Heifer Body Weight Research Articles

Impact of 24-h feed or water, or both, deprivation on feed intake, metabolic, and inflammatory response in beef heifers.

This experiment evaluated the effects of 24-h feed or water, or both, restriction on hay intake, metabolic, and inflammatory response in growing beef heifers. Forty Angus × Hereford heifers were ranked by initial body weight (BW) (275 ± 6 kg) and age (278 ± 6 d) and randomly allocated to 20 drylot pens (two heifers per pen) in 5, consecutively run, 4 × 4 Latin squares containing four periods of 17 d each. From days 5 to 0 of each period, all pens were offered alfalfa-grass hay ad libitum plus 454 g of dried distillers' grains with solubles (as-fed basis) per heifer/d. On day 0 of each period, pens received one of the four treatments: 1) feed and water restriction for 24 h (FWR), 2) feed restriction for 24 h (FR), 3) water restriction for 24 h (WR), or 4) full access to feed and water (CON). Treatments were concurrently applied from days 0 to 1. Heifer full BW was collected for two consecutive days (days 6 and 5), before (day 0) and after (day 1) treatment application, and on days 3, 6, and 10 of each period. Hay dry matter intake was recorded daily from days 5 to 10. Blood was collected on days 5, 0, 1, 3, 6, and 10 of each experimental period. Following treatment on day 1, BW loss was greater, and heifer BW was less (P < 0.01), for WR, FWR, and FR compared with CON, whereas similar (P > 0.13) for BW loss and heifer BW among heifers that received nutrient restriction. No treatment effects were detected (P = 0.88) for overall ADG. Plasma cortisol concentration was greater (P < 0.01) in FR and FWR vs. WR and CON on day 1, and similar (P = 0.46) between CON and WR. Serum NEFA concentration was greater (P < 0.01) in FR and FWR vs. WR and CON on day 1, and also greater (P < 0.01) in WR vs. CON heifers on day 1. No treatment effects were detected (P = 0.53) for plasma haptoglobin concentration. Hence, feed or water, or both, restriction for 24 h did not affect hay intake and ADG, whereas metabolic results suggest that nutrient deprivation is the major contributor to the increased cortisol and NEFA response of growing beef heifers.

Winter grazing of stockpiled native forages during heifer development delays body weight gain without influencing final pregnancy rates.

The objective of this study was to test the effects of protein supplementation strategy and different stockpiled forage species on growth, nutritional status, and reproductive performance of yearling beef heifers. In a 5-yr study, yearling beef heifers (n = 266) were stratified by body weight (BW) at weaning to 1 of 3 stockpiled forages: 1) endophyte-infected tall fescue (TF, Schedonorus arundinaceus (Schreb.) Dumort; 7.21% crude protein [CP] and 67.13% neutral detergent fiber [NDF], dry matter [DM] basis), 2) big bluestem (Andropogon gerardi Vitman) and indiangrass (Sorghastrum nutans L.) combination (BI; 4.32% CP and 71.06% NDF, DM basis), or 3) switchgrass (SG,Panicum virgatum L.; 3.87% CP and 76.79% NDF, DM basis). Forage treatments were then randomly assigned to receive 1 of 2 supplement types: 1) 0.68 kg heifer-1 d-1 of dried distillers grains with solubles (DDGS: 28% CP and 108% total digestible nutrients [TDN]) or 2) 0.22 kg heifer-1 d-1 of blood meal and fish meal (BF: 72.5% CP and 77.5% TDN), resulting in a 3 × 2 factorial arrangement of treatments. Each year, twenty-one 1.2-ha pastures (7 pastures per forage type) were utilized with 2 to 3 heifers per pastures. Treatments were initiated in January and terminated in April at the initiation of breeding. Initial BW was not different (P ≥ 0.22) by forage or supplement type. During the rest of the grazing period, BW was greater (P < 0.01) for TF heifers. However, average daily gain (ADG) was greater (P < 0.01) for BI and SG heifers from breeding to final pregnancy diagnosis. Heifers grazing TF pastures had greater (P < 0.01) overall ADG than their counterparts. The percentage of mature BW (MBW) at breeding was greater (P < 0.01) for TF heifers. Heifer BW and ADG was not influenced (P ≥ 0.06) by supplementation strategy. Serum glucose concentrations were not different (P ≥ 0.44) among forage type or supplement strategy. Pregnancy rates at fixed timed-artificial insemination and overall pregnancy rates did not differ (P ≥ 0.38) by forage or supplement treatment. Owing to forage nutritive value differences, heifers grazing low-quality, warm season grasses lost BW prior to the initiation of the breeding season. However, a negative BW gain prior to breeding did not negatively impact overall pregnancy rates.

