Effects of Short Dry Periods on Performance and Metabolic Status in Holstein Dairy Cows

Abstract

To evaluate effects of different dry period lengths on milk yield, milk composition, and energy balance of dairy cows, 122 multiparous and primiparous Holstein dairy cows were used in a completely randomized experimental design with 56-, 42-, and 35-d dry period lengths. Actual dry period lengths for respective treatments (TRT) were 56 +/- 5.1 d, 42 +/- 2.1 d, and 35 +/- 2.7 d. Overall, cows in the 42- and 56-d TRT gained more body condition than those in 35-d TRT during the dry period; however, postpartum body condition score did not change substantially among the TRT. Although from 3 to 210 DIM, differences were not detected in the milk yield of multiparous cows between the 35- and 56-d TRT, primiparous cows in the 35-d TRT produced less milk than those in 56-d TRT. In primiparous cows, the milk production at wk 9, 10, and 11 of lactation was lower in the 35-d compared with the 56-d TRT. Primiparous cows in the 35-d compared with the 56-d TRT produced less milk protein. In the 35-d TRT, serum triglyceride concentration was greater in primiparous cows than in multiparous cows during the peripartum period. Among primiparous cows, those in the 56-d TRT had greater concentrations of nonesterified fatty acids than those in the 35-d TRT during the peripartum period. No significant differences were observed in concentrations of serum glucose, insulin, and insulin-like growth factor-I during early lactation among TRT. There was also no difference among TRT for incidence of metabolic disorders. Thus, this study indicates that shortening the dry period to 35 d may be beneficial in multiparous and overconditioned cows, but not in primiparous cows.

Effects of continuous lactation and short dry periods on mammary function and animal health

“…Although some recent studies have demonstrated small (3.6%) or no decrease in milk production following SDP with or without recombinant bovine somatotropin (rbST) supplementation in dairy cows (Schairer, 2001;Bachman, 2002;Gulay et al, 2003), most recent studies support the previous demonstration of milk yield depression in cows with SDP Pezeshki et al, 2007 andWatters et al, 2008). Discrepancies between studies reporting an effect of SDP on subsequent milk production may arise from a multitude of factors, such as differences in parities, management schemes, genetic potential for milk production, breed, experimental models (between-cow, within-cow or half-udder model) and the number of cows used in a specific study (statistical power).…”

“…However, a 30-day SDP in multiparous cows has often been shown to have no impact on subsequent milk yield. When the additional 30 days of production in the previous lactation are included in the milk yield estimate there is often a production advantage for use of 30-day SDP in multiparous cows (Annen et al, 2004a;Pezeshki et al, 2007 and.…”

“…Further, dairy cows experience many endocrine, nutritional and metabolic changes around calving (Goff and Horst,1997;Goff et al, 2002). During this transition period, factors that are known to influence immune function could be affected by DPL (Pezeshki et al, 2007).…”

“…It has been suggested that cows with short or omitted dry periods show improved dry matter intake, metabolic profiles, body condition score, BW and mean negative energy balance ( Pezeshki et al, 2007 andWatters et al, 2008). It appears that following short or eliminated dry periods, the energy balance is improved around calving by reduced milk production, less nutritional and metabolic stress and the resulting ease of transition to lactation (Pezeshki et al, 2007 andSchlamberger et al, 2010).…”

Dry period length of dairy cows : milk composition and quality

“…Shortening the dry period to 28 -35 days also resulted in a statistically significant milk yield loss (-1.4 kg/d). Milk yield loss as a result of dry period reduction was reported to be stronger for primiparous cows than for multiparous cows (Annen et al, 2004, Pezeshki et al, 2007. Cows without a dry period were reported to produce approximately 800 -1200 kg milk during the last 56 -60 days of lactation (Schlamberger et al, 2010, Annen et al, 2004.…”