Body Weight Of Hens Research Articles

Effect of Dietary Fat Type on Broiler Breeder Performance and Hatching Egg Characteristics

SUMMARY The effect of dietary fat type on broiler breeder performance was evaluated in the experiment. Three different fat sources (sunflower oil, fish oil, tallow) were supplemented into a corn-soybean meal-based broiler breeder diet. The control diet included no supplemental fat. All diets were isocaloric and isonitrogenous. Feeding of experimental diets was initiated when breeders (Ross 508) were 22 wk old. Body weights of hens and males were not affected by dietary treatments during the experimental period. Tallow supplementation to breeder diet significantly decreased hen-day egg production and cumulative settable egg yield (P < 0.01) when compared with other treatments. Hens fed with tallow and sunflower oil-added diets produced significantly heavier settable eggs than control and fish oil treatments. However, settable egg weight of hens fed with fish oil was lower than other dietary treatments (P < 0.01). Egg yolk weight, albumen weight, and eggshell weight were not affected by dietary treatments. These data suggest that supplementation of different fat sources at a level of 1.5% to the corn-soybean meal diet may affect egg production performance, fertility, egg weight, chick weight, hatch of eggs set, and specific gravity without any adverse effects on body weight and settable egg characteristics.

Effect of rooibos tea (Aspalathus linearis) on Japanese quail growth, egg production and plasma metabolites

1. Birds have been proposed as a suitable model for studies on ageing because of their long life in comparison with similar-sized mammals. However, some weak fliers, such as Galliformes, are the exception to this rule. The aim of the present study was to determine the effects of the treatment with rooibos tea (Aspalathus linearis), a natural source of flavonoid antioxidants and compounds with phyto-oestrogenic activity, on postnatal development and egg production of aged Japanese quail (Coturnix coturnix japonica). 2. Substitution of drinking water with traditional rooibos tea or diet supplementation with ground rooibos tea affected body weight of Japanese quail up to 100 d of age. The body weight of males drinking rooibos tea or eating rooibos-supplemented food decreased significantly. There was a trend toward increased body weight of tea drinking females and a significant increase in the body weight of hens fed the rooibos-supplemented diet. Although rooibos treatment did not significantly increase egg production in young hens, the decrease in egg production of rooibos-treated aged hens (360 d of age) was significantly reduced, regardless of the egg production levels (high—80%; low—20%) before the treatment. 3. The results suggest that treatment with rooibos tea positively affected body weight and egg production in quail hens and prolonged the productive period of aged animals. Further studies would be needed to address the question whether these effects are due to the antioxidant or phyto-oestrogenic activities of rooibos.

Nickel induced alteration of hen body weight, egg production and egg quality after an experimental peroral administration

In this study the effects of nickel (NiCl2) administered in drinking water (0.02; 0.2 and 2.0 mg NiCl2/L for 28 days) on laying hen body weight, egg production and egg quality is reported. Growth parameters during the experiment were significantly decreased mainly in the group with the highest nickel concentration. In total egg production dose–dependent decrease in all experimental groups was found. Egg weight was mainly affected in the group with the highest nickel concentration. Specific egg weight was not altered. Albumen weight and albumen content was significantly decreased in groups with the highest nickel concentration in comparison with the control group. Egg yolk analysis detected significantly decreased yolk weight in the group with the highest nickel experimental level. In yolk color a significant difference was detected between the group receiving 0.02 and 0.2 mg NiCl2/mL. Eggshell compactness was increased in all experimental groups what could be induced by altered mineralization of eggshell. Results of this study clearly report a negative effect of nickel as an environmental pollutant on laying hen body weight, egg production as well as egg quality.

