Periódicos Brasileiros em Medicina Veterinária e Zootecnia

p. 2849-2860

Crude protein levels in diets containing pelleted concentrate for lactating goats: intake, digestibility, milk production and composition

de Jesus dos Santos, EdileusaLúcia Albuquerque Pereira, MaraFerreira da Cruz, JurandirPereira de Figueiredo, MauroJosé Presídio Almeida, Paulode Jesus Novaes, EduardoéaAndréaAndréaAndréaAndréaAndréade Oliveira Alencar, DaianeBorges Sousa, LeandroCristina de Jesus Pereira, Taiala

This study aimed to evaluate the effects of crude protein (100, 130, 160 and 190 g kg-1 of dry matter) of diets composed of 200 g kg-1 of Tifton 85 grass hay and 800 g kg-1 of pelleted concentrate on intake, nutrient digestibility, production and composition of milk in lactating goats. Eight female Saanen goats with 42.7 ± 1.43 kg and 57.7 ± 7.37 days of lactation and milk production of 2 ± 0.22 kg at the beginning of the experiment were housed in individual 1.32 × 3.10 m stalls and distributed into two 4 × 4-balanced Latin squares. Intake of dry matter, organic matter, crude protein, neutral detergent fiber corrected for ash and protein, ether extract and total digestible nutrients showed a quadratic effect, with maximum intake of 2.030; 2.000; 305; 769; 55 and 1.574 g day-1 at the levels of 140.7; 140.8; 189.2; 140.9; 144.9 e 142.7 g kg-1 DM, respectively. Digestibility of dry matter, organic matter, crude protein, non-fibrous carbohydrates, ether extract and total digestible nutrient level varied linearly, with increases estimated at 0.54; 0.50, 2.02, 0.49, 0.80 and 0.63 g/100g for each percentage unit of protein added to the diet, respectively. Milk production was affected, with increase of 0.54 g for each 1% crude protein added to the diet. Milk lactose level decreased linearly, unlike the fat level, which increased linearly. Protein level showed a quadratic behavior, with

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