Hair Sheep Ewes Research Articles

117 Supplementation with soy hull during late gestation and lactation on parasite indicators in hair sheep ewes

Abstract Before lambing and up to 8 wk during lactation, ewes experience a temporary loss of immunity to gastrointestinal nematodes (GIN). This can result in a periparturient increase in fecal egg counts (FEC) along with clinical symptoms of parasitism. This increase in FEC can lead to greater larval numbers on pasture, consequently exposing lambs to a greater level of infection that can impair production. Adequate supplementation during late gestation and lactation has been shown to reduce the impact of this temporary loss in immunity and decrease GIN infection levels in ewes. This study evaluated the supplementation of an agro-byproduct (soy hull) on GIN infection parameters in hair sheep ewes. Pregnant ewes (n = 36) were allocated, balanced by breed, parity and fetal numbers to either corn/soybean (CS) or soy hull (SH) supplementation during the last trimester of pregnancy. Ewes rotationally grazed predominantly fescue pastures subdivided into 6 sections (0.13 ha) using electro-netting (3 sections of 6 ewes/supplement type). Ewes were supplemented at either 0.75% BW (late gestation) or 1.5% BW (lactation) using a single feeder per section. Ewes lambed on pasture and lambs were weaned at approximately 63 d. Lambs had access to the supplement provided to their dams. Blood and fecal samples were collected in prepartum, postpartum and at weaning for determination of packed cell volume (PCV) and FEC. Pooled treatment group feces were also collected and cultured to determine GIN genera. Body condition scores (BCS) were also recorded at each sampling. Data were analyzed in a model with supplement type and breed as the main effects and FEC were log transformed before analysis. There was a mixed population of GIN throughout the study with H. contortus (49.5%) and Tricostrongylus spp. (46.6%) being the most common. Supplement type had no effect on ewe BCS prepartum, postpartum or at weaning (averaging 2.6 ± 0.1, 2.3 ± 0.1 and 2.0 ± 0.1, respectively). Supplement type influenced PCV at weaning only, with ewes supplemented with CS having a greater (P < 0.03) PCV than those supplemented with SH (33.0 ± 0.7% and 30.8 ± 0.7%, respectively). PCV was similar between treatments prepartum (38.4 ± 1.3%) and postpartum (34.4 ± 0.9%). Ewe FEC was similar between CS and SH supplemented ewes prepartum (271.6 ± 0.5 epg) and at weaning (298.5 ± 80.5 epg); however, at postpartum sampling CS ewes tended (P = 0.09) to have reduced FEC (234.1 ± 62.0 epg) compared with SH (414.1 ± 59.6 epg) supplemented ewes. At weaning, lamb FEC was not influenced by supplementation or breed and averaged 502.3 ± 83.2 epg. Data indicate that substituting SH for a more traditional corn-based supplement in landrace hair sheep ewes managed in a pasture-based system had no influence on GIN infection. Agro-byproduct supplementation should be explored further for their use in sustainable, forage-based sheep production systems.

46 Use of soy hull as a supplement during late gestation and lactation for landrace hair sheep ewes in a forage-based system