The Influence of Stocking Density on Body Weight, Egg Weight, and Feed Intake of Adult Broiler Breeder Hens

The influence of stocking density on BW, egg weight (EW), and feed intake (FI) in Ross broiler breeder hens (n = 120) was investigated during the late medium egg production period (from 50 to 54 wk of age). Birds were randomly allocated to 6 pens in densities of 15, 20, and 25 birds/pen, giving rise to a floor space allowance of 5, 6.67, and 8.33 birds/m(2), respectively. Each density was replicated twice, and the order among the 6 pens was chosen at random. Data were analyzed using the repeated measures techniques of the Statistical Analysis System, considering the covariance structure of the observed data. There was a significant effect attributable to stocking density, time (in days), and their interaction for BW, EW, and FI. Birds in density of 6.67 per m(2) were lighter but had heavier eggs than birds in density of 5 per m(2); however, birds in density of 8.33 per m(2) had similar BW and EW with birds in the other 2 groups. The mean FI were statistically different among the 3 groups, with a reduction in FI as density increases. Total egg production within the 3 density groups and average egg production per bird were also analyzed using categorical data techniques. The results indicated that stocking density influenced egg production, with birds at higher density producing fewer eggs per bird. Although generous floor space allowances were allocated per bird in this experiment, stocking density influenced the performance of broiler breeder hens.

Cumin seed meal as an alternative to wheat bran in commercial laying hen diets

AbstractTo evaluate the nutritional significance of cumin seed meal (CSM) as a commercial poultry feedstuff on laying hen performance and quality of laid eggs, an experiment was conducted using 144 (48‐week‐old) laying hens receiving diets containing 0, 25 and 50 g CSM kg−1 with or without polyethylene glycol (PEG 6000) and xylanase enzyme (Grindazym™ GP 15000) for 9 weeks. Body weight on the first and last days of the experiment and daily egg production and egg weight and weekly feed intake during the first, fifth and ninth weeks of the experiment were recorded. Shell weight, shell thickness, Haugh unit and yolk colour were measured during the last week of the experiment. The results showed that inclusion of CSM in laying hen diets had no negative influence on the parameters measured compared with the control diet (P &gt; 0.05), but enhanced egg yolk colour (P &lt; 0.05). PEG increased the daily feed intake of birds receiving CSM diets (P &lt; 0.01) and tended to enhance daily egg production and egg weight, although not significantly. Grindazym decreased shell weight and thickness of laid eggs (P &lt; 0.05) and tended to increase hen body weight, but had no influence on other parameters measured. The results demonstrated that CSM can be substituted for wheat bran in layer diets at 25 or 50 g kg−1 dietary inclusion level without any adverse effect on hen performance or egg quality, and might enhance egg yolk colour. In view of the low price of CSM, it could be concluded that inclusion of CSM in the diet might be beneficial to the commercial laying hen industry and reduce the overall cost of egg production. Copyright © 2006 Society of Chemical Industry

Diseases of indigenous chickens in Bokaa village, Kgatleng district, Botswana

This study examined flock size and management, level of internal and external parasite burden and seroprevalence of antibodies to poultry pathogens in indigenous chickens in Bokaa village, Kgatleng district, Botswana. The mean flock size was 22.6 +/- 6.85 with a range of 11-34. The mean body weights of cocks and hens were 2.28 +/- 0.56 kg and 1.70 +/- 0.38 kg, respectively. Housing and commercial poultry feed were not provided. Ascaridia galli, Heterakis gallinarum and Syngamus trachea were found in some birds. Although the chickens were not vaccinated against any poultry diseases, serum antibodies to Newcastle disease, infectious bursal disease and infectious bronchitis were detected.