Effect of repeated trace mineral injections on beef heifer development and reproductive performance.

To determine the effects of repeated trace mineral injections on heifer development and reproductive performance, commercial Angus heifers (n = 290; 199 ± 34.3 kg; 221 ± 22 d of age) were utilized in a completely randomized design. Heifers were stratified by body weight (BW) and were administered an injectable trace mineral (MM; Multimin 90) or saline (CON) given subcutaneously, post-weaning at 221, 319, 401, and 521 ± 22 d of age. Throughout development, heifers grazed endophyte-infected fescue, red clover pastures and were supplemented with corn distillers grains (2.7 kg per heifer per day) and given access to free choice inorganic minerals. Heifer BW and body condition scores (BCS) were collected at trial initiation and 4- to 7-wk intervals thereafter. Hair coat scores (HCS) and respiration rates (n = 30 heifers per treatment) were collected at 269, 310, and 361 ± 22 d of age. Blood and liver samples were collected at trial initiation and estrous synchronization from 30 heifers per treatment to determine trace mineral status. At 319, 372, and 421 ± 22 d of age, antral follicle count and ovarian size were determined via ultrasonography. Two blood samples from all heifers were collected 10 d apart, concurrent with ultrasound dates, for cyclicity determination. Estrous synchronization was initiated, and reproductive tract scores (RTS) were collected at 421 ± 22 d of age, and heifers were bred via artificial insemination (AI) at 430 ± 22 d of age. Heifer BW, BCS, and HCS did not differ (P ≥ 0.12) throughout development, except at 268 ± 22 d of age when BCS was greater (P = 0.03) for MM than CON heifers. Respiratory rates were greater (P = 0.05) for MM than CON heifers at 269 ± 22 d of age but did not differ (P ≥ 0.66) at 310 and 361 ± 22 d of age. Plasma Mn and Zn concentrations did not differ (P ≥ 0.54). However, MM heifers had greater (P ≤ 0.01) plasma and liver concentrations of Cu and Se compared to CON. Interestingly, MM decreased (P = 0.02) liver Zn concentrations compared to CON, and there was no difference (P = 0.60) in liver Mn. Antral follicle count and ovarian size did not differ (P ≥ 0.51) due to treatment. Throughout development, number of heifers cycling was lesser (P < 0.01) for MM than CON heifers. However, there was no difference (P ≥ 0.19) in RTS, AI pregnancy rates, or overall pregnancy rates. Supplementing an injectable trace mineral increased heifer Cu and Se status; however, no effect was noted on ovarian development or pregnancy rates.

The effects of increasing amounts of milk replacer powder added to whole milk on mammary gland measurements using ultrasound in dairy heifers

The aim of this study was to determine the effect of increasing total solids (TS) in the liquid diet during the preweaning phase on mammary gland development in dairy heifers. The increase in TS was obtained with the addition of milk replacer powder to whole milk. Crossbreed Holstein-Gyr heifers (n = 60) were distributed in 4 treatments with different TS concentrations: 13.5% (n = 15), 16.1% (n = 15), 18.2% (n = 15), and 20.4% (n = 15). The liquid diets were provided from 5 to 55 d of age. From 56 to 59 d of age, the total amount of liquid feed was reduced by half. Heifers were weaned at 60 d and monitored until 90 d of age. Ultrasound mammary gland evaluations were performed weekly between 5 to 11 wk of age, using a B-mode ultrasound equipped with microconvex transducer at a frequency of 6 MHz. In those same weeks, the manual palpation of mammary parenchyma (PAR) was performed. Increased TS concentration of liquid diet during the preweaning period increased body weight of heifers, but did not alter PAR growth and the deposition of adipose tissue in the mammary gland evaluated by ultrasonography. The oval-shaped structure of PAR was altered after 2 mo of age. In the evaluated period, PAR growth was isometric with respect to the body growth rate. Palpation scoring of PAR had a strong correlation with the ultrasound evaluation of the PAR.