Abstract Forage-based production systems can be limiting in providing adequate nutrition as the result of seasonal fluctuations in forage quality and quantity, especially during periods of increased nutritional demands such as late gestation and lactation. This study evaluated the use of an agro-byproduct supplementation (soy hull) to fill these demands. Barbados Blackbelly (BB) and St. Croix (STX) hair sheep ewes were bred November 1 in a 25-d breeding season in two single-sire groups to like breed sires, and initially managed as one group. Pregnant ewes (n = 36) were allocated, balanced by breed, parity and fetal numbers to either a corn/soybean (CS) or soy hull (SH) supplementation starting the last trimester of pregnancy. Ewes rotationally grazed predominantly fescue pastures subdivided into 6 sections (0.13 ha) using electro-netting (3 sections of 6 ewes per supplement type). Ewes were supplemented at either 0.75% BW (late gestation) or 1.5% BW (lactation) using a single group feeder per section. Ewes lambed on pasture and lambs were weaned at approximately 63 d. Lambs had access to the supplement provided to their dams. Data were collected on ewe BW changes and reproductive performance, and analyzed in a model with supplement type and breed as main effects. Results are presented as LSM. Supplement type had no effect on ewe prepartum (54.7 kg), postpartum (47.3 kg) and weaning BW (44.7 kg), whereas BW was consistently heavier in STX than BB ewes. Ewe late gestation (61 g/d) and lactation ADG (-51 g/d) were not affected by supplement type though breeds differed (P < 0.01) in lactation ADG (BB: -14 vs STX: -78 g/d). Lambing performance was also not affected by supplement type with 1.97 lambs born live, and 1.69 lambs weaned per ewe. There was a supplement type by breed interaction (P < 0.05) for number of lambs weaned with STX ewes receiving SH having a larger litter size at weaning than ewes receiving CS (1.40 vs. 2.10 lambs per ewe) with no difference in BB ewes (1.71 vs. 1.50 lambs per ewe, respectively). Neither litter birth (6.14 kg) and weaning weights (19.9 kg) nor litter ADG (233 g/d) were affected by supplement type. Litter BW was significantly greater (P < 0.01) in STX than BB (6.85 vs 5.18 kg), but not different at weaning. Lamb birth and weaning weights were not affected by supplement type, though preweaning ADG tended (P < 0.1) to be greater in CS than SH (162 vs. 142 g/d). Data indicate that substituting SH for a more traditional corn-based supplement in landrace hair sheep ewes managed in a pasture-based system did not affect ewe growth, reproductive performance, and lamb performance. Agro-byproduct supplementation should be explored further for use in sustainable, forage-based sheep production systems.

121 Breed and Mating Season Effects on Gestation Length in Landrace Hair Sheep Ewes

Abstract Gestation length in sheep varies with breed, but little information is available on hair sheep and any effects of time of year of mating. Data were collected between 1997 and 2021 on straight-bred Barbados Blackbelly (BB) and St. Croix (SC) ewes managed under pasture-based, accelerated mating. Rams were fitted with marking harnesses and ewe gestation length was determined as the difference between lambing and marking date. Gestation length (n = 1291) was analyzed with fixed class effects of ewe breed (BB or SC), age class at mating (4 levels), mating month (March, July, or November), and litter size (1, 2, or ≥ 3) and the linear and quadratic effects of total litter birth weight (LBW). Two-way interactions were initially fit but removed as none were significant (P > 0.15). Random effects included ewe and mating month – year (n = 350 and 32, respectively). Gestation length was 0.8 d longer for SC than BB ewes and 0.5 to 0.7 d longer (P ≤ 0.03) for > 5.5 yr-old ewes than all younger age classes. However, mating month did not impact gestation length (P = 0.11). Ewes that gestated a single lamb had longer gestation length (149.8 ± 0.20 d; P < 0.001) than twin- (147.4 ± 0.14 d) and triplet-bearing ewes (146.7 ± 0.28 d), which were also different from each other (P = 0.01). Finally, both quadratic and linear effects of LBW were significant (P < 0.001) and indicated gestation length increased with LBW until reaching an inflection point at approximately 9.1 kg. Gestation length in landrace hair sheep ewes was in line with the 147 d commonly used in gestation calculators. Slight adjustments can be made for ewe age, breed, and litter size, but are not needed for mating month.

360 Body Temperature of Hair Sheep Ewes During the Postpartum Period and Around the Time of Mating in an Accelerated Lambing System in the Tropics

