Effect of changes in body condition during the dry period, milk yield and genetic groups on the metabolic profiles of high-producing Holstein × Gir cows

Highlights

• Subclinical hypocalcemia was the most important metabolic disorder.

• A high concentration of NEFA was not related to the presentation of diseases.

• Prepartum body condition had little influence on the metabolic profile.

• High milk yield did not influence the variation in the metabolic profile.

Introduction

High-producing dairy cows have a high metabolic demand around calving because the nutrient requirements increase and the dry matter intake (DMI) is lowered. This period is known as the transition period, comprising the three weeks before and after calving, and is characterized by a negative energy balance (NEB) (Mulligan et al., 2006). Dietary, physiological and energy balance changes in the transition period increase the presentation of metabolic imbalances and increase the risk of diseases (Herdt, 2000; Roche et al., 2013).

To monitor the transition period, metabolic profiles are used, which are analyses of blood biochemical constituents that assess the cows’ nutritional status (Puppel and Kuczyńska, 2016). Metabolite determination in cows before calving helps to predict disease after calving. The nonesterified fatty acids (NEFA) concentration is an indicator of body fat mobilization, and the prepartum increase is related to the increased risk of presenting diseases such as displaced abomasum, clinical ketosis, metritis, and retained placenta (Ospina et al., 2010a). Low concentrations of albumin or cholesterol before calving are associated with the presentation of retained placenta and mastitis (Ruprechter et al., 2018).

Body condition score (BCS) is used to monitor the energy status and helps to predict disease in early lactation (Mansouryar et al., 2018; Sheehy et al., 2017). Cows with a high BCS at calving have a greater BCS loss during lactation and an increased risk of developing clinical hypocalcemia and ketosis (Mansouryar et al., 2018). Cows that lose BCS over the transition period have increased concentrations of NEFA and beta-hydroxybutyrate (BHB), decreased fertility and increased health problems compared to cows that had no change in or gained BCS (Barletta et al., 2017). To reduce BCS loss and the risk of diseases in early lactation, energy-rich diets are recommended for cows during the close-up period (Roche et al., 2017). The diet in the far-off period, on the other hand, should be low in energy (Dann et al., 2006). However, a high energy intake during the far-off period for cows with a low BCS improves their metabolism around calving (Roche et al., 2017).

To improve aspects related to health, reproductive parameters and longevity in Holstein cows, crosses are made with other breeds (Mendonça et al., 2014). In tropical countries of Asia, America and Africa, the Gir breed (zebu) is particularly interesting because of its capacity for milk production on pasture, lower nutritional requirements and tolerance to heat and parasites (Santana et al., 2014). Girolando (5/8 Holstein × 3/8 Gir) is a breed created in Brazil in 1979 (Canaza-Cayo et al., 2014). The current milk yield of some Holstein × Gir herds is comparable to that of Holstein herds. The magazine Dairy Global (DairyGlobal - Brazil, 2020) reported that a Girolando cow became the world record holder of daily milk yield (127 kg/day).

Brazil is the third-highest milk producer in the world (Embrapa, 2019), and Holstein × Gir cows produce approximately 80% of this total volume (Canaza-Cayo et al., 2014). It is important to determine and understand the metabolic profile of Holstein × Gir cows, since they can behave differently from Holstein cows. Few studies have evaluated the metabolic profiles of Holstein × Gir cows. These studies compared different seasons (Moreira et al., 2018, 2017, 2015a, 2015b), characterized the behavior in cows with a low BCS at calving (Oliveira et al., 2014), compared cows with uterine diseases and healthy cows (Daibert et al., 2018; Silva Filho et al., 2017), and compared different genetic groups (Franzoni et al., 2018). In general, few differences were found, but the studies were carried out in cows with low or moderate milk yield. We hypothesized that in high-producing Holstein × Gir cows, the BCS gain before calving, the genetic group and the volume of milk yielded could influence the metabolic profile and the occurrence of imbalances in early lactation. The objectives of the present study were to evaluate the effects of changes in body condition during the dry period, of genetic groups, and of milk production groups on the metabolic profile (energy, protein, and mineral) of high-producing Holstein × Gir cows.