ARTICLE 54 FEED & ADDITIVE MAGAZINE September 2022 Improved Reproduction Pregnancies from first service were higher (P = 0.09) for cows fed ReaShure as compared to cows that were not (41.3 vs. 23.6%, Figure 3). These results emphasize the importance of having an excellent transition period. Calf Performance Researchers in this study followed the performance of heifer calves out to one year of age. Heifers born to the cows receiving ReaShure during the closeup dry period tended to be slightly smaller at birth than calves from control cows (Table 1). However, by 50 weeks of age heifers from cows fed ReaShure were significantly larger (P = 0.05) than those from cows not fed ReaShure during the close-up dry period. Average daily gain of heifers whose dam was fed ReaShure during the close-up dry period was 0,85 kg per day which was 40 gr per day faster than heifers from dams not fed ReaShure (P = 0.06). SUMMARY This study is consistent with previous peerreviewed ReaShure research that demonstrated improvements in health and production parameters during and immediately following the transition period. However, this is the first study to measure the impact of feeding ReaShure on milk production over the entire lactation. Cows receiving ReaShure during the transition period (21 days prepartum to 21 days postpartum) produced more milk per day over the 40-week lactation, had a lower prevalence of subclinical milk fever, showed improvements in first service conception rates, produced more immunoglobulin G in the colostrum and their heifer calves grew significantly faster through one year of age. About Marcos Zenobi, MSc., PhD. Marcos Zenobi is originally from Argentina. After receiving his Master of Science degree in 2013, he moved to Gainesville, Florida to start his PhD under Dr. Charles Staples and Dr. Jose Santos in the Animal Sciences Graduate Program at the University of Florida. Dr. Zenobi is a specialist in dairy nutrition and management. He now lives in Cordoba where he leads Balchem Technical Services, mostly in Latin America. He also teaches undergraduate and graduate students in Argentina. Table 1. Effect of in utero exposure to ReaShure on calf performance Variable Body Weight, kg Calving Weaning 50 wk of age ADG (kg/d) From calving to weaning From weaning to 50 weeks From calving to 50 weeks ReaShure 38,3 77,6 335 0,63 0,89 0,85 P Value 0.07 0.80 0.05 0.67 0.05 0.06 Control 40,4 76,7 321 0,61 0,85 0,81 Figure 3. Effect of feeding ReaShure during transition on reproduction
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