Abstract The study was conducted to evaluate body temperature of hair sheep ewes at various stages of the production cycle in an accelerated lambing system in the tropics. Multiparous St. Croix White (STX: n = 7) and Dorper x STX (DRPX; n = 7) ewes lambing in October and raising single lambs weaned at 120 d were used. Synchronized breeding began at 96 d postpartum. Vaginal temperature (VT) was measured at 10-min intervals for 96 h at 38 and 66 d post-partum (PP1, PP2) and at 2 days after mating (PM) using data loggers. Daily minimum, maximum and range of VT were determined for ewes within PP1, PP2 and PB. Data were analyzed using GLM procedures of SAS with breed, day and time (PP1, PP2, PM) in the model. Mean ambient temperature, temperature-humidity index and solar radiation at PP1, PP2 and PM were 24.8 °C, 25.2 °C, 23.8 °C, and 74.7, 74.9, 73.3, and 180 W/m2, 160 W/m2 and 155 W/m2, respectively. Minimum VT was lower (P < 0.002) in STX than DRPX ewes at PP1, PP2 but not PM (38.27 ± 0.04 vs 38.44 ± 0.04 °C, 38.16 ± 0.04 vs 38.33 ± 0.04 °C, 38.47 ± 0.04 vs 38.58 ± 0.04 °C, respectively). There was no difference in maximum VT between breed or time (P > 01.0). There was no breed difference (P > 0.10) in range of VT, but the range of VT was lower (P < 0.0001) at PM compared to PP1 and PP2 (1.22 ± 0.04 vs 1.77 ± 0.04 vs 1.63 ± 0.04 °C, respectively). These results show that tropically adapted STX ewes have lower body temperatures, as shown by the lower minimal VT which indicates a degree of nighttime cooling, during the postpartum period compared to DRPX ewes in a tropical environment.

Indicadores fisiológicos de respuesta al estrés térmico en ovejas de pelo durante el verano subtropical

With the aim to assess the effect of short-term thermal stress on physiological traits of ewes an experiment was designed. Fourteen hair sheep ewes were selected during early reproductive management and randomly segregated in two groups. Control group (CG) with indoor conditions, and an experimental group (EG) under continuous outdoor conditions without shadow accessing during 14 days (d). Respiratory frequency (RF), rectal temperature (RT) and infrared image temperatures were estimated. Traits were measured for 8 d twice a d (9:00 am and 15:00 pm). Environmental temperature and humidity were monitored, and temperature and humidity index was estimated. All physiological and environmental traits showed significantly variation by group and time of measurement (P < 0.001). RT and RF were significantly higher for EG and during pm measurements. Environmental conditions indicated thermal stress conditions for outdoor EG during the afternoon was related ultimately with respiratory mechanism as the main indicator of continuous thermal stress. Head infrared image temperature was a good predictor of body temperature.

Developing a continuous adjustment factor for dry matter intake of gestating and lactating ewes

Intake is a multifactorial process that is influenced by animal type, environmental factors, and diet characteristics. Sheep, especially, have specific eating habits, with a greater selection of ingested feed compared to cattle. Thus, predictive equations for dry matter intake (DMI) must constantly be reviewed. The objective of this study was to combine different adjustment factors to develop one continuous adjustment factor for predicting the DMI of pregnant, dry, and lactating ewes. The equations evaluated for non-lactation ewes accounts for metabolic body weight and weight gain, and the equation for lactating ewes includes milk production and its fat content. The database used in this study was pooled from hair sheep ewes, two to four years old, with controlled feeding, during the pregnancy and lactating physiological phases. For the overall predictions (gestating and lactating ewes), the adjusted DMI prediction had greater accuracy but lower precision than the unadjusted DMI prediction. However, adjusting DMI increased the adequacy of the prediction as the mean square error of prediction difference (ΔMSEP) decreased (p = 0.0328). Similarly, for gestating ewes, the adjusted predicted DMI had a lower ΔMSEP than the unadjusted predicted DMI (p < 0.001). For lactating ewes, no difference was detected between the adjusted and unadjusted predicted DMI based on the ΔMSEP statistics (p = 0.3672), but the assumption that peak milk was 28 days (default) worsened the predictability of the adjusted predicted DMI as it had lower precision and accuracy. Adjustments for predicted DMI of dry and lactating ewes are necessary to increase adequacy and precision.

