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Effect of timing of post‐partum introduction to pasture and supplementation with S accharomyces cerevisiae on milk production, metabolic status, energy balance and some reproductive parameters in early lactation dairy cows
Author(s) -
Al Ibrahim R. M.,
Whelan S. J.,
Pierce K. M.,
Campion D. P.,
Gath V. P.,
Mulligan F. J.
Publication year - 2013
Publication title -
journal of animal physiology and animal nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.651
H-Index - 56
eISSN - 1439-0396
pISSN - 0931-2439
DOI - 10.1111/jpn.12048
Subject(s) - nefa , zoology , lactose , pasture , lactation , ovulation , randomized block design , total mixed ration , biology , ice calving , medicine , endocrinology , food science , hormone , pregnancy , insulin , agronomy , genetics
Summary Dietary change, an inconsistent nutrient intake and high levels of milk production make the early post‐partum period ( PP ) a challenging time for the lactating dairy cow. This experiment investigates the effects of two early PP nutritional management strategies ( NM ): abrupt introduction to pasture ( AP ) or a total mixed ration ( TMR ) for 21 days followed by a gradual introduction to pasture over 7 days ( GP ), with ( Y ) or without ( C ) live yeast ( YS ) on milk production, energy balance ( EB ) and selected metabolic and reproductive variables. Forty multiparous dairy cows were assigned to one of four dietary treatments in a two ( AP vs. GP ) by two ( Y vs. C ) factorial, randomized block design. The experiment was conducted from days 1 to 70 PP . Blood samples were taken on day 1, day 5 and every 10 days until day 45 to determine metabolites, whilst intake ( DMI ), and EB were determined during week 6 PP . Milk was sampled weekly for fat, protein and lactose. Trans‐rectal scanning for reproductive variables commenced on day 10 PP . Animals in the GP group had a higher DMI (p = 0.04), higher fat yield (p = 0.08) and fewer days to first ovulation (p = 0.09) vs. those in the AP group. EB (−3.5 ± 0.67 units of energy for milk production) and body condition score loss (0.70 ± 0.09) were not affected by NM . However, non‐esterified fatty acids ( NEFA ) (p < 0.01) were higher, and glucose (p = 0.02) was lower in the AP vs. the GP group. Supplementary YS tended to improve EB (p = 0.09) and reduced NEFA (p < 0.01) vs. non‐supplemented animals. These data suggest that offering animals a nutritionally balanced TMR during the first 3 weeks PP followed by a gradual introduction to pasture can improve DMI vs. pasture‐based diets. Additionally, the blood metabolic profile suggests a more favourable energy status in the GP group or where YS was supplemented during the early PP period.