The physiological responses of anovulatory ewes to the introduction of rams — A review

If pre-conditioned by a period of isolation from rams, prepubertally, seasonally or lactationally anovulatory ewes of many breeds can be stimulated to ovulate by the reintroduction of rams. The signal from the rams is partly pheromonal and activates neural connections between the main olfactory tract and the anterior hypothalamus. This leads to an increase in the frequency of pulses of luteinizing hormone (LH), a process which is essential for the induction of ovulation and is usually completed within a few minutes. The high pulse frequency stimulates follicular growth and oestradiol secretion by the ovaries. The subsequent build-up of oestradiol in the blood has two effects: in the short term (the first 2–12 h) it reduces the levels of follicle-stimulating hormone (FSH) and the amplitude of the LH pulses; in the long term (12–48 h) it induces preovulatory surges of both LH and FSH. The LH surge induces ovulation and the formation of a corpus luteum.In some ewes, the corpus luteum is normal and a normal luteal phase follows the first ovulation. In other ewes, the first corpus luteum secretes little progesterone and regresses within 6 days. A second LH surge is then released, inducing a second ovulation and the formation of an apparently normal corpus luteum. If the ewes are treated with progestagen before the rams are introduced, all the corpora lutea formed after the first ovulation appear to be normal. This appears to be effected both through a delay in the onset of the LH surge and through a direct action of progesterone on the ovary.     

The effect of estrus synchronization treatments on somatic cell count of transitional-anestrus Awassi ewes’ milk

Fifty-three transitional-anestrus Awassi ewes, randomly assigned to three groups: fluorogestone acetate (FGA, n = 18), FGA-Prostaglandin (FGA-PGF, n = 18) and control (n = 17), were used to examine the effect of estrus synchronization protocols and steroid hormones concentrations on milk somatic cell count (SCC). Intravaginal FGA sponge was inserted for 13 days and 600 IU equine chorionic gonadotropin was administered for ewes of FGA and FGA-PGF groups at the time of sponge removal (day 0). In addition, 10 mg was administered to ewes of FGA-PGF group on day 0. Blood and milk samples were collected from all ewes on days -13, -6, 0, 1, 2, 7 and 14. Estradiol had significant positive correlation with the SCC during the periods of sponge insertion (P = 0.015, r = 0.235) and within two days (P = 0.063 r = 0.23) after sponge removal with no correlation with SCC of both udder halves during the luteal phase. Progesterone concentrations, on the other hand, had a significant positive correlation (P < 0.001; r = 0.420) with the SCC of both udder halves during the luteal phase of the experiment, but not during the periods of sponge insertion and expected estrus. SCC returned under the influence of endogenous progesterone on days 7 and 14 to pre-synchronization values. In conclusion, sheep milk SCC is affected significantly with induction of estrus and steroid hormones concentrations. However, peak SCC recorded during estrus was far below the upper limit of the current standard for normal milk. With the current standards for SCC of 1,000,000/ml as legal limit for abnormal milk control programs in sheep, estrus synchronization programs and the estrus status should not be considered when bulk-tank milk SCC is being investigated, but should be considered during the process of setting new standards.     

Risk factors to incidental leptospirosis and its role on the reproduction of ewes and goats of Espírito Santo state,Brazil

Ovine and caprine stockbreeding have been gaining attention in developing countries as an attractive investment. On these animals, infectious diseases of the reproductive tract, such as leptospirosis, can compromise the production leading to economic losses. The present study aimed to determine the risk factors associated with incidental leptospirosis and its influence on the reproductive parameters of ewes and goats of Espírito Santo state, Brazil. A total of 737 animals distributed on 24 herds/flocks were studied, and an overall prevalence of 10.9 % seroreactive animals was observed. Serogroup Icterohaemorrhagiae was the most frequent in goats (97.0 %) as well as in ewes (78.3 %). Regarding risk factors related to leptospirosis, the presence of waterholes and the semi-intensive breeding system were the most important associated to seroreactivity. Besides, there was an observed association between seroreactivity and reproductive failures (P?<?0.05). Moreover, seroreactive ewes (relative risk (RR)?=?1.3) and goats (RR?=?1.9) presented more chances to have abortions than seronegative animals. Furthermore, seroreactive ewes presented 11.6 more chances of having premature births when compared to the seronegative ones. It can be concluded that Leptospira infection, mainly those caused incidental strains (such as Icterohaemorrhagiae serogroup), is a significant factor to reduce the productivity of small ruminants’ herds/flocks in the studied region, and environmental measures must be considered on control programs.