PSX-28 Using estrus detection patches or a ram wearing a marking harness to monitor estrus in synchronized hair sheep ewes

Abstract Determining when a ewe is in estrus is important when using estrous synchronization and artificial insemination in sheep. This study was conducted to compare the efficacy of estrus detection patches (Estrotect™) and rams wearing marking harnesses for monitoring estrus in synchronized hair sheep ewes. St. Croix White (STX) ewes (3.5 ± 0.3 y of age, 89.7 ± 2.2 d post-partum) were synchronized using progesterone releasing inserts (Eazi-Breed™ CIDR) for 12 d. On the day of CIDR removal (d 1) ewes were administered prostaglandin (Lutalyse®; 15 mg i.m.) and placed with fertile STX rams in 0.55 ha pastures. One group of ewes (n =10; MH) was placed with a ram wearing a marking harness and a second group (n = 16; EP) had estrus detection patches placed on their rumps before being placed with a ram without a harness. Estrus detection was conducted using visual observations twice a day through d 7. A ewe was considered to be in estrus when crayon marks were observed on the rump or the patch was activated, based on product guidelines. Cumulative percentage of ewes in estrus was analyzed using the CATMOD procedure with treatment, day and the interaction in the model. All patches stayed in place on the EP ewes through d 7. By d 4 90% of MH ewes and 75% of EP ewes had been observed in estrus (P &amp;lt; 0.05). By d 7 90% of MH ewes and 81.25% of EP ewes had been observed in estrus (P &amp;lt; 0.05). With costs of $1.33 per patch or $29.33 for one harness and crayon the patches may be more economical when dealing with up to 21 ewes per ram. Estrus detection patches can be used on hair sheep ewes to detect estrus just as effectively as a ram with a marking harness.

142 Reproductive performance of land race hair sheep ewes in different breeding seasons under a semi-continuous production

Abstract A system for semi-continuous lamb production was evaluated using Barbados Blackbelly and St. Croix hair sheep ewes under 8-mo accelerated mating. Ewes were managed in a forage-based production system using rotational grazing. Two flocks of ewes (n = 30–35), equally representing the breeds, were bred 4 mo apart. Ewes were synchronized by feeding melengestrol acetate for 10 d, and mated in two single sire groups to like breed sires in November (NOV), March (MAR), and July (JUL) in a 25-d mating period. Pregnancy was recorded by transrectal ultrasound 22 d after breeding. Ewes were supplemented with corn/soybean meal during late gestation (0.75% of BW) and during lactation (1.5% of BW). They lambed on pasture with limited supervision, and lambs were weaned at 2 mo of age. Lambs had access to the supplement provided to ewes. Ewe performance (pregnancy rate, litter size, lamb survival, and birth and weaning weight) was recorded during a 2 yr production cycle, and analyzed for the effect of mating season. Pregnancy rate was not statistically different (P &amp;gt; 0.1) between season, and ranged from 93.9% in NOV, to 85.9 and 86.6% in MAR and JUL. Litter size (lambs born/ewe lambing) was higher (P &amp;lt; 0.05) in NOV (2.09) than MAR (1.68) and JUL (1.82). Lamb survival at birth was reduced (P &amp;lt; 0.001) in JUL (86.5%) compared to NOV (99%) and MAR (100 %), but was not different between seasons for survival to weaning (86 to 90%). Lamb birth weights were higher (P &amp;lt; 0.05) in MAR (3.16 kg) than JUL (2.99 kg), with NOV (3.05 kg) intermediate, while lamb weaning weights were higher (P &amp;lt; 0.001) in NOV (13.6 kg) compared with MAR (11.9 kg) and JUL (11.4 kg) mating. Data suggest that dual flock, accelerated mating of landrace hair sheep ewes can produce lamb cohorts of similar size in 4 mo intervals under a low-input, forage-based production system.

