1561
Slow-release urea in diets of crossbred lactating cows

Monday, July 21, 2014
Exhibit Hall AB (Kansas City Convention Center)
Fernando P Leonel , Federal University of São João del Rei (UFSJ), São João del Rei, Brazil
Bruno T Santiago , Federal University of Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, Brazil
Severimo D J Vilella , Federal University of Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, Brazil
Jonas M Carvalho , Federal University of São João del Rei (UFSJ), São João del Rei, Brazil
Juliana C Carvalho , Federal University of Viçosa (UFV), Viçosa, Brazil
Mayra M Assis , Federal University of São João del Rei (UFSJ), São João del Rei, Brazil
Tamara C Nunes , Federal University of São João del Rei (UFSJ), São João del Rei, Brazil
Leonardo M Moreira , Federal University of São João del Rei (UFSJ), São João del Rei, Brazil
Abstract Text:

Slow-release urea in diets of lactating crossbred cows

This work was carried out to evaluate the performance of F1 lactating cows (Holstein x Zebu) in response to different levels of substitution of soybean meal by non-protein nitrogen equivalent protein derived from slow-release urea (SRU). Eight cows were used in a duplicate 4 x 4 Latin square design, according to the following treatments: control (100% soybean meal and 0% SRU), 34SRU (66% soybean meal and 34% SRU), 66SRU (34% soybean meal and 66% SRU) and 100SRU (0% soybean meal and 100% SRU). The forage sorghum silage was used. Intakes of dry matter (DMI), crude protein (CPI), neutral detergent fiber (NDFI) were measured. The apparent digestibility of dry matter (MDad) and neutral detergent fiber (NDFad) were evaluated using chromic oxide as an external marker. Milk production was measured. Data were subjected to analysis of variance using the statistical program SAEG, adopting the 5% level of probability. Treatments did not affect DMI, CPI, and NDFI (P>0.05; Table 1). The results of apparent digestibility of the dry matter and neutral detergent fiber also do not present differences (P>0.05) between treatments. Milk production and composition demonstrated also similar results (P>0.05), when are compared the treatments evaluated in this work. The replacement of soybean meal by slow-release urea (SRU) does not affect the variables of intake and digestibility of dry matter or milk production of crossbred cows.

Table 1. Intake and digestibility of DM and nutrients and milk production

Variable

Treatments

Control

34ULL

66ULL

100ULL

CV (%)

P

DMI (kg/dia)

18,20

18,44

18,76

17,99

6,898

0,555

CPI (kg/day)

2,50

2,65

2,62

2,70

11,207

0,678

NDFI (kg/ day)

5,92

5,59

6,29

5,63

13,216

1,408

DMad (%)

57,78

59,77

57,35

57,74

4,213

0,235

NDFad (%)

38,89

36,40

34,27

35,29

9,860

0,101

Milk production (kg/day)

13,39

13,88

13,44

12,05

19,621

0,744

 1DMI = dry matter intake; CPI = crude protein intake; NDFI = neutral detergent fiber intake; DMad = apparent digestibility of dry matter; NDFad = apparent digestibility of neutral detergent fiber; CV = coefficient of variation

 Keywords: digestibility, intake, milk production, soybean meal

See more of: Ruminant Nutriton Posters I
See more of: Ruminant Nutrition
<< Previous Abstract | Next Abstract >>