Effects of Feeding Zinc, Manganese, and Copper Amino Acid Complexes and Cobalt Glucoheptonate to Dairy Replacement Heifers on Claw Disorders

Professional Animal Scientist, Jun 2005 by Drendel, T R, Hoffman, P C, St Pierre, N, Socha, M T, Et al

Abstract

Five hundred seventy-two Holstein replacement heifers were fed a control diet or control diet plus complex trace minerals (CTM), which included 360 mg zinc/d, 200 mg manganese/d, and 125 mg copper/d from amino acid complexes and 12 mg cobalt/d from cobalt glucoheptonate. Dietary treatments were fed from 12 mo of age until 1 mo prepartum. Heifer claws were examined at 12 mo of age, 1 mo prepartum, and 2 mo postpartum. All claws disorders were identified and scored for severity on a scale of 1 = mild to 3 - severe. A claw disorder incidence and severity index (CIS) was calculated by multiplying, for each disorder, number of zones affected in each claw by average severity score of the disorder by 10. Heifers with daw disorders at 12 mo of age or at 1 mo prepartum had increased odds (P≤0.05) of developing claw disorders at 2 mo postpartum. Supplementing growing heifers with CTM increased (P≤0.05) CIS for sole hemorrhages and tended to increase (P≤0.15) CIS for claw disorders and heel erosion at 1 mo prepartum. Compared with control heifers, heifers fed CTM during rearing had a lesser (P≤0.05) CIS for white line separation and tended to have a lesser (P≤0.15) CIS for overall claw disorders and sole ulcers at 2 mo postpartum. In conclusion, presence of claw disorders during rearing increased risk of heifers developing claw disorders during lactation. Feeding CTM to heifers did not reduce incidence of claw disorders during rearing, but reduced incidence of claw disorders in early lactation.

(Key Words: Complexed Trace Minerals, Dairy Replacement Heifers, Claw Disorders, Lactation Performance.)

Introduction

According to the NAHMS (2002) survey, 16.3% of dairy cows are culled because of lameness. However, this survey may underestimate dairy cows culled because of lameness, as cows culled for low production (19.3%) or reproductive failure (26.5%) might have been lame, resulting in productive or reproductive failure. Lameness has been shown to reduce milk production (Hernandez et al., 2002b; Juarez et al., 2003) and reproductive performance (Sprecher et al., 1997; Hernandez et al., 2002a; Melendez et al., 2002). In addition, dairy producers tend to underestimate extent and severity of lameness within their herd (Whay et al., 2002). Research has indicated that mature cows that develop claw disorders are more prone to future reoccurrences of these claw disorders (Peterse, 1986; Raven, 1989; Enevoldsen et al., 1991). Thus, preventing animals from becoming lame must be a key management objective. Currently, data are limited on the extent of lameness and claw disorders in growing dairy replacement heifers and whether development of claw disorders during the rearing phase predisposes heifers to reoccurrence during lactation. Supplementing cows with a combination of complexed trace minerals (CTM) has reduced incidence (Nocek et al., 2000; Ballantine et al., 2002) and severity of claw disorders (Ballantine et al., 2002). However, the effects of CTM supplementation to dairy heifers during the rearing phase on claw disorder incidence and severity during the rearing phase or during the subsequent lactation have not been examined.

The first objective of this study was to determine incidence and severity of claw disorders in dairy heifers at 12 mo of age, 1 mo prepartum, and 2 mo postpartum and to estimate probabilities of reoccurrence of claw disorders. The second objective of this study was to determine the effects of feeding dairy heifers CTM from 12 mo of age until 1 mo prepartum on incidence and seventy of claw disorders both during the rearing phase and in the first lactation.

Materials and Methods

Five hundred seventy-two Hoistein heifers at a commercial heifer rearing facility were randomly assigned to one of two dietary treatments at 12 mo of age. Treatments consisted of a diet formulated to meet trace mineral requirements (NRC, 2001; control diet) or the control diet plus 360 mg zinc/d, 200 mg manganese/d, and 125 mg copper/d from amino acid complexes and 12 mg cobalt/d from cobalt glucoheptonate (CTM; Availa®4; Zinpro Corporation, Eden Prairie, MN). Heifers were assigned to the study over an 11-mo period of time and, once assigned to the study, received treatments from 12 mo of age until 1 mo prepartum.

Heifers originated from one of four source dairies that ranged in size from 300 to 700 lactating cows. Heifers from three of the source dairies arrived at the commercial heifer rearing facility at 2 to 3 mo of age; heifers from the fourth dairy operation were placed in the commercial heifer rearing facility at 4 to 5 mo of age.

Heifers were managed in groups of approximately 100 heifers per pen and were housed in open, earthenmounded lots without overhead protection. Concrete feed platforms and manure alleys integral to the open mound lots were scraped twice weekly, and mounds were bedded with coarse bark when needed as determined by the operator of the commercial heifer rearing facility.

A CTM supplement was formulated to contain 31.00% Availa-4®, 51.80% rice hulls, 16.45% calcium carbonate, and 0.75% white oil. The CTM supplement was fed at a daily rate of 22.7 g per head and incorporated into a total mixed ration (TMR) prior to feeding. The TMR fed to the control heifers and CTM heifers were similar in ingredient content, with the primary difference between the TMR being the CTM supplement. The TMR were fed once daily. Average ingredient and chemical compositions of diets are in Tables 1 and 2. Diet components were sampled bimonthly, and chemical composition was determined (AgSource Soil and Forage Laboratory, Bonduel, WI). Pen intakes were recorded daily. Diets were reformulated weekly based on changes in DMI and forage moisture content and every 2 mo based on changes in chemical composition of dietary ingredients. Dietary energy contents were increased from 1.48 to 1.54 Meal NEi/kg from November to March to account for increased maintenance energy requirements in open lot winter environments. Energy concentration of the diet was increased by replacing a portion of the corn silage, alfalfa silage, and alfalfa hay with ground, high moisture ear corn.