| The experimental studies have measured the suitable phosphorus levels in the diets of Laoshan bred rams and lactating ewes in Laoshan dairy goats,and was aimed to provide theoretical basis for the scientific feeding and feeding standards of Laoshan dairy goats in the period of incubation and lactation.1.Study on phosphorus levels of bred ram in Laoshan dairy goat.30 bred ram in Laoshan dairy goats with a body weight of(21.07 + 0.30)kg were enrolled,and single factor design was adopted in the experiment.The sheep were randomly divided into 3 groups,10 replicates in each group,and 1 sheep each replicates.Phosphorus levels in diets of each group were 0.25%,0.35%and 0.45%,in which the energy,protein,and other nutrients were basically the same.The test period was 105 d,of which the trial period was 15 d,and the official period was 90 d.Regularly measured the dry matter intake,body weight,body size and serum biochemical indexes of the tested sheep,and the balance of phosphorus was determined by digestion and metabolism test.The result showed that:The effects of dietary phosphorus levels had no significant effect on the dry matter intake,the weight and average daily gain in 7,8,9 month old,the feed weight ratio and body size,the calcium,phosphorus,urea nitrogen content and alkaline phosphatase activity in serum,and the apparent digestibility of dry matter,crude protein,neutral detergent fiber(NDF),acid detergent fiber(ADF),and calcium(P>0.05).But the apparent digestibility of phosphorus in the 0.25%and 0.35%groups was significantly higher than 0.45%groups(P<0.05),and there was no significant difference in apparent digestibility of phosphorus between the 0.25%groups and the 0.35%groups(P>0.05).In the matter of the intake phosphorus,fecal phosphorus,urinary phosphorus,total phosphorus excretion,phosphorus deposition and digestible phosphorus,The 0.45%groups were significantly higher than the 0.25%group and the 0.35%group(P<0.01),the 0.35%groups were significantly higher than the 0.25%groups(P<0.01).In summary,the level of phosphorus in the ram of Laoshan dairy goat should be no more than 0.25%.2.Study on phosphorus levels of the lactating ewes in Laoshan dairy goat.30 healthy Laoshan dairy goats of 2 fetal were selected,whose weight was(56.55 ± 1.17)kg,milk yield(2.20± 0.07)kg/d,and the body condition and lactation period were similar.Single factor randomized grouping design was adopted,the sheep were randomly divided into 3 groups,10 replicates in each group,and 1 sheep each replicates.Phosphorus levels in diets of each group were 0.26%,0.36%and 0.46%,in which the energy,protein,and other nutrients were basically the same.The trial period was 15d,and the test period was 60d.The feed intake,milk yield,milk composition and blood biochemical indexes of dry matter were measured regularly.The result showed that:The there was no significant effect of dietary phosphorus level on dry matter intake in each group(P>0.05).When the phosphorus level was 0.36%,the milk yield was higher,which was significantly higher than that in the 0.26%and 0.46%groups(P<0.01),and the difference between the 0.26%,0.46%was not sigjnificant(P>0.05);The ratio of feed to milk was also lower in 0.36%groups,which was significantly lower than that in group 0.26%and group 0.46%(P<0.01),and there was no significant difference between the 0.26%and 0.46%groups(P>0.05).The dietary phosphorus level had no significant effect on dairy quality index including fat,milk protein,lactose,non fat milk solids,milk phosphorus and calcium(P>0.05);And had no significant effects on serum calcium,phosphorus,alkaline phosphatase and urea nitrogen(P>0.05).There was no significant difference in apparent digestibility of dry matter,crude protein,NDF,ADF and calcium(P>0.05),but the apparent digestibility of phosphorus in the 0.26%groups was significantly higher than that in the 0.36%groups and the 0.46%groups(P<0.01),and the 0.36%groups were significantly higher than those in the 0.46%groups(P<0.01).In the matter of the intake phosphorus,fecal phosphorus and total phosphorus excretion,the phosphorus levels in the 0.46%groups were significantly higher than those in the 0.26%groups and the 0.36%groups(P<0.01),and the 0.36%groups were significantly higher than those in the 0.26%groups(P<0.01);There was no significant difference of diet phosphorus levels between milk phosphorus and phosphorus excretion(P>0.05);In the matter of the digestible phosphorus,the phosphorus levels in the 0.36%groups were significantly higher than those in the 0.26%and 0.46%groups(P<0.01),and the 0.46%groups were significantly higher than those in the 0.26%groups(/P<0.01);In the matter of the phosphorus deposition,Phosphorus levels in the 0.36%groups were significantly higher than those in the 0.26%groups(P<0.05).the difference between the 0.26%groups and the 0.46%groups was not significant(P>0.05),and there was no significant difference between the 0.36%groups and the 0.46%groups(P>0.05).To sum up,the phosphorus level of 0.36%was suitable for Laoshan dairy goat in lactation period. |
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