• Journal of Animal Science and Technology
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• v.51 no.4
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• pp.337-342
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• 2009

The feasibility of reutilization of magnesium ammonium phosphate (MAP) or struvite slurry recovered from the process through microwave irradiation was studied in this experiment. For this purpose, 4 different operations were performed with or without Mg source addition and different levels of MAP recycled in a batch reactor. Dissolution rate of MAP, ${NH_4}^+$ elimination pattern and physicochemical changes of MAP during microwave irradiation were also studied. The result showed that only 33% orthophosphate ($PO_4-P$) and 27% $NH_4-N$ removal occurred without adding any external Mg source (run A), whereas 87% $PO_4-P$ and 40% $NH_4-N$ removed when 1.0 M ratio of $MgCl_2$ (run B) was added based on $PO_4-P$ in influent. Although the addition of 1.0 molar ratio of microwave irradiated MAP (Run C) removed lower $PO_4-P$ and $NH_4-N$ than 1.0 M $MgCl_2$ (run B), $PO_4-P$ removal was double when compared with no Mg addition (run A). Addition of half MAP and half $MgCl_2$ (run D) showed the similar removal efficiency (88% $PO_4-P$ and 35% $NH_4-N$) with sole $MgCl_2$ addition (run B). Based on these results, the reutilization of MAP irradiated by microwave would be a feasible way to enhance the removal efficiencies of N and P, as well as curtail the Mg chemical usage. Track study showed that $NH_4-N$ gradually increased at initial stage of microwave irradiation of MAP, and then started eliminating from liquor as temperature increased over $45^{\circ}C$. Dissolution rate of ${PO_4}^{-3}$ during microwave irradiation was proportional to the initial MAP concentration, having $0.0091x^{0.6373}$ mg/sec. It was found from the scanning electron microscope (SEM) study that physical structure of MAP crystal started breaking down into small cube granules within very short time by electromagnetic vibration force during microwave irradiation and then gradually melted down into solution.

• Journal of Animal Environmental Science
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• v.7 no.1
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• pp.1-12
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• 2001

This study was conducted to develope an automatic liquid feeder for early weaning piglets and to test the efficacy of the system. The liquid feeder consists of water heating and discharge unit, dry diet storing and discharge unit, mixing and discharge unit, mixed liquid feed-delivering unit, and the central control part which control each unit, feeding frequency and the amount of feeding. For investigating the possibility of practical use, a feeding trial was carried out using eighteen three way crossbred piglets weaned on 19 days of age for the experimental period of six weeks. Experimental diet was provided in liquid form using the automatic liquid feeder for the first three weeks and in dry form for the later three weeks. The water heating and discharge unit exactly supplied warm water by 27 $m\ell$/s, into the mixing unit. The dry diet storing and discharge unit supplied dry feed by 3.7g/s, into the mixing unit. Being compared with the standard growth rate suggested by NRC, average daily gain of the piglets during the first three weeks of liquid feeding was lower by 10%, while it was higher during three weeks of dry feeding and over the whole experimental period by 24 and 17%, respectively. Feed/gain was 1.09, 2.14 and 1.89 for the first 3 weeks, later 3 weeks, and whole period, respectively. Diarrhea was observed for three days from day 3 to day 7 after feeding liquid diet, but no pig died of it. In conclusion, a preliminary test for the newly developed an automatic liquid feeder using 19 days of age weaning piglets showed that the unit was successfully operated without any major problems. Piglets raised on a liquid diet through the unit developed grew less during the first three weeks, but their growth and feed intake were greatly improved thereafter, indicating the developed automatic liquid feeder may be practically used in swine industry.

• Journal of agriculture & life science
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• v.44 no.3
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• pp.41-52
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• 2010

This study was conducted to estimate genetic parameters for growth traits using multivariate animal models in Yorkshire breed. For the study, 16,202 records for growth traits collected between the year 1999 and 2005 from Yorkshire pigs in K GGP were used. The effects of environmental factors such as sex, birth year, birth season, parity and birth weight group affected growth traits significantly (p<0.01). Birth weight tended to be positively correlated with average daily gain (ADG) and lean percent. But it seemed to affect age at 90 kg, average adjusted backfat thickness (BF), and eye muscle ares (EMA) negatively. For average pig suckling weight (ASW) and total weight at suckling (TWS), the higher birth weight is the better performance. But, in case of total number of born and number of suckling, the result was shown vice versa. Approximately 10~30% lower heritability estimates were obtained for growth traits by using the model that includes descriptions of common litter effects (CL) than by using the model that ignores those (NCL) for more accurate estimation of heritability. The estimates of heritabilities were 0.468, and 0.328 for ADG, 0.474 and 0.326 for age at 90 kg, 0.452, and 0.396 for BF, 0.240 and 0.200 for EMA and, 0.458, and 0.380 for lean percent in NCL and CL, respectively. Therefore, in order to estimate optimal genetic parameters, it could be inferred that the statistical model which considers litter effects must be applied.