Lipid Composition of Egg Yolk and Serum in Laying Hens Fed Diets Containing Black Cumin (Nigella sativa)

Laying hens were fed diets without or with 10 or 30 g of the whole seed of black cumin (Nigella sativa)/kg. The concentrations of total lipids, total cholesterol, phospholipids and triacylglycerols in serum and egg yolk were measured. Feeding of the diets with 1 and 3% black cumin seeds for a period of three months reduced egg yolk total cholesterol by 34 and 42%, respectively. Serum cholesterol concentrations averaged for the whole feeding period were lowered by 15 and 23% after feeding the diets with 1 and 3% black cumin seeds, respectively. Black cumin seeds in the diet of laying hens also caused a lowering of serum and egg-yolk concentrations of triacylglycer ols and phospholipids. Inclusion of black cumin seeds in the diet caused a significant reduction in egg production, without any effect on egg width and length, while there was a significant increase in hen's body weight. The increase in body weight in the hens fed black cumin seeds is explained by the ingested feed energy not used for egg production. It is concluded that black cumin seeds and/or the active principle are of interest as potential egg-yolk cholesterol-lowering agents.

Effects of Dietary Zinc Supplementation on Hen Performance, Ammonia Volatilization, and Nitrogen Retention in Manure

This investigation was undertaken to evaluate the effects of dietary ZnSO4 supplementation on ammonia volatilization and nitrogen retention in hen manure. One hundred twenty, 45-wk-old commercial Leghorn laying hens were sequentially fed diets with 1000, 2000, and 3000 ppm Zn as ZnSO4 (Zn-1000, Zn-2000, and Zn-3000), then followed by two control dietary periods with 114 ppm Zn (Control-1 and Control-2) for a total of five consecutive eight-day experiment periods, respectively. When hens were fed the 1000 and 2000 ppm Zn treatment diets, room ammonia levels were significantly reduced compared to the control diets. Dietary Zn treatments reduced the decomposition of uric acid, resulting in an increase in manure total-N retention compared to the control fed birds. The 1000 ppm Zn supplement had no adverse effects on hen body weight, feed consumption, egg production, egg weight, albumen height, or shell thickness. However, hens fed the diet containing 3000 ppm Zn had significantly depressed body weight, feed consumption, egg production, egg weight, and shell thickness. Zinc levels of egg contents increased linearly as dietary Zn levels increased. These levels in eggs would not be a problem for human consumption because these are much less than the daily Zn recommended dietary allowance. Although land application of such manure will not cause environmental problems or crop toxicity, proper monitoring of soil and crop Zn levels and effective nutrient management planning would be well advised.

Performance Comparison and Nutritional Requirements of Five Commercial Layer Strains in Phase IV

Five commercial white egg layer strains (Current-Bovans, Older-Bovans, Oldest-Bovans, Experimental-Bovans, and Dekalb) were used to compare performance and nutrient requirements when fed three protein levels (16.00, 14.85 and 13.99%). There were eight replicates of 15 hens (67 wk of age) for each treatment and the trial lasted 10 weeks. The results showed that there were no interactions between protein and strain on feed intake, egg production, egg mass, egg weight, feed conversion, egg specific gravity, and body weight of hens. Protein had significant effects on feed intake, egg mass, egg weight, egg specific gravity, and body weight. There were significant strain effects on feed intake, egg production, egg mass, egg weight, feed conversion and egg specific gravity. Current-Bovans had the best overall performance among the five layer strains. However, Dekalb had significant higher egg weight compared to Bovans. The best performance of Current-Bovans and Dekalb was obtained with hens fed the diet containing 16.00% protein. Current-Bovans hens required 16.5 g protein, 640 mg TSAA, 856 mg lysine, and 296 kcal ME per hen daily or 0.31 g protein, 12.00 mg TSAA, 16.07 mg lysine, and 5.55 kcal ME per g egg for the best performance. Dekalb hens required 17.8 g protein, 691 mg TSAA, 925 mg lysine, and 319 kcal ME per hen daily or 0.34 g protein, 13.04 mg TSAA, 17.45 mg lysine, and 6.03 kcal ME per g egg for the best performance.