Effects of the level and duration of maternal diets with negative dietary cation-anion differences prepartum on calf growth, immunity, and mineral and energy metabolism

The objectives were to investigate the effects that maternal diets containing negative dietary cation-anion differences (DCAD) fed in the last 42 d of gestation may have on the acid-base status, hematology, mineral and energy metabolism, growth, and health of calves. The experiment was a randomized block design with a 2 × 2 factorial arrangement of 2 levels of negative DCAD (-70 or -180 mEq/kg) and 2 feeding durations (the last 21 d prepartum and the last 42 d prepartum). Bulls and heifers (n = 60) born to these dams were weighted at birth and fed 3.8 L of colostrum for their first feeding, and only heifers (n = 44, 9-12/treatment) were kept thereafter. Heifer body weight was also recorded at 21 d, 42 d, 62 d, 3 mo, and 6 mo of age. Blood was collected at birth, before colostrum feeding, and at 1, 2, 3, 21, and 42 d of age and assayed for minerals, metabolites, and cell counts. Heifers born to dams fed the last 42 d prepartum weighed 2.8 and 4.8 kg less at birth and 62 d, respectively, compared with calves born to dams fed the last 21 d prepartum; however, body weight at 3 and 6 mo of age was similar. Concentrations of ionized calcium did not differ among treatments at birth, but heifers born to -180 DCAD dams had increased blood concentrations at 3 d of age, whereas those born to -70 DCAD dams did not. At birth, heifers born to -180 DCAD dams experienced a subtle and transient metabolic acidosis (pH = 7.33 ± 0.02; pCO2 = 53.0 ± 2.4 mmHg; HCO3- = 27.6 ± 0.7 mmol/L) compared with the more evident metabolic acidosis observed in those born to -70 DCAD cows (pH = 7.28 ± 0.02; pCO2 = 59.3 ± 2.4 mmHg; HCO3- = 27.8 ± 0.7 mmol/L). Heifers born to -180 DCAD dams had reduced concentrations of β-hydroxybutric acid and nonesterified fatty acids compared with those born to -70 DCAD dams. Efficiency of IgG transfer from colostrum into blood and serum concentrations did not differ among treatments. There was no relationship between measures of metabolic acidosis and measures of efficiency of IgG absorption. Percentage of lymphocytes and neutrophils was altered by maternal treatments; however, treatments did not affect calf morbidity. Extending the duration of feeding up to 42 d or reducing the level of negative DCAD to -180 mEq/kg in maternal diets exerted a transient metabolic acidosis in the calves and slightly affected measures of mineral, energy metabolism, and growth.

Biomass flows and defoliation pattern of ryegrass grazed by supplemented heifers

To strategically define the best stocking rate management strategy for ryegrass, it is important to know the growth process of forage plants in detail. The study was conducted to analyze the leaf biomass flows and the defoliation intensity and frequency of Italian ryegrass (Lolium multiflorum Lam) grazed by heifers fed exclusively on pasture or on pasture and supplemented with corn or white oat grain. The experimental design was completely randomized following a repeated measures arrangement with three feeding systems and three area replications. Biomass flows (kg DM leaf blades ha1 day1) for leaf growth (40.6), leaf senescence (40.7), and leaf intake (29.7) were similar in the different feeding systems. Leaf blade intake adjusted to body weight was lower in supplemented heifers regardless of grain type. Actual and potential utilization efficiencies and ryegrass biomass net balance were not affected by feeding system. The leaf intake flow was 1.4 times lower than the growth flow, resulting in an actual utilization efficiency less than one (0.7), whereas the senescence flow was higher than the growth flow, resulting in a negative potential utilization efficiency (0.2). Leaf defoliation intensity was similar (54.4%) across feeding systems and defoliation frequency was higher in supplemented heifers. The 29.2% increase in stocking rate of heifers fed corn or oat grain as supplement did not affect the dynamics of ryegrass biomass flows, but reduced leaf blade intake adjusted to heifer body weight leading to alterations in the defoliation frequency of ryegrass pasture.

Short communication: Verifying Holstein heifer heart girth to body weight prediction equations

The estimation of Holstein heifer body weight (BW) from heart girth measurements is needed, as many farms do not have animal scales to make the management decisions that require BW. The correlation between heart girth and BW is known to vary with differing animal conformation. The previous equation to correlate the 2 measures for Holstein dairy heifers was done 25 yr ago. Data were derived from 6 US experiment stations that are part of Regional Research Project NC-2042: Management Systems to Improve the Economic and Environmental Sustainability of Dairy Enterprises. After deriving a new equation from a data set of observations and using a second validation data set, it was determined that the equation developed in 1992 was still valid and further equation development was not needed at this time.

