A2B-Lancaster Fanning, Saturday, November 18, 2000 A WINTER TEMPERATURE, was to document winter ventilation RELATIVE HUMIDITY strategies and environmental condi- AND AMMONIA CONTROL tions and relate these to bird produc- IN BROILER HOUSES: tivity. Three Pennsylvania broiler A PENNSYLVANIA houses were each monitored over CASE STUDY three complete 35-day production cycles with the goal of stimulating Eileen F. Wheeler more informed management deci- Assistant Professor sions in relation to control of broiler Environmental Control house environment. Agricultural And Biological Engineering The Study Penn State Broiler houses from one integrator company were studied to minimize R. Michael Hulet variability among houses. Three Associate Professor houses were selected which were as ditions due to uneven heat and fresh Broiler And Turkey similar to each other in size, age, a ' r distribution. An ammonia sensor Management Department type of construction, equipment was centrally located in the house. It Of Poultry Science (water and heating equipment, in was hung about one-foot off the floor Penn State particular), and litter conditions. in a wire cage suspended from the The houses contained space unit ceiling to discourage roosting, yet the Winter Ventilation heaters mounted about 40 inches off birds could get under the sensor for Cold winter weather provides the floor. Studying the same houses normal manure deposition around challenges for maintaining a com- for all three cycles was done in an at- the sensor site. Weekly data down fortable indoor environment, wheth- tempt to provide repetition of condi- loading and collection trips included er it is in our own homes or the pool- tions and results. Growers and man- hand-held instrument readings to try house. agement were interviewed to supplement and verify the electronic A healthy environmental condi- determine ventilation goals, fuel use Sta tion with economical production of practices, and general growout poli broilers is a primary ventilation goal, cies. The winter of 1997/1998 was Indoor Environment yet minimization of fuel use often unusually warm compared to aver- Conditions drives management decisions. age and affected results. Environmental data from three Birds will substitute costly feed for Data collections were primarily different flocks from one farm are fuel if conditions are too cool. Penn- electronic using small, portable sen- presented in Figures 1,2, and 3 with sylvania has relatively cold winters sors with data loggers. One set of one graph for each flock cycle. These compared to other major poultry- outdoor temperature and relative temperature (T), relative humidity producing regions that makes man- humidity sensors provided a sense of (RH), and ammonia (NH3) data agement of fuel use and ventilation the challenge faced by the environ- were measured at about 1 foot off strategies more challenging. mental control system. Inside, three the litter. For this reason, the Pennsylvania sets of temperature and relative hu- Temperature of 90 degrees Fis de- Broiler Research Program funded a midity sensors were used to desirable at litter-level for chicks dur study where the primary objective termine any variation in interior con- ing the first three days after Daily Inside/Outside RH, T & NH3 Flock 2 10° ; s * ■ c '' \ / \/ \ ri 180l 80 v '' r ( , uT y- avg T 2 &> -■ -- -y | avg RH I _.J -X---avgNH3 £ 40 . avg Outside T x b_-.r-i-. av gQ ul * deßH X 0 —I —I —I —I —I —I —I—I —I —K-l -f—I —I—+—I —I —l —l—l—| —l—l —| —| —l—|—|—|—|—l-H—H—l cooococooocooooooooDoocooooooocoaooo g>a>a>a>g>g>g>g>d>p>g>g>o>oo>g>a>C7> Date Figure 2. Flock 2 on new litter. Outside T and RH along with indoor bird-level ammo nia, T and RH. Each daily data point is an average of 3-minute interval data over a 24-hour period. | 100 x., /r v .^/V^"" >**S- cocococooooocoooqococococooocoqooooo 3)0)0)5010101010)0)0)0)0)0)010)0)0) or3'^<s®B?s^tDos3*-r r )inP:o)^ : ? ! ) toco<ofoco(oco?5<ocof0 Figure 3. Flock 3 on once-used litter. Outside T and RH along with indoor bird-level ammonia, T and RH. Each daily data point is an average of 3-minute interval data over a 24-hour period. Daily Inside/Outside RH, T & NH3 Flock 3 >" N^\ - v -.\ Date Daily Inside/Outside RH, T & NH3 Flock 1 P"\ TV/vr 7* 7i >i..-v-x-x / v V \ / \ / /\ \ / 1 80 •: - -y— V v V \\y a. V ' yC_ ■>, *6O \ A--'-'-'-'-' I- ->vgT 8 W . " \ av ® RH S’ N / / \ -X— -avgNH3 Q 40 '‘•■s.— ' avg Outside T 5 *~*^iy / *-**.