Daily Intake of Essential Amino Acids in Sow's Milk Fed to Piglets With ad Libitum Access

In this study, daily intake of essentilal amino acids in sow's milk fed to piglets with ad libitum access was determined at 3, 7 and 14 days of age. Three sows (L, LW, WL) and their litters (31 piglets) were used. Sow's milk intake of piglets was measured from 10:00 to 18:00 (8 hour) at 3, 7 and 14 days of age by weigh-suckle-weigh method. Three times the value of the measured one was defined as daily sow's milk intake. Piglets had no access to creep feed. Milk samples were obtained by an oxytocin injection on the following day of the measurement of milk intake to determine amino acid concentrations of total protein hydrolysate. Daily sow's milk intake increased as time progressed: 523±218g, 809±215g and 979±182g at the age of 3, 7 and 14 days, respectively. Sow's milk intake per piglet decreased as litter size enlarged. Daily intake of essential amino acids, except for tryptophan, from sow's milk also increased linerly from 15.7g at 3 days and to 23.2g at 14 days of age. Amino acids ratios to lysine of sow's milk in this study well agreed with those in ARC (1981). Average daily gain of 7 days (BW 2.7±0.3kg) and 14 days of age (BW 3.8±0.7kg) were 237±50g and 254±44g, respectively. When the daily gain of piglets is 237g at 7 days and 254g at 14 days of age, requirements for each essential amino acid ranged from 75% to 96% of amino acid requirements in Japanese Standard for Swine (JFSS: 1993). However, threonine requirements of piglets at the age of 7 days and 14 days were 66% and 71%, and they consumed methionine+cystine of 56% and 59% of JFSS, respectively, which were the lowest rates. In conclusion, the results of this study indicated that when the daily gain of 1-5kg piglet was 200g, the amino acid requirements met those of JFSS, except for threonine and methionine+cystine.