FEEDING LOW CALCIUM AND ZINC MOLT DIETS SUSTAINS GASTROINTESTINAL FERMENTATION AND LIMITS SALMONELLA ENTERICA SEROVAR ENTERITIDIS COLONIZATION IN LAYING HENS

ABSTRACT The objective of these experiments was to determine whether alternative molting diets would minimize Salmonella enterica serovar Entertitidis (S. Enteritidis) colonization in molting hens. Hens were randomly assigned to four treatment groups of 12 hens either full‐fed (nonmolt, NM), molted by feed withdrawal (molt, M), a low calcium (LC containing 800 mg calcium), or LC diet supplemented with 110 mg zinc/ kg of diet (LC‐ZN) in two trials. All hens were challenged orally with 10 5SE on day 4 of experiment. Hen body weight loss was significantly (P &lt; 0.05) increased and ovarian weight was significantly (P &lt; 0.05) decreased in hens fed the LC or LC‐ZN diets compared to NM. Cecal lactic acid concentrations were significantly (P &lt; 0.05) increased in hens fed alternative molting diets. Feed withdrawal molted hens exhibited significantly (P &lt; 0.05) more S. Enteritidis positive and S. Enteritidis crop, cecal, and organ colonization than NM, LC and LC‐ZN hens. Alternative molt diets retain sufficient fermentative activity to limit S. Enteritidis colonization and therefore may have potential to avoid the risk of increasing S. Enteritidis colonization associated with feed withdrawal.

Defective eggs and their relationship to egg yield, egg and body weight in hens of five original laying lines

We investigated 3 985 individually housed hens of five original laying lines of two breeds RIR and BPR. The proportion of abnormal eggs out of the eggs laid before the age of 240 days ranged between 7.0% and 9.7%, in dependence on the line. The average number of cracked eggs ranged between 2.5% and 4.4%, double-yolk eggs between 2.2% and 3.0% and shell-less eggs between 2.0% and 2.7%. The correlation between the number of eggs laid at the beginning of the laying period and during the period of observation, and the frequency of double-yolk eggs was positive (r&lt;sub&gt;P &lt;/sub&gt;= 0.00 to r&lt;sub&gt;P &lt;/sub&gt;= 0.21) and mostly statistically highly significant (P &amp;lt; 0.01). On the other hand, statistically highly significant negative correlations (P &amp;lt; 0.01) were found between the number of eggs laid during the period of observation and the frequency of cracked eggs, where the correlations in the individual lines ranged between r&lt;sub&gt;P &lt;/sub&gt;= &amp;ndash;0.04 and r&lt;sub&gt;P &lt;/sub&gt;= &amp;ndash;0.23. Positive correlations, mostly statistically highly significant (P &amp;lt; 0.01), were found between the number of eggs laid during the period of observation and the frequency of shell-less eggs (r&lt;sub&gt;P &lt;/sub&gt;= 0.00 to r&lt;sub&gt;P &lt;/sub&gt;= 0.15). With the increasing weight of eggs the frequency of abnormal eggs also increased, in particular of double-yolk eggs (r&lt;sub&gt;P &lt;/sub&gt;= 0.08 to r&lt;sub&gt;p&lt;/sub&gt;= 0.32), for the most part statistically highly significantly (P &amp;lt; 0.01). The correlations between the individual types of abnormal eggs were positive. Statistically highly significant correlations (P &amp;lt; 0.01) were discovered between the frequency of double-yolk eggs and cracked eggs (r&lt;sub&gt;P &lt;/sub&gt;= &amp;ndash;0.02 to r&lt;sub&gt;p&lt;/sub&gt;= 0.22) on the one hand and, between double-yolk eggs and shell-less eggs (r&lt;sub&gt;P &lt;/sub&gt;= 0.16 to r&lt;sub&gt;P &lt;/sub&gt;= 0.24) on the other. &amp;nbsp;