     

The use of melatonin and progestagen–eCG to initiate reproductive activity in prepuberal Awassi ewe lambs

This experiment was conducted to evaluate the effect of administering hormonal treatments (melatonin and progestagen/equine chronic gonadotropin (eCG)) on advancing puberty in Awassi ewe lambs. Fifty-one 6-month-old ewe lambs of similar body weights (around 28 kg) were randomly assigned into four treatment groups; control (CON; n?=?14), melatonin (MEL; n?=?13), melatonin plus progestagen–eCG (MELPP; n?=?11), and progestagen–eCG (PP; n?=?13). Ewe lambs in the PP and MELPP groups were fitted with intravaginal progestagen sponges containing 60 mg medroxyprogesterone acetate for 14 days; 400 IU eCG were administered to each of these ewe lambs on the day of sponge removal. Ewe lambs in the MEL and MELPP groups received subcutaneous melatonin implants (Regulin®, 18 mg melatonin) 36 days before sponge insertion. Hormonal treatment had no effect on ewe lamb body weight change. Estrous behavior was greater (p?p?p?p?相似文献   

The effect of post-mating hCG or progesterone administration on reproductive performance of Afshari × Booroola-Merino crossbred ewes

To investigate the efficiency of hCG/CIDR after breeding to increase the reproductive performance, 35 synchronized ewes were mated with fertile rams and were assigned to three treatment groups. Ewes in hCG group (n?=?12) received 400 IU hCG on day 11 post-mating, and ewes in CIDR group (n?=?11) received CIDR from day 7 until day 19 post-mating. Ewes in the control group (n?=?12) did not receive any treatment. Blood samples were collected on days 7, 12, 17, and 22 post-mating. Plasma P₄ concentrations were higher on days 12 and 17 post-mating in hCG- and CIDR-treated groups (P?<?0.05). However, the concentrations of P₄ on day 22 post-mating in hCG and control groups were higher than that in CIDR group (P?<?0.05). Ewes in hCG group produced more quadruplets (P?<?0.05) and triplets, and as a result, they had a larger litter size (P?<?0.05). The lamb mortality rate by weaning in hCG group (3.6%) was less than that in control (11.8%; P?<?0.05) and CIDR (9.1%; P?>?0.05) groups. Post-mating administration of hCG or CIDR did not affect the lamb birth weight in single and quadruplet births (P?>?0.05), but the birth weight of twin lambs was higher in the hCG and CIDR groups (P?<?0.05). Weaning weights of twin lambs were higher in the hCG and CIDR groups (P?<?0.05). In conclusion, hCG/CIDR administration post-mating increased the maternal P₄ concentrations and enhanced reproductive performance.     

Effects of Concentrate Level on Carcass Composition,Tenderness and Growth Rate of Angus × NRF and Limousin × NRF Bulls

