Performance and metabolic profile of dairy cows during a lactational and deliberately induced negative energy balance with subsequent realimentation

Abstract

Homeorhetic and homeostatic controls in dairy cows are essential for adapting to alterations in physiological and environmental conditions. To study the different mechanisms during adaptation processes, effects of a deliberately induced negative energy balance (NEB) by feed restriction near 100 d in milk (DIM) on performance and metabolic measures were compared with lactation energy deficiency after parturition. Fifty multiparous cows were studied in 3 periods (1=early lactation up to 12 wk postpartum; 2=feed restriction for 3 wk beginning at 98±7 DIM with a feed-restricted and control group; and 3=a subsequent realimentation period for the feed-restricted group for 8 wk). In period 1, despite NEB in early lactation [-42 MJ of net energy for lactation (NE(L))/d, wk 1 to 3] up to wk 9, milk yield increased from 27.5±0.7 kg to a maximum of 39.5±0.8 kg (wk 6). For period 2, the NEB was induced by individual limitation of feed quantity and reduction of dietary energy density. Feed-restricted cows experienced a greater NEB (-63 MJ of NEL/d) than did cows in early lactation. Feed-restricted cows in period 2 showed only a small decline in milk yield of -3.1±1.1 kg and milk protein content of -0.2±0.1% compared with control cows (30.5±1.1 kg and 3.8±0.1%, respectively). In feed-restricted cows (period 2), plasma glucose was lower (-0.2±0.0 mmol/L) and nonesterified fatty acids higher (+0.1±0.1 mmol/L) compared with control cows. Compared with the NEB in period 1, the decreases in body weight due to the deliberately induced NEB (period 2) were greater (56±4 vs. 23±3 kg), but decreases in body condition score (0.16±0.03 vs. 0.34±0.04) and muscle diameter (2.0±0.4 vs. 3.5±0.4 mm) were lesser. The changes in metabolic measures in period 2 were marginal compared with the adjustments directly after parturition in period 1. Despite the greater induced energy deficiency at 100 DIM than the early lactation NEB, the metabolic load experienced by the dairy cows was not as high as that observed in early lactation. The different effects of energy deficiency at the 2 stages in lactation show that metabolic problems in early lactating dairy cows are not due only to the NEB, but mainly to the specific metabolic regulation during this period.

Analysis of daily body weight of dairy cows in early lactation and associations withproductive and reproductive performance

“…The difference between mean BW at calving and nadir BW (−51 kg of weight loss) was expected, due to the typical NEB in early lactation as described by Gross et al (2011), who investigated BW loss and BCS associated with decreased dry matter intake (DMI) leading to mobilization of body reserves. Cumulative yields over the first 100 DIM of multiparous cows were greater (P<0.01) than those of primiparous cows, as it is well established that mature cows produce more milk than first-lactation ones (NRC, 2001).…”

Evaluation of blood metabolites in dairy cows grazing under two pasture allowances and supplemented with corn silage under restricted grazing conditions

“…Metabolic disorders of nutritional origin are common in the first months of lactation, because cows are accompanied by a degree of negative energy balance, increasing the rate of mobilization of lipid reserves and increasing concentrations of NEFA and ketone bodies in blood and milk (Gross et al, 2011;Urdl et al, 2015). During periods of herbage shortage and swards with low herbage mass, to control the presentation of nutritional metabolism imbalances and mitigate the effects of an unbalanced diet based on pasture, the use of supplementary food is necessary to ensure a stable supply in quantity and quality of nutrients, in conjunction with proper grazing management (Bjerre-Harpøth et al, 2012;Barrientos et al, 2013;Morales et al, 2014;Ruiz-Albarrán et al, 2016).…”

Indices of heart rate variability as potential early markers of metabolic stress and compromised regulatory capacity in dried-off high-yielding dairy cows

“…In concert with these energy-saving mechanisms, NEFA plasma concentrations are increased indicating that nutrients are provided by lipolysis (Gross et al, 2011;Weber et al, 2013). In addition, a marked elevation (179%) of the growth hormone-releasing and orexigenic peptide hormone ghrelin (Wertz-Lutz et al, 2006;Bradford and Allen, 2008) has been observed in all cows.…”

“…On the other hand, dairy cows experience distinct metabolic stress during periods of high metabolic load and inadequate energy/fuel availability leading to a negative energy balance (NEB), for example, as a result of infectious or metabolic/digestive disorders, during heat stress, and in particular during the transition period around parturition (Gross et al, 2011). Subclinical disorders of the energy metabolism facilitate failure of homeorhetic and homoeostatic adaptations resulting in health problems and reduced performance (Mudron et al, 2005).…”