC in the diet did not affect nutrient retention but lecithin inclusion improved TTAR of dry matter (P<0.05), organic matter (P<0.05), ether extract (P<0.001) and gross energy (P<0.001). In summary, the inclusion of 70gglycerol/kg diet hindered feed conversion ratio per kilogram of eggs but did not affect any other production or digestibility trait. The replacement of animal fat by lecithin improved egg weight, egg yolk color and nutrient digestibility. Consequently, lecithin can be used as a lipid source in laying hen diets with beneficial effects on egg production.

Comparison of the environmental footprint of the egg industry in the United States in 1960 and 2010

The US egg industry has evolved considerably over recent decades by incorporating new technologies and production practices. To date, there has been no comprehensive assessment of the resource demand and environmental effects of these changes. This study quantifies the environmental footprint of egg production supply chains in the United States for 2010 compared with 1960 using life cycle assessment. The analysis considers changes in both foreground (e.g., hen production performance) and background (e.g., efficiencies of energy provision, fertilizer production, production of feed inputs, and transport modes) system variables. The results revealed that feed efficiency, feed composition, and manure management are the 3 primary factors that determine the environmental impacts of US egg production. Further research and improvements in these areas will aid in continual reduction of the environmental footprint of the US egg industry over time. Per kilogram of eggs produced, the environmental footprint for 2010 is 65% lower in acidifying emissions, 71% lower in eutrophying emissions, 71% lower in greenhouse gas emissions, and 31% lower in cumulative energy demand compared with 1960. Table egg production was 30% higher in 2010; however, the total environmental footprint was 54% lower in acidifying emissions, 63% lower in eutrophying emissions, 63% lower in greenhouse gas emissions, and 13% lower in cumulative energy demand compared with 1960. Reductions in the environmental footprint over the 50-yr interval considered can be attributed to the following: 27 to 30% due to improved efficiencies of background systems, which outweighed the declining energy return on energy invested for primary energy sources; 30 to 44% due to changes in feed composition; and 28 to 43% due to improved bird performance.

Effects of balanced dietary protein levels on egg production and egg quality parameters of individual commercial layers

The effects of a series of balanced dietary protein levels on egg production and egg quality parameters of laying hens from 18 through 74 wk of age were investigated. One hundred forty-four pullets (Bovans) were randomly assigned to individual cages with separate feeders including 3 different protein level series of isocaloric diets. Diets were separated into 4 phases of 18-22, 23-32, 33-44, and 45-74 wk of age. The high protein (H) series contained 21.62, 19.05, 16.32, and 16.05% CP, respectively. Medium protein (M) and low protein (L) series were 2 and 4% lower in balanced dietary protein. The results clearly demonstrated that the balanced dietary protein level was a limiting factor for BW, ADFI, egg weight, hen day egg production (HDEP), and feed per kilogram of eggs. Feeding with the L series resulted in lower ADFI and HDEP (90.33% peak production) and more feed per kilogram of eggs compared with the H or M series (HDEP; 93.23 and 95.68% peak production, monthly basis). Egg weight responded in a linear manner to balanced dietary protein level (58.78, 55.94, and 52.73 g for H, M, and L, respectively). Feed intake of all hens, but especially those in the L series, increased considerably after wk 54 when the temperature of the house decreased due to winter conditions. Thus, hens fed the L series seemed particularly dependent on house temperature to maintain BW, ADFI, and HDEP. For egg quality parameters, percent yolk, Haugh units, and egg specific gravity were similar regardless of diets. Haugh units were found to be greatly affected by the variation of housing temperature (P = 0.025). Maximum performance cannot always be expected to lead to maximum profits. Contrary to the idea of a daily amino acid requirement for maximum performance, these results may be used to determine profit-maximizing levels of balanced dietary protein based on the cost of protein and returns from different possible protein levels that may be fed.