Efficacy of high available phosphorus corn in laying hen diets

Our objective was to determine if high available phosphorus corn would provide sufficient available phosphorus (AP) to laying hens fed corn-soybean meal diets from 57 to 69 wk of age. Six replications of 12 Dekalb Sigma Leghorn hens were fed a normal yellow dent (YD) corn-soybean meal diet or high available phosphorus (HAP) corn-soybean meal diet without and with 0.04% supplemental inorganic P. The unsupplemented YD diet was calculated to contain 17% CP, 3.8% Ca, and 0.10% AP, and the unsupplemented HAP diet contained 17% CP, 3.8% Ca, and 0.16% AP. In addition, a positive control, YD diet (17% CP, 3.8% Ca, 0.45% AP) was also fed. The HAP corn was directly substituted for YD on a weight basis, and the amount of soybean meal was kept constant in all diets. Egg production, hen body weight, egg weight, egg mass, feed consumption, and feed efficiency were measured. The YD and the YD + 0.04% P treatments were terminated at 61 and 65 wk of age, respectively, due to severe depressions in egg production. Egg production and egg mass for hens fed HAP diets were not different (P > 0.05) from those of hens fed the 0.45% AP diet; however, hens fed the unsupplemented HAP diet did have lower hen body weights and feed intake (P < 0.05) compared to hens fed the positive control diet. Our results indicate that HAP corn contains more available P than normal YD corn and that hens can be fed HAP corn-soybean meal diets containing little or no P supplementation with only minimal effects on production performance.

Eggshell Quality and Egg Weight of Late-cycle Broiler Breeders on One or Two-stage Feeding Programs

Hess, J.B., Lien, R.J. and Berry, W.D. 2003. Eggshell quality and egg weight of late-cycle broiler breeders on one or two-stage feeding programs. J. Appl. Anim. Res., 23: 145–152. To determine effects of diet on late cycle eggshell quality, broiler breeders were provided a standard breeder feed (one stage program) or a lower protein, lower methionine, lower phosphorus, higher calcium feed (two stage program) from 45 to 65 weeks of age. Equal daily allotments of each feed were provided to 8pens of 15 hens per program. Although there was no measurable reduction in egg production in hens fed the two stage program, hen body weights did increase relative to the one stage program. The two stage program did not limit increase in egg weight. Eggshell quality variables did not decrease as much with age as expected and were not influenced by feed treatment. Under these conditions, the lower ingredient costs of the two stage program reduced feed cost with little loss in performance.

Influence of Calsporin on Commercial Leghorns

A study was conducted to determine if Calsporin (Bacillus subtilis C-3102), a direct-fed microbial (probiotic), improved performance of commercial Leghorns and eggshell quality. Hyline W36 hens (n = 1,440; age = 65 wk) in 90 groups (16 hens/group) were randomly allocated to three dietary protein levels (17.3, 16.1, and 15.0%), and three Calsporin levels (0.0, 0.003 and 0.006%) in a 3 × 3 factorial for 10 wk. A Calsporin × protein interaction was observed on egg specific gravity (SG; P < 0.01). Egg SG increased more in hens fed the higher Calsporin level than in hens fed the lower level when dietary protein was 15%. This Calsporin level effect was reversed as dietary protein was increased to 16.1%. Trends similar to that of SG were also observed on eggshell thickness. Increasing dietary protein had a beneficial effect (P < 0.001) on egg production, feed consumption, and egg weight. Addition of Calsporin to hen diets had no significant influence on feed consumption, egg production, egg weight, or body weight of hens. More research is required to optimize any potential benefit of Calsporin with respect to dietary protein on eggshell quality.

Influence of genetic selection for antibody production against sheep blood cells on energy metabolism in laying hens