160 A comparison of body temperature among pregnant, non-pregnant and lactating hair sheep ewes in the tropics

Abstract St. Croix White hair sheep are well adapted to the tropics. The objective of this study was to evaluate the impact of pregnancy on body temperature of hair sheep. Multiparous St. Croix White ewes (n = 9) were evaluated over 4 d at 128 d of gestation (PREG) and 45 d postpartum (PP) while lactating. A set of non-pregnant, non-lactating (DRY) ewes (n = 9) were also evaluated at each time. Temperature data loggers recorded vaginal temperature (VT) at 10-min intervals for 96 h. Ewes were kept in a 0.6 ha pasture. Data were analyzed using GLM procedures of SAS for repeated measures with pregnancy status and time of day in the model. Mean temperature and solar radiation were 26.3 °C and 212.3 W/m2, respectively. Ewe VT was lowest (P &amp;lt; 0.0001) between 0 and 0700 h and greatest between 1400 and 1900 h (38.21 ± 0. 02 vs 39.11 ± 0.02 °C, respectively). Ewe VT was lowest (P &amp;lt; 0.004) in PREG ewes compared to DRY or PP ewes (38.38 ± 0.02 vs 38.76 ± 0.02 vs 38.77 ± 0.02, °C, respectively). The VT of PREG ewes was lower than that of DRY ewes (P &amp;lt; 0.0001) during 0 to 0480 and 1920 to 2400 h, but there was no difference (P &amp;gt; 0.10) between 0480 and 1920 h. There was no difference in VT between PP and DRY ewes at any time of the day (P &amp;gt; 0.10). The VT of PREG ewes was lower than that of PP ewes (P &amp;lt; 0.0001) during 0 to 0480 and 1920 to 2400 h, but there was no difference (P &amp;gt; 0.10) between 0480 and 1920 h. The lower VT of PREG ewes compared to PP and DRY ewes may be a protective mechanism for the developing fetus.

PSXVI-3 Evaluating the lag between body temperature and ambient temperature in hair sheep ewes in the tropics.

PSXVI-3 Evaluating the lag between body temperature and ambient temperature in hair sheep ewes in the tropics.

Comparing body condition score and FAMACHA© to identify hair-sheep ewes with high faecal egg counts of gastrointestinal nematodes in farms under hot tropical conditions

Data from a targeted selective treatment (TST) survey in three sheep farms was used to compare body condition scores (BCS) ≤ 2 and FAMACHA© scores ≥4 or ≥3 as criteria to identify ewes with ≥ 750 eggs per gram of faeces (EPG), and to confirm whether that EPG threshold allowed maintaining a large proportion of animals with no anthelmintic (AH) treatment. The survey included monthly data from all grazing adult ewes in three commercial farms. Farms 1 and 3 were surveyed for 11 months, and Farm 2 for 6 months, with a total of 7342 events recorded. Mean monthly population consisted of 330 ewes (Farm 1), 129 ewes (Farm 2) and 265 ewes (Farm 3). The FAMACHA© scores and BCS of adult ewes were recorded monthly. Ewes with FAMACHA© ≥ 4 or BCS ≤ 2 were faecal sampled to determine faecal egg counts (FEC) (2788 events). Ewes with ≥ 750 EPG were treated with an AH (658 events). The TST survey showed that BCS ≤ 2 was the best criteria to find ewes with FEC ≥ 750 EPG, with 1.1% false negatives. Meanwhile, FAMACHA© ≥4 or ≥3 failed to identify half of the events with ≥ 750 EPG (50–55% false negatives). Thus, the TST scheme could focus on screening ewes with BCS ≤ 2, and the FEC of those animals can avoid unnecessary AH treatments. The TST scheme was easier to implement at the farm with largest ratio of ewes with BCS > 2, as fewer ewes were sampled and treated, compared to farms where many ewes had BCS ≤ 2. In the surveyed farms a threshold of ≥ 750 EPG resulted in 63.5% of all ewes maintained with no AH treatment for the duration of the survey.

124 The Effect of Water Restriction at Weaning on Hair Sheep Ewes and Lambs in the Tropics.

124 The Effect of Water Restriction at Weaning on Hair Sheep Ewes and Lambs in the Tropics.

506 Evaluating the relationship between environment and body temperature of hair sheep ewes in the tropics

506 Evaluating the relationship between environment and body temperature of hair sheep ewes in the tropics

Evaluating the impact of breed, pregnancy, and hair coat on body temperature and sweating rate of hair sheep ewes in the tropics.