Effects of energy concentration of the diet on productive performance and egg quality of brown egg-laying hens differing in initial body weight

The influence of AMEn concentration of the diet on productive performance and egg quality traits was studied in Hy-Line brown egg-laying hens differing in initial BW from 24 to 59 wk of age. Eight treatments were arranged factorially with 4 diets varying in energy content (2,650, 2,750, 2,850, and 2,950 kcal of AMEn/kg) and 2 initial BW of the hens (1,733 vs. 1,606 g). Each treatment was replicated 5 times (13 hens per replicate), and all diets had similar nutrient content per unit of energy. No interactions between energy content of the diet and initial BW of the hens were detected for any trait. An increase in energy concentration of the diet increased (linear, P < 0.05; quadratic P < 0.05) egg production, egg mass, energy efficiency (kcal of AMEn/g of egg), and BW gain (P < 0.05) but decreased ADFI (linear, P < 0.001) and feed conversion ratio per kilogram of eggs (linear, P < 0.01; quadratic P < 0.01). An increase in energy content of the diet reduced Haugh units and the proportion of shell in the egg (P < 0.01). Feed intake (114.6 vs. 111.1 g/hen per day), AMEn intake (321 vs. 311 kcal/hen per day), egg weight (64.2 vs. 63.0 g), and egg mass (58.5 vs. 57.0 g) were higher for the heavier than for the lighter hens (P < 0.01), but feed conversion ratio per kilogram of eggs and energy efficiency were not affected. Eggs from the heavier hens had a higher proportion of yolk and lower proportion of albumen (P < 0.01) and shell (P < 0.05) than eggs from the lighter hens. Consequently, the yolk-to-albumen ratio was higher (P < 0.001) for the heavier hens. It is concluded that brown egg-laying hens respond with increases in egg production and egg mass to increases in AMEn concentration of the diet up to 2,850 kcal/kg. Heavy hens had higher feed intake and produced heavier eggs and more egg mass than light hens. However, feed and energy efficiency were better for the lighter hens.

Effects of dietary probiotic (Pediococcus acidilactici) supplementation on performance, nutrient digestibility, egg traits, egg yolk cholesterol, and fatty acid profile in laying hens

The objective of this study was to determine the effect of dietary probiotic Pediococcus acidilactici (PA) strain MA18/5M on performance, egg traits, egg cholesterol content, and fatty acid composition in laying hens during a 24-wk period. A total of 222 Hy-Line Brown laying hens, 22 wk of age, were divided into 3 treatment groups. Control group (C) hens were fed a basal diet with no probiotic added. In group PA1, the basal diet was supplemented with PA at 100 mg.kg(-1) of feed for the first 12 wk and 50 mg.kg(-1) feed for the next 12 wk, whereas treatment PA2 was supplemented with 100 mg.kg(-1) feed for the whole trial period. Dietary treatments did not significantly affect the BW, feed intake, and egg production of hens. Pediococcus acidilactici supplementation increased egg weight (P < 0.05), eggshell thickness, eggshell relative weight, and egg specific gravity, and it improved feed efficiency ratio per kilogram of eggs (P < 0.01). Moreover, PA dietary supplementation resulted in a significant (P < 0.05) decrease in the number of broken eggs and eggs without the shell, leading to a significant (P < 0.01) reduction in the number of downgraded eggs (39% for PA1 and 52% for PA2). After 6 mo of probiotic supplementation, significant differences were also found in the fatty acid composition and cholesterol content of egg yolk. The yolk cholesterol content, regardless of PA dose, decreased by more than 10%. The concentrations of total polyunsaturated fatty acids, including linoleic acid and linolenic acid, were significantly higher in treatment PA2 (6.5% increase) than in C and PA1. In conclusion, dietary supplementation of Pediococcus acidilactici MA 18/5M at 100 mg.kg(-1) has potential commercial applications for improvements in hen performance and eggshell quality during the early laying period.

