Body Temperature in Free-Roaming Beef Cattle

Body temperature (BT) measurements are traditionally used in diagnosing sick animals, but may also be used as an indicator of stress or activity. Based on results of metabolism studies, Mader et al. (1999) reported that BT can vary as much as 0.9oC and can depend on metabolisable energy (ME) of the diet consumed. Acceptable measures of BT can be obtained from the rectum, vagina, or ear canal. Technologies are also being developed for continuously monitoring BT via radio-telemetry. The objectives of this study were to determine the effect of high concentrate (low fibre) versus high fibre diets on BT, assess the capabilities of obtaining BT in free-roaming cattle, and compare temperatures taken in the rumen with vaginal and tympanic temperatures

USING NONLINEAR GROWTH CURVES TO ESTIMATE HEAT STRESS IN PROCESSING FEEDLOT CATTLE

Summertime heat waves cause excessive discomfort and, in extreme cases, death of feedlot cattle. During such emergencies, extension specialists are called upon for recommendations of management practices to minimize heat stress. Since moving cattle is believed to raise body temperature 1 degree, one recommendation is to move cattle before mid-day or reschedule to another day. More knowledge of body temperature dynamics could lead to more specific recommendations of how far cattle can be moved without stress. Several models are investigated - especially those involving exponential growth(challenge) and decay (recovery) such as the bi-exponential, single compartment and other models in pharmacokinetics. Data from feedlot trials can be messy and judgement calls involving starting and ending times, model parametrization, and statistical assumptions can influence the results. Analyzes from SAS: proc NLIN and checks on nonlinear assumptions are discussed

Determination of climatologically suitable places in the Midwest for feedlot cattle production by using the comprehensive climate index model

Citation: Koknaroglu, H., Harrington, J. A., & Mader, T. L. (2016). Determination of climatologically suitable places in the Midwest for feedlot cattle production by using the comprehensive climate index model. Journal of Animal Science, 94, 28-29. doi:10.2527/msasas2016-062The objective of this study was to determine climatologically suitable places to raise feedlot cattle in the Midwest. Hourly average temperature, relative humidity, and wind speed values for 22 locations (Des Moines, Mason City, Sioux City, Waterloo, Concordia, Dodge City, Goodland, Russell, Topeka, Wichita, Columbia, Kansas City, KCI, Springfield, St. Louis, Grand Island, Lincoln, Norfolk, North Platte, Omaha, Scottsbluff, and Valentine), spanning the last 10 yr, were obtained. Daily solar radiation values could not be obtained from the weather stations and were calculated based on a formula that takes hemisphere, latitude, and day of the year into account. The comprehensive climate index (CCI) model was used to predict DMI, ADG, and feed efficiency of feedlot cattle. The CCI enables one to quantify beef cattle performance for a number of breeds based on environmental conditions (temperature, relative humidity, wind speed, and solar radiation) at any time in the year. Because mostly beef cattle breed calves are placed into the feedlot in the Midwest, the British (beef breed) option in CCI was chosen to calculate the maintenance energy requirement of cattle. It was assumed that calves would be placed on feed at 340 kg and be marketed at 613 kg and that diets would have 3200 kcal/kg metabolic energy and would have DMI of 2.10% of the BW. Results comparing the 22 locations showed that Mason City had the highest and Columbia had the lowest DMI (P < 0.05). Cattle raised in Kansas and Missouri had lower DMI than those raised in Iowa and Nebraska. Cattle had ADG ranging from 1.74 to 1.69 kg/d; Scottsbluff and Goodland had the highest ADG and Columbia had the lowest ADG (P < 0.05). As it is observed in DMI, cattle raised in south latitudes had lower ADG than those raised in northern latitudes. Springfield and Wichita had better feed efficiency than other locations, and Mason City had the worst feed efficiency. Cattle raised in Kansas and Missouri had better feed efficiency than those raised in Iowa and Nebraska (P < 0.05). Results showed that there are differences in terms of performance of cattle raised in different locations in the Midwest and this should be taken into consideration for economical beef production

Cultural energy analyses of climatologically suitable places in Turkey for feedlot cattle production determined by using the comprehensive climate index model