The objective of this study was to evaluate the effect of pregnancy, breed, and hair coat on body temperature and sweating rate (SR) of hair sheep. St. Croix White (STX; = 9) and Dorper × STX (DRPX; = 9) ewes (3.6 yr of age) were evaluated over 4 d at 126 d of gestation (PREG) and over 4 d at 46 d postpartum (OPEN) in the shade and sun and in the morning (AM; 0900 to 1200 h) and afternoon (PM; 1300 to 1600 h) after a 20 min acclimation to each condition on each day. Data loggers recorded vaginal temperature (VT) at 10-min intervals for 96 h. Rectal temperature (RT) was measured using a digital veterinary thermometer, and respiration rate (RR) was measured as breaths per minute (bpm). Sweating rate was calculated from measured air properties passing over a shaved (300 cm) and unshaved area of the ewes' body using a portable calorimeter. Data were analyzed using GLM procedures of SAS (SAS Inst. Inc., Cary, NC) with breed, pregnancy status, sun exposure, and time of day as main effects. Mean temperature, relative humidity, temperature-humidity index, wind speed, and solar radiation on the days of data collection were 28.2°C, 82.8%, 80.3, 4.2 km/h, and 237.5 W/m, respectively. There was no difference ( > 0.10) in RT, RR, and SR between DRPX and STX ewes. The PREG ewes had lower RT ( < 0.007) and SR ( < 0.0001) and higher RR ( < 0.007) than OPEN ewes (38.5 ± 0.2 vs. 39.1 ± 0.2°C, 70.2 ± 3.1 vs. 88.3 ± 3.1 g⋅m⋅h, and 79.5 ± 2.2 vs. 72.1 ± 2.2 bpm, respectively). During the PM, RR, RT ( < 0.05), and SR ( < 0.006) were higher than in the AM. In the sun, RR ( < 0.001) and SR ( < 0.0001) were higher than in the shade, but there was no difference ( > 0.10) in RT. There was no difference in SR ( > 0.10) between the shaved and unshaved area of the ewe. The DRPX ewes had higher ( < 0.0001) VT than STX ewes. The PREG ewes had higher ( < 0.001) VT than OPEN ewes during the night time and lower VT than the OPEN ewes during the day time ( < 0.0001). The OPEN ewes had a greater ( < 0.009) daily range of VT than PREG ewes did (2.5 ± 0.4 vs. 1.1 ± 0.4°C, respectively), but there was no breed difference ( > 0.10). Hair coat did not have an influence on the SR of the ewes, and PREG ewes appeared to use increased respiration as opposed to sweating to help control RT. The narrower range of body temperature, measured as VT, of PREG compared to OPEN ewes may be a protective mechanism for the developing fetus.

Maternal undernutrition during the pre- and post-conception periods in twin-bearing hairsheep ewes: effects on fetal and placental development at mid-gestation.

To evaluate the effects of pre- and post-conception undernutrition (UN) on fetal and placental development at mid-gestation, 28 Katahdin × Pelibuey multiparous ewes were blocked by weight and assigned to the following four dietary treatments (n=7 each): ewes fed 100% (control) or 60% of their nutritional requirements 30days before mating (UNPre), 50days after mating (UNPost) or during both periods (UNB). Four twin-bearing ewes were selected per treatment at day 50 post-conception and then slaughtered at day 75 of gestation to analyze their fetuses. Control fetuses were heavier (P<0.05) than UNPost and UNB fetuses in 14.6 and 9.4%, respectively. Organ weights as percentage of the fetal weight (except for liver) and morphometric measurements (except for abdominal girth) were similar between control and UN fetuses (UNPre, UNPost, and UNB). Placental mass was heavier (P<0.05) in control ewes than UNB ewes, but not relative to ewes of other treatments. The number of placentomes per ewe and placental efficiency were unaffected by UN treatments. Compared to control, only UNB ewes exhibited variations (P<0.05) in the proportion of placentomes, specifically for type A (+13.8%) and B (-12.6%). Placentomes of type A and B had lower weight, length, and width of placentas in UNPost and UNB ewes than placentas of control ewes (P<0.05). Overall results indicate that fetal and placental development of ewes carrying twins is mainly altered when nutritional restriction occurs simultaneously before conception and during the first third of pregnancy.

