Abomasally infused SFA with varying chain length differently affect milk production and composition and alter hepatic and mammary gene expression in lactating cows

Abstract

The aim of the present study was to compare the effects of post-ruminally infused fat supplements, varying in fatty acid (FA) chain length, on animal performance, metabolism and milk FA. Eleven multiparous Holstein dairy cows were used in a replicated incomplete 3 × 3 Latin square design with 7-d periods, separated by 7-d washouts. Treatments were administered as abomasal infusions of enrichments providing 280 g/d of FA: (1) palmitic acid (98·4 % 16 : 0; PA), (2) caprylic and capric acids (56·2 % 8 : 0, 43·8 % 10 : 0; medium-chain TAG (MCT)) and (3) stearic acid (99·0 % 18 : 0; SA). Relative to PA, SA decreased the efficiency of fat-corrected milk production, which was associated with a tendency for higher DM intake and lower FA absorption with SA, whereas MCT was not different from PA for these variables. Milk fat concentration and yield were increased by PA relative to SA, but only fat yield tended to be greater relative to MCT. Relative to PA, MCT increased milk fat concentration of FA < 16 C, whereas SA increased FA > 16 C. Expression of mammary stearoyl-coA desaturase 1 was lower with SA than with PA. Relative to PA, liver expression of adenosine monophosphate-activated protein kinase-1 and pyruvate kinase was increased with MCT, whereas expression of these genes tended to be increased by SA. The mechanism of increased fat secretion with PA does not seem to be related to a modulation of the expression of lipogenesis-related genes, but rather to increased substrate availability as reflected by milk FA profile.

Effects of abomasal infusions of fatty acids and 1-carbon donors on apparent fatty acid digestibility and incorporation into milk fat in cows

“…The apparent digestibility of FA in our study was found to be well within the range of previously reported estimates in ruminants (Andrews and Lewis 1970;Rico et al, 2017Rico et al, , 2020. Comparability across studies may be limited by methodological differences, such as FA feeding level and method of delivery, as well as by species-related differences (Steele and Moore, 1968;Boerman et al, 2015).…”

“…Some of the major factors influencing FA digestibility include the dietary FA load, FA matrix (e.g., whole seeds vs. calcium salts), degree of esterification (i.e., free FA vs. triglyceride), degree of saturation (i.e., unsaturated vs. saturated), and carbon chain length (Andrews and Lewis, 1970;Palmquist, 1991;de Souza and Lock, 2019). Compared with UFA, the digestibility and absorbability of long-chain SFA are generally limited (Andrews and Lewis, 1970;Pantoja et al, 1996;Rico et al, 2020) because of higher melting points relative to FA with shorter carbon chains (Steele and Moore, 1968). Although the diet of dairy cows is mostly composed of 18-carbon (18C) PUFA, extensive rumen hydrogenation dictates that the majority of FA reaching the small intestine are SFA (Doreau and Ferlay, 1994), and the duodenal flow of FA is high in stearic acid (18:0), at rates commonly exceeding 500 g/d (Lock et al, 2006).…”

“…As the duodenal flow of 18:0 increases, linear reductions in 18:0 and total FA digestibility are observed (Boerman et al, 2015), thus limiting the availability of FA for metabolic use. The duodenal flow of palmitic acid (16:0) is typically lower than that of 18:0, and its digestibility is comparable overall (Boerman et al, 2015), although it has sometimes been reported to be higher (Steele and Moore, 1968;Rico et al, 2020). Intriguingly, the digestibility of 16:0 does not seem to be related to its duodenal flow (Boerman et al, 2015), which may help explain why dietary supplementation of 16:0 results in better production responses in lactating cows (Rico et al, 2014).…”

Stearic acid does not overcome conjugated linoleic acid trans-10, cis-12-induced milk fat depression in lactating ewes

“…In contrast to ACACAα PII, the expression of FASN was not affected by SA relative to Control and seemed to counter the effects of CLA in the CLASA treatment. Rico et al (29) reported no effect of abomasal infusions of C18:0 on ACACAα and FASN gene expression in dairy cows. Further, the mRNA abundance of PPAR-γ, a key transcription factor for lipogenic genes, was increased by the SA treatment, which suggests that this saturated FA is a natural agonist for PPAR-γ.…”

Peroxisome Proliferator-Activated Receptor Activation in Precision-Cut Bovine Liver Slices Reveals Novel Putative PPAR Targets in Periparturient Dairy Cows

“…The minor effect on the transcription of the RT-qPCR measured putative PPAR target genes in the PCLS treated with the various PPAR agonists may indicate poor response of the liver to PPAR agonist. This is a possibility, considering the poor response observed in prior studies using in vivo supplementation of C16:0 on liver transcriptome ( 16 , 44 , 45 ) or the lack of response on P450 enzyme activity to the PPARα agonist Wy-14643 in goats ( 46 ). This possibility would be a major obstacle for any nutrigenomic interventions to improve liver performance in dairy cows via activation of PPAR, as previously advocated ( 13 ).…”