본 연구는 6개 핵돈군생산농장(Great grand parents, GGP)에서 2015년 이후 태어난 Landrace종과 Yorkshire종의 두 품종에 대하여 생시체중 (Birth weight; BW), 복당평균생시체중(Mean of litter birth weight; MBW0)과 변이계수(Coefficient of variation in MBW0; CVMBW0) 및 산자수(Litter size) 등에 대한 유전모수를 추정하였다. Landrace종에서 총산자수(Total number of piglets born; TNB), 생존산자수(Number of piglets born alive: NBA), 복당평균생시체중 및 복당평균생시체중 변이계수의 유전력은 각각 0.14, 0.09, 0.33 및 0.16. Yorkshire종에서는 각각 0.11, 0.99, 0.28 및 0.07로 추정되었다. 산자수와 복당평균생시체중 간에는 부(-)의 상관관계를 나타내었으며, 복당평균생시체중과 변이계수사이의 표현형상관과 유전상관이 두 품종에서 모두 –0.40에서 –0.45로 높게 나타났다. 자돈 생시체중에 대한 균일도를 개량하기 위해서는 복당평균생시 체중(MBW0)과 복당평균생시체중변이계수(CVMBW0)를 선발지수식에 포함시키는 것이 바람직하다고 생각된다.

본 연구는 두록종 돼지의 복당 생시체중 형질(복당 생시체중 평균, 복당 생시체중 표준편차)과 산자수 형질(총 산자수, 생존 산자수, 사산두수)의 유전모수를 추정하고 이들 형질간의 상관관계와 개량방안을 알아보기 위해 실시하였다. 분석에는 국립축산과학원에서 2006~2016년 사이에 분만한 두록 모돈 1,081복의 자료를 이용하였다. 분석형질은 복당 생시체중 평균(ABW), 복당 생시체중 표준편차(BWSD), 총 산자수 (NB), 생존 산자수(NBA) 및 사산두수(NBD)이다. 유전모수 추정은 다형질 개체모형을 이용하였다. 각 형질에 대한 유전력은 복당 생시체중 평균(ABW), 복당 생시체중 표준편차(BWSD), 총 산자수(NB), 생존 산자수(NBA) 및 사산두수(NBD)에 대해 각각 0.32, 0.13, 0.11, 0.10, 및 0.06으로 추정되었다. 복당 생시체중 평균(ABW)과 복당 생시체중 표준편차(BWSD)는 0.75의 높은 정의 유전상관을 보인 반면 생존 산자수(NBA)와 복당 생시체중 평균(ABW), 복당 생시체중 표준편차(BWSD)간의 유전상관은 각각 –0.26, -0.40로 생존 산자수(NBA)가 증가함에 따라 복당 생시체중 평균과 복내 개체간 체중의 표준편차는 감소하는 것으로 나타났다. 생존 산자수(NBA)와 사산두수(NBD)간의 유전상관은 0.24로 생존 산자수(NBA)가 증가하면 사산두수(NBD)도 증가하는 유전적 관계를 나타내었다. 한편 복당 생시체중 평균(ABW)과 복당 생시체중 표준편차(BWSD), 사산두수(NBD), 총 산자수(NB)간의 유전상관은 각각 0.75, 0.81과 0.08로 추정되어 복당 생시체중 평균(ABW)이 증가하면 총 산자수(NB)의 큰 변화 없이 복당 생시체중 표준편차(BWSD), 사산두수(NBD)가 증가하는 것으로 나타났다. 본 결과로 미루어 볼 때 유전력이 높은 복당 생시체중 평균(ABW)은 직접선발을 통한 빠른 개량이 가능한 반면 복당 생시체중 표준편차(BWSD), 총 산자수(NB), 생존 산자수(NBA) 및 사산두수(NBD) 형질은 직접선발을 통한 개량 효과가 낮을 것으로 판단된다. 특히 자돈 생시체중의 균일도를 개량하고자 한다면 복당 생시체중 표준 편차(BWSD)에 대한 직접선발 방법과 더불어 복당 생시체중 평균(ABW)을 이용해 간접선발하는 방법 또한 이용 가능할 것으로 사료된다.