Nutritional levels of digestible methionine + cystine to brown-egg laying hens from 50 to 66 weeks of age

The objective of this study was to determine the requirement of digestible methionine + cystine of brown-eggs laying hens from 50 to 66 weeks age at the end of the first production cycle. The design was completely randomized, with 150 Brown Shaver hens, which were distributed in five treatments with six replications of five birds each. Birds received a basal diet with 2857 kcal/kg metabolizable energy and 15.97% crude protein, supplemented with 0.132; 0.174, 0.215, 0.256 and 0.298% DL-methionine (98%), in order to provide 0.572, 0.613, 0.653, 0.693 and 0.734% digestible methionine + cystine. The levels of digestible methionine + digestible cystine followed, respectively, the relations of 67, 72, 77, 81 and 86% with lysine fixed at 0.851%. Feed intake, methionine + cystine intake, feed conversion per dozen eggs, egg weigth and mass, percentage of egg components, internal egg quality and weight gain were evaluated. Methionine + cystine levels showed a quadratic effect on feed conversion per dozen eggs and egg weight, a linear effect on feed conversion per kilogram of eggs and percentage of albumen. There was also a positive linear effect on yolk percentage. The methionine + cystine requirement was estimated at 0.572%, corresponding to 682 mg of digestible methionine + cystine/bird/day.

Effect of crude protein and fat content of diet on productive performance and egg quality traits of brown egg-laying hens with different initial body weight

A trial was conducted to study the influence of CP and fat content of the diet on performance and egg quality traits of brown egg-laying hens from 22 to 50 wk of age. The experiment was conducted as a completely randomized design with 8 treatments arranged factorially with 4 diets and 2 initial BW of the hens (1,592 vs. 1,860 g). Three of these diets differed in the CP content (16.5, 17.5, and 18.5%) and included 1.8% added fat. The fourth diet also had 18.5% CP but was supplemented with 3.6% fat instead of 1.8% fat. Each treatment was replicated 4 times, and the experimental unit consisted of 21 hens allocated into groups of 7 in 3 adjacent cages. All diets were isocaloric (2,750 kcal of AME/kg) and met the recommendations of brown egg-laying hens for digestible Arg, Ile, Lys, Met, Thr, Trp, TSAA, and Val. Productive performance and egg quality were recorded by replicate every 28 d. For the entire experimental period, diet did not affect any of the productive performance traits studied, but the heavier hens had higher ADFI (120.6 vs. 113.9 g; P < 0.001), egg production (92.5 vs. 89.8%; P < 0.01), and egg weight (64.9 vs. 62.4 g; P < 0.001) than the lighter hens. Initial BW did not affect feed conversion per kilogram of eggs or hen mortality, but BW gain was higher (289 vs. 233 g; P < 0.01) and feed conversion ratio per dozen of eggs was better (1.52 vs. 1.57; P < 0.01) for the lighter than for the heavier hens. None of the egg quality variables studied was affected by dietary treatment or initial BW of the hens. It is concluded that brown egg-laying hens, irrespective of their initial BW, do not need more than 16.5% CP to maximize egg production, provided that the diet meets the requirements for key indispensable amino acids. Heavier hens produce more eggs that are larger than lighter hens but feed efficiency per kilogram of eggs is not affected.

Evaluation of the possibility of using oligosaccharide-free pea in Japanese quail nutrition

