Whole-lactation feed intake, milk yield, and energy balance of Holstein and Swedish Red dairy cows fed grass-clover silage and 2 levels of byproduct-based concentrate

Abstract

Ruminants can produce meat and milk from fibrous feed and byproducts not suitable for human consumption. However, high-yielding dairy cows are generally fed a high proportion of cereal grain and pulses, which could be consumed directly by humans. If high production of dairy cows could be maintained with ingredients of low human interest, the sustainability of dairy production would improve. In the present study, 37 multiparous [Holstein (n = 13) and Swedish Red (n = 24)] dairy cows were followed over a whole lactation. A low-concentrate diet of up to 6 kg concentrate per day (6kgConc) was fed to 27 cows, whereas 10 cows were fed a high-concentrate diet of up to 12 kg concentrate per day (12kgConc). The concentrate was mainly based on byproducts (sugar beet pulp, wheat bran, rapeseed meal, distiller's grain). Grass-clover silage of high digestibility was offered ad libitum. Over the whole lactation, cows on the 6kgConc diet had lower dry matter intake and higher forage intake than cows on the 12kgConc diet. Milk yield and energy balance were not influenced by dietary treatment. However, the cows on the 6kgConc diet numerically produced 2.4 kg less energy-corrected milk than cows on 12kgConc diet. The study lacked the statistical power to identify treatment effects on daily yield below 2.8 kg of milk due to low number of animals per treatment. Feed efficiency (as energy-corrected milk yield/dry matter intake or residual feed intake), body weight change, body condition change, milk fatty acid concentration in total milk fatty acids, plasma nonesterified fatty acids, glucose, β-hydroxybutyrate, and fertility measurements were not affected by diet, supporting the energy balance results. However, higher plasma concentrations of insulin-like growth factor-1 and insulin were observed in cows fed the 12kgConc diet. These findings show that cows can adapt to a high-forage diet virtually without humangrade ingredients, without compromising feed efficiency or energy balance, thereby contributing to sustainable food production.

Genetic parameters of forage dry matter intake and milk produced from forage in Swedish Red and Holstein dairy cows

“…Replacing cereal grain and pulses in the diet of dairy cows with forage not suitable for human consumption would increase net food production (Ertl et al, 2015(Ertl et al, , 2016Karlsson et al, 2018). Forage cannot be consumed by humans, but high-quality forage has the potential to sustain high milk production in dairy cows (Randby et al, 2012;Karlsson et al, 2020). Inclusion of forage production in crop rotations contributes to several ecosystem services, such as improved soil quality, carbon sequestration, and control of pests and weeds (Weißhuhn et al, 2017).…”

Ruminal kinetics and degradability of energetic feedstuffs used in diets for ruminants

“…In addition, NDF from industrial derivatives, such as soybean hull, does not limit dry matter intake, such as forage NDF (24) . And soybean hull contains higher potentially degradable NDF than most forages, which can contribute to an increase in the rate of passage (25) .…”

Full-lactation performance of multiparous dairy cows with differing residual feed intake

“…The cows were also subjected to another study [16] and therefore fed two different levels of concentrate. The concentrate ration was increased over 21 d, starting at 3 kg/d at calving, to a maximal concentrate ration of 12 kg/d or 6 kg/d in the two different groups which included concentrate offered in the milking unit.…”

“…Also during the first 14 weeks of lactation, a similar pattern was observed with a more marked loss of BCS in LRFI NorFor and IRFI NorFor cows than in HRFI NorFor cows. We chose to study variables related to energy balance during the first 14 weeks after parturition because many cows require that period to reach energy balance [16].…”