Karami-Shabankareh H, Kafilzadeh F, Piri V, Mohammadi H
Department of Animal Science, Faculty of Agriculture, Razi University, Kermanshah, Iran.
Reprod Domest Anim. 2013 Dec;48(6):945-53. doi: 10.1111/rda.12192. Epub 2013 Jun 18.
This study examined the effects of dry glycerol supplementation on follicular growth, post-partum interval to first ovulation, concentration of serum metabolites and hormones related to fertility, body condition score (BCS) and body weight (BW) in primiparous Holstein dairy cows. Sixty primiparous Holstein dairy cows were randomly assigned to two groups (control: n = 30 and glycerol supplemented: n = 30). Dry glycerol (250 g/day/cow) was fed as a top dressing to the common lactating total mixed ration (TMR) from parturition to 21 days post-partum. Ovaries were examined four times using ultrasonography on days 13, 19, 25 and 36 post-partum to determine ovarian follicular growth. Concentration of serum metabolites and hormones was determined weekly. Body condition score was evaluated weekly from weeks 1 to 5 after parturition, and BWs were recorded three times on days 1, 11 and 21 during the experimental period. The cows fed dry glycerol had more large follicles (p < 0.0001) and corpora lutea (CL) (p = 0.02) compared with the control cows. Days to the first ovulation (p = 0.06), days to first oestrus (p = 0.05), services per conception (p = 0.06) and days open (p = 0.004) were positively affected by dry glycerol supplementation. Serum concentration of glucose and insulin was higher in dry glycerol-supplemented cows (p = 0.1; p = 0.06, respectively). Feeding glycerol had no effect on mean serum concentrations of β-hydroxybutyrate, non-esterified fatty acids and IGF-1 during the experimental period. However, significant differences were observed at concentration of BHBA and IGF-1 (p = 0.02 and p = 0.04, respectively) between two groups on day 21 after calving. The cows in the glycerol-fed group had higher serum progesterone concentrations on days 33 (p = 0.007) and 36 (p = 0.004) after calving. Supplemented cows had lower body condition loss during weeks 1-5 after calving compared with the control cows (0.34 vs 0.41 BCS). In week 13 post-partum, the proportion of cycling cows was 83.3 and 69.9% for those which received supplemented or non-supplemented diet, respectively. These results demonstrated that feeding dry glycerol as a glucogenic supply may be useful to improve negative energy balance and reproductive efficiency in young cows which calve with high requirement of energy.
本研究考察了补充干甘油对初产荷斯坦奶牛卵泡生长、产后至首次排卵间隔、与繁殖力相关的血清代谢物和激素浓度、体况评分（BCS）及体重（BW）的影响。60头初产荷斯坦奶牛被随机分为两组（对照组：n = 30；补充甘油组：n = 30）。从分娩至产后21天，将干甘油（250克/天/头）作为顶层添加物添加到普通泌乳全混合日粮（TMR）中。在产后第13、19、25和36天，使用超声检查卵巢4次，以确定卵巢卵泡生长情况。每周测定血清代谢物和激素浓度。产后第1至5周每周评估体况评分，在实验期间的第1、11和21天记录3次体重。与对照组奶牛相比，补充干甘油的奶牛有更多的大卵泡（p < 0.0001）和黄体（CL）（p = 0.02）。补充干甘油对首次排卵天数（p = 0.06）、首次发情天数（p = 0.05）、每次受孕配种次数（p = 0.06）和空怀天数（p = 0.004）有积极影响。补充干甘油的奶牛血清葡萄糖和胰岛素浓度较高（分别为p = 0.1；p = 0.06）。在实验期间，饲喂甘油对血清β-羟基丁酸、非酯化脂肪酸和IGF-1的平均浓度没有影响。然而，在产犊后第21天，两组之间的BHBA和IGF-1浓度存在显著差异（分别为p = 0.02和p = 0.04）。在产犊后第33天（p = 0.007）和36天（p = 0.004），甘油饲喂组奶牛的血清孕酮浓度较高。与对照组奶牛相比，补充组奶牛在产后第1至5周的体况损失较低（0.34对0.41 BCS）。在产后第13周，接受补充或未补充日粮的奶牛中，发情周期奶牛所占比例分别为83.3%和69.9%。这些结果表明，作为生糖物质饲喂干甘油可能有助于改善能量需求高的初产奶牛的负能量平衡和繁殖效率。