In this paper, evaluation of the effect of processed pea seeds (free of raffinose family oligosaccharides) on the performance traits and the results of reproduction in Japanese quails is presented. A flock of 72 quails was divided into 3 groups consisting of equal numbers of birds (18 females and 6 males). Birds were kept in cages in an environmentally controlled room with a lighting cycle of 17 h of light and 7 h of dark, and they were fed 1 of 3 different diets. Whereas diet 1 served as the control, diet 2 was supplemented with 5% and diet 3 with 10% peas (cultivar Piast) from which oligosaccharides were removed. Feed consumption in the experimental groups was similar and at the same time significantly higher than that in the control group. Significant improvement of feed conversion ratio per 1 egg was found in the group fed with feed mixture containing 5% oligosaccharide-free pea. Lower feed conversion per kilogram of eggs was also observed in both experimental groups fed with pea diet. The use of processed pea (without oligosaccharides) in feed had a favourable effect on laying performance. Better production results were achieved in group 2 fed with feed containing 5% pea in the feed mixture, whereas in group 3 (10% oligosaccharide-free peas) the highest egg weight was found. The other egg quality traits analysed were similar and did not differ significantly irrespective of the type of applied diet. Introduction of oligosaccharide-free pea to quail diet in the amounts of 5% and 10% favourably influenced quail fertilisation rates. Improvement of the hatchability from fertilised eggs was also observed, in particular in the group fed with fodder containing 5% processed pea.

GLUTAMINA NA DIETA DE POEDEIRAS LEVES SUBMETIDAS AO ESTRESSE PELO CALOR E À TERMONEUTRALIDADE

The aim of this study was to evaluate the effect of glutamine supplementation of the diet on intestinal mucosa morphology, performance, and egg quality of commercial laying hens, submitted to heat stress and thermoneutral conditions. In this study, 96 (Isa Babcock) laying hens at 35 weeks of age were used and distributed in a completely randomized design according to a 2x2 factorial arrangement, with two levels of ambient temperature (thermoneutral and hot) and two levels of glutamine in the diet (0.0 and 1.0% of inclusion), in 6 replicates of 4 hens per box. Feed intake, daily egg production, feed conversion per kilogram of eggs, and egg quality were obtained in two periods of 28 days each. Heat stress decreased egg production and quality, and glutamine supplementation improved egg quality and feed conversion. The heat and glutamine supplementation provided an increase in calliciform cells quantity in duodenum and ileum, respectively. Significant morphological modifications in the intestinal mucosa of laying hens were not found. KEYWORDS: egg quality; glutamine; intestinal morphology; thermal stress.

Effects of Energy and Protein Supplementation on the Production and Economic Efficiency of Scavenging Improved (Tamhoang) and Local (Ri) Breed Hens under Smallholder Conditions in North Vietnam

The objectives of this study were to evaluate the effects of supplementing maize meal and soybean meal, separately or mixed, on egg production performance of two breeds of scavenging hens under on-farm conditions. Treatments were: (1) confined, with a mixed feed (75% maize meal and 25% soybean meal) ad libitum (CMF); (2) scavenging, with a supplement of 60 g/bird per day of maize meal (ScM); (3) scavenging, with a supplement of 25 g/bird per day of soybean meal (ScS); (4) scavenging, with 54 g/ bird per day of the mixed feed (ScMF). Mean hen-day production was 21.8%, 19.8%, 17.7% and 22.8% for the CMF, ScM, ScS and ScMF treatments, respectively (p <0.05), and was significantly (p <0.001) higher for the improved Tamhoang breed (24.4%) than for the local Ri hens (16.7%). Mean egg weight was significantly higher for the Tamhoang (53.2 g) compared to the Ri hens (45.0 g) (p<0.01). Feed consumption per kilogram of eggs was significantly higher for the CMF treatment compared to the other treatments and was lower for the ScS compared to the other scavenging treatments (p <0.05). Feed cost per kilogram of eggs was lowest for the ScM treatment and was 30 to 40% higher for the confined treatment compared to the scavenging treatments. Feed consumption and cost of feed per kilogram of eggs were significantly lower for the Tamhoang than for the Ri hens.

