Effect of Body Fatness and Glucogenic Supplement on Lipid and Protein Mobilization and Plasma Leptin in Dairy Cows

Abstract

Twenty-four multiparous Ayrshire cows were used in an experiment to test the effect of body fatness and glucogenic supplement, fed during the transition period, on lipid and protein mobilization and plasma hormone concentrations. Eight weeks before their expected calving date, the cows were divided into blocks of 4. Two cows with the highest body condition score within each block were then allocated to a test (T) group and the other 2 cows to a control (C) group. To scale up the differences between fatter and thinner cows, the estimated energy allowance was 40% higher in group T than in group C between d 56 and 21 prepartum. For the final 3 wk before calving, all the cows were fed according to energy recommendations for pregnant cows. Within C and T groups and blocks, cows were randomly assigned into groups with (G1) or without (G0) glucogenic supplement. Division to G0 and G1 groups was made 2 wk before the expected calving and continued for 56 d postpartum. After calving, all the cows received grass silage ad libitum and a common daily concentrate allowance. No significant differences were detected in feed intake and milk yield between C and T. The T groups showed an earlier rise of nonesterified fatty acids as calving approached and had higher plasma nonesterified fatty acids during the final week of pregnancy and lactation wk 1 to 3. At the same time, adipose tissue samples from fatter cows tended to show higher in vitro lipolytic responses to added norepinephrine, as monitored by glycerol release. Protein mobilization was elevated during the final week of pregnancy and tended to be more increased in fatter cows. Glucogenic supplement did not decrease lipid or protein mobilization. Fatter cows had higher plasma leptin concentration prepartum, showed a more pronounced decrease in leptin concentration near calving, and had higher plasma leptin concentration after calving. In conclusion, fatter cows initiated more extensive mobilization of body fat before calving and this continued during the first lactation weeks. Plasma leptin concentration in early-lactation cows was associated with body fatness and not with estimated energy balance.

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

“…The higher plasma NEFA and BHBA concentrations for cows in the high group around parturition are in accordance with other studies (Kokkonen et al, 2005;Ohgi et al, 2005;Hammon et al, 2009) and can be explained by high fat mobilization, resulting in excessive hepatic fat accumulation after calving.…”

“…On the other hand, cows in the low group, with the lowest mobilization, had the lowest plasma leptin concentrations, and cows in the high group, with highest the mobilization, had comparable plasma leptin concentrations before calving as those in the medium group but showed the greatest decrease in plasma leptin after calving. Findings by Kokkonen et al (2005) that BCS is related to plasma leptin cannot be completely confirmed by our study, but our results are in accordance with those of Hammon et al (2009). For cows in the high group, the capacity for hepatic fat oxidation was obviously limited.…”

“…Thus, plasma leptin concentrations decreased around calving in all groups, as shown before (Reist et al, 2003;Kokkonen et al, 2005), but were highest for cows in the medium group, which exhibited the greatest subcutaneous fat mobilization at the same time. The greater leptin concentration for cows in the tsen and Bosclair (2001).…”

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

“…High-yielding dairy cows are not able to compensate completely for the energy lost due to milk production during early lactation by a sufficient increase of feed intake (Bell and Bauman, 1997;Drackley et al, 2001;Kokkonen et al, 2005). This leads to the mobilization of body reserves resulting in a negative energy balance that may be associated to health problems.…”

Effect of various dietary fat supplementations on liver lipid and glycogen of high-yielding dairy cows in the peripartal period

“…To avoid such metabolic disorders, additional energy sources like glycogen precursors (Kokkonen et al, 2005) and/or different rumen-protected fat supplements at various degrees of saturation, such as calcium soaps (Jenkins and Palmquist, 1984;Grummer, 1988), hydrogenated fatty acids (Jenkins and Palmquist, 1984) and triglycerides (Grummer, 1988) are added to the diet of highyielding or multiparous dairy cows. However, the effects of these different fat supplementations on hepatic lipid metabolism in ruminants are not fully understood.…”