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Feeding Patterns Of Growing Pigs At Warm Constant And Cyclic Temperatures, Hongwei Xin, James A. Deshazer
Feeding Patterns Of Growing Pigs At Warm Constant And Cyclic Temperatures, Hongwei Xin, James A. Deshazer
Hongwei Xin
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).
Responses Of Pre-Fasted Growing Turkeys To Acute Heat Exposure, Hongwei Xin, James A. Deshazer, Mary M. Beck
Responses Of Pre-Fasted Growing Turkeys To Acute Heat Exposure, Hongwei Xin, James A. Deshazer, Mary M. Beck
Hongwei Xin
Nicholas turkeys at the age of 15 to 16 weeks were fasted for 24 hours in a moderate environment and then subjected to acute heat exposures of various dry-bulb and wet-bulb temperatures (T^u, and T^jj). Total feed intake was not influenced by T^^ of 32*' C, 36"* C or 40° C (P > 0.10), although differences existed in dynamic feeding profiles. Total heat production rate (THP) varied quadratically with T^^, and respiratory quotient (RQ) decreased linearly with T^u,. The lower RQ values at the higher T^i^ levels may have resulted from reduced feed assimilation. No differences were detected on feed intake, …
Swine Responses To Constant And Modified Diurnal Cyclic Temperatures, Hongwei Xin, James A. Deshazer
Swine Responses To Constant And Modified Diurnal Cyclic Temperatures, Hongwei Xin, James A. Deshazer
Hongwei Xin
Ad libitum fed and individually penned crossbred gilts (39 ± 2 kg) were exposed to a constant air temperature of 30.8*" C (CON) and equal-mean diurnal cyclic temperatures cycling from 26° to 33*^ C (RPK) and from 23.4° to 40° C (RNT). Fluorescent lighting with an intensity of 800 to 1100 L/m/m2 was provided from 0600 h to 2100 h. Measurements of feed intake, heat loss rates, water usage, growth, and ingestion behavior were made for a five-day period and replicated six times. Daily average heat loss rates, water usage, and feed conversion of the RPK and RNT pigs could …
Pig Vocalizations Under Selected Husbandry Practices, Hongwei Xin, James A. Deshazer, D. W. Leger
Pig Vocalizations Under Selected Husbandry Practices, Hongwei Xin, James A. Deshazer, D. W. Leger
Hongwei Xin
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-gestation 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 …
Post-Effect Of Ammonia On Energetics Of Laying Hens At High Temperatures, Hongwei Xin, James A. Deshazer, M. M. Beck
Post-Effect Of Ammonia On Energetics Of Laying Hens At High Temperatures, Hongwei Xin, James A. Deshazer, M. M. Beck
Hongwei Xin
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, …