不同苜蓿草粉水平对初产母猪生产和繁殖性能的影响

为了探讨初产母猪的后备期、妊娠期饲粮中不同比例的苜蓿草粉,对其生长性能和繁殖性能的影响,试验选用640头日龄110 d、体重45 kg左右的健康后备母猪(长×大),采用单因子完全随机设计,分为4个处理,分别为:对照组(0%草粉组)、5%草粉组、10%草粉组、15%草粉组,每个处理4个重复,每个重复40头猪。妊娠期选取增重和发情较好的5%草粉组后备期母猪,发情配种后分为对照Ⅰ组(0%草粉组)、10%草粉组、15%草粉组、20%草粉组,后备期对照组母猪继续作为妊娠期的对照组,共5个处理,每个处理4个重复,每个重复3头猪。结果表明:1)在后备期45~70 kg阶段,试验组的采食量均低于对照组,随着苜蓿草粉用量的增加,采食量依次下降;5%草粉组的日增重显著高于、料重比显著低于10%和15%草粉组(P<0.05),但与对照组无显著差异;3个试验组中,只有5%草粉组的增重成本低于对照组,且使用苜蓿草粉愈多,成本愈高。在后备期70~130 kg阶段,无论是采食量还是日增重,3个试验组均低于对照组,随着草粉用量增加,采食量和日增重均依次下降,其中10%和15%草粉组显著低于对照组(P<0.05),但与5%草粉组差异不显著;3个试验组的料重比和增重成本均高于对照组,且有随着苜蓿草粉用量增加而依次增加的趋势,其中15%草粉组显著高于对照组(P<0.05)。添加5%的苜蓿草粉对母猪发情率有改善,但各组之间差异不显著。2)在妊娠期阶段,草粉组的背膘增厚显著高于对照组和对照Ⅰ组(P<0.05);对照Ⅰ组和10%、15%、20%苜蓿草粉组的初生活仔率均显著高于对照组,初生窝重分别比对照组提高了14.88%、6.89%、12.31%、24.48%,弱仔率分别降低了53.44%、36.39%、87.37%、62.78%,尽管均未达到显著差异程度,但说明后备期饲粮中使用苜蓿草粉对妊娠期母猪产仔数及仔猪健康有良好的后续效应,后备期用5%苜蓿草粉妊娠期使用20%苜蓿草粉效果最佳。综合得出,后备期添加5%的苜蓿草粉不会影响后备母猪生长但会提高发情率,后备期添加5%草粉妊娠期不添加时,母猪的繁殖效果也得到改善;妊娠期添加20%的苜蓿草粉产活仔率和初生窝重最佳。

Effect of different levels of alfalfa meal on productivity and reproductive performance of primiparous sows

The objective of this study was to explore the effects of different proportions of alfalfa meal in the diet of replacement gilts and pregnant sows on production and reproductive performance. 640 healthy gilts (Landrace×Large white) 110 days of age and 45 kg live weight were randomly divided into four treatment groups; control group (0% alfalfa meal), 5% alfalfa meal group, 10% alfalfa meal group and 15% alfalfa meal. Each treatment was replicated 4 times with 40 pigs in each replicate. The gilts offered 5% alfalfa meal had the best daily weight gain and estrus percentage. These animals were selected for on-going assessment and divided into a control group-Ⅰ(0% alfalfa meal), 10% alfalfa meal group, 15% alfalfa meal group and 20% alfalfa meal group following estrus and artificial insemination. The replacement gilts in the initial control group were retained in the control group (0% alfalfa meal) during the gestation period. There were 5 treatments with 4 replicates each treatment and 3 pigs in each replicate during pregnancy. The results showed that in replacement gilts weighing 45-70 feed intake of the alfalfa meal groups was lower than the control group, with greater reductions as alfalfa meal proportion increased. The daily gain and feed conversion rate in the 5% alfalfa meal group were significantly higher than those of 10% and 15% alfalfa meal groups (P<0.05), however, there were no differences between 5% alfalfa and control group. The weight gain cost of the 5% alfalfa meal group was lower than the control group. At 70-130 kg live weight, both feed intake and the daily gain in the three alfalfa meal groups were lower than the control group; the 10% and 15% alfalfa meal groups were significantly lower than the control group (P<0.05), declining linearly as alfalfa meal increased. The F/G (ratio of feed to gain) and the weight gain cost of the 3 alfalfa meal groups were higher than the control group, and had an increasing tendency with increasing % of alfalfa meal in the diets; the 15% alfalfa meal group was significantly higher than the control group (P<0.05). The estrus rate of gilts in the 5% alfalfa group was improved, but there were no difference among the 4 treatments. In pregnancy, the back fat thickness of the all alfalfa meal groups were significantly higher than the control group and the control group- Ⅰ(P<0.05). The live birth litter size of control group-Ⅰand the 10%, 15%, 20% alfalfa meal groups was significantly higher than that of control group, and the newborn litter weight was increased by 14.9%, 6.9%, 12.3% and 24.5% respectively, while the % of weak piglets declined by 53.44%, 36.39%, 87.37% and 62.78%, respectively. It was concluded that the growth performance of gilts fed 5% alfalfa meal was not affected but estrus rate and reproductive performance were improved. During pregnancy, live birth litter size, birth litter weight and piglets' health were greatest in the group fed 20% of alfalfa meal in the diet.