Genetic selection in chickens has been utilized to enhance immune responses that may influence resistance to diseases. It is important, however, to investigate the effects of this selection on other physiological processes. Therefore, this study was conducted to determine whether selection for antibody (Ab) production against SRBC has an effect on energy metabolism. Laying hens from three lines were used in this study, two of which were selected for 15 generations for Ab response against SRBC, and the third was nonselected and randombred. The hens used were from four different groups. The first two groups were from the lines that were selected for either high (SH) or low (SL) Ab production. The second two groups were control birds (nonselected) that had either high (CH) or low (CL) Ab titers that were similar to those in the SH and SL lines, respectively. The birds were housed in climate-respiration chambers. Body weights and energy metabolism were measured. Body weights of SL hens were significantly (P < 0.05) higher than those of SH hens. However, the BW for the two nonselected groups were similar but significantly less than the SL group. Energy partitioning was similar in all groups; however, ME for maintenance for the selected groups (119 kcal x kg(-0.75 x d(-1)) was numerically, but not significantly (P < 0.09), higher than that of the nonselected groups (112 kcal x kg(-0.75) x d(-1)). These results suggest that divergent selection for Ab may result in an increase in the requirements of energy for maintenance, which is not directly related to the amount of Ab produced. Furthermore, these results support previous findings of the presence of a negative correlation between BW and the levels of Ab in selected lines.

Effects of fenfluramine on body weight, feed intake, and reproductive activities of broiler breeder hens

Inherited overfeeding and fattiness reduce laying performance in broiler breeder pullets. Although feed restriction is used to compensate for overeating and weight gain, this management practice leads to increases in BW variation, labor cost, and bird stress. Dietary supplementation of anorectic agents, such as fenfluramine, may be an alternative. Anak female prebreeder hens (19 wk of age; n = 10 per group) were treated as follows: daily oral administration of 5, 10, 20, or 40 mg DL-fenfluramine/kg BW or saline with food provided for ad libitum intake or administration of saline and feed restriction. Daily feed intake (FI), laying rate, egg composition, and BW were measured. At 40 wk of age, adipose tissue and ovary weights were measured. Fenfluramine depressed (P < 0.05) BW and FI in a dose-dependent manner, but was less effective in reducing BW than feed restriction. Suppression of FI occurred in two phases: a dynamic phase, coinciding with the rapid growth phase, during which FI declined progressively and a static phase during which FI reached a plateau at a significantly low level until the end of the experimental period. Egg production peaked first in saline-treated hens fed for ad libitum intake, but soon after started to decline. In all fenfluramine-treated and feed-restricted hens, egg production peaked 3 to 4 wk later and remained high until the end of the experiment. There were no differences in egg and egg component weights among the experimental groups. Abdominal adipose tissue weight was reduced by fenfluramine in a dose-related manner, and its weight in the group treated with the highest dose was similar to that of feed-restricted hens. In these two groups, ovarian weight was significantly higher than in the saline-treated hens fed for ad libitum intake, and a small, nonsignificant increase in ovary size was observed in groups treated with the two median doses of fenfluramine. The effect of fenfluramine on egg production was similar to that of feed restriction, but it was not dose-dependent and, thus, not directly related to its leaning effect. In broiler breeder hens, oral fenfluramine may be used for chemical feed restriction and diminution of fattiness without reducing egg production relative to manually feed-restricted hens.

Effect of induced molting in laying hens on production and immune parameters

A total of 600 commercial strain (DeKalb) Single Comb White Leghorn hens, 80 wk of age, were used in this study to determine the effects of different induced molting programs on production and immune parameters. The hens were randomly divided into four treatment groups (three experimental and one control) of 150 hens each. The hens in the first treatment group were fed a layer ration containing 20,000 ppm of zinc for 5 d, and received a reduced photoperiod of 8 h/d for 5 d (Zn group). In the second group, feed was withdrawn for 10 d, the photoperiod was reduced to 8 h/d and oyster shell and water were provided for ad libitum consumption. At Day 11, hens consumed corn and oyster shell ad libitum until Day 30 and at Day 31, hens were returned to a full feed layer ration and received 16 h of light/d [California treatment (CAL group)]. In the third treatment, light was reduced to 8 h/d, and oyster shell was provided for ad libitum consumption until Day 60. Feed and water were removed for the first 2 d and on Days 4, 6, and 8. On Days 3, 5, 7, and 9, hens were fed 45 g of feed per hen. On Day 10 until Day 60, hens were fed 90 g/hen and at Day 61, hens were returned to the layer ration ad libitum and received 16 h of light/d [on-again, off-again program (ON-OFF group)]. The last group served as controls (CONT). Body weight, egg production, egg size, internal egg quality, shell weight, and mortality were determined. Total circulating leukocytes, differential leukocyte counts, and antibody production were also measured. The results demonstrated that induced molting significantly increased egg production from 64% to 77 to 83%, Haugh units from 80.4 to 85.9 to 87.3, and shell weight from 5.3 g to 6.3 to 6.4 g when compared to CONT. The body weight of the molted hens decreased significantly to 84.8, 74.5, and 88% of the initial body weight for Zn, CAL, and ON-OFF groups, respectively. The total circulating leukocytes was significantly lower in molted hens than in CONT hens. Differential leukocyte counts were affected by all induced molting programs and the heterophil to lymphocyte ratio was significantly increased, reaching 0.61, whereas that of CONT was only 0.20. Antibody production was largely unaffected by any of the induced molting programs.