***'>C±*‘ //^\ V ; I: -avg Outside RH * zo >r il o —t-H—l —l —l —l —l—l —l—l —l I—l—l—l—l—l—l—l—l—l—l—l—t—t—l—l—l—l Date Figure 1. Flock 1 on once-used litter. Outside T and RH along with indoor bird-level ammonia, T and RH. Each daily data point is an average of 1-minute interval data over a 224-hour period. I ...L, \ V- v; . . avg T avg RH -X avg NH3 avg Outside T avg Outside RH placement. Temperature is then dropped about one degree every day until 70 degrees F at market age is reached. During these three flock cy cles, temperatures at chick-level were about 82 degrees F on day 1 but the temperature increased a few de grees over the following three days. The thermostat was located at about 5 feet off the floor. Its setpoint tem perature was obviously not matching temperature conditions at the lower bird level. More information about temperature stratification findings will follow in a subsequent article. Relative humidity indoors was within the acceptable 40 to 60% range during the early parts of all three cycles. Later in the cycles, when ventilation rates were in creased to accommodate the larger bird weights, the RH was more likely to follow outdoor RH trends, which is acceptable. Especially during the first three weeks, when timer fans and minimum ventilation for ammo nia and humidity control were em ployed, the RH was within accept able limits for all three flocks (except during some very humid days during the second week of Flock 3). Ammonia level was generally within the desirable 0 to 25 ppm range during the first two weeks of Flock 2 on new litter, but was well above acceptable levels during week one for the other flock cycles on re used litter. Day 1 average ammonia level was 84 ppm for Flock 1 and 122 ppm for Flock 3. These high lev els decreased dramatically during the following week. Flock 1 ammo nia level settled into a fairly steady 28 to 38 ppm level over the balance of the flock cycle while the Flock 3 level fluctuated from 26 to 56 ppm. The major difference contributing to the low Flock 2 ammonia level was the use of new litter. The first and third flocks were both on once-used litter that volatilized large quantities of ammonia. Flock Performance The productivity results among the three flocks were diverse. Flock 1 performed the worst of the nine flocks under study in bird productiv ity, mortality, and financial return to the grower. The second flock was second best of the nine flocks in return in cents/ lb bird grown and the best in terms of a growth index our research group derived to measure flock productivi ty. The third flock was in the mid- to low-range of these measurements. More About Ammonia And Humidity One old “rule of thumb” that by controlling humidity, the ammonia level would likewise be at an accept able level was not confirmed by these data. Especially during week one when chicks would be most suscepti ble to ammonia challenge, the am monia fluctuations and humidity pattern were not related. Acceptable humidity during week one was only matched with acceptable ammonia in Flock 2 on new litter. With old lit- ter, it would appear that relative hu midity and ammonia level are not positively correlated. This has been found in other studies. There has been discussion among our research group that exposure to elevated levels of ammonia during the first few days after chick placement has a greater impact than after the brood period. Other recent research has demonstrated the more detrimental effect of high (100 ppm) ammonia level exposure for 19 days versus continuous exposure to mod erate (50 ppm) ammonia over 33 days. That experiment was on older birds from 28 to 65 days of age. Our experiment suggests that even short term exposure to high ammonia lev els during the first one, two, or three days of life can inhibit bird produc tivity. Further analysis is underway to better quantify this effect into an industry-usable guideline. Conclusions Ammonia levels were much higher than expected in the houses during early stages of the growout. We were ‘ ' all a bit surprised at this. The inte grator personnel were disappointed, as one might expect, especially since f these managers have a very good un derstanding of ventilation concepts. The growers were not aware of the magnitude of the ammonia level. One might think that these results were unusual or that we chose the worst case to present here. In fact, this was an above-average grower who has a “typical” understanding of ventilation and environmental control. Similar results were found at the other two study farms. Upcoming articles will address more aspects of the cool tempera tures found at chick level and more specifics of the ammonia control issue. Application Of Results Place more emphasis on having a service person present when chicks are placed in a house to assure that environmental conditions, such as ammonia level and floor tempera ture, and other established husband ry practices are in place for the chicks. We suggest a service person do this, as the integrator company is more likely to own the instrumenta tion necessary to perform these func tions. Purchase instrumentation capable of detecting ammonia. Sampler pumps with ammonia tubes are com mon. Passive sampler tubes are also an effective tool. The growers, in particular, recognized their dimin ished ability to detect ammonia stemming from repeated exposure during chores. A sampler tube will offer a way of providing quantifica tion of ammonia conditions that are difficult to detect. Instrumentation information is available from the au thors. Consider litter additives, fresh lit ter during winter flocks, or increased winter ventilation for ammonia con trol. A follow-up study will be evalu ating the effectiveness and costs of these alternatives.
Significant historical Pennsylvania newspapers