This study was conducted to find out the environmental, service sire and genetic effects for reproductive trait in certain purebred of pigs on Landrace and Yorkshire, and to suggest selection indicator which is to improve genetic capability on reproductive traits. There are five traits used on this analysis which are total number of born (NBT), number of born alive (NBA), piglets weight within litter (LW), average of birth weight on piglets within litter (ABW) and variation of birth weight on piglets within litter (VBW). With these data, the mixed model was established using 10,342 records collected from 2,527 sows of Landrace and 13,817 records collected from sows of 3,056 Yorkshire breeds and the variation of random effects and the genetic parameter were estimated by the REML method including service sire effects, permanent environmental effects and sow genetic effects. Due to characteristics of closed nucleus herd for using data on this study, given that it has been isolated breeding for about 19 years that progressed over 16 generations, genetic analysis was performed on all of these data and partial data of the current genetic group in which animals were born after 2011. The effects of service sire were estimated to be less than about 8% of total variation in all traits considered in the analysis. Permanent environmental effects were estimated about 2~14% of total variation in all traits considered. The heritability, which is the ratio of genetic variance among the total variance, was estimated to be 20~35% for LW and ABW in Landrace and Yorkshire, while it was about 10~14% for NBT. The genetic correlations between NBT and LW were 62~74% and between NBT and ABW were –28~-7%. Therefore, indirect selection for improving litter size could be possible with considering LW. Whereas, the genetic effect of the service sire effects for litter traits would be trivial.

The objective of this study was to estimate the genetic and phenotypic parameters of litter size and birth weight traits in three Korean black goat lines (Dangjin, Jangsoo and Tongyung) raised at the Animal Genetic Resources Station (AGRS) of the National Institute of Animal Science (NIAS). A total of 1,861 records collected from 2001 to 2013 were used for analyses with single trait animal models. The average litter size of Dangjin line was the largest (1.72 kids) and the average birth weight of Jangsoo line was the heaviest (1.88 kg) among the three lines. Heritability estimates of litter size and birth weight were 0.07 and 0.26, respectively. The average breeding value of litter size and that of birth weight of Jangsoo line were the greatest of all three lines, 0.15 heads and 1.88 kg, respectively. The correlation coefficients between phenotypic values and breeding values of litter size in the lines of Dangjin, Jangsoo and Tongyung were 0.054, -0.031 and 0.131, respectively. The correlation coefficients between phenotypic values and breeding values of birth weight in the lines of Dangjin, Jangsoo and Tongyung were 0.570, 0.454 and 0.521, respectively. The phenotypic correlation and breeding value correlation between litter size and birth weight were 0.031 and 0.003 in Dangjin line, -0.038 and 0.094 in Jangsoo line, and 0.109 and 0.121 in Tongyung line, respectively. These data suggest that the genetic parameters estimated for litter size and birth weight in this study could be used to improve genetic potentials of Korean black goats in industrial level

This study investigated the effect of adding poultry litter additive containing probiotics and amino acids to the litter on weight gain in ducks and ammonia content in poultry litter. Nine hundred 1-day-old ducks (Pekin) were randomly distributed into three groups (300 birds per treatment divided into three replicates) using a randomized block design. Treatments were top-dressed on the litter surface at rates of 2 kg poultry litter additives (T1) and 2 kg macsumsuk (T2) per m2, and untreated poultry litter was used as the control. Overall, a significant difference (p<0.05) in weight gains was observed at 3 and 4 weeks, but not at 5 and 6 weeks. After 4 weeks, when compared to other treatments, the addition of poultry litter additive tended to increase the average body weight gain (90-130 g). The ammonia content was affected by all treatments (p<0.05) over time except at 3 weeks, however, compared to other treatments, the poultry litter additive decreased the ammonia content. In particular, the rate of ammonia reduction by the poultry litter additives over time was approximately 20.2%-49.2%. Regarding temperature, a significant difference was observed in all treatment groups (p<0.05), except at 3 weeks. In conclusion, considering poultry litter additives and temperature, the increase in duck weight gain was associated with a decrease in ammonia content in the poultry litter.