• ANNALS OF ANIMAL RESOURCE SCIENCES
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• v.29 no.4
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• pp.172-182
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• 2018

The present study was undertaken to examine if the carcass and pork quality of finishing pigs reared on a low plane of nutrition (LPN) could be improved compared with that of the pigs finished on a high plane of nutrition (HPN). Sixty-eight crossbred (LYD) barrows and 68 LYD gilts weighing approximately 50 kg were fed a diet containing 3.54 Mcal DE/kg with 1.00% lysine (HPN) or 3.02 Mcal DE/kg with 0.68% lysine (LPN) in eight pens up to approximately 120 kg and slaughtered. The belly, loin, ham, and Boston butt were cut out from a total of 20 carcasses, after which physicochemical and sensory quality attributes of the belly and the representative muscle of each of the loin, ham, and Boston butt were evaluated. The ADG, gain:feed ratio, and backfat thickness were less for LPN than for HPN (p<0.05). The cooking loss, hardness, and chewiness values for the Boston butt were less for LPN vs. HPN. In sensory evaluation for fresh meat (muscle), the subjective quality scores were greater for LPN vs. HPN in color, marbling, and acceptability for the loin, the muscle:fat balance score for the belly tending to be greater for LPN (p<0.10). In addition, LPN was superior to HPN in the flavor and juiciness in sensory evaluation for cooked ham. In conclusion, the present results suggest that the carcass and pork quality of finishing pigs could be improved with reduced growth performance by using LPN.

• Korean Journal of Agricultural Science
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• v.8 no.1
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• pp.51-63
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• 1981

The results of a crossbreeding experiment with a total of 315 litters and 325 pigs of Berkshires, Hampshires, Durocs, Landraces, Large Whites, eight different two-breed crosses and twelve different three-breed crosses, produced at Livestock Experiment Station from 1975 through 1979, are summarized as follows. 1. Number born alive per litter was largest in the D♂${\times}$(Lw♂${\times}$L♀) $F_1$ ♀ mating, followed by the D♂${\times}$(H♂${\times}$L♀) $F_1$ mating, and smallest in the Hampshires. The pigs in the 3rd-6th parities had larger litter size at birth than those in other parities. 2. Birth weight of pig was heaviest in L♂${\times}$Lw♀ mating and lightest in the Large White. The total litter weight at birth was heaviest in the D♂${\times}$(Lw♂${\times}$L♀) $F_1$ ♀ mating, followed by D♂${\times}$(H♂${\times}$L♀) $F_1$ ♀ and Lw♂${\times}$L♀ matings, and was smaller in Hampshires and Birkshires. 3. Litter size at weaning was largest in the D♂${\times}$(Lw♂${\times}$L♀) $F_1$ ♀ mating, followed by D♂${\times}$(H♂${\times}$L♀) $F_1$ ♀ and Lw♂${\times}$L♀ matings, and was smaller in Durocs and Hampshires. The pigs in the 3rd-6th parities had larger litter size at weaning than those in other parities. 4. The total litter weight at weaning was heaviest in the D♂${\times}$(Lw♂${\times}$L♀) $F_1$ ♀ mating, followed by H♂${\times}$(Lw♂${\times}$L♀) $F_1$♀ and Lw♂${\times}$L♀ matings, and was lighter in Durocs and Hampshires. The weaning weight of pig was largest in D♂${\times}$(Lw♂${\times}$L♀) $F_1$ ♀ mating and lightest in L♂${\times}$H♀ mating. 5. Survival rate at weaning was highest in L♂${\times}$Lw♀ mating, followed by D♂${\times}$(L♂${\times}$H♀) $F_1$ ♀ and D♂${\times}$(H♂${\times}$L♀) $F_1$ ♀ mating, and was lowest in Durocs. 6. The three-breed cross from D♂${\times}$(H♂${\times}$L♀) $F_1$ ♀ mating had the highest average gain and lowest feed requirement per unit gain, followed by the D♂${\times}$(Lw♂${\times}$L♀) $F_1$ ♀ and H♂${\times}$(Lw♂${\times}$L♀) $F_1$ ♀ matings. The Birkshires and Landraces ranked lowest among the 25 mating groups compared for both of the traits. Males had higher average daily gain than females by about 0.06kg and had lower feed requirement by about 0.14. 7. The three-breed crosses from D♂${\times}$(H♂${\times}$L♀) $F_1$ ♀, D♂${\times}$(Lw♂${\times}$L♀) $F_1$ ♀ and H♂${\times}$(Lw♂${\times}$L♀) $F_1$ ♀ matings reached 90kg body weight at younger age than the other groups. The D♂${\times}$(H♂${\times}$L♀) $F_1$ ♀ group reached 90kg at younger age than the Landrace by 39 days. 8. The dressing percentage and lean meat percentage tended to be higher in H♂${\times}$(Lw♂${\times}$L♀) $F_1$ ♀, H♂${\times}$L♀ and L♂${\times}$B♀ matings compared to the other mating groups. The loin-eye area was largest in the Lw♂${\times}$L♀ mating and smallest in the B♂${\times}$L♀ mating. Males had higher dressing percentage, higher lean meat percentage and lion-eye area than females. The backfat was thinnest in purebred Hampshire and was thickest in B♂${\times}$L♀ mating. 9. The results obtained in this study suggest that the two-breed cross from Lw♂${\times}$L♀ mating, and the three-breed crosses from D♂${\times}$(Lw♂${\times}$L-♀) $F_1$ ♀ and D♂${\times}$(H♂${\times}$L♀) $F_1$♀ matings are superior crossbreds for reproductive and pork prodnction performance.