In total, 56 bulls of Angus 2 NRF or Limousin 2 NRF were fed two levels (either 2.5 or 5.0 kg animal -1 day -1 ) of concentrate from 12 weeks of age to slaughter in a 2 2 2 factorial design with cross-breed and concentrate level as fixed factors. The concentrate was a mixture with barley, oats, wheat, soyabean and molasses as main components. In addition, the animals had ad libitum access to grass silage. As expected, the bulls fed the high concentrate diet had higher growth rate than bulls fed moderate level of concentrate. Angus 2 NRF bulls fed the high level of concentrate showed the highest growth rate of the four subgroups and were on average slaughtered at the age of 15 months. Limousin 2 NRF bulls fed the moderate level of concentrate were the subgroup with the lowest growth rate and needed 20 months to reach the target slaughter weight, which on average was 280 and 340 kg for Angus 2 NRF and Limousin 2 NRF, respectively. Although the animals at the high concentrate level had a greater intake of energy day -1 , there was no significant difference in feed conversion calculated as FUm kg -1 gain between the subgroups. The Limousin cross-breeds had significantly higher relative proportions of muscle in the carcass, but less bone and fat than the Angus cross-breeds. Consequently, the Limousin 2 NRF bulls achieved better muscularity grading in the EUROP system than the Angus 2 NRF bulls. Concentrate level yielded different fatness scores in the EUROP system, while breed did not. The correlation between carcass weight and psoas major or longissimus dorsi muscles was stronger for the former muscle. There was a tendency for Angus 2 NRF bulls fed the moderate concentrate level to have more tender longissimus muscle than the other subgroups, but this difference was not significant.     

Quantitative effects of pelleting on performance,gastrointestinal tract and behaviour of meat‐type chickens

1. In an attempt to quantify the effects of “degree” of pelleting, two experiments were conducted. Diets were prepared by mixing together a mash composed mainly of maize (experiment 1) or sorghum (experiment 2) with soft pellets, or soft pellets mixed with hard pellets.

2. The pelleting degrees (PDs) were as follows: 0 mash; 0·5 mixture of soft pellets and mash 1 to 1; 1 soft pellets pelleted once; 1·5 mixture of soft and hard pellets 1 to 1; 2 hard pellets pelleted twice.

3. In experiment 2, the weight and length of the digestive organs were determined as well as digestive enzyme activities. In both experiments, the behaviour recorded was eating, standing, sitting and drinking.

4. Food intake and body weight gain were related to the degree of pelleting in a curvilinear manner. PD had a positive effect up to a peak (1 to 1·5 PD), after which its effect decreased. Food efficiency was not related to PD. In experiment 1, food efficiency of PDs 1 to 2 were superior to PDs 0 to 0·5 and in experiment 2, PDs 1·5 to 2 were superior to PD 0.

5. The relative weight of the gizzard was reduced by pelleting, whereas pelleting increased the relative weight of abdominal fat. The content of the crop was not affected by PD, whereas that of the proventriculus was lowest in the PD 2 group. Gizzard content was inversely related to PD. Pelleting reduced the length of the jejunum and ileum: which were shortened by about 15% with PDs 1 to 2, as compared to PD 0. The weight/length ratio of the jejunum and ileum tended to increase with increasing PD to a peak at PD 1·5, and to decrease thereafter.

6. Trypsin activity in the pancreas and amylase activity in the intestinal content were reduced by pelleting.

7. Chicks fed pelleted diets were less active: they ‘sat’ more and spent less time eating than their mash‐fed counterparts.     

Survival and Antibody Response of Channel Catfish,Blue Catfish,and Channel Catfish Female × Blue Catfish Male Hybrids after Exposure to Edwardsiella ictaluri