Effect of age and body weight on plasma concentrations of luteinizing hormone in turkey hens before and after photostimulation

The independent effects of age and body weight (BW) on photostimulatory response in turkey breeder hens were studied by measuring changes in plasma luteinizing hormone (LH; ng/mL) before and 3 d after photostimulation. The study was conducted with hens from two BW groups at 24–25, 27–28, and 31–32 wk of age. There was approximately a 1-kg difference in BW between groups within an age. Six hens per BW and age group were cannulated (jugular vein) and serially sampled during each of two 6-hr periods. Samples were collected at 10-min intervals. The two sampling periods were the last 6 hr of the short-day photoperiod (SD) and the same period during the third long day after photostimulation (LD). The photostimulatory response (PR) or difference between the SD and LD baseline LH concentrations was greatest in the 24–25-wk-old hens. The PR was unaffected by hen BW at any age. The baseline LH concentration during the SD photoperiod declined as hens aged. After photostimulation, baseline LH and LH peak amplitude concentrations were higher in 24–25-wk-old hens compared with the older ages. The number of LH peaks increased after photostimulation, but there were no significant effects attributable to age or BW within an age. In conclusion, the PR was affected by hen age but not hen BW or BW within a particular age.

Drinking water contaminants (arsenic, cadmium, lead, benzene, and trichloroethylene). 2. Effects on reproductive performance, egg quality, and embryo toxicity in broiler breeders

Broiler breeder hens were used to determine the effect of drinking water containing a low concentration of a chemical mixture (arsenic, 0.8 ppm; benzene, 1.3 ppm; cadmium, 5.1 ppm; lead, 6.7 ppm; and trichloroethylene, 0.65 ppm) and a high (10 times greater than the low concentration of the chemical mixture) levels of the chemical mixture. These chemicals are present in ground water near hazardous waste sites. Water consumption significantly decreased in chickens provided the high concentration of the chemical mixture, whereas feed consumption was not affected in any treatment. There was a linear relationship between increasing concentration of the chemical mixture in drinking water and decreasing body weight of hens. The low concentration of the chemical mixture significantly decreased egg production and egg weight, and increased percentage embryonic mortality. These results suggest that reproductive function in hens is sensitive to adverse effects of contaminated drinking water.

Ability of Commercial Laying Hens Producing Different Egg Outputs to Meet Their Methionine and Energy Requirements When Fed the Same Diet

An experiment was conducted to determine whether commercial laying hens with different egg outputs could meet their Met requirement when fed the same diet. Three groups of hens were selected with either low, medium, and high egg output. Body weight of hens was positively related to egg output. As egg output increased, feed consumption increased. This resulted in essentially the same amount of energy consumed per gram of egg content (EC) for all three groups. Egg weight was greatest with hens producing the greatest EC. The Met intake of hens was increased with increased EC; however, the Met per gram of EC was not different for the three groups of hens. These data indicate that the Met and energy requirements of commercial layers can be met with one feed when individual hens produce different amounts of EC.