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ARS Home » Plains Area » Miles City, Montana » Livestock and Range Research Laboratory » Research » Publications at this Location » Publication #109961
Title: EFFECTS OF STAIR-STEP NUTRITION AND TRACE MINERAL SUPPLEMENTATION ON ATTAINMENT OF PUBERTY IN BEEF HEIFERS OF THREE SIRE BREEDS

Author
item Grings, Elaine
item STAIGMILLER, R - RETIRED ARS
item Short, Robert
item Bellows, Robert
item Macneil, Michael

Submitted to: Research Update for Fort Keogh Livestock and Range Research Laboratory
Publication Type: Other
Publication Acceptance Date: 10/1/1999
Publication Date: N/A
Citation: GRINGS, E.E., STAIGMILLER, R.B., SHORT, R., BELLOWS, R.A., MACNEIL, M.D. EFFECTS OF STAIR-STEP NUTRITION AND TRACE MINERAL SUPPLEMENTATION ON ATTAINMENT OF PUBERTY IN BEEF HEIFERS OF THREE SIRE BREEDS. RESEARCH UPDATE FOR FORT KEOGH LIVESTOCK AND RANGE RESEARCH LABORATORY. 1999. pages C9.1-3.

Interpretive Summary: A study was conducted to evaluate the influence of nutrition and sire breed on age at puberty in crossbred beef heifers. Milk yield during their first lactation was also measured. After weaning, 210 heifers, sired by Hereford (H), Limousin (L), or Piedmontese (P) bulls were assigned either a control (CG) or stair-step gain (SSG) dietary regimen plus a mineral supplement with or without Cu, Zn, and Mn. Heifers on the SSG regimen were fed a diet to support gains at a rate of 120% of the CG diet for 55-d and then were switched to a diet formulated to produce an ADG at 70% of the rate of the CG diet for 84-d. They then switched back to the 120% diet for 30-d. Total weight gain and overall rate of gain did not differ among treatments. Hereford and L-sired heifers gained at similar rates while P-sired heifers gained an average of .11 kg/d slower. Mineral supplementation had no direct effect on weight gains. However, in the period of low growth for the SSG heifers, P-sired heifers on the CG diet gained .19 kg/d faster when supplemented with mineral than when not. On the SSG diet, L-sired heifers tended to gain faster (.99 vs .86 kg/d) when supplemented with Cu, Zn, and Mn than when not. Piedmontese-sired heifers reached puberty at the earliest age followed by H- and then L-sired heifers. There were no treatment effects on milk yield at 70-d of lactation. However, at 120-d of lactation, L- sired heifers were producing more milk than either H- or P-sired heifers. Hereford-sired heifers had lower plasma Cu concentrations than P-sired heifers. Sire breed of heifer had greater effects on growth, reproduction, milk yield, and plasma mineral concentrations than did dietary treatments.

Technical Abstract: A study was conducted to evaluate the influence of nutrition and sire breed on age at puberty in crossbred beef heifers. Milk yield during their first lactation was also measured. After weaning, 210 heifers, sired by Hereford (H), Limousin (L), or Piedmontese (P) bulls were assigned either a control (CG) or stair-step gain (SSG) dietary regimen plus a mineral supplement with or without Cu, Zn, and Mn. Heifers on the SSG regimen were fed a diet to support gains at a rate of 120% of the CG diet for 55-d and then were switched to a diet formulated to produce an ADG at 70% of the rate of the CG diet for 84-d. They then switched back to the 120% diet for 30-d. Total weight gain and overall rate of gain did not differ among treatments. Hereford and L-sired heifers gained at similar rates while P-sired heifers gained an average of .11 kg/d slower. Mineral supplementation had no direct effect on weight gains. However, in the period of low growth for the SSG heifers, P-sired heifers on the CG diet gained .19 kg/d faster when supplemented with mineral than when not. On the SSG diet, L-sired heifers tended to gain faster (.99 vs .86 kg/d) when supplemented with Cu, Zn, and Mn than when not. Piedmontese-sired heifers reached puberty at the earliest age followed by H- and then L-sired heifers. There were no treatment effects on milk yield at 70-d of lactation. However, at 120-d of lactation, L- sired heifers were producing more milk than either H- or P-sired heifers. Hereford-sired heifers had lower plasma Cu concentrations than P-sired heifers. Sire breed of heifer had greater effects on growth, reproduction, milk yield, and plasma mineral concentrations than did dietary treatments.