Abstract

Juvenile Norris strain channel catfish Ictalurus punctatus, blue catfish I. furcatus, and Norris strain channel catfish female × blue catfish male hybrids were challenged with Edwardsiella ictaluri by bath immersion or intraperitoneal injection (high or low dose) in aquaria. Survival (%) after bath immersion was highest for blue catfish (89.5 ± 2.8), intermediate for hybrids (73.8 ± 6.7), and lowest for channel catfish (62.0 ± 4.2). Prechallenge antibody levels to E. ictaluri, measured by enzyme-linked immunosorbent assay, were negative (mean ± SE optical density [OD] = 0.010 ± 0.003). Postchallenge antibody response for blue catfish (OD = 0.132 ± 0.045) was significantly lower than that of channel catfish (OD = 0.350 ± 0.045), whereas the response of the channel × blue catfish F₁ hybrids (OD = 0.263 ± 0.051) was intermediate and not significantly different from either parental species. Intraperitoneal injections of E. ictaluri resulted in significant mortality only in channel catfish (88.3 ± 2.6% survival) and were sublethal to hybrid catfish and blue catfish with 100.0% and 99.3 ± 0.4% survival, respectively. Antibody responses after the injection challenge were significantly different among catfish groups and injection dose with no group × dose interaction. Antibody responses after the injection challenge were consistent with the immersion challenge, and means of high and low challenge doses were lowest in blue catfish (OD = 0.061 ± 0.014), intermediate in hybrids (OD = 0.187 ± 0.014), and highest in channel catfish (OD = 0.272 ± 0.014). For all fish groups combined, the high injection challenge dose resulted in higher antibody levels (OD = 0.206 ± 0.011) than low injection challenge dose (OD = 0.140 ± 0.012). Overall results indicate greater resistance to E. ictaluri and lower antibody response in blue catfish, and show the potential to identify molecular markers linked with disease resistance and introgression of resistance genes from blue catfish into channel catfish.     

Does sward height grazed by ewes in mid- to late-pregnancy affect indices of colostrum intake by twin and triplet lambs?

AIMS: To determine if sward height grazed by ewes in mid- to late-pregnancy affects subsequent indices of colostrum intake by twin and triplet lambs, and the extent of the variation in colostrums intake between twin and triplet litter-mates. METHODS: Blood samples were collected from 75 twin and 46 triplet litters, respectively, 24-36 h after birth. Samples were not collected from lambs that died before this age. Lambs were born to ewes which had grazed one of four sward heights (2, 4, 6 and 8 cm) during mid- to late-pregnancy. Serum samples were analysed for gamma-glutamyl transferase (GGT) activities and glucose concentrations. The number of lambs present at weaning was used to determine lamb survival rate. RESULTS: GGT activities of lambs born to ewes that grazed swards 2 cm high were lower than those born to ewes that grazed swards 4 and 6 cm high (p=0.053 and p=0.037, respectively). Glucose concentrations were higher in twin than triplet lambs (p=0.003) and in lambs born to ewes grazed on swards 6 cm high than those born to ewes grazed on swards 2 cm high (p=0.033). These differences were not evident after correction for differences in birthweight. There was significant (p<0.001) variation within litter-mates for GGT activities and glucose concentrations in both twins and triplets. The blood constituent status of lambs that died before the 24-36 h collection period is not known. However, lambs which died after this period had significantly lower GGT activities (p=0.009) and glucose (p=0.010) concentrations at the time of sampling than those which survived. CONCLUSIONS: Farmers should ensure twin- and triplet-bearing ewes in mid- to late-pregnancy are grazing at least 4 cm of herbage to ensure colostrum intake of lambs in the postpartum period is not adversely affected.     

Does sward height grazed by ewes in mid- to late-pregnancy affect indices of colostrum intake by twin and triplet lambs?

AIMS: To determine if sward height grazed by ewes in mid- to late-pregnancy affects subsequent indices of colostrum intake by twin and triplet lambs, and the extent of the variation in colostrum intake between twin and triplet litter-mates.

METHODS: Blood samples were collected from 75 twin and 46 triplet litters, respectively, 24–36 h after birth. Samples were not collected from lambs that died before this age. Lambs were born to ewes which had grazed one of four sward heights (2, 4, 6 and 8 cm) during mid- to late-pregnancy. Serum samples were analysed for gamma-glutamyl transferase (GGT) activities and glucose concentrations. The number of lambs present at weaning was used to determine lamb survival rate.