Performance of Heifers Grazing Bermudagrass Pastures Strip or Solid Seeded with Clovers

Core Ideas Strip‐seeding of clovers into bermudagrass swards resulted in similar clover stand percentage compared with solid planting of clovers. Heifers grazing pastures that were strip seeded performed similarly to heifers grazing clovers that were seeded in solid stands. Red clovers persisted longer into the summer than either white or subterranean clovers. Red clover provided greater animal performance than white and subterranean clovers. Even though clovers can provide improved forage quality and reduced N fertilization when grazing stocker calves on warm‐season grass pastures, stand establishment remains a concern. The objective of this research was to determine if alternative methods of seeding legumes into warm‐season perennial swards could improve legume establishment. This research took place on 18, four‐acre mixed bermudagrass [Cynodon dactylon (L.) Pers.], crabgrass [Digitaria ciliaris (Retz.) Koeler], and dallisgrass (Paspalum dilatatum Poir.) pastures at the University of Arkansas Southwest Research and Extension Center Stocker Unit. Pastures were seeded in October of 2013 to white (Trifolium repens L.), red (Trifolium pratense L.), or subterranean (Trifolium subterraneum L.) clovers either in solid stands at the recommended rate (2.0, 8.0, and 11 lb/acre, respectively) or in four 0.25‐acre strips at twice the recommended seeding rate in a 3 × 2 factorial arrangement of treatments with three pasture replications per treatment combination. Growing heifers (n = 216; 614 ± 44.4 lb) grazed pastures from May to September 2014 and April to September 2015. Red clover was present later into the summer than white or subterranean clovers, but there were no differences due to seeding method. At the end of the grazing season, heifer bodyweight and gain was greater when grazing red clover than when grazing subterranean clover. Strip‐seeded clovers in only 50% of the pasture area provided similar stands to conventional solid seeding and equivalent animal performance. Red clover grew later into the summer grazing season and provided greater animal performance than white and subterranean clovers.

Social dominance in prepubertal dairy heifers allocated in continuous competitive dyads: Effects on body growth, metabolic status, and reproductive development

The objective of this study was to compare the body weight (BW) and size, metabolic status, and reproductive development of dominant and subordinate prepubertal dairy heifers allocated in competitive dyads. Sixteen Holstein and Jersey × Holstein prepubertal heifers (means ± SEM; 250.8 ± 9.8 d; 208.5 ± 13.9 kg of BW) were assigned to 8 homogeneous dyads according to breed, age, and BW. Dyads were housed in pens separated 1 m from each other during 120 d, receiving a total mixed ration on a 5% restriction of their potential dry matter intake, and had access to the same feeder (60 cm) throughout the experiment. Dominant and subordinate heifers were defined based on the winning agonistic interactions in each dyad. Body development was recorded every 20 d in all heifers, and blood samples were collected on the same days to determine endocrine and metabolic status. The maximum follicle diameter, number of follicles >6 mm, and the presence of corpus luteum were observed weekly by ultrasound. Heifer BW (269.3 vs. 265.3 ± 1.5 kg) and average daily gains (0.858 vs. 0.770 ± 0.02 kg/d) were greater in dominant than subordinate heifers. On d 30, 37, and 53, dominant heifers had more follicles than subordinate heifers, and maximum follicle diameter was greater in dominant than in subordinate heifers (10.0 vs. 9.0 ± 0.3 mm). Dominant heifers achieved puberty earlier than subordinate heifers (313.9 ± 4.9 vs. 329.6 ± 5.7 d) with similar BW (279.4 ± 2.6 vs. 277.4 ± 5.8 kg). Glucose concentrations were greater in dominant than subordinate heifers (89.2 vs. 86.8 ± 1.2 mg/dL), but cholesterol concentrations were greater in subordinate than dominant heifers (86.1 vs. 90.2 ± 2.6 mg/dL). We concluded that, under continuous competitive situations, dominant heifers were more precocious than subordinate ones, achieving an earlier puberty. Dominant heifers had greater body growth and glucose concentrations than subordinate heifers, which may be responsible, at least in part, for the differences on reproductive development between heifers of different social status.

Effect of Organic and Inorganic Zinc Combinations on Growth Performance and Nutrient Digestibility in Buffalo Heifers

In current experiment eighteen buffalo heifers (261.1±11.6 kg) were randomly allotted to 3 dietary groups, prepared by replacing the source of Zn supplementation (80 ppm) in concentrate mixture, i.e. Zn supplied from 100% ZnSO4 (100I–0O), 75% Zn from ZnSO4 and 25% from Zn proteinate (75I-25O), and 50% Zn from each source (50I-50O), to study their on growth performance (90 days) and nutrient digestibility (7 days digestibility trial). Replacement of inorganic Zn with organic source had no significant effect on heifers’ body weight and feed intake; and intake and digestibility of day matter, organic matter, crude protein, crude fibre, ether extract, nitrogen free extract and fibre fractions in all the dietary groups. It was concluded that growth performance and nutrient digestibility were comparable in heifers fed diets supplemented with 80ppm Zn from 100% ZnSO4 or as combination of ZnSO4 and ZnProt in ratio of 75:25 and 50:50.

