N.A. MUSHARAF and W.M. JANSSEN

Spelderholt Centre of Poultry Research and Extension, Beekbergen, The
Netherlands.

SUMMARY

An experiment was conducted in a climate chamber to study the ef­fects of water temperature and feed density on the production characteris­tics of laying hens during heat stress. Following a preliminary period of ad­aptation, pullets at 25 weeks of age, were moved to the climate chamber and maintained at 38 °C from 8.00 Hrs to 17.00 Hrs and at 28 °C from 17.00 His to 8.00 Hrs at constant 55% relative humidity. A low density diet

• (15% C.P.; 10.54 MJ/ kg ME) was compared to a high density diet
• (25% C.P.; 12.15 MJ/ kg ME) at cool running water “C” of 7 °C and warm stagnant water “W” one °C lower than the ambient temperature in the chamber. The treatments were tested with 120 birds, arranged in 24 groups of 5 birds over 11 periods of 14 days.

Cool water and high density feed improve feed consumption, egg weight, feed efficiency and final body weight (p < 0.01). Apart from egg weight, other egg quality characteristics were not affected by water tem­perature.

INTRODUCTION

The documented effects of heat stress on the performance of laying hen include reductions in feed consumption, egg production, egg

* Department of Animal Science, Faculty of Agricultural Sciences, University of Gezira, Wad Medani, Sudan.

weight, egg shell quality and an increase in mortality (Deaton, 1983). However, as a result of decreased feed consumption, often an improve­ment in feed efficiency occurs (De Andrade, Rooler and Featherstone, 1976). Despite the fall in maintenance requirement, the energy intake is then lowered to such an extent that body weight is also reduced and considerable mortality may take place (Smith and Oliver, 1971; Musha­raf and Hassan, 1973; Sykes, 1976). the intake of all other essential nu­trients is lowered and the hen is unable to maintain production. For this reason, it is necessary to increase the concentration of essential nutrients in the diet (De Andrade et. al., 1976).

When exposed to heat stress, the fowl starts to par’, drinks more water and releases its metabolic heat through evaporatiot. . Under these conditions cool drinking may help dissipate the metabolic heat. Limited information is available on the effect of cool drinking water on the per­formance of laying hen at high temperature (Hill, 1976). Wilson and Edwards (1952) reported a decrease in body temperature of 0.4 °C with cool drinking water of 0 °C. Feed consumption was increased in two of their tests. Leeson and Summers (1975) reported-a rise in feed con­sumption and egg production when provided cool water at environmen­tal temperature of 35 °C, but this was accompanied by a considerable body weight loss. A report by Miller and Sunde (1975) explained the absence of mortality under heat stress on the basis of availability of cool drinking water to the birds. Experiments with cattle (Bianca, 1964; Lof­green, Givens, Morrison, and Bond, 1975) showed also some favoura­ble effects of cool water on these animals when kept under heat stress.

This study was undertaken to examine the effects of drinking water temperature and nutrient density on the performance of white leghorn kept under heat stress.

MATERIALS AND METHODS

Birds:

One hundred and twenty S.C. White Leghorn laying hens were used in this experiment. They were selected at 25 weeks of age from a pool of 240 pullets on the basis of equal bodyweight, egg production and

general condition.

Rousing and climate:

During a preliminary period of six weeks, prior to the experiment, temperature was gradually raised from 20 °C to 32 DC in order to adapt the birds to the experimental conditions. During the last three weeks of this preliminary period, the temperature was maintained con­stantly at 32 °C.

Following the selection, the experimental birds were housed in a cli­matic chamber (Weiss Co, Giessen, W. Germany), and randomized in 24 cages, 4 batteries of six gages each, arranged in three tiers. In the first experimental week, the temperature was gradually changed from 32 °C to the experimental condition of 38 °C between 8.00 Hrs to 17.00 Hrs and to 28 °C from 17.00 Hrs to 8.00 Hrs. The light period of 14 hours was from 4^–a.m. to 6 p.m. The relative humidity was main­tained constantly at 55%. The ambient temperature and relative humidi­ty could be maintained with an accuracy of 0.75 °C and 1.5% respec­tively. The climatic conditions were arbitrary chosen to simulate summer in central Sudan.

Water supply:

Water was offered through nipples. Half of the cages received stag­nant water as commonly used in the practice. This was the warm water with a temperature of 1 °C lower than the ambient temperature in the cli­matic chamber. The remaining cages received a running water tempera­ture of 7 8 °C. In the running Water system, the pressure of the water was slightly higher than normal, so the velocity of the running water had to be carefully controlled to enable the birds to drink. The two wa­ter systems were randomly assigned to the tiers of the four batteries. The temperatures of the two water systems was continuously recorded.

Experimental feeds:

The composition of the diets is given in table 1. Each diet was fed to 60 birds; 12 replicates, each with 5 birds per cage. Feed “A” presented the conventional laying ration used in the Sudan. Feed “B” was corn-

puted to have a higher nutrient density to cater for the expected low feed intake of about 60 g/ bird/ day recorded by Musharaf and Scheele (1978). Oyster shell was provided ad libitum in separate troughs to all birds to ensure sufficient calcium supply. Polyethylene was mixed in the diets as an indicator for determination of metabolizable energy (ME) of the diets (Janseen, Waanders and Terpstra, 1975).

