This study aimed to determine the factors affecting the body weight (BW) of Hanwoo steers by collecting a large number of BW measurements using an automated weighing system (AWS). The BW of 12 Hanwoo steers was measured automatically using an AWS for seven days each month over three months. On the fourth day of the BW measurement each month, an additional BW measurement was conducted manually. After removing the outliers of BW records, the deviations between the AWS records (a) and manual weighing records (b) were analyzed. BW measurement deviations (a − b) were significantly (p < 0.05) affected by month, day and the time within a day as well as the individual animal factor; however, unexplained random variations had the greatest impact (70.4%). Excluding unexplained random variations, the difference between individual steers was the most influential (80.1%). During the day, the BW of Hanwoo steers increased before feed offerings and significantly decreased immediately after (p < 0.05), despite the constant availability of feeds in the feed bunk. These results suggest that there is a need to develop pattern recognition algorithms that consider variations in individual animals and their feeding patterns for the analysis of BW changes in animals.
This study was conducted to investigate the effects of protease supplementation
and different nutrient density of diets in growing-finishing pigs. A total of
one hundred-eight crossbred growing pigs ([Landrace × Yorkshire] ×
Duroc) with an initial body weight (BW; 18.74 ± 3.46 kg) were used for 15
weeks. Pigs were randomly assigned to six dietary treatments with 6 replicates
of 3 pigs per pen in a 3 × 2 factorial through the following arrangement:
Three groups of protease (1, Basal diets; 2, Protease A: 125 mg/kg protease
derived from
Streptomyces
sps; 3, Protease B: 100 mg/kg
protease derived from
Bacillus licheniformis
) at two different
nutrient density diets (1, Basal requirement; 2, 0.94%–0.98% higher than
requirement in dietary protein and 50 kcal/kg in energy). High nutrient (HN)
diets showed higher average daily gain (ADG) (
p
< 0.05)
and apparent total tract digestibility (ATTD) of crude protein (CP)
(
p
< .0001) compared to basal nutrient (BN) diets
during growing periods. Supplementation of protease showed higher BW
(
p
< 0.05) and ADG (
p
<
0.05) compared to non-supplementation of protease during growing periods. Also,
supplementation of protease showed higher ATTD of CP (
p
< 0.01), ATTD of gross energy (
p
< 0.05) and
decreased blood urea nitrogen (BUN) level (
p
= 0.001) compared
to non-supplementation of protease during finishing periods. Pigs which fed the
protease showed decreased ammonia (NH
3
) emissions (
p
< 0.05) during experiment periods and decreased hydrogen sulfide
(H
2
S) emissions (
p
< 0.01) during
finishing periods. Interactions between nutrient density and protease were
observed, which decreased the feed conversion ratio (
p
<
0.05) in HN diets without protease compared to BN diets without protease during
weeks 4 to 6. Also, interaction between nutrient density and protease was
observed, which resulted in improved ATTD of CP (
p
<
0.01) in response to PTA supplementation with HN diets during the finishing
period. In conclusion, supplementation of protease reduces NH
3
in
feces and BUN in whole blood by increasing the digestibility of CP and improves
growth performance. Also, diets with high nutrient density improved growth
performance and nutrient digestibility in growing periods.
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