Herbage intake, ingestive behaviour, and growth performance in unbred and once-bred Hereford × Friesian heifers

Abstract

The once-bred heifer beef production system involves mating heifers at 15 months of age to calve as 2-year-olds. This study compared the performance of once-bred Hereford x Friesian heifers mated to Limousin or Charolais sires and the herbage intake of once-bred and never-bred heifers during periods corresponding to late pregnancy and early lactation in the former group. Heifers carrying Limousin-sired (LS) calves had gestation lengths slightly longer than those carrying Charolais-sired (CS) calves (290.4 versus 286.6, pooled SE (PSE) = 1.2 days, P < 0.10), but there was no effect of calf sex on gestation length. The average birth weight of calves was 40 ± 1 kg, there being no difference between female and male, or LS and CS, calves. Dystocia caused mortality rates of 19% in calves and 9% in heifer dams. Female calves had 9 kg lower weaning weights at 142 days of age than male calves, whereas the CS calves had greater weaning weights than LS calves (218.3 versus 204.9 kg, PSE =3.6 kg, P < 0.01). Dam weaning weights were 443.5 versus 394.7 kg (PSE = 9.5 kg, P < 0.01) and 437.5 versus 400.7 kg (PSE = 9.5 kg, P < 0.05) in heifers suckling female versus male and LS versus CS calves, respectively. During late pregnancy, pregnant heifers had similar ingestive behaviour, herbage intake, and liveweight gains to never-pregnant heifers when offered a restricted pasture allowance of 7 kg dry matter (DM)/head per day. During early lactation, however, never-pregnant and lactating heifers consumed 9.19 versus 11.36 kg organic matter (OM)/head per day, (PSE = 0.63 kg OM/head per day P < 0.05) at a pasture allowance designed to permit ad libitum intakes. During this period, liveweight gains of 1.70 versus 0.61 kg/day (PSE = 0.28 kg/day, P < 0.05) were recorded for the neverpregnant versus lactating heifers. Results are discussed in the context of beef production from unbred and once-bred heifers.

Herbage intake, growth performance, and carcass and meat quality characteristics of once‐bred Hereford × Friesian heifers weaned at 12 or 21 weeks of lactation

“…The OM, DM, and ME intakes recorded for heifers during the mid-lactation period (Experiments 1 and 2) were similar to those recommended for suckling and growing heifers under New Zealand pasture conditions (Joyce et al 1975;Geenty & Rattray 1987). Likewise the grazing, ruminating, and idling times recorded for heifers in this study were similar to those reported for lactating heifers by Khadem et al (1993). Grazing times similar to those observed for heifer dams in this study were reported for pregnant or non-pregnant heifers (509 versus 482 min/day, Inwood et al 1992) and for Friesian, Piedmontese x Friesian, and Belgian Blue x Friesian bulls (497, 520 and 454 min/day, respectively, Morris et al 1993).…”

“…Intraruminal chromium (Cr) controlled-release capsules (CRC, Captec (NZ) Ltd, 4.06 cm core, 65% Cr 2 O 3 , multi-orifice end-plate) were inserted into the rumen of heifers on Dl of the experiment (5 November 1991) and were used to measure faecal output of the heifers. Daily faecal samples were collected for up to 10 days per animal, pooled into two replicate samples per animal, and analysed to determine chromic oxide concentration (Khadem et al 1993). Hand-plucked herbage samples were used to estimate digestibilities (i.e.…”

“…The W84 and W147 calves were then sold and the heifer dams (both W84 and W147 groups) were grazed together until slaughter in late March 1992. The sward heights on the experimental area were measured and the herbage masses estimated as described by Khadem et al (1993), to ensure that adequate herbage was offered to the three groups of animals, from 22 November (i.e. Day 84 of lactation (L84)) until 24 January (LI47).…”

“…The low quality of pastures during January-March in New Zealand (Reid 1986;Nicol & Nicoll 1987;McCall & Scott 1988), and the relatively low growth rates of once-bred heifers weaned in late January (Khadem et al 1993(Khadem et al , 1995, suggest that weaning heifer dams in November, rather than in January, might allow calves to grow well and also permit the heifers to reach the target slaughter weights recommended for New Zealand OBH beef production systems (Morris & Khadem 1991). The main purpose of this study was, therefore, to compare the herbage intake, ingestive behaviour, liveweight gain, calf performance, and the carcass and meat quality characteristics of once-bred heifers weaned either in November, (i.e.…”

Parasitism and production in fleece‐weight‐selected and control sheep

“…Chromium content of faecal samples was determined by the method of Costigan & Ellis (1987). Pasture dry matter (DM) digestibility was estimated by in vitro analysis of a hand-plucked representative sample of pasture (Khadem et al 1993).…”