Factors influencing the rates of pregnancy, calving and peri-parturient disorders in heifers at selected char areas of Bangladesh

The study was conducted to evaluate the factors affecting the rates of pregnancy, calving and peri-parturient disorders in heifers in selected char areas (low lying flood and erosion-prone areas in or adjacent to major rivers) of Lalmonirhat district of Bangladesh. A total of 101 artificial inseminated (AI) heifers were randomly selected for monitoring rates of pregnancy, calving and peri-parturient disorders with respect to breed of semen, source of semen, breed, age, body weight and body condition score (BCS) of heifers. The overall rates of pregnancy, calving and peri-parturient disorder were 51.5%, 45.5% and 32.6%, respectively. The differences were not significant with respect to the factors evaluated (P&gt;0.05).Bangl. vet. 2015. Vol. 32, No. 2, 65-72

Pre-breeding beef heifer management and season affect mid to late gestation uterine artery hemodynamics

The objective of the present study was to evaluate the effects of beef heifer development practices and the influence of season on uterine artery hemodynamics during mid to late gestation. Metrics of uterine artery blood flow (BF) of fall calving and spring calving crossbred beef heifers (n = 27) developed on either a low-input (LOW|FALL n = 6; LOW|SPRING n = 6) or a conventional (CON|FALL n = 9; CON|SPRING n = 6) heifer development scheme were evaluated. Heifer body weight (BW) was measured every 30 days, and uterine BF, arterial diameter (AD), pulsatility index (PI), and resistance index were measured for uterine arteries ipsilateral and contralateral to the conceptus on days 180, 210, and 240 of gestation. Calf birth weight was assessed at parturition. Repeated-measures ANOVA was performed. There were significant treatment × season (P = 0.0001) and season × day (P = 0.003) interactions on heifer BW. Main effects of season (P = 0.04) and gestational day (P = 0.0001) were observed on contralateral BF, and there was a season × day interaction (P = 0.03) on ipsilateral BF. As such, there was a season × day interaction on total blood flow (TBF; P = 0.05), whereby TBF increased as gestation progressed and spring calving heifers displayed increased TBF. However, when adjusted for BW, an additional main effect of treatment was observed (P = 0.0007) in which LOW heifers had increased TBF compared with CON heifers. Correspondingly, LOW heifers displayed increased AD compared with CON heifers, and spring calving heifers had greater AD than fall calving females. There was also a main effect of season on calf birth weight (P = 0.02). It was concluded that developing replacement heifers with low-input management schemes does not yield compromised uteroplacental hemodynamics compared with traditionally developed females when nutrition during gestation is adequate. Furthermore, spring calving 2-year-old heifers have increased uteroplacental BF compared with their fall calving counterparts. Our results imply that producers who seek to decrease development costs by feeding replacements to lighter target breeding weights may do so without compromising mid to late gestation uterine BF when heifers are not nutrient restricted during pregnancy.

Performance of Beef Replacement Heifers Supplemented with Dried Distillers Grains or a Mixture of Soybean Meal and Ground Sorghum Grain

The feed, labor, and equipment costs of developing heifers in a confined feeding system are relatively high. High Plains beef producers can reduce input costs by developing heifers on dormant native range; however, heifers are typically unable to consume sufficient crude protein (CP) from the low-quality ( 30% CP). Traditionally, producers have used oilseed meals in this capacity, but with the expansion of the ethanol industry, dried distillers grains with solubles (DDG) have become widely available as an alternative protein source for producers in corn and sorghum-producing regions. Adequate heifer body weight and body condition score at first breeding are essential to minimize age at first calving and to increase lifetime productivity. Therefore, the objective of our study was to evaluate the effects of supplementation of DDG or an approximately isonitrogenous mixture of soybean meal and ground sorghum grain on growth and reproductive performance of replacement heifers grazing low-quality, dormant native range.

