Key Laboratory for Animal Disease-Resistant Nutrition of the Ministry of Education of China, and Animal Nutrition Institute, Sichuan Agricultural University, Wenjiang, Chengdu 611130, People's Republic of China.
Chengdu Agricultural College, Wenjiang, Chengdu 611130, People's Republic of China.
J Anim Sci. 2021 Jun 1;99(6). doi: 10.1093/jas/skab121.
We investigated the effects of dietary fiber (DF) supplementation in normal or low crude protein (CP) diets on reproductive performance and nitrogen (N) utilization in primiparous gilts. In total, 77 Landrace × Yorkshire pregnant gilts were randomly allocated to four dietary treatments in a 2 × 2 factorial design. The groups comprised 1) equal intake of normal CP (12.82% and 0.61% total lysine), 2) low CP (LP) (10.53% and 0.61% total lysine), and 3) with or 4) without DF supplementation (cellulose, inulin, and pectin in a 34:10:1 ratio). A low-protein diet during gestation significantly reduced daily weight gain from days 91 to 110 of pregnancy (-162.5 g/d, P = 0.004). From N balance trials conducted at days 35 to 38, 65 to 68, and 95 to 98 of pregnancy, DF addition increased fecal N excretion at days 65 to 68 (+24.1%) and 95 to 98 (+13.8%) of pregnancy (P < 0.05) but reduced urinary N excretion (P < 0.05), resulting in greater N retention at each gestational stage. DF increased fecal microbial protein levels and excretion during gestation. An LP diet also reduced urinary N excretion at different gestational stages. An in vitro fermentation trial on culture media with nonprotein N urea and ammonium bicarbonate (NH4HCO3) as the only N sources revealed that microbiota derived from feces of gestating gilts fed the high DF diet exhibited a greater capacity to convert nonprotein N to microbial protein. Microbial fecal diversity, as measured by 16S rRNA sequencing, revealed significant changes from DF but not CP diets. Gilts fed an LP diet had a higher number of stillbirths (+0.83 per litter, P = 0.046) and a lower piglet birth weight (1.52 vs. 1.37 kg, P = 0.006), regardless of DF levels. Collectively, DF supplementation to gestation diets shifted N excretion from urine to feces in the form of microbial protein, suggesting that the microbiota had a putative role in controlling N utilization from DF. Additionally, a low-protein diet during gestation negatively affected the litter performance of gilts.
我们研究了在正常或低粗蛋白（CP）饮食中添加膳食纤维（DF）对初产母猪繁殖性能和氮（N）利用的影响。总共，77 头长白×约克妊娠母猪随机分配到 4 种日粮处理的 2×2 因子设计中。这些组包括 1）等量摄入正常 CP（12.82%和 0.61%总赖氨酸），2）低 CP（LP）（10.53%和 0.61%总赖氨酸），和 3）添加或不添加 DF 补充剂（纤维素、菊粉和果胶以 34:10:1 的比例）。妊娠期间的低蛋白日粮显著降低了妊娠第 91 天至第 110 天的日增重（-162.5g/d，P=0.004）。从妊娠第 35 天至第 38 天、第 65 天至第 68 天和第 95 天至第 98 天进行的氮平衡试验表明，DF 增加了妊娠第 65 天至第 68 天（+24.1%）和第 95 天至第 98 天（+13.8%）的粪便 N 排泄（P<0.05），但减少了尿 N 排泄（P<0.05），导致每个妊娠阶段的氮保留增加。DF 增加了妊娠期间粪便微生物蛋白水平和排泄。LP 日粮也减少了不同妊娠阶段的尿 N 排泄。以非蛋白氮尿素和碳酸氢铵（NH4HCO3）作为唯一氮源的培养物的体外发酵试验表明，来自高 DF 日粮饲养的妊娠母猪粪便的微生物群具有更大的将非蛋白氮转化为微生物蛋白的能力。16S rRNA 测序测量的粪便微生物多样性显示，DF 但不是 CP 日粮有显著变化。饲喂 LP 日粮的母猪产死胎数增加（每窝增加 0.83 头，P=0.046），仔猪初生重降低（1.52 公斤比 1.37 公斤，P=0.006），而不管 DF 水平如何。总的来说，DF 补充到妊娠日粮中，将氮排泄从尿液以微生物蛋白的形式转移到粪便中，表明微生物群在控制 DF 中的氮利用方面可能具有作用。此外，妊娠期间的低蛋白日粮对母猪的产仔性能产生负面影响。
