Effects Of Partial Substitution Of Concentrate With Green Forage And Supplemental Fat On Reproductive Performance Of Changjia Sows

The objective of this study was to evaluate effects of partial substitutionof concentrate with ryegrass and supplemental fat on reproductiveperformance, serum items, and milk yield and composition in Changjiasows.Two experiments were carried out in Expt.1, twenty Changjia sows weredivided into two groups. Sows in control group were offered 100%concentrate (2.93Mcal DE/Kg, 13.78% CP in gestation and 3.01McalDE/Kg,15.61% CP during lactation). In another group,20-30% ryegrasswas used to substitute for concentrate. Reproductive performance in sowsand litter performance were determined, and economical benefit wasanalyzedThirty multiparous sows were used in Expt.2. They were devided into 6groups:Control group (C1,C2), Treatment 1 (T11,T12) and Treatment 2(T21,T22). A 2×2 factorial experiment was designed to investigate theeffect of ryegrass substitution (40% in Treatment 1 and 50% in Treatment2) and supplemental fat (10% in C2,T12 and T22 from late gestation tolactation) on sows' reproductive performance, growth rate of piglets,serum items, and milk yield and composition.Substitlltion of concentfate with ryegrass at 20-30% or 40-50% increasedweaning piglets, and improved firstborn litter weight,weaning litterweight and average litter weight gain (P>0.05). Supplemental fatenhanced piglits bom alive, weaning piglets and firstbom litter weight(P>0.05).The level of serum insulin (P>0.05) was increased with inclusion ofryegrass in the diet, but there was little effects on the concentration oftriglycerides, total protein. high density choIesterin. lower densitycholesterin and urine nitrogen in serum of sows. SuPplemental fatobviously enhanced the concentration of cholesterin(P<0.05), but littleeffects were observed on insulin, triglycerides, total protein, high densitycholesterin, lower density cholesterin and urine nitrogen in serum.Average daily milk yield and total milk yield were decreased withsubstitution of concentrate with ryegrass (P>0.05) and/or suPplementalfat(P<0.05).Inclusion of ryegrass in diets obviously decreased total solidconcentration (P<0.0l ) in milk of sows, but contents of protein and fat inmilk were uneffected(P>0.05). Supplemental fat increased milk solid,milk fat and IGF-l concentYation, but differences were not statisticallysignificant(P>0.05).Compared with the control, 20-30% Green forage substitution ofconcentrate decreased feed cost by 40.73talead during a propagateperiod, and profitted 44.23boead. The feed cost was 33.54ytaleadand 47.4l yUan/head lower than control when formula feed was substitutedwith ryegrass at 40 and 50% respectiely.In summary green forage such as ryegrass can substitute as many as 50%of fOrmula feed in sows diet. There is little positive effects ofsupplemental dietary fat on reproductve performance of sows and growthrate of piglets. There were no signit1cant differences in serum items, andmilk yield and milk composition between control and ryegrass replaced orfat-added groups. Substitution of formula feed with green forage maysignificantly decrease feed cost and increased income.