Catheterization of Arteria Epigastrica Cranialis, Measurement of Nutrient Arteriovenous Differences and Evaluation of Daily Plasma Flow Across the Mammary Gland of Lactating Sows

Abstract

Catheterization of arteria epigastrica cranialis, measurement of nutrient arteriovenous differences and evaluation of daily plasma ow across the mammary gland of lactating sows.The objectives of the present study were: (i) to evaluate a novel procedure for catheterization of the mammary artery; (ii) to measure amino acid, glucose and calcium arteriovenous differences in lactating sows; and (iii) to evaluate the use of different markers in estimating mammary plasma ow by the Fick principle. Five multiparous sows were tted with two catheters, in the cranial epigastric artery and anterior mammary vein. Catheterization of the cranial epigastric artery was carried out with a new surgical technique. Implanted catheters remained functional until day 15 (in two animals), day 21 (one animal) and day 27 (one animal), whereas in one case this technique failed. Sampling of arterial and venous blood took place on days 9, 15, 21 and 27 of lactation. Mean extraction rates 9 SEM (percent) were 31.2 9 3.1 arginine (Arg), 16.4 92.5 glutamine (Gln), 27.2 9 5.7 threonine (Thr), 8.3 9 2.6 glycine (Gly), 12.4 9 2.7 alanine (Ala), 20.2 9 3.4 tyrosine (Tyr), 18.1 92.8 proline (Pro), 28.2 96.2 methionine (Met), 18.592.2 valine (Val), 26.4 9 3.1 phenylalanine (Phe), 30.2 9 3.1 isoleucine (Ile), 41.4 9 3.4 leucine (Leu), 32.2 9 4.0 lysine (Lys) and 20.09 2.76 glucose. There was a relatively high abundance of lysine in milk compared with the amount extracted from plasma. This suggests lysine to be limiting in the present experimental situation, which was probably due to a low feed intake only providing 31.4 g Lys day ¼ 1 on average.

14. Mammary blood flow and nutrient uptake

“…Plasma:milk values as high as 1,050 and 858 were also reported when lysine and methionine, respectively, were used as internal markers (Nielsen et al, 2002a, Table 14.1). These values raise questions when considering the reported low average daily milk production of 7.4 kg for a litter size of 12 (Nielsen et al, 2002a). In that same study, when calcium was used as marker, the average plasma flow was 2.8 l/min, a value falling within the reported range.…”

“…Unlike amino acids, calcium is not metabolized hence (Farmer et al, 2008b). Guan et al (2004a) Fick (lysine) 11 4.5 11.4 560 Guan et al (2004b) Fick (lysine) 11 3.6 10.7 490 Linzell et al (1969a) 2 Fick ( 3 HO) 6 1.9 3 6.2 441 3 Nielsen et al 2002bFick (lysine) 8 3.2 10 550 Nielsen et al 2002aFick (lysine) 12 5.5 7.4 1,050 Nielsen et al (2002a) Fick (methionine) 12 4.4 7.4 858 Nielsen et al (2002a) Fick (calcium) 12 2.8 7.4 548 Renaudeau et al (2002) Flow probe 12 3.6 3 11 471 3 Renaudeau et al 2002Fick (lysine) 12 3.9 4 11 511 Trottier et al (1997) Fick (lysine) 11 3.0 8.1 541…”

Review: Current knowledge on mammary blood flow, mammary uptake of energetic precursors and their effects on sow milk yield

“…Both Nielsen et al (2002a) and Dourmad et al (2000) showed a positive mammary AVD for calcium, and Dourmad et al (2000) also noted a positive uptake of phosphorus, with its AVD across mammary tissue increasing after a meal. However, the extraction rates of calcium and phosphorus from arterial blood (4.1 and 3.1%, respectively) were much lower than those of other major nutrients (ranging from 20 to 35%).…”

“…Plasma:milk ratios of 1050 and 858 using lysine and methionine, respectively, as internal markers were also reported (Nielsen et al 2002a, Table 1). These high ratios and corresponding plasma flow rate values raise questions when considering the reported low average daily milk production of 7.4 kg for a litter size of 12 (Nielsen et al 2002a). On the other hand, when, in that same study, calcium was used as marker, an average plasma flow value of 40599747 L d…”

“…Thus, one may question the validity of the lysine and methionine analytical measurements in milk and plasma used to estimate plasma flow rate in the study by Nielsen et al (2002a). The marker used may also come into play since it was suggested that calcium could potentially be a more adequate marker than organic components, which can be accreted or mobilized depending on mammary nutrient supply and milk output (Nielsen 2002a). However, calcium did not prove to be an ideal marker due to its extremely low mammary AVD.…”