Influence of energy supplementation on dietary nitrogen utilization and milk production in cows fed foliage of Leucaena leucocephala

• Published in: Tropical animal health and production 2020-09, Vol.52 (5), p.2319-2325
• Main Authors: Arjona-Alcocer, Víctor Adrián, Aguilar-Pérez, Carlos Fernando, Ku-Vera, Juan Carlos, Ramírez-Avilés, Luis, Solorio-Sánchez, Francisco Javier
• Format: Article
• Language: English
• Subjects: Animal Feed - analysis; Animal Nutritional Physiological Phenomena; Animals; Biomedical and Life Sciences; Blood; Blood Urea Nitrogen; Body weight; Carbohydrates; Cattle; Cattle - metabolism; Cattle - physiology; Cow's milk; Dairy cattle; Diet - veterinary; Dietary Supplements; Dry matter; Energy; Excretion; Fabaceae; Female; Fermentation; Fermented milk products; Foliage; Lactation; Lactose; Lactose - metabolism; Leaves; Leucaena; Leucaena leucocephala; Life Sciences; Milk; Milk - metabolism; Milk production; Milk Proteins; Molasses; Nitrogen; Nitrogen - metabolism; Polishing; Pulp; Regular Articles; Rice; Rumen - metabolism; Sorghum; Starch; Starch - metabolism; Sugarcane; Syrups & sweeteners; Urea; Veterinary Medicine/Veterinary Science; Zoology
• ISSN: 0049-4747; 1573-7438
• DOI: 10.1007/s11250-020-02254-1

The aim of the study was to assess the effect of four energy supplements (two highly fermentable; two starch-based carbohydrates) on blood urea nitrogen (BUN), urinary urea excretion, and milk yield, in dual-purpose cows fed foliage of Leucaena leucocephala (Leucaena). Five Holstein-Zebu cows with 450 kg body weight in their second third of lactation were used in a 5 × 5 Latin square design. Cows were fed (dry basis) a mixture of 45% Leucaena and 55% Pennisetum purpureum grass. Treatments were supplementation with (i) sugarcane molasses (Mo), (ii) sorghum grain (So), (iii) fresh citrus pulp (CitP) or (iv) rice polishing (RP), all of them incorporated into the diet at 25 MJ of ME/cow/day. There was a control group (Cont) without energy supplementation. The study comprised five periods of 20 days (15 days adaptation, 5 days measurements). Dry matter intake (kg/day) was lower ( P   0.05). Milk yield (kg/day) was higher ( P   0.05) from Cont or other treatments. Milk protein, fat and lactose were not different among treatments ( P  > 0.05). Blood urea nitrogen and urinary urea excretion were both reduced ( P   0.05) among cows fed different sources of energy. It is concluded that in dual-purpose cows fed Leucaena foliage, supplementation with sugarcane molasses, citrus pulp or rice polishing reduced blood urea nitrogen and urinary urea excretion. Milk yield was increased by sorghum and rice polishing whereas energy supplementation did not affect milk composition.