All the feed was prepared at the same time before the start of the experi­ment and stored at – 20 °C. Whenever necessary, feed enough for one month was defrozen. The criteria of response were egg production, egg weight, feed consumption, feed efficiency, mortality and egg shell quality. The latter includes specific gravity, shell thickness, shell per­centage and shell weight per cm square. Specific gravity was measured by floatation in saline solution (Hamilton, 1982). Measurements of shell thickness were done by a micrometer. Daily egg production was recorded. For egg weight, average weight was determined four days per period of 14 days (Tuesdays and Fridays). Bodyweight was deter­mined at every period of 14 days. The experiment lasted 154 days i.e. 11 periods. All data were subjected to standard analysis of variance ac­cording to Snedecor and Cochran (1967).

RESULTS AND DISCUSSION

The performance of the laying hens at the end of period 2, four weeks after the start of the experiment, is shown in table 2. Feed con­sumption (g/ hen/ day) of the two warm water groups was very low. Cool water, on the other hand, caused a substantial rise in feed con­sumption, approximately 23 – 35% or 10 – 15 g/ hen/ day (p < 0.01).

The long term effects of the treatments is presented in table 3. The sustained effects of water temperature and nutrient density is well illus­trated on most parameters. Cool water and high density feed seem to improve feed consumption, egg weight, feed efficiency and final body weight (p < 0.01). Egg production (%) was not affected, but it re­mained well above 70% in all treatments, whilst it never dropped below 80% for cool water/ feed B (CB) throughout the study.

The effects of water temperature on egg quality characteristics is giv­en in table 4. Apart from the effect on egg weight, there seems to be no influence on egg quality. Four birds died during the study, two from (CA) and another two from (WB) treatment.

The results confirm the favourable effects of cool water on the per­formance of the laying birds mentioned earlier by Wilson and Edwards (1952) and Leeson and Summers (1975). It shows the need to increase

the nutrient density during summer in order to maximize egg production without losing body weight. The balance has to be maintained carefully between the extra feed ^^cts when the nutrient density is increased and the expected returns. Tit, .une applied if cool water is used in practice. Underground water is generally cooler than the ordinary tap-water and the possibility of using it with a running water system needs to be in­vestigated.

ACKNOWLEDGEMENT

The help of the staff of the nutrition and the technical departments is greatly appreciated.

REFERENCES

De Anrade, A. N., Rooler, J. C. and Featherstone, W. R. (1976). Influence of constant elevated temperature and diet on egg pro­duction and shell quality. Poultry Sci. 55: 685 – 693.

Bianca, W. (1964). Thermoregulatory responses of dehydrated Ox to drinking cold and warm water environment. Res. Vet. Sci. 5:75

Deaton, J. W. (1983). Alleniation of heat for avian egg production – A

review. World’ Poultry Sci. J. 39: 210 – 217.

Hamilton, R. M. G. (1982). Methods and factors that affect the

measurement of egg shell quality. Poultry Sci. 61: 2022 – 2039.

Hill, J. A. (1976). The water consumption of poultry. Agric. Development and advisory service. Poultry Section. Quarterly Journal Ministry of Agric. Fish. Food No. 122 “Woodthorne” Wolverhampton, U.. K

Janssen, W. M. M. A., Waanders, J. and Terpstra, K. (1975). The metabolizable energy of feedstuffs. Report No. 6275. Spelde­rholt Centre for Poultry Research and Extension, Beekbergen. The Netherland

Leeson, S. and Summers, J. D. (1975). Cool water during heat stress results in more eggs. Poultry Digest. 369 – 370.

Lofgreen, G. P., Givens, R. F., Morrison, S. R. and Bond, T. E. (1975). Effect of drinking water temperature on beef cattle per­formance. J. Anim. Sci. 40: 223.

Miller, P. C. and Sunde, M. L. (1975). The effect of precise constant and cyclic environments on shell quality and other lay performance factors with leghorn pullets. Poultry Sci. 54: 36 –46.

Musharaf, N. A. and Hassan, 0. E. M. (1973). Comparative performance of medium and light egg production strains under Sudan conditions. Sudan J. Vet. Sci. Anim. Husb. 14 (1): 5 –11.

Musharaf, N. A. and Scheele, C. W. (1978). Balance studies with laying hens under tropical conditions. Part HI Protein metabo­lism. Report 190.78 V. Nutrition Department Spelderholt In­stitute for Poultry Research, Beek Kbergen, The Netherland.

Snedecor, G. W. and Cochran, W. G. (1967). Statistical methods. 6th ed. The Iowa State University Press, Ames, IA.

Smith, A. J. and Oliver, J. (1971). Some physiological effects of high environmental temperature on the laying hen. Poultry Sci. 50: 912 – 925.

Sykes, A. H. (1976). Nutrition environment interactions in poultry. In: Nutrition and the climatic environment. (W. Haresign. H Swan and D. Lewis Eds.). London Butterworths.

Wilson, W. 0. and Edwards,. A. (1952). Response of hens during thermal stress to hydration and chilled drinking water. Amer. J. Physiol. 169: 102 – 107.

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