Effects of forage source and extruded linseed supplementation on methane emissions from growing dairy cattle of differing body weights

Changes in diet carbohydrate amount and type (i.e., starch vs. fiber) and dietary oil supplements can affect ruminant methane emissions. Our objectives were to measure methane emissions, whole-tract digestibility, and energy and nitrogen utilization from growing dairy cattle at 2 body weight (BW) ranges, fed diets containing either high maize silage (MS) or high grass silage (GS), without or with supplemental oil from extruded linseed (ELS). Four Holstein-Friesian heifers aged 13mo (BW range from start to finish of 382 to 526kg) were used in experiment 1, whereas 4 lighter heifers aged 12mo (BW range from start to finish of 292 to 419kg) were used in experiment 2. Diets were fed as total mixed rations with forage dry matter (DM) containing high MS or high GS and concentrates in proportions (forage:concentrate, DM basis) of either 75:25 (experiment 1) or 60:40 (experiment 2), respectively. Diets were supplemented without or with ELS (Lintec, BOCM Pauls Ltd., Wherstead, UK; 260g of oil/kg of DM) at 6% of ration DM. Each experiment was a 4×4 Latin square design with 33-d periods, with measurements during d 29 to 33 while animals were housed in respiration chambers. Heifers fed MS at a heavier BW (experiment 1) emitted 20% less methane per unit of DM intake (yield) compared with GS (21.4 vs. 26.6, respectively). However, when repeated with heifers of a lower BW (experiment 2), methane yield did not differ between the 2 diets (26.6g/kg of DM intake). Differences in heifer BW had no overall effect on methane emissions, except when expressed as grams per kilogram of digestible organic matter (OMD) intake (32.4 vs. 36.6, heavy vs. light heifers). Heavier heifers fed MS in experiment 1 had a greater DM intake (9.4kg/d) and lower OMD (755g/kg), but no difference in N utilization (31% of N intake) compared with heifers fed GS (7.9kg/d and 799g/kg, respectively). Tissue energy retention was nearly double for heifers fed MS compared with GS in experiment 1 (15 vs. 8% of energy intake, respectively). Heifers fed MS in experiment 2 had similar DM intake (7.2kg/d) and retention of energy (5% of intake energy) and N (28% of N intake), compared with GS-fed heifers, but OMD was lower (741 vs. 765g/kg, respectively). No effect of ELS was noted on any of the variables measured, irrespective of animal BW, and this was likely due to the relatively low amount of supplemental oil provided. Differences in heifer BW did not markedly influence dietary effects on methane emissions. Differences in methane yield were attributable to differences in dietary starch and fiber composition associated with forage type and source.

Short- and long-term effects of forage supplementation of calves during the preweaning period on performance, reproduction, and milk yield at first lactation

Sixty female Holstein calves [body weight (BW)=39.5±3.76kg] were fed a ground starter concentrate [19% crude protein, 19% neutral detergent fiber (NDF)] during the preweaning period. Furthermore, oats hay (68% NDF) was supplemented only during the postweaning period (CON) or during both pre- and postweaning periods (OH) to evaluate performance until first breeding, diet digestibility after weaning, reproductive performance, and milk yield at first lactation. Calves were individually housed and bedded with wood shavings. All calves were offered 6 L/d of milk replacer (MR) at 12% dry matter (DM) in 2 feedings until 28d of age, 3 L/d of MR at 12% DM in 2 feedings from 29 to 44d of age calves, and 1.5 L of MR at 12% DM in 1 feeding from 45 to 51d of age. Animals were weaned at 52d of age. Starter concentrate and forage intake were recorded daily and BW weekly until 65d of age. Two weeks after weaning, total-tract apparent digestibility was determined in 6 calves per treatment. Heifer BW was recorded at 10 mo of age. Breeding and milk yield at first lactation were also recorded. Starter concentrate intake was greater in OH compared with CON animals during the preweaning period. As a result, calves in the OH treatment had greater average daily gain (ADG) than CON animals during the preweaning period. After weaning, OH calves consumed more forage than CON animals, but we found no differences between treatments in ADG and starter concentrate intake. Similarly, total-tract apparent digestibility did not differ between treatments, and BW and ADG from 2wk after weaning to 10mo of age did not differ between treatments. Moreover, no differences in reproductive performance [age at first artificial insemination (AI), age at fertile insemination, conception rate at first AI, and number of AI] or milk yield at first lactation were observed between treatments, although a positive relationship between growth rate early in life and future energy-corrected milk yield was found. We conclude that offering forage to young calves early in life allows improvements in growth before weaning and could help in the transition to mixed diets, but the improvement in growth achieved early in life was not maintained at 10mo of age.

