Effects Of Dietary Amino Acid Levels On The Productive Performance, Blood Indicators And Amino Acid Concentrations Of Milk In Lactating Sows

The present study was conducted to investigate the effects of four dietary amino acid levels on the reproductive performance, blood indicators and amino acid concentrations of milk in lactating sows.200 Large White×Landrace sows, with similar parity, body condition and presumed parturition date, were allocated to four diets with 50 replicates of one sow in each group. Four diets were formulated by 0.9% (0.9% group),1.0%2(1:0% group),1.1%(1.1% group) and 1.2%(1.2% group) of dietary lysine levels, and crystalline valine, threonine, methionine and Trpptophan were supplemented into diets to ensure the same digestible amino acid pattern for all the four diets. The results were as follows:1. Dietary amino acid levels of lactating sows affected the backfat laoss and the performances of litter. Backfat loss in 1.0% group was 0.57 mm lower than 1.2% group (P< 0.05).1.0% group resulted in 4.48% and 4.34%(P<0.01) greater litter weaning weight than0.9% group and 1.2% group.1.0% group improved average daily weight gain by 5.45% and 4.74%compared with 0.9% group andl.2% group (P<0.01).1.1% group resulted in 4.25% and 4.12% (P<0.01) greater litter weaning weight than 0.9% group and 1.2% group.1.1% group improved average daily weight gain by 4.73% and 4.03% compared with 0.9% group and 1.2% group (P<0.01). Dietary amino acid levels had no significant effects on interval from weanling to estrus (P>0.05).2. Dietary amino acid levels of lactating sows affected the plasma urea nitrogen and 3-Methylhistidine concentration. The concentrations of plasma urea nitrogen of sows on the 10th day of lactation in 1.0% group were significantly lower than other groups (P<0.05); The concentrations of plasma urea nitrogen of sows on the 17th day of lactation in 1.0% group and 1.1% group were lower than that in 1.2% group (P<0.05). The concentrations of plasma 3-Methylhistidine of sows on the 17th day of lactation in 1.0% group were significantly lower than 1.2% group (P<0.05).3. Dietary amino acid levels of lactating sows affected the plasma creatinine concentrations. The concentrations of plasma creatinine of sows on the 10th day of lactation in 1.0% group were significantly lower than that in 1.1%group (P<0.05); The concentrations of plasma creatinine of sows on the 17th day of lactation in1.0% group,1.1% group andl.2% group were significantly lower than that in0.9% group (P<0.05).4. Dietary amino acid levels had no significant effects on the cincentrations of plasma Triglyceride and cholesterol of sows on 10th and 17th day of lactation (P>0.05).5. Dietary amino acid levels of lactating sows affected the plasma amino acid concentrations. The concentrations of plasma lysine, threonine, valine,methionine, isoleucine, citrulline, glutamic acid, glycine (P<0.01)and leucine (P<0.05) of sows on the 10th day of lactation in 1.0% group were significantly lower than that in 1.2% group. The concentrations of plasma lysine, threonine, valine, isoleucine, citrulline, glutamic acid and leucine (P<0.01)and phenylalanine(P<0.05) of sows on the 17th day of lactation inl.0% group were significantly lower than that in 1.2% group.6. Dietary amino acid levels of lactating sows affected the amino acid concentrations in milk. Lysine concentration in milk was higher as the dietary amino acid level (P<0.01), valine, isoleucine, leucine, phenylalanine (P<0.01) and methionine (P<0.05)concentrations in milk in 1.0% group were lower than that in 1.2% group.We can draw conclusions from above results that:Based on an ideal dietary amino acid pattern(Dlys:Val:Thr:Met+Cys:Trp= 100: 85:66:60:19),with daily feed intaking 5.9kg/d and intaking total lysine 59 g/d, the lactational sows could maxlmum the amino acid utilization and had the best productive performance.