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
| Autor: | Johanna Karlsson, Maria Åkerlind, Kjell Holtenius, Mikaela Lindberg |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Dietary Fiber
Silage Forage Biology Poaceae Feed conversion ratio Eating 03 medical and health sciences Animal science Animal and Dairy Science Lactation Medicago Genetics medicine Animals Dry matter 030304 developmental biology Sweden 0303 health sciences Meal 3-Hydroxybutyric Acid Bran Brassica napus 0402 animal and dairy science food and beverages 04 agricultural and veterinary sciences Animal Feed 040201 dairy & animal science Diet Milk medicine.anatomical_structure Cattle Digestion Female Animal Science and Zoology Beta vulgaris Residual feed intake Energy Metabolism Food Science |
| Popis: | 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, beta-hydroxybutyrate, and fertility measurements were not affected by diet, supporting the energy balance results. However, higher plasma concentrations o f insulin-like growth factor-1 and insulin were observed in cows fed he 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. |
| Databáze: | OpenAIRE |
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