The Correlation of Body Morphological Size Toward the Body Weight of PO Steers and Heifers

Abstract. The study was conducted to determine the correlation between the body morphology size of PO steers and heifers which kept in the group housing of Litbangtan Models. The materials of this study used 24 PO steers and heifers (each cow was 15 to 18 months old). The data were analyzed using descriptive statistics and correlation analysis. Due to the significant value, it stated that the body length and chest circumference influenced positively to the gain of the weight body of PO steers and heifers . The value of determination analysis (R2) both PO steers and heifers was 92.70% and 86.80%; It indicated that the gain of the body length size and chest circumference would increase the body weight. The result of calculation shown that the average of body weight of PO steers and heifers after having used two body morphological measurement (body length and chest circumference) was relativeely close to the real measurement. This phenomenon indicated that the body length and chest circumference had a close relationship with the body weight either in PO steers and heifers. Key words: PO steers and heifers, body morphological size, body weight Abstrak. Penelitian ini dilaksanakan untuk menentukan korelasi antara ukuran morfologi tubuh PO steers dan heifer yang dipelihara di kandang kelompok Litbangtan Model. Materi yang digunakan dalam penelitian ini adalah 24 PO steer dan heifer (masing-masing berumur 15 sampai 18 bulan). Data dianalisis menggunakan deskriptif statistik dan analisis korelasi. Berdasarkan nilai signifikan, dinyatakan bahwa panjang badan dan lingkar dada berpengaruh positif terhadap peningkatan bobot badan PO steer dan heifer. Nilai koefisien determinsasi (R2) PO steer dan heifer adalah 92,70% dan 86,80%; mengindikasikan bahwa peningkatan ukuran panjang badan dan lingkar dada akan meningkatkan bobobt tubuh. Hasil perhitungan menunjukkan bahwa rataan bobot tubuh PO steer dan heifer setelah menggunakan dua ukuran morfologi tubuh (panjang badan dan lingkar dada) serupa dengan ukuran nyata. Fenomena ini menunjukkan bahwa panjang badan dan lingkar dada berkaitan erat dengan bobot tubuh pada PO steer maupun heifer. Kata kunci: PO steer dan heifer, ukuran morfologi tubuh, bobot tubuh

Spatial Arrangement of Forages Affects Grazing Behavior of Beef Heifers Continuously Stocked at Low Stocking Rate

ABSTRACTSpatially separated pastures may reduce foraging costs and provide a better balance of nutrients. The objective was to evaluate the grazing behavior of stocker heifers grazing different spatially arranged pastures. Treatments (three replicates) were: (i) annual ryegrass (Lolium multiflorum Lam.; RG); (ii) mixed (MIX) sward of annual ryegrass and clover mix (berseem [Trifolium alexandrinum L.], white [T. repens L.], and red clover [T. pratense L.]); (iii) clover mix (CL) alone; and (iv) adjacent areas (ADJ) of annual ryegrass and clover mix. Crossbred beef heifers (n = 48; 224 ± 14 kg) were continuously stocked at 2.5 heifers ha−1. Visual and video recording observations and pedometers were used to study grazing behavior. Forage mass and nutritive value and body weight of heifers were determined every 15 d. Crude protein content of CL and ADJ was greater (P = 0.02) than RG. Concentration of water‐soluble carbohydrate (WSC) was greater in RG than on CL. Heifers spent more time (P &lt; 0.05) walking on RG and MIX when compared to those on ADJ. Grazing time was greater for heifers on RG compared to CL. Annual ryegrass had a greater concentration of WSC in the afternoon (221 g kg−1 DM) than in the morning hours (129 g kg−1 DM) and was greater than the concentration in the CL (99 and 61 g kg−1 DM, respectively). The concentration of WSC may explain the increase in grazing preference of RG during the afternoon; however, the reduction in the proportion of berseem clover during the last 30 d may have affected heifers’ grazing behavior.

Increasing home-grown forage consumption and profit in non-irrigated dairy systems. 3. Intake, milk production and composition, bodyweight and body condition score

This paper reports the performance [intake, milk production, bodyweight and body condition score (BCS)] of cows managed under two feeding systems over 4 years (June 2005–May 2009) in south-west Victoria, Australia. The feeding systems were ‘Ryegrass Max’ (RM) a well managed perennial ryegrass pasture-based system stocked at 2.2 cows/ha, and a ‘Complementary Forage’ (CF) system based on perennial ryegrass, tall fescue and a double crop of winter-sown cereal and summer-sown brassica crops stocked at 2.82 cows/ha. There were no significant differences in milk production per lactation between feeding systems, with an average of 543 and 553 kg milk solids per cow (1246 and 1642 kg milk solids per ha) produced in the RM and CF systems, respectively. These production levels were 20.9 and 10.8% above pre-experimental model targets, respectively. The bodyweight and BCS of multiparous cows were not significantly different between the two feeding systems; however, bodyweight of heifers in early lactation declined more rapidly in the CF compared with RM feeding system. Over the 4-year study in the RM system pasture comprised 60% of total DM consumed (grazed + conserved), with 26% of the ration being concentrate and the balance being purchased hay supplements. In the CF system, home-grown forage contributed 57.9% of total DM consumed of which 46.6% was pasture (grazed + conserved) and 11.3% was from the double cropping system. These levels of home-grown forage consumption were lower than those predicted by the pre-experimental modelling, leading to higher than predicted levels of purchased concentrates and conserved forages being fed. The lower than expected levels of consumption of the forages produced in the double cropping system reflected both the low intake potential and moderate nutritive value of cereal silage, and the failure of establishment and subsequent low DM yields from the summer brassica crop. Further work is required to determine the risk of implementing CF in rain-fed dairy systems reflecting uncertainties in forage management planning and nutrient delivery to support high levels of milk production.

