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Intake and digestibility of diets without forage in Nellore and Angus young bulls

Monday, July 21, 2014: 10:15 AM
2103A (Kansas City Convention Center)
Marcio Machado Ladeira , Universidade Federal de Lavras, Lavras, Brazil
Jose Rodolfo R Carvalho , Universidade Federal de Lavras, Lavras, Brazil
Mario L Chizzotti , Universidade Federal de Višosa, Višosa, Brazil
Daniel R Casagrande , Universidade Federal de Lavras, Lavras, Brazil
Priscilla D Teixeira , Universidade Federal de Lavras, Lavras, Brazil
Maria Cecilia L Alves , Universidade Federal de Lavras, Lavras, Brazil
Rafael A Gomes , Universidade Federal de Lavras, Lavras, Brazil
Leslie A Silveira , Universidade Federal de Lavras, Lavras, Brazil
Abstract Text: The objective was to evaluate intake and digestibility of nutrients in Nellore and Angus young bulls fed a corn silage/concentrate diet and a whole shell corn (WSC) diet without the use of forage. Thirty-six animals with average body weight of 381.2 ± 11.87 kg were used in a completely randomized design using a 2 x 2 factorial arrangement (2 breeds and 2 diets). The corn silage/concentrate diet contained 30% silage and 70% of concentrate based on corn and soybean meal. The WSC diet had 85% whole shell corn and 15% of a pellet based on soybean meal and minerals. Both diets had 12.5% of crude protein and 2.88 Mcal/kg of ME. The animals were allocated in individual pens and fed during 81 days of experiment. However, the digestibility trial started at day 65 with total collection of feces and orts for five consecutive days. Intake was measured daily. Data were analyzed using PROC GLM of SAS 9.3. Angus animals had greater nutrient intake (kg/d) due to their greater body weight, compared to Nellore (Table 1). However, there weren’t differences on dry matter (DM) and neutral detergent fiber (NDF) intake, when data were analyzed on live weight percentage. WSC diets decreased DMI on both breeds studied. Breeds affected digestibility of non-fiber carbohydrates (NFC) only when WSC diet was used, being greater in Angus animals. WSC diet had greater digestibility of NDF, less digestibility of NFC and a tendency to increase DM digestibility. In conclusion, Angus young bulls have more capacity to digest NFC than Nellore. Funded by Fapemig, CNPq, CAPES and INCT-CA.

Table 1. Intake and digestibility of diets without forage (WSC) and with 30% corn silage (30:70) in Nellore and Angus young bulls.

Item

Nellore

Angus

SEM

P Value

30:701

WSC2

30:70

WSC

Breed

Diet

B*D

DMI (kg/d)

14.1

7.5

16.2

9.6

0.71

<0.01

<0.01

0.97

DMI (%LW)

3.0

1.8

3.0

1.8

0.15

0.92

<0.01

0.92

NDFI (kg/d)

4.7

1.7

5.2

2.2

0.20

0.02

<0.01

0.93

NDFI (%LW)

1.0

0.4

1.0

0.4

0.04

0.83

<0.01

0.67

NFCI (kg/d)

6.7

4.0

7.8

5.3

0.38

<0.01

<0.01

0.93

DMDig (%)

78.6

80.7

78.0

83.7

1.91

 0.58

0.07

0.39

NDFDig (%)

68.8

78.5

64.0

81.7

2.35

0.73

<0.01

0.12

NFCDig (%)

98.6 a

88.9 c

99.1 a

94.4 b

1.21

0.02

<0.01

0.04

CPDig (%)

78.3

78.9

77.1

80.3

1.77

0.96

0.27

0.45

Keywords: breeds, corn, feedlot