Acidification of the drinking water has become very popular in the broiler industry as a tool for improving bird performance. However, little is known about the exact effects of water acidification on weight gains, feed conversion efficiency and livability for turkey production. In addition, little documentation exists which compares different drinking water pH adjustment products for turkeys. Therefore a trial was conducted to determine how turkeys respond to different products used to adjust the drinking water pH.
Materials and Methods
Nine hundred and sixty turkey hen poults (day-old) were randomly placed in 48 floor pens to give 20 birds/pen and six replications per treatment. Each pen was equipped with one hanging tube feeder and a water plasson. Each pen had its own water supply via a 5 gallon sealed bucket. Plassons were cleaned every day and water usage was measured for the first 28 days. This measurement involved accounting for the water added to each pen as well as the water removed each time the plassons were cleaned. Seven treatments were compared to a control (Fayetteville city water). The treatments (outlined in Table 1) included PWT (Jones-Hamilton Co., Walbridge, OH) added to the control water to an adjusted pH of 4 and 6, I.D. Russell Citric Acid (Alpharma, Fort Lee, NJ) added to the water to adjust the pH to 4 and 6, Dri Vinegar (BVS, (Willmar, MN)) added to the water to adjust the pH to 6, Acid Sol (BVS, Willmar, MN)) added to the water to adjust the pH to 6 and Ema-Sol (Alpharma, Fort Lee, NJ) added to the water to adjust the pH to 4. Each solution was prepared in a 50 gallon container and then dispersed to the corresponding replicate pens. Each container was filled with Fayetteville city water and allowed to sit over night to allow residual chlorine to dissipate. Prior to the preparation of each solution a hand-held pH meter was first standardized using pH 4, 7 and 10 buffer solutions. The pH was continuously checked as each solution was slowly mixed to the desired pH. To enhance the dissolving of the dry products, PWT and citric acid, concentrated stock solutions of each was prepared in room temperature water. This concentrated solution was slowly stirred into the appropriate treatment container until the desired pH was achieved. Fresh solutions were made at lease twice weekly and more frequently during the last four weeks of the trial. The pH was verified and recorded, as each batch was prepared. All water and feed added to the pens was weighed. Birds received a commercial diet regime supplied by Cargill. Diets were changed every two weeks.
The birds were group weighed by pen at day 1 and then individually weighed on days 14, 28, 42, 56, 70 and 84. Feed consumption was measured for each period. Pens were checked twice daily for mortality. The weight of all dead and cull birds was recorded for use in determining an adjusted feed conversion rate. At week six and twelve, one bird per pen was weighed and sacrificed by suffocation with carbon dioxide. The pH of the crop and gizzard was measured by emptying approximately 20 grams if the contents and blending with an equal amount of distilled, de-ionized water. Results were analyzed using the GLM procedure of SAS. Pens served as the experimental unit. The mortality percentage data was transformed using square root transformation to normalize the distribution. All means which were statistically significant at the P<. 05 level were separated using the repeated t-test. The feed-conversion rates were calculated as cumulative values. The mortality was calculated for each weigh period.
The average body weights of the hens are shown in Table 2. At day 14 the hens receiving the Acid Sol were significantly heavier and the hens receiving the Ema-Sol adjusted to a pH of 4 were significantly lighter than all of the birds receiving the other treatments and the control water. At this time the decision was made to raise the Ema-Sol treatment pH to 6. By day 28 there were no significant differences in body weight and this trend remained throughout the remainder of the trial. Though not significant, the hens receiving the Ema-Sol water lagged behind slightly in weight through day 56 but by day 70 the Ema-Sol birds had similar body weights to the other treatments. Again while not significant, it is interesting to note that the birds receiving the PWT 4, Citric acid 4 or Dri Vinegar 6 treatments had the highest numerical body weights at day 84. No statistical differences were seen for feed conversions for any of the periods measured (Table 3). Birds receiving the Ema-Sol treatment had a significantly higher mortality rate for the first fourteen days. However, overall mortality remained very low and after fourteen days there were no additional losses of Ema-Sol birds until day 56 (Table 4).
Water usage was measured through day 28. However, since the drinkers were plasson and were cleaned daily, this measurement can only be considered an estimation of water usage (Table 5). For the first fourteen days water usage for the Ema-Sol birds significantly lagged behind all other treatments. This trend continued through day 28 and even after raising the Ema-Sol treatment pH to 6 the birds receiving this treatment still lagged slightly behind in consumption. At the time that the pH of the gizzard and crop contents were to be measured, only a small amount of dry material was found in these organs, so an equal weight of distilled de-ionized water (pH 6.68) was added to each sample (Table 6.). While this addition probably influences final pH, the same amount of water added to each sample so that the effect would be the same across all treatments. As seen in the broiler trial, the pH of the gizzard was in the 3 to low 4 range while the crop pH was higher but did not necessarily reflect the pH of the water treatments.
The results of this trial indicate that lowering the pH of the drinking water with PWT, citric acid, Dri vinegar, Acid Sol and Ema-Sol resulted in turkey hen performance similar to the birds receiving the control water. Starting the poults on Ema-Sol adjusted to a pH of 4 resulted in a significantly higher mortality and reduced weights through day 14. The pH of the Ema-Sol treatment was then raised to 6 for the remainder of the trial and the birds had final weights statistically similar to the birds receiving the other treatments.