scholarly journals Targeting ADG of Developing Replacement Heifers Using Age and Body Weight

EDIS ◽  
2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
John Arthington ◽  
Philipe Moriel

This publication was prepared to assist beef cattle producers and livestock agents in determining the target ADG and management system to develop replacement beef heifers in Florida. Written by John Arthington and Philipe Moriel, and published by the UF/IFAS Department of Animal Sciences, revised October 2021.

1997 ◽  
Vol 77 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Julie A. Small ◽  
E. Charmley ◽  
A. V. Rodd ◽  
A. H. Fredeen

A study was undertaken to examine serum mineral concentrations in relation to estrus and first service conception (FSC) in beef cattle fed conserved forage. Blood samples were taken from yearling nulliparous heifers, and suckled 2-yr-old primiparous heifers and multiparous cows at first service which occurred within 12 h of observed standing heat and 21 d after. Serum was analyzed for calcium (Ca), phosphorus (P), magnesium (Mg), potassium (K), sulfur (S), sodium (Na), iron (Fe), copper (Cu), manganese (Mn), zinc (Zn) and boron (B) concentrations by ICAP. Heifers were fed in four groups based on parity and given 3.0 and 2.5 kg hd d–1 of a grain supplement, respectively, plus free-choice grass hay (1.71% K; 0.20% P; 8% protein; 41% ADF). Cows were individually fed ad libitum (21 g kg–1 body weight) grass-legume silage (2.82% K; 0.35% P; 14% protein, 34% ADF). Heifers and cows gained body weight over the breeding season and at turnout had body condition scores of 5 to 6 for heifers and 6 to 7 for cows. Rates of FSC were 53% (10/19), 48% (10/21) and 64% (18/28) for nulli-, primi- and multiparous groups, respectively. Serum Ca, Na, S, Cu, Fe, Zn and Mn did not differ (P > 0.05) between FSC groups, but Na and Cu were higher (P < 0.05) at estrus than at day 21, especially in nulliparous heifers. Concentrations of serum Mg were low (<0.74 mmol L–1) and K high (>4.5 mmol L–1) in heifers and cows but in nulliparous heifers only, serum Mg and K were lowest (P < 0.05) at estrus for those that conceived. Serum B concentrations were generally higher (P < 0.05) in animals that conceived especially on day 21 when B concentrations were higher (P < 0.05) than at estrus. Serum P concentrations were high (>3.5 mmol L–1), but highest in animals that conceived especially on day 21. It is concluded that P and B may be dietary factors limiting first service conception in beef cows fed conserved forage. Key words: Beef cattle, estrus, conception, minerals, boron, phosphorus


2002 ◽  
Vol 74 (3) ◽  
pp. 547-552 ◽  
Author(s):  
D. Cavestany ◽  
N. Negrin ◽  
R. Negrin ◽  
J. F. Groth

AbstractThe objective was to evaluate different oestrous synchronization schemes in beef cattle under range conditions. In experiment 1, 202 heifers averaging 26 months of age were assigned randomly to three treatments: (a) GnRH-PG. (no. = 44) day 0 (D0): injection of GnRH; D7: injection of PGF2α; D0 to D25 oestrous detection (OD) and artificial insemination (AI); (b) OD-PG. (no. = 45) D0 to D4; OD + AI; D5: injection of PGF2α; D5 to D25 OD + AI; and (c)Ovsynch. (no. = 113) D0: injection of GnRH; D7: injection of PGF2α; D9: injection of GnRH and 16 h later AI at fixed time. In experiment 2, 318 non-suckling cows were assigned randomly to three treatments: (a) GnRH-PG. (no. = 106) D0: injection of GnRH; D7: injection of PGF2α; D0 to D25 OD + AI; (b) GnRH-MAP-PG. (no. = 106) D0: injection of a GnRH analogue and insertion of an intravaginal sponge impregnated with 250 mg of medroxyprogesterone acetate; D7: injection of PGF2α and sponge withdrawal; D0 to D25 OD + AI; (c) controls. (no. = 106) OD and AI. The experimental period lasted 25 days and, with exception of the Ovsynch treatment, oestrous detection was carried out twice a day (a.m./p.m.) and inseminations performed 12 h later. The pregnancy rates assessed by ultrasonography 30 days after AI were: experiment 1: (a) 30·0%; (b) 28·6% and (c) 62·3% (P < 0·05); experiment 2: (a) 60·2%; (b) 57·8% and (c) 45·5% (P < 0·05). It is concluded that in heifers and non-suckling cows, oestrous synchronization treatments result in higher pregnancy rates. In non-suckling cows, the addition of a progestagen did not improve the response.


