James A. DeShazer

Pig Vocalizations Under Selected Husbandry Practices

Acoustical characteristics of vocalizations of sows, piglets, and nursery pigs under selected husbandry practices were analyzed with a digital signal processing system. The duration (D) and major energy-resonance frequency (P) for each call were determined as follows: a) processing of piglets (D = 0.81 s and f* = 3 700 Hz); b) food anticipation of breeding-gest ation sows (2.50 s and 3 000 Hz); c) isolation of piglet (0.34 s and 500, 3 500 Hz); d) startling of nursery pigs (0.29 s and 900 Hz); e) sows in heat (3.07 s and 1 375 Hz); f) farrowing (0.10 s and 3 000 Hz); g) sow nursing (0.15 s and 1 000 Hz); and h) mate greeting of sow (0.13 s and 1 000 Hz). Calls a) to d) are responses to human generated stressors, and calls e) through h) responses to social and physiological states of the pigs. Thus, vocalizations can be segmented for different pig production situations.

Feeding Patterns Of Growing Pigs At Warm Constant And Cyclic Temperatures

Feeding behavior of ad libitum-fed^ 39-kg, crossbred gilts was investigated under mean ambient temperatures of 30.8° C with 0, 7, and 16.6° C cycles. Average meal size, 160 to 170 g/pig; meal duration, 13.3 to 14.3 min; and ingestion rate, 12.2 g/min-pig did not appear to be influenced by the temperature conditions. However, meal frequency, 9 to 11 per day, tended to be reduced by elevated hours of exposure to high temperatures. Consequently daily feed intake of the pigs was signiflcantly less in the 16.6° C cycle treatment than in the 0 or 7° C cycle treatments (P<0.01). Feed consumed during the lighting period (0600 h to 2100 h) accounted for 75%, 61%, and 37% of daily feed intake for the 0, 7, and 16.6° C cycle treatments, respectively. Pigs under the 0° C cycle had most feeding activities in the afternoon and evening (55% of daily feed intake). In contrast, pigs under the 16.6° C cycle had most feeding events at night and early morning (91 % of daily feed intake).

Post-Effect of Ammonia on Energetics of Laying Hens at High Temperatures

ABSTRACT WHITE Leghorn layers were monitored for heat loss, feed intake, egg production and respiratory rate at various environmental temperatures (TJ after first being exposed to aerial ammonia (NH3). The initial exposure was to 10 or 60 ppm NH3 at a T, of 25 °C for 30 days to simulate a winter environmental condition in a poultry facility. Hens were then allowed to recover in an environment of 5 ppm of NH3 at a T^ of 22 °C for seven days to simulate a spring environmental condition. Birds were then placed individually in a partitional calorimeter free of NH3 at 25, 29, 33, or 37 °C for 24 h to simulate initial summer environmental conditions. There were no statistical differences (P>0.05) between the two groups of NH3-treated hens for sensible or latent heat losses, apparent respiratory efficiency of latent heat loss, egg production, or feed intake. From these resutls, it is hypothesized that interplay between cutaneous evaporative heat loss and respiratory evaporative heat loss may play a more important physiological role than previously thought in maintaining homeothermy of the bird at high environmental temperatures. This physiological reponse could thus provide an energetics compensation for lung damage caused by aerial ammonia.

Variable Base Heating Degree-Day Data

ABSTRACT HEATING degree-day (HDD) data are often used to estimate annual fuel energy requirements for heating buildings. Commonly, a base temperature of 18.3°C (65°F) is used for calculating HDD. This fixed-base data is generally not appropriate for structures housing livestock since the balance or base temperature of the structure can vary significantly from 18.3°C. A simplified technique, using fitted-curve equations, has been developed to estimate average annual heating degree-days as a function of base temperature and location. This paper presents the method of calculation and specific equations for 70 cities in the United States. In addition, generalized heating degree-day equations for 25 states are presented and discussed.