Laying hen productivity as affected by energy, supplemental fat, and linoleic acid concentration of the diet

A trial using 720 Isabrown hens was conducted to determine the influence of energy (AMEn), supplemental fat (SFAT), and linolenic acid (LIN) concentration of the diet on performance and weight of eggs and egg components throughout the laying cycle (22 to 65 wk of age). There were six treatments whose calculated AMEn, SFAT, and LIN content were, respectively: 1) 2,810 kcal/kg, 0%, 1.15%; 2) 2,810 kcal/kg, 4%, 1.15%; 3) 2,810 kcal/kg, 4%, 1.65%; 4) 2,680 kcal/kg, 0%, 1.15%; 5) 2,680 kcal/kg, 4%, 1.15%; and 6) 2,680 kcal/kg, 4%, and 1.65%. All diets were formulated to have the same crude protein, lysine, TSAA, calcium, and nonphytin phosphorus levels per kilocalorie of AMEn. The data were analyzed with SFAT constant (4%) and AMEn, and LIN variables (Diets 2, 3, 5, and 6) and with LIN constant (1.15%) and AMEn and SFAT variables (Diets 1, 2, 4, and 5). When LIN was maintained at a constant of 1.15%, an increase in the AMEn of the diets from 2,680 to 2,810 kcal/kg decreased feed intake by 4% (P < 0.001). Increasing AMEn also improved feed conversion per dozen eggs and per kilogram of eggs by 4.9 and 4.7% (P < 0.05), respectively, and increased BW gain by 55.7% (P < 0.05). Egg production rate, egg weight, egg mass output, and energy intake were not modified by treatments. An increase in SFAT within both energy levels from 0 to 4% improved all of the traits studied except feed conversion. Supplemental fat increased both yolk and albumen weight, but the effect was more pronounced on the latter. When SFAT was maintained constant at 4%, an increase in AMEn of the diets decreased feed intake and improved feed conversion per dozen and per kilogram of eggs by 5.7, 5.5, and 5.2%, respectively (P < 0.001). An increase in LIN content from 1.15 to 1.65% did not modify any of the parameters studied. The results indicate that SFAT consistently improves productivity of hens and egg weight and that the LIN requirement for maximal productivity is 1.15% or less. The beneficial effects of adding SFAT to diets containing more than 1.15% LIN are due to the fat itself rather than to an increase in LIN or AMEn of the diet.

International Comparison of Egg Production Cost and Marketing Margin-A Study of 15 Selected Countries.

The present study examined the production cost factors and marketing margin involved in producing eggs in the surveyed countries. In this study the egg production cost is defined as the total of the direct costs (feed and chick) and indirect costs (labor, machinery & implement, building, power and medicine). Marketing margin is considered as the difference between egg retail price and producer price. The cost of production for eggs varies widely around the world and the feed cost is the single most important factor among them followed by labor and bird depreciation cost. The objectives of this study are; to analyze the different cost factors affecting the production of a kilogram of eggs; to compare the marketing margin from producer to retailer. In order to fulfill the objectives, 15 selected countries around the world were surveyed during 1996. Data were collected based on different cost factors as well as producer and retailer prices for the respective countries.It is evident from the study that grain producing countries like USA, Brazil, China and India had a considerably low cost in producing eggs. Other developing countries, even though not considered as grain producers, had a lower cost due to cheap labor and low chick cost. Countries such as Netherlands and UK where technical standards are similar to United States, have high production cost due to the high competitive cost of feed and labor. The surveyed countries were divided into high cost, medium cost and low cost according to the cost of production levels. With the favorable trade in the future, world egg production will expand and may concentrate in areas where the low cost feed grains are available. China will continue to be the largest egg producer in the world and its export potential is high especially since the opening of new markets with the annexation of Hong Kong. India and Brazil too have tremendous future potential with the large consumer market and increasing household income. Egg trade will continue to improve within the respective regions and therefore the share of major exporters like Netherlands will have a reduction of its export to Asia as well as within the EU countries.

