Plante-Dubé M, Bourassa R, Luimes P, Buczinski S, Castonguay F, Gervais R
Département des sciences animales, Université Laval, Pavillon Paul-Comtois, 2425 rue de l'Agriculture, Québec, QC, G1V 0A6, Canada.
Veterinary Hospital of Sherbrooke, 1771 rue King E, Sherbrooke, QC, J1G 5G7, Canada.
Animal. 2025 Jan;19(1):101382. doi: 10.1016/j.animal.2024.101382. Epub 2024 Nov 28.
In late gestation, the increased energy demand to support the rapid fetal growth can induce an acute negative energy balance associated with a high risk of pregnancy toxemia, especially for prolific ewes (carrying two or more fetuses). The current study was conducted to evaluate the effects of dietary energy during the last 6 weeks prepartum on the energy metabolism dynamic responses and the newborn lamb metabolic profile in prolific ewes. Forty-five crossbred (Dorset × Romanov) ewes were randomly assigned to 1 of 3 dietary energy densities: E: 8.36 MJ of metabolizable energy (ME)/kg DM for weeks -6 to -3 relative to lambing, followed by 10.01 MJ ME/kg DM for weeks -2 and -1; E: weekly increments from 7.99 to 12.69 MJ ME/kg DM; and E: 10.87 MJ ME/kg DM for the last 6 weeks of gestation. Dry matter intake (DMI; daily) and energy intake (MEI; daily), blood concentrations of beta-hydroxybutyrate (BHB) and glucose (every other day), as well as plasma concentrations of non-esterified fatty acids (NEFAs; weekly), BW and body condition score (BCS; twice weekly) were determined throughout the experimental period. The effect of time on DMI and MEI varied based on dietary energy densities and litter size. During the last week before lambing, DMI decreased for E and E ewes, as well as for ewes carrying quadruplets. On average, during week -5 to week -2 of gestation, E promoted the highest DMI and MEI, resulting in an increase of 0.16 BCS points between the pretreatment week and week -1 prepartum. In contrast, during the same period, BCS of E and E ewes decreased by 0.35 and 0.19 points, respectively, which was reflected by higher NEFA concentrations compared with E ewes. The greater litter size was also associated with decreased BCS. Compared with twin-bearing ewes, for which BCS remained stable, BCS decreased for triplet-, and even more intensively for quadruplet-bearing ewes. Consequently, plasma NEFA concentrations were higher for quadruplet-bearing ewes than for twin- and triplet-bearing ewes, especially during the last week prepartum. Blood BHB concentrations increased from 0.63 to 1.13 mM over time. Regardless of dietary treatments, in the last week prepartum, blood BHB concentrations increased for quadruplet-bearing ewes, being 2.6 and 2.2 times greater than for twin- and triplet-bearing ewes, respectively. These results suggest that dynamic responses of energy metabolism in late gestation of prolific ewes are influenced by both dietary energy level and litter size.
在妊娠后期，为支持胎儿快速生长而增加的能量需求会引发急性负能量平衡，这与妊娠毒血症的高风险相关，尤其是对于多胎母羊（怀有两个或更多胎儿）。本研究旨在评估产前最后6周的日粮能量对多胎母羊能量代谢动态反应和新生羔羊代谢特征的影响。45只杂交（多塞特×罗曼诺夫）母羊被随机分配到3种日粮能量密度中的1种：E组：相对于产羔，在妊娠第-6至-3周为8.36兆焦代谢能（ME）/千克干物质，随后在妊娠第-2和-1周为10.01兆焦ME/千克干物质；E组：每周从7.99兆焦ME/千克干物质递增至12.69兆焦ME/千克干物质；E组：在妊娠最后6周为10.87兆焦ME/千克干物质。在整个实验期间测定干物质摄入量（DMI；每日）、能量摄入量（MEI；每日）、β-羟基丁酸（BHB）和葡萄糖的血液浓度（每隔一天），以及非酯化脂肪酸（NEFA）的血浆浓度（每周）、体重（BW）和体况评分（BCS；每周两次）。时间对DMI和MEI的影响因日粮能量密度和产仔数而异。在产羔前的最后一周，E组和E组母羊以及怀有四胞胎的母羊的DMI下降。平均而言，在妊娠第-5至-2周期间，E组促进了最高的DMI和MEI，导致产前预处理周与第-1周之间的BCS增加0.16分。相比之下，在同一时期，E组和E组母羊的BCS分别下降了0.35分和0.19分，这表现为与E组母羊相比NEFA浓度更高。更大的产仔数也与BCS下降有关。与BCS保持稳定的双羔母羊相比，三羔母羊的BCS下降，四羔母羊下降更为明显。因此，怀有四胞胎的母羊的血浆NEFA浓度高于怀有双胞胎和三胞胎的母羊，尤其是在产前最后一周。血液BHB浓度随时间从0.63毫摩尔/升增加到1.13毫摩尔/升。无论日粮处理如何，在产前最后一周，怀有四胞胎的母羊的血液BHB浓度增加，分别是怀有双胞胎和三胞胎母羊的2.6倍和2.