Citation: Koknaroglu, H., Harrington, J. A., & Mader, T. L. (2016). Cultural energy analyses of climatologically suitable places in Turkey for feedlot cattle production determined by using the comprehensive climate index model. Journal of Animal Science, 94, 26-26. doi:10.2527/msasas2016-057The objective of this study was to conduct cultural energy analyses on feedlot cattle production in Turkey. The comprehensive climate index (CCI) model was used to predict DMI, ADG, and feed efficiency of feedlot cattle in 15 locations in Turkey. The CCI enables one to quantify beef cattle performance for a number of breeds based on environmental conditions (temperature, relative humidity, wind speed, and solar radiation) at any time in the year. Because mostly dairy breed calves are placed into the feedlot in Turkey, the Holstein (dairy breed) option in the CCI was chosen to calculate the maintenance energy requirement. Based on previous feedlot feeding studies conducted in Turkey, it was assumed that calves would be placed on feed at 250 kg and be marketed at 520 kg and that the diet would have 2600 kcal/kg metabolic energy and would have DMI of 2.31% of the BW. It was assumed that cattle would receive 2 kg/d straw and that the concentrate mixture would consist of 52.65% barley, 26% corn, 19% cotton seed meal, 1.5% limestone, 0.25% vitamins, 0.5% salt, and 0.1% minerals. Cultural energy inputs were calculated by multiplying the amount of inputs and their corresponding cultural energy based on values from existing literature. Cultural energy used for feed was derived from DMI of cattle and corresponding values for each feed ingredient. Transportation energy was also included in the analysis, including costs for shipping calves from animal market to the farm, shipping yearlings to slaughterhouse, and shipping feed ingredients to the farm. Cultural energy expended for feed made up more than half of the total cultural energy and differed among cities (P < 0.05). Cultural energy for feed was highest for the coldest places and lowest for hot locations. Cultural energy of transportation constituted the second highest cultural energy expenditure. Cultural energy expended per kilogram live weight gain (defined as total cultural energy expended divided by kg live weight gain) was highest for the coldest location and lowest for relatively hotter cities (P < 0.05). Cultural energy use efficiency (defined by kcal input/kcal output) followed the feed efficiency ranking with cattle having better feed efficiency also have better cultural energy use efficiency. Results showed that cattle having higher ADG did not mean that they would also have better cultural energy use efficiency

COMPARING EXPERIMENTAL DESIGNS FOR A BI-LOGISTICAL MODEL USED TO ESTIMATE HEAT STRESS WHEN MOVING FEEDLOT CATTLE

Processing and handling cattle requires expenditure of energy causing an elevation of body temperature, depending on the ambient conditions. Therefore, caution should be exercised in moving cattle, especially during summer. More knowledge of the dynamics of body temperature, (Tb), could lead to specific recommendations on how far and under what conditions cattle can be moved before becoming thermally challenged. Data comes from feedlot trials conducted over four days. A bi-logistic mixed model of Tb is used to describe the effects of moving and handling on Tb. This model provides estimates for several important biological parameters describing the thermal challenge and recovery: the maximum Tb challenge, challenge rate constant (rate constant for increase in Tb), time to maximum rate of challenge (challenge inflection point), baseline for recovery, recovery rate constant (rate constant for decrease in Tb) and time to maximum recovery rate (recovery inflection point). Fitting a nonlinear mixed model with six parameters under extremely variable animal and environmental conditions is difficult especially when the treatment factor (distance) is introduced into the model. Additional difficulties in fitting the model arise as the experimental design increases in complexity from a CRD to a replicated Latin square. The objectives of this study are: to examine the bi-logistic model with distance as a treatment factor and estimate the relative efficiencies as the experimental design is simplified

LOGISTIC REGRESSION ANALYSIS TO DETERMINE FACTORS CONTRIBUTING TO SUMMER FEEDLOT DEATHS

Summer heat has already been identified as a major factor for cattle deaths in the feedlot. This study attempts to assess what other factors contribute to and/or influence cattle deaths. Identifying multiple factors that contribute to summer feedlot deaths could aid feedlot managers in implementation of mitigation strategies and minimize the loss of nearly finished cattle. Daily pen, cattle, and nutritional characteristics were recorded and included in this generalized linear mixed model analysis. Cattle data were obtained from cattle pens at a single location from July 1, 2010 to July 31, 2010. Hourly weather data were acquired from this feed yard while solar radiation was received from a neighboring town. Rather than using multiple weather variables, a single comprehensive climate index that summarizes several weather variables is used to capture the apparent feel of the weather. After reviewing the data, a statistical model is developed and odds ratios are computed for statistical inference. According to these odds ratios, cattle fed on severe west slopes had significantly higher odds of death than other types of slopes. Analysis of feed intake indicates pens consuming 16 pounds of feed per head or less during July 16 – 18 have higher odds of death than other consumption levels

USING THE BI-LOGISTIC MODEL TO ESTIMATE BODY TEMPERATURE IN FEEDLOT CATTLE

Processing and handling cattle require an expenditure of energy causing an elevation of body temperature, depending on the ambient conditions. More knowledge of body temperature, Tb, dynamics could lead to more specific recommendations of how far cattle can be moved without stress. The bi-Iogistic model has been used to describe the handling process. This model estimates several important biological parameters: rate of increase in Tb (rate of heat challenge), the maximum Tb (max Tb), time to reach maximum Tb (tmax) and recovery rate (rate of decrease in Tb). The objectives of this study are: to compare parameter estimates from the bi-Iogistic model with a segmented version of the model; to investigate the robustness of the model for different definitions of recovery; and, to check for hormetic behavior using switching functions

CASE STUDY: Tympanic Temperature and Behavior Associated with Moving Feedlot Cattle

Body temperature is often used as an indicator of animal health status. In a series of handling experiments, tympanic temperatures (TT) were obtained in unrestrained feedlot cattle. In a January experiment (BW = 531 ± 54 kg), TT were increased (