PERFORMANCE OF LAYING HENS FED DIETS CONTAINING SOYBEAN GUMS, RAPESEED GUMS OR RAPESEED MEALS WITH AND WITHOUT GUMS

Two experiments were conducted to study the effect of soybean and/or rapeseed gums (SBG and/or RSG) on general performance and mortality of laying hens. In exp. 1 a total of 1824 SCWL hens of two commercial genotypes (912 of each) were fed a corn-soy-based control diet or this diet to which was added 2.0% be weight of either SBG or RSG. In exp. 2, 1824 hens of the more sensitive genotype used in exp. 1 were fed a control diet or diets containing approximately 15% of gummed and gumless Tower and Candle rapeseed mean (RSM) or gumless Tower RSM to which was added 3.33% Candle gums. The addition of SBG and RS3 to the diet (exp. 1) caused a significant increase in mortality, increased the amount of feed required to produce a kilogram of eggs, and decreased heart and liver weights. Feeding RSM with and without the commercial level (2.0% of the RSM, or in this study 0.3% of the diet) of added gums had no effect on body weight or egg weight. Hen-housed egg production and feed per dozen eggs were significantly depressed by feeding Candle RSM with gums and by feeding gumless Tower RSM to which had been added Candle gums, indicating that Candle gums but not Tower gums are deleterious to laying hens even at the commercial level of addition to RSM. Accumulated mortality to 497d was significantly higher for all groups fed RSM with or without gums compared to the control-fed group. The increase in mortality with this sensitive genotype appeared to be related to the mere presence of RSM in the diet and not due to the presence of gums per se. The major cause of mortality in both experiments was diagnosed as fatty liver syndrome, and from results of exp. 2 appeared to be related to the presence of RSM in the diet and not due to the presence of gums.

Urea and Diammonium Citrate for Laying Hens

In two experiments, urea, diammonium citrate (DAC), and soybean meal were added at 2 or 4% protein equivalent to a basal 10.14% protein ration. In the first experiment, crystalline amino acids were added to equal the levels supplied by a 14.14% protein corn-soybean meal ration or the National Research Council (1966) recommended levels, whichever were higher. No attempt was made to equalize amino acids in the second experiment.Egg weight, egg production, feed consumption, and feed consumption per kilogram of eggs were significantly better when the basal diet was supplemented by additional soybean meal than when urea or DAC were added. Urea and DAC were both equally inferior to soybean meal. Addition of 4% protein from soybean meal did not result in significant improvements compared with 2% protein supplementation from the same source.Serum total nitrogen and protein nitrogen concentrations paralleled the pattern of production data and were greater in serum of hens fed soybean meal diets. Serum uric acid was not significantly affected by diets. Haugh unit and shell thickness were not affected by urea- and DAC-supplementation.

Studies on the Feeding Program for Growing Egg-Type Pullet

Collaborative experiments at 6 Perfectural Poultry Experiment Stations with 1, 400 White Leghorn pullets were carried out to study the effect of regulation of body weight and egg production by restricting the daily feed supply. Feed supply was so restricted that 80, 70 or 60% level fo that of control pullets fed ad libitum at each of the Stations. After 20 weeks, all the pullets were fnll-ted the layer diet.1. Average intake of feed of the pullets fed ad libitum was 7.8kg and those of pullets fed 80, 70 and 60% diet were 6.4kg, 5.6kg and 4.5kg, respectively.Body weight gains of the pullets at 20 weeks of age were found to be linear, being lower in obedience to restrictive extent. The difference in body weight among the groups was shown even at 68 weeks of age.2. Sexual maturity of the pullets was delayed and the weight of the 1st egg was heavier in obedience to restrictive extent, although the first egg weight of the restrictive grops was not heavier than that of the control at the identical age.3. The quantity of egg production of each restrictive group for the period from 20 to 68 weeks of age was smaller than that of the control, and the difference of quantity nearly corresponded to that of the egg production during 20 to 32 weeks of age.4. Kilograms of feed per kilogram of eggs of 60% restrictive group for entire period was the lowest among those of the other groups, the difference being significant at 5% lovel between 60% and 80% restrictive groups.5. It was suggested that either the pragram of 70%-restrict feeding or of full feeding is the most economic for growing egg-type pullets,