Effect of strategic nutrient supplementation on the reproductive performance of anoestrus crossbred cattle in Malwa region of Madhya Pradesh

In Malwa region of Madhya Pradesh anoestrus is a major problem in crossbred cattle under field conditions due to under feeding and non availability of balanced ration. Thirty anoestrus crossbred cattle {20 heifers (average body wt. 224.75 ± 7.41 Kg) + 10 cows (average body wt. 316.50 ± 15.48 Kg, milk yield 4.9 ± 1.25 litre/h/d)} having normal genitalia were selected randomly from ten villages of Indore district. Average daily feed intake of each animal was recorded and proximate principle, major (Ca and P) and trace elements (Fe, Zn, Mn, Cu and Co) in available feedstuffs were determined to find out nutrient availability. Deficiency of nutrients was calculated by comparing the standard requirements of the animals. A strategic nutrient supplement [soya-De oiled cake, sodium dihydrogen orthophosphate dihydrate, zinc oxide, copper sulphate, vitamin A & E] containing deficient nutrients was formulated on the basis of nutrient deficiency observed in rations of anoestrus cows. Supplementation study was carried out in the same thirty affected anoestrus crossbred cattle by dividing them into two groups of 15 (10 heifers + 5 cows) in each. One of them served as control (un-supplemented), while another was supplemented with strategic nutrient supplement (Treatment). This supplementation study was continued for a period of two months. During which individual animal was regularly examined for onset of estrus and artificially inseminated and after two months of the artificial insemination, pregnancy diagnosis of each animal was carried out per rectally to find out the conception status. Onset of estrus (control vs treatment group) in heifers (10% vs 70%) and lactating cows (20% vs 60%) and conception rate (control vs treatment group) in heifers (10% vs 50%) and lactating cows (20% vs 60%) were higher in the animals of supplemented group, while an additional advantage in the form of improvement (P< 0.05) in the body weight of heifers of treated group was also observed. Thus it can be concluded that strategic nutrient supplementation not only improved the reproductive performance of the crossbred anestrous heifers and cows, but it also improved the growth performance of the heifers.

Heifer Body Weight Gain and Reproductive Achievement in Response to Protein and Energy Supplementation While Grazing Dormant Range Forage

Heifers grazing winter range require supplemental nutrients to complement dormant forage to achieve optimal growth and performance. A study was conducted to evaluate nutritional envi- ronment and effect of different supplementation strategies for developing heifers grazing dor- mant winter range. Eighty-four Angus crossbred heifers were stratified by body weight at weaning, allocated to one of six replicated pastures, and randomly assigned one of three supplemental treatments: 1) 908 g/d of a control supplement providing 340 g·hd −1 ·d −1 of CP with 130 g of rumen undegradable protein (RUP) and 614 MJ of ME (LRUP); 2) 908 g/d of a RUP supplement providing 340 g·hd−1·d−1 of CP with 170 g of RUP and 567 MJ of ME (HRUP); or 3) 1814 g/d of a protein and energy supplement providing 340 g·hd−1·d−1 of CP with 120 g of RUP + 100 g of propionate salt (NutroCal ™ , Kemin Industries, Inc.) and 1222 MJ of ME (LRUP + E). Body weights were taken in No- vember, with monthly 12 h shrunk BW from January thru April, and again in September (at time of pregnancy diagnosis). Heifer average daily gain was similar throughout the developmental period except from d125 to d159 where LRUP + E supplemented heifers had greater gains (P < 0.01) than LRUP and HRUP supplemented heifers (0.33, 0.04, and 0.14 ± 0.05 kg/d, respectively). LRUP + E heifers had a greater percentage (P = 0.04) of heifers pubertal at time of artificial insemination compared to LRUP and HRUP heifers (57, 29, and 30, respectively). However, no differences were * Corresponding author.