RESULTS: GGT activities of lambs born to ewes that grazed swards 2 cm high were lower than those born to ewes that grazed swards 4 and 6 cm high (p=0.053 and p=0.037, respectively). Glucose concentrations were higher in twin than triplet lambs (p=0.003) and in lambs born to ewes grazed on swards 6 cm high than those born to ewes grazed on swards 2 cm high (p=0.033). These differences were not evident after correction for differences in birthweight. There was significant (p<0.001) variation within litter-mates for GGT activities and glucose concentrations in both twins and triplets. The blood constituent status of lambs that died before the 24–36 h collection period is not known. However, lambs which died after this period had significantly lower GGT activities (p=0.009) and glucose (p=0.010) concentrations at the time of sampling than those which survived.

CONCLUSIONS: Farmers should ensure twin- and tripletbearing ewes in mid- to late-pregnancy are grazing at least 4 cm of herbage to ensure colostrum intake of lambs in the postpartum period is not adversely affected.     

Effect of Brazilian red propolis administration on hematological, biochemical variables and parasitic response of Santa Inês ewes during and after flushing period

Brazilian red propolis was administered orally to Santa Inês ewes, and evaluation was made of general health and hematological, biochemical, and parasitic responses during and after flushing. Thirty mature, nonlactating, nonpregnant Santa Inês ewes (40?±?2 kg and 2.5 years old) were grazing tropical pasture (Brachiaria decumbens and Pennisetum purpureum) and, as flushing after synchronization, were supplemented with a concentrate–roughage mixture at a rate of 4 % body weight (BW). Ewes were divided according to BW and fecal egg count (FEC) into two groups (n?=?15 each): control and propolis that received propolis ethanolic extract at rates of, respectively, 0 and 3 g/ewe/day. The treatments lasted 21 days until the end of flushing period. BW and body condition score (BCS) were recorded, and blood and fecal samples were taken weekly for 8 weeks. Mean values of BW and BCS were not (P?>?0.05) affected by propolis administration. Propolis increased (P?<?0.01) total leukocytes (WBC), but no significant differences were observed for other hematological parameters. Propolis increased (P?<?0.01) total protein and globulin concentrations and decreased (P?<?0.01) triglycerides, glutamate oxaloacetate transaminase, and glutamate pyruvate transaminase. Propolis decreased (P?<?0.05) FEC. Propolis administration had good impact on ewe health and may be a promising feed additive during critical periods such as flushing.     

Relationships of incubational hatching egg characteristics to posthatch body weight and processing yield in Ross × Ross 708 broilers,

The characteristics of broiler hatching eggs have the potential to effect broiler posthatch growth and processing yield. The association of set egg weight (SEW), length of incubation (LI), and mean daily percentage of incubational weight loss (MDPEWL) of embryonated Ross × Ross 708 broiler hatching eggs with subsequent posthatch BW and processing yield was investigated. Sixty Ross × Ross 708 broiler hatching eggs were randomly set on each of 8 replicate tray levels of an incubator. Weight loss of individual embryonated eggs between 0 and 10.5, 10.5 and 18.5, and 0 and 18.5 d of incubation was determined for the calculation of MDPEWL. Furthermore, on 18.5 d of incubation, embryonated eggs were transferred to a hatcher unit where they were individually monitored for hatch every 12 h for determination of LI. Chicks were placed in corresponding replicate floor pens and were grown out from 0 (21.5 d of incubation) to 49 d posthatch. Live bird BW as a percentage of SEW on 21.0 d of incubation and d 0 and 49 posthatch, and bird sex on d 49 posthatch were determined. After commercial processing, carcass weight as a percentage of SEW, and carcass, abdominal fat pad, wings, breast muscle, tenders, drumsticks, and thighs weights as percentages of live BW were determined. Bird BW on 21.0 d of incubation and on d 0 and 49 posthatch were positively correlated or interrelated with SEW. Between 0 and 10.5 d of incubation, MDPEWL was negatively correlated with absolute and relative BW on 21.0 d of incubation, absolute BW on d 0 posthatch, and relative tenders weight. Further, LI was positively correlated with absolute and relative BW on 21.0 d of incubation and d 0 posthatch, but was negatively correlated with relative (percentage of live BW) carcass weight on d 49 posthatch. The MDPEWL of modern strain broiler hatching eggs should be closely monitored, particularly during the first half of incubation, for the regulation of LI and hatchling BW and for their potential effects on processing yield characteristics.     

