Protein supplementation to early lactation dairy cows grazing tropical grass: Performance and ruminal metabolism
| Autor: | L. J. Chagas, José Maurício Santos Neto, Camila Delveaux Araujo Batalha, Rodrigo S Marques, Flávio Augusto Portela Santos, Marina de Arruda Camargo Danés, Fernanda Macedo |
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| Rok vydání: | 2021 |
| Předmět: |
Rumen
Nitrogen VACAS Poaceae Excretion 03 medical and health sciences Animal science Latin square Casein Lactation Grazing medicine Animals Herbivory Feces Dairy cattle 030304 developmental biology Tropical Climate 0303 health sciences Chemistry 0402 animal and dairy science food and beverages 04 agricultural and veterinary sciences General Medicine 040201 dairy & animal science Diet Milk medicine.anatomical_structure Dietary Supplements Animal Nutritional Physiological Phenomena Cattle Female Dietary Proteins General Agricultural and Biological Sciences |
| Zdroj: | Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP |
| ISSN: | 1740-0929 1344-3941 |
| Popis: | This experiment was designed to evaluate the effects of different concentrate crude protein (CP) concentration on performance, metabolism and efficiency of N utilization (ENU) on early-lactation dairy cows grazing intensively managed tropical grass. Thirty cows were used in a ten replicated 3 × 3 Latin square design. The treatments consisted of three levels of concentrate CP: 7.9%, 15.4%, and 20.5% offered at a rate of 1 kg (as-fed basis)/3 kg of milk. The cows fed low and medium CP had negative balance of rumen degradable protein and metabolizable protein. Increasing CP tended to linearly increase DMI, 3.5% FCM and milk casein, and linearly increased the yields of milk fat and protein. Increasing CP linearly increased the intake of N, the concentration of rumen NH3 -N, and the losses of N in milk, urine, and feces. Increasing dietary CP linearly increased the molar proportion of butyrate but had no effect on the other rumen VFAs and no effect on microbial yield. In conclusion, feeding a concentrate with 20.5% of CP to early-lactation dairy cows grazing tropical grasses, leading to a 17.8% CP diet, tended to increase DMI, increased the yield of 3.5% FCM and the milk N excretion, and decreased ENU by 32%. |
| Databáze: | OpenAIRE |
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