Relationship of body weight at first calving with milk yield and herd life

Abstract

The objectives of this study were to investigate the association of body weight (BW) at first calving (BWFC) and maturity rate (MR; BWFC as a percentage of mature BW) with first-lactation 305-d milk yield (FLMY), milk yield (MY) in the 24 mo following first calving (24MMY), herd life, and BW change (BWC) through the first month of lactation in Holstein heifers. We retrieved daily milk production records and daily BW records from AfiFarm (S. A. E. Afikim, Kibbutz Afikim, Israel). The data set included daily records for 1,110 Holstein cows from The Pennsylvania State University (n = 435,002 records) and 1,229 Holstein cows from University of Florida (n = 462,013 records) that calved from 2001 to 2016. Body weight at first calving was defined as mean BW from 5 to 10 d in milk of the first lactation, whereas BWC represented change from BWFC to average BW from 30 to 40 d in milk. Firstlactation 305-d MY and 24MMY were analyzed with a linear model that included effects of farm-year-season of calving, age at calving, and quintiles of BWFC, MR, or BWC. Body weight change was analyzed with the same model to determine associations with BWFC. Survival analysis was performed to estimate the effect of BWFC on survival. Heifers in the top 60% of BWFC had significantly higher FLMY (10,041 to 10,084 kg) than lighter heifers (9,683 to 9,917 kg), but there was wide variation in every quintile, and no relationship of BWFC and FLMY existed within the top 60%. Relationships between BWFC and 24MMY were not significant. Heifers with higher BWFC or MR lost significantly more BW in early lactation. Although BWFC and MR were significant predictors of FLMY, they accounted for <3% of variation in FLMY or 24MMY, suggesting that BWFC and MR are not primary contributors to variation in MY. Compared with the lightest heifers, the heaviest heifers were 49% more likely to be culled at a given time. These data indicated that, among heifers managed similarly, heavier heifers produced more milk in first lactation than lighter heifers but lost more BW, faced a higher risk of being culled, and did not produce more milk in the long term. Based on our data, heifers that reach between 73 and 77% MR at first calving can produce more milk in their first lactation without sacrificing long-term MY and herd life.

Effect of diet energy level and genomic residual feed intake on bred Holstein dairy heifer growth and feed efficiency

“…The excess fat gain and condition for heifers fed HE can have negative consequences around calving such as increased calving difficulty (Hoffman et al, 1996). Recent work by Han et al (2021) found that heifers which were heavier at first calving and likely with greater condition had greater first-lactation production, however, were culled from the herd at an earlier age due to greater negative energy balance and metabolic disease postcalving, and reduced reproduction. These results confirm the validity of the ultrasound technique, as the rump fat depth followed closely the observed final BCS.…”

“…Delayed breeding or poor conception allowed heifers to gain additional weight and condition before calving; thus, the reproduction and nutrition programs both play important roles in heifer management. In addition, a study by Han et al (2021) found that heifers with higher BW (>570 kg) and maturity rate (>80% of mature BW at first calving) after first calving had somewhat higher first-lactation milk yields, but did not have greater milk yield through the first 24 mo after first calving. Heavier first-lactation cows also had greater BW loss during the first month of lactation, greater culling risks, and less longevity.…”

ADSA Foundation Scholar Award: New frontiers in calf and heifer nutrition—From conception to puberty

“…After fully transitioning to solid feed, there are many different strategies that can be employed to ensure proper development during the next crucial stages of life (i.e., puberty, pregnancy, calving). The established guidelines for heifers in our industry is to target first calving between 22 and 24 mo at 0.82 × mature BW (Van Amburgh et al, 2019); however, recent data suggests that a target of 0.73 to 0.77 × mature BW increases milk production in first lactation without compromising long-term production (Han et al, 2021). Certainly, heifer rearing targets and requirements are not well understood during the prepubertal and postpubertal phases and may be influenced by nutrition earlier in life.…”

Relative variability of phenotypic traits and indicators of milk productivity of cows

“…Інтенсивність росту телиць залежить також від генотипових чинників, а також тісно пов'язана з рівнем молочної продуктивності (Laduka et al, 2010;Romanenko et al, 2010;Poslavska et al, 2016b;Fedorovych et al, 2016). Багатьма вченими (Gil et al, 2018;Polupan & Siriak, 2019, Ferenz et al, 2018Han et al, 2021) доведено, що між інтенсивністю росту телиць та їхньою майбутньою молочною продуктивністю існує кореляційна залежність.…”