Effect of Prepartum Energy, Body Condition, and Sodium Bicarbonate on Production of Cows in Early Lactation

Abstract

In trial 1, the effects of dietary energy (102, 131 or 162% of requirement) in the dry period and of sodium bicarbonate (0 or .75% of diet dry matter) in early lactation were assessed with 31 cows in a 3 X 2 factorial arrangement of treatments. Body condition and weight increased linearly with prepartum energy. Dry matter intake and milk yield were similar across treatments through 12 wk postpartum. Sodium bicarbonate increased milk fat content only in the 131% group, an effect apparently related to greater mobilization of fat in that group. In trial 2, energy treatments imposed in late lactation (145 to 55 d prepartum) and in the dry period (55 to 0 d) were 1) cows fed to requirement in both periods, 2) cows overfed in the first and underfed in the second period, 3) cows fed to requirement in the first and overfed in the second period, and 4) cows overfed in both periods. Cows in treatments 1 and 2 (normal) calved in a thinner state than those in 3 or 4 (fat). In the first 12 wk postpartum, intake did not differ, but cows in groups 3 and 4 produced more milk. Sodium bicarbonate imposed factorially postpartum increased milk fat content. Overconsumption of energy prepartum did not impair production when high energy total mixed rations were fed postpartum.

Effect of prepartum compensatory nutrition regimen on metabolism and performance of dairy cows

“…No differences in milk yield were apparent during the first 12 weeks of early lactation. This data is supported by other studies, which found that dietary energy manipulation during the far-off dry period does not affect subsequent milk yield (Boisclair et al, 1986;Grum et al, 1996). In contrast, primiparous cows that had previously been reared on multi-step compensatory growth regimens from prepuberty through gestation have an average of 10% enhancement of lactation performance, and this increase carries through to the next lactation (Park et al, 1989;Ford and Park, 2001).…”

“…Vazquez-Anon et al (1997) fed rations differing in energy density and concentrate type during late lactation and documented no residual effects of higher dietary energy on DMI during the dry period or early lactation. Cows consuming energy at levels above requirements throughout the dry period do not have improved postpartum DMI compared with cows fed at recommended energy requirements (Boisclair et al, 1986;Agenas et al, 2003;Dann, 2004). In the present study energy intake of cows during the transition period and early lactation was not altered by previous plane of nutrition, as DMI did not differ, and a common diet was fed.…”

“…Cows in both treatments lost comparable amounts of body condition in the first 12 weeks of the ensuing lactation. Several studies have shown that overfeeding during the dry period and overconditioning at calving have detrimental effects on postpartum BW and body condition (Boisclair et al, 1986;Treacher et al, 1986;Smith et al, 1997). Our study was designed to achieve moderate body condition through the use of alternating periods of dietary energy restriction and refeeding, thus overconditioning was not an issue.…”

Effects of increasing days of exposure to prepartum transition diets on milk production and milk composition in dairy cows

“…Nonetheless, two of the three prepartum transition diets had strongly positive metabolisable protein balances and all had a positive ME balance, attributes that may have increased subsequent milk production by providing adequate substrate for fetal and mammary development. Similarly, increased BCS at calving, reflecting improved body tissue reserves, increased subsequent milk production 32,33 …”

“…Similarly, increased BCS at calving, reflecting improved body tissue reserves, increased subsequent milk production. 32,33 The importance of mobilised tissue protein as a source of amino acids for mammary metabolism and gluconeogenesis may be small over the period from calving to peak lactation, 34 but may PRODUCTION ANIMALS be important in the first 1 to 2 weeks of lactation. 16 An observed reduction in skeletal muscle fibre diameter of 25% immediately after calving 35 and a decline in the muscle protein:DNA ratio in ewes during early lactation 36 support the concept that skeletal muscle is an important source of endogenous amino acids in early lactation.…”