Detection of stapylococcal enterotoxin,methicillin-resistant and Panton–Valentine leukocidin genes in coagulase-negative staphylococci isolated from cows and ewes with subclinical mastitis

Coagulase-negative staphylococci (CNS) are the most prevalent mastitis pathogens. However, virulence characteristics of CNS have not been well determined. The presence of genes for enterotoxins (sea-sej), toxic shock syndrome toxin-1 (tst), the exfoliative toxins (eta, etb), Panton–Valentine leukocidin (pvl) and mecA of CNS species isolated from cows and ewes with subclinical mastitis was investigated in this study. A total of 121 CNS (81 cows, 40 ewes) representing 18 different Staphylococci species were examined by PCR, and 38.1% (33 cows and 13 ewes) of CNS isolates had one or more se genes. The difference between percentages for SE toxin genes of CNS strains isolated from cows (40.7%) and ewes (32.5%) was not statistically significant (P > 0.05; χ ² = 0.380). It was found that S. simulans isolates had the highest prevalent se genes. Furthermore, the most common SE gene types was seh-sej. In this study, none of the isolates harbored the toxic shock syndrome toxin gene (tsst) and the exfoliative toxin genes (eta, etb). Five cow (6.17%) and three ewe CNS (7.5%) isolates had mecA gene. Three cow (3.7%) and two ewe CNS (5.0%) isolates had pvl gene. In conclusion, the present study showed that CNS species isolated from cows and ewes could serve as potential reservoir of se, mecA, and pvl genes.     

Inclusion of intensively manipulated silage in total mixed ration to growing pigs – influence on silage consumption,nutrient digestibility and pig behaviour

ABSTRACT

This study investigated how intensively manipulated grass/clover silage (finer structure than chopped silage) fed in total mixed ration (TMR), influenced feed consumption, total tract apparent digestibility (TTAD) and pig behaviour. Ten Yorkshire x Hampshire (YH) pigs were included in a digestibility experiment and 64 YH pigs in a behaviour experiment. Pigs received TMR with 20% dry matter inclusion of either intensively manipulated (SI) or chopped silage (SC). Behaviour was registered with instantaneous and continuous sampling. SI pigs consumed more silage (p?=?0.001) and spent more time eating from the through (p?<?0.01), however no significant difference in TTAD was found (p?>?0.05). Less social interactions prior to feeding (p?=?0.029) and less rooting after feeding (p?<?0.05) were found among SI pigs, indicating SI pigs being more satisfied for a longer time after feeding. We conclude that TMR with intensively manipulated silage benefits feed consumption and increases the opportunities for pigs perform feed-related behaviours.     

Toxicokinetic profile of swainsonine following exposure to locoweed (Oxytropis sericea) in naïve and previously exposed sheep

