Metabolism and lactation performance in dairy cows fed a diet containing rumen-protected fat during the last twelve weeks of gestation

Abstract

Effects of dietary fat supplementation prepartum on liver lipids and metabolism in dairy cows are contradictory. Thus, we examined in 18 German Holstein cows (half-sib; first lactation 305-d milk yield >9,000 kg) whether dietary fat:carbohydrate ratio during the last trimester of gestation affects lipid metabolism and milk yield. The diets were formulated to be isoenergetic and isonitrogenous but differed in rumen-protected fat (FD; 28 and 46.5 g/kg of dry matter during far-off and close-up dry period; mainly C16:0 and C18:1) and starch concentration [carbohydrate diet (CD); 2.3 times as much starch as FD]. Diets were given ad libitum starting 12 wk before expected parturition. After parturition all cows were fed a single lactation diet ad libitum for 14 wk. With the FD treatment, dry matter intake was depressed prepartum, milk yield during first 4 wk of lactation was lower (36.9 vs. 41.0 kg/d), and postpartum energy balance during this period was more negative. During the first 4 wk, cows in the FD group had lower lactose percentage and yield but higher milk fat, whereas milk protein and fat yield as well as energy-corrected milk did not differ. Between wk 5 and 14, milk fat and milk protein percentage was lower in CD than in FD. Milk fat C14:0 was lower and C16:1 was higher in the FD group. For FD cows, plasma triacylglycerol, nonesterified fatty acids, and cholesterol concentrations were higher prepartum, whereas plasma beta-hydroxybutyrate and glucose concentrations were lower. During the first 10 d after parturition, plasma triacylglycerol concentration was higher in FD, and prepartum plasma glucose and cholesterol differences persisted during the first 14 wk of lactation. Irrespective of prepartum nutrient composition, concentrations of plasma leptin and subcutaneous fat leptin mRNA decreased between -10 d to +10 d relative to parturition, and liver lipids and glycogen reached maximum and minimal values, respectively, 10 d after parturition. Acetyl-coenzyme A carboxylase alpha mRNA abundance in subcutaneous fat decreased between -10 d to +1 d relative to parturition by 97%, whereas it was generally much lower in the liver and remained at a low level until wk 14 of lactation. In conclusion, feeding a diet containing rumen-protected fat during late lactation and dry period until calving negatively affected dry matter intake, energy balance, and milk yield during subsequent lactation, did not change acetyl-coenzyme A carboxylase alpha mRNA abundance in subcutaneous fat, and was not beneficial for liver lipid accumulation.

Variation in fat mobilization during early lactation differently affects feed intake, body condition, and lipid and glucose metabolism in high-yielding dairy cows

“…A marked decrease in plasma glucose concentrations in cows with excessive fat mobilization was seen in other studies (Ohgi et al 2005;Hammon et al, 2009). Lower plasma glucose concentrations after calving were also observed in some studies in which cows were fed fat (Hammon et al, 2008;Duske et al, 2009), but not consistently . Obviously, more glucose was spared for cows in the high group than in the medium and low groups by using NEFA and BHBA as energy-yielding substrates instead of glucose (Drackley et al, 2001).…”

“…Liver glycogen was determined using a commercial photometric test kit based on amyloglucosidase-catalyzed release of glucose (no. 10207748035; Boehringer Mannheim, Mannheim, Germany; Duske et al, 2009). …”

“…Carbon and nitrogen contents were analyzed by combustion and by elemental analysis using mass spectrometry (EA 1108, Carlo Erba Instruments, Rodano, Italy; Delta S, Finnigan MAT, San Jose, CA). The concentration of total liver fat was calculated according to the following equation: liver fat (% of DM) = 1.3038 × C (% of DM) − 4.237 × N (% of DM) − 0.58 × glycogen (% of DM) − 0.5215 × glucose (% of DM) (Duske et al, 2009). Liver glycogen was determined using a commercial photometric test kit based on amyloglucosidase-catalyzed release of glucose (no.…”

Supplementation of conjugated linoleic acid in dairy cows reduces endogenous glucose production during early lactation

“…Energycorrected milk and energy balance were calculated as described . Body weight, BCS, and back fat thickness (BFT) were recorded weekly (Duske et al, 2009). …”

Spirulina platensis (Arthrospira spp.): A Potential Novel Feed Source For Pasture-Based Dairy Cows

“…In addition, shortly after consumption, lipids are extensively hydrolysed and bio hydrogenated by lipase bacteria into different fatty acid intermediates in ruminants [30]. To combat the effect of bio hydrogenation, research on developing encapsulated rumen by-pass fat has been on-going [31]. Encapsulated fats can avoid bio hydrogenation and facilitate post-ruminal deposition of essential fatty acids [32].…”