2007 ◽  
Vol 87 (4) ◽  
pp. 615-621 ◽  
Author(s):  
K. C. Swanson ◽  
M. Ko ◽  
C. J. Mader

This experiment was conducted to evaluate the effects of corn or soybean hull incorporation into haylage-based diets on backgrounding calf performance and subsequent feedlot performance. Crossbred steers [n = 48, initial body weight (BW) = 303 ± 3.4 kg] were individually fed dietary treatments consisting of: (1) haylage [17.5% crude protein, dry matter (DM) basis; control], (2) haylage + 20% (DM basis) cracked corn, and (3) haylage + 20% (DM basis) soybean hulls during a 112-d backgrounding period. After the backgrounding period, all steers were adapted to a common high moisture corn-based finishing diet and fed until an ultrasound estimated backfat thickness of 7 mm was obtained. During the backgrounding period, steers fed cracked corn or soybean hulls had greater (P < 0.01) average daily gain, dry matter intake and gain:feed and lower (P = 0.05) plasma urea N as compared with controls. However, when finished on a common high-concentrate diet, steers previously fed cracked corn had greater (P < 0.08) average daily gain, final body weight, and longissimus muscle area than those fed soybean hulls, suggesting that source of supplemental energy during the backgrounding period may influence subsequent feedlot performance. Key words: Beef cattle, backgrounding, energy supplementation


SURG Journal ◽  
2008 ◽  
Vol 1 (2) ◽  
pp. 57-72
Author(s):  
Sarah Core ◽  
Stephen Miller ◽  
Matthew Kelly

Linear measurements combined with surface area and volume calculations were used to develop formulas to estimate body weight (BW) in beef cattle. These measurements were evaluated directly or estimated using a laser remote caliper (LRC) and digital imaging software. Seventy-two dry, late gestation beef cows aged 3-13 years were measured and weighed Six measurements for each cow were taken; the cattle were weighed, a body condition score (BCS) was assigned, heart girth (HG), hip width (HW), and hip height (HH) were measured directly and 3 digital pictures were taken. The digital pictures portrayed three different views; side view (restrained), rear view (restrained), and side view (free-stall). Body length, HW, HH, surface area and volume were indirectly calculated from the digital images. For each view a complete (C-) formula (direct and indirect measures) and remote (R-) formula (only indirect measures) to estimate BW was developed. The R-squared values 0.7459, 0.7937, 0.8078, 0.5016, 0.611, 0.5553 were attained for C-side view free-stall, C-side view (restrained), C-rear view (restrained), R-side view free-stall, R-side view (restrained), and R-rear view (restrained). The accuracy of these formulas was 81% on average. BCS, HG and HW were the most significant factors when developing a formula for BW (p-value < 0.001). Side view (restrained) image measurements were most accurate in estimating BW. These measurements were highly correlated with the direct measurements and digital linear body measurements were not distorted (due to poor posture/positioning) as seen with the other views. The results or this study show that linear measurements collected by digital imaging methods can be a useful tool for estimating BW.


2019 ◽  
Vol 59 (10) ◽  
pp. 1931
Author(s):  
E. Giaretta ◽  
A. L. Mordenti ◽  
G. Canestrari ◽  
A. Palmonari ◽  
A. Formigoni

Rumination and activity behaviours are important welfare indexes in beef-cattle housing. The main objective of the present study was to assess whether the automatic collars are able to reliably assess the rumination and activity patterns of beef heifers. For this purpose, individual rumination time and activity (RT and AT respectively) were continuously recorded using an automatic neck-collar system (Hr-Tag, SCR Engineers Ltd, Israel) on the three trials performed. For Experiment 1, 60 Italian crossbred heifers were randomly assigned to one of two experimental diets for 9 months: the corn–silage diet (CS), which included 50% forage on a dry-matter (DM) basis (43% corn–silage, 7% wheat straw) and the hay diet (HAY), with 57% forage on DM basis (28.5% grass hay, 28.5% alfalfa hay). Heifers consuming HAY diet showed greater (P &lt; 0.05) RT (min/day) and AT (bits/day) than did those on CS diet. Rumination time per kilogram of dry matter and per kilogram of amylase- and sodium sulfite-treated neutral detergent fibre corrected for ash residue (aNDFom) intake were similar in the two experimental groups, while RT per kilogram of physical effective NDF (peNDF) intake was greater (P &lt; 0.05) in the CS group than in the HAY one. Daily rumination and activity patterns (min/2 h and bits/2 h respectively) were significantly different between CS and HAY groups. In the second experiment, 32 beef heifers were randomly allocated in two homogeneous pens, each containing eight animals, and two non-homogeneous ones, in which animals were added at different periods. The AT of non-homogeneous pens was significantly higher than that of the homogeneous ones, suggesting a distress condition for values higher than 309 bits/day AT. In the third experiment, RT and AT of three animals with respiratory disease were collected using the automatic collar system and compared with AT and RT of the healthy animals. Sick animals presented a significantly lower RT and higher AT than did the healthy ones. The cut-off to distinguish sick from healthy heifers was set to 537 bits/day AT and 381 min/day RT. In conclusion, the present study demonstrated that automatic collars can reliably monitor different rumination and activity behaviours of beef animals in various management conditions and different health statuses.


2002 ◽  
Vol 80 (7) ◽  
pp. 1791-1800 ◽  
Author(s):  
P. J. Guiroy ◽  
L. O. Tedeschi ◽  
D. G. Fox ◽  
J. P. Hutcheson
Keyword(s):  

Proceedings ◽  
2020 ◽  
Vol 36 (1) ◽  
pp. 71
Author(s):  
Wickersham ◽  
Oney ◽  
Sawyer

Sustainability of beef cattle production is, in part, dependent on a supply of females selected andadapted to meet the production environment of a given operation. [...]


2018 ◽  
Vol 11 ◽  
pp. 63-68
Author(s):  
Chung-Wei Chang ◽  
Yu-Yun Hsu ◽  
Su-E. Kuo ◽  
Ting-Wei Hou

Sign in / Sign up

Export Citation Format

Share Document