AIM: To determine the toxicokinetic profiles of swainsonine (SW) in sheep previously (subacute) and not previously (acute) exposed to locoweed. METHODS: Twenty-nine wethers were stratified by bodyweight (BW; 68.0 (SE 7.6) kg) and randomly assigned to one of six treatments. Treatments were: 0 (n=5), 0.4 (n=5), and 1.6 (n=5) mg SW/kg BW for Trial 1, and 0 (n=4), 0.2 (n=5), and 0.8 (n=5) mg SW/kg BW for Trial 2. Acute exposure in both trials included adaptation to blue grama (Bouteloua gracilis) hay for 14 days and no previous exposure to locoweed (i.e. SW), followed by administration of a single oral dose of SW prepared from an extract of locoweed, in the doses described above. Subacute exposure comprised ingestion of a blue grama and locoweed (428 microg SW/g locoweed) diet for 21 days in Trial 1 and 28 days in Trial 2, followed by removal from locoweed for 5 days, then an oral dose of SW, as above. Quantities of locoweed fed in the diet were adjusted to achieve the dose rates specified for each treatment. Blood samples were collected via jugular venepuncture twice daily for 3 days prior to initial exposure to SW and then every 7 days for the duration of the trials, to monitor serum alkaline phosphatase (Alk-P) and aspartate aminotransferase (AST) activities. For intensive sampling periods, SW was administered immediately following blood sampling at 0 h, and blood samples were collected at hourly intervals from 0-12 h, 3-h intervals from 15-24 h, 6-h intervals from 30-48 h, and 12-h intervals from 60-168 h. Concentrations of SW in serum and locoweed extract were determined using the alpha-mannosidase inhibition assay (detection limit=25 ng/ml). Rates of absorption and elimination of SW from serum were calculated for each animal, using exponential curve fits of the concentration of SW in serum concentration vs time plots. RESULTS: In both trials, SW was detected in serum in all animals exposed to locoweed. Elevated (p<0.05) serum Alk-P and AST activities indicated that subclinical SW intoxication was induced during the subacute exposure phase. Calculated rates of elimination were faster (p<0.001) for the 1.6 vs 0.4 (Trial 1) and 0.8 vs 0.2 (Trial 2) mg SW/kg BW doses. Rates of elimination indicated that, in both trials, SW was removed from serum faster (p<0.06) following acute exposure than subacute exposure. Higher exposure rates to SW resulted in higher concentrations of SW in serum within a trial. CONCLUSIONS: Multiple compartments were involved in the kinetics of SW, and dose and previous exposure altered the toxicokinetics of SW. CLININCAL RELEVANCE: Should the true elimination half-life prove to be as high or higher than the 95 h demonstrated for the treatment using 0.4 mg SW/kg BW in Trial 1, then withdrawal periods for clearing SW from sheep should be >40 days (assuming 10 half-lives to clear the compound).     

Gestational, Periparturient and Preweaning Growth Traits of Holstein versus Gir × Holstein F1Crossbred Dairy Calves Born to Holstein dams

The objectives of this study were to assess the gestational, periparturient and preweaning growth traits of Holstein vs Gir × Holstein (G × H F₁) crossbred dairy calves. Holstein cows (n=64) pregnant with Holstein (H × H) calves (bulls, n=16; heifers, n=18) or G × H (bulls, n=8; heifers, n=22) calves were sampled from 60 days of gestation through calving for serum progesterone (P₄) and in utero placentome sizes, and at parturition for calving ease scores (CES), calf vigour scores (CVS), and placental characteristics. Post-calving calf measures included birth weight (day 0) and body weight (kg), hip width (HW), body length (BL), wither height (WH), hip height (HH) and heart girth (HG) through 42 days of age. Serum IgG and calf vital function tests (respiration rate (RR), heart rate (HR), rectal temperature (RT) and fecal scores) were recorded on days 1, 3, 7 and 14 of age (a.m. and p.m.). Serum gestational P₄ was higher (p<0.05) for cows with H × H than G × H calves. Placentome measurements in utero were greater (p<0.01) for H × H calves than for G × H calves, while at parturition placental characteristics did not differ (p0.10). Gestation length, CES and CVS also did not differ (p0.10) between H × H and G × H calves. Calf RR and HR were higher (p<0.05) for H × H than G × H calves at both a.m. and p.m., while RT, fecal scores and serum IgG did not differ (p0.10) between H × H and G × H calves. Birth weight did not differ (p0.10) between H × H and G × H calves within sex. Moreover, bulls did not differ (p0.10) in any of the growth measures between H × H and G × H calves, whereas H × H heifers at days 28 and 42 of age were greater (p<0.05) in all growth traits than G × H heifers. Nevertheless, the relative change in growth measures over time (days 0 to 42) did not differ (p0.10) between H × H and G × H calves. While subtle differences in gestational, early growth and vital function characteristics were observed, these data suggest very similar developmental profiles between H × H and G × H calves.