Evaluating the impact of breed, pregnancy, and hair coat on body temperature and sweating rate of hair sheep ewes in the tropics

Evaluating the impact of breed, pregnancy, and hair coat on body temperature and sweating rate of hair sheep ewes in the tropics

071 Comparison of plasma and hair cortisol concentrations in hair sheep ewes and lambs in response to weaning with or without fence line contact

071 Comparison of plasma and hair cortisol concentrations in hair sheep ewes and lambs in response to weaning with or without fence line contact

Susceptibility of hair sheep ewes to nematode parasitism during pregnancy and lactation in a selective anthelmintic treatment scheme under tropical conditions

The objective was to determine the influence of year, season and age of hair sheep ewes on their susceptibility to gastrointestinal nematodes during pregnancy and lactation and to record the number of treatments within a selective anthelmintic (AH) treatment programme. A trial was performed with 46 grazing ewes kept in hot humid tropical conditions. Data included: average daily weight gain (ADG, kg), packed cell volume (PCV, %) and nematode eggs per gram of faeces (EPG) obtained during 2 years (2009 and 2011–2012). Ewes reaching 1000 EPG were treated with AH. Irrespective of year, season and age, ewes were more susceptible to GIN during lactation (higher EPG, lower PCV and net weight loss) and less susceptible during gestation (lower EPG, higher PCV and net weight gain). As a result, 24.4% of the ewes were left untreated during lactation, while 63.0% of the ewes needed no AH treatment during pregnancy. Even under the hot humid tropical conditions of the farm, the individual EPG helped to maintain a considerable proportion of animals without an AH treatments within the flock.

The effect of a split feeding regimen and breed on body temperature of hair sheep ewes in the tropics1

Lactating St. Croix White and Dorper×St. Croix White ewes were used to evaluate the effect of breed and feeding a split ration on body temperature during the cool (March-April) and warm (July-August) seasons in the U.S. Virgin Islands. Within each season ewes were assigned to treatments (n=8/treatment) based on breed, age, and number of lambs. Treatments consisted of individually feeding ewes daily 0.9 kg concentrate (16.4% CP and 68% TDN) in the morning (AM) or afternoon (PM), 0.45 kg in the morning and afternoon (AM-PM), or no feed (Control) for 56 d beginning on d 7 (lambing=d 0). Ewes were fitted with intravaginal temperature data loggers, set to record vaginal temperature (VT) at 5-min intervals, for 48 h in wk 2 (d 8-14), 5 (d 29-35), and 8 (d 50-56) postpartum. Repeated measures analysis of VT was conducted using a model including treatment, season, and breed as fixed effects. There was no effect of season so data were pooled across season. The interaction of breed with treatment or season was not significant so breed comparisons were made using data pooled across treatments and season. The mean temperature, relative humidity, and temperature-humidity index during the cool and warm seasons were 25.8°C, 85.9%, and 76.1 and 28.3°C, 86.7%, and 80.6, respectively. There was no effect of season or the breed×treatment×season interaction on VT (P>0.10) so all data were pooled across season and breed for analysis of the treatment effect. During wk 2 there was no difference (P>0.10) in VT among treatment groups. During wk 5 the AM-PM ewes had higher (P<0.01) VT than AM, PM, or Control ewes. During wk 8 the AM-PM and PM ewes had higher VT (P<0.01) than either the AM or Control ewes. To evaluate breed effect, data were pooled across treatments and seasons and analyzed using breed as the single main effect. Dorper×St. Croix White ewes had higher (P<0.0001) VT than St. Croix White ewes. The results show that body temperature of ewes can be influenced by time of feeding and breed. The local breed of sheep, St. Croix White, had a lower body temperature than Dorper×St. Croix White sheep. Ewes that were fed in the afternoon for an extended time during the postpartum period developed elevated body temperatures, which could make them more susceptible to heat stress.

Evaluation of Split Feeding Regimens on Growth and Productivity of Hair Sheep Ewes and Lambs in the Tropics

Evaluation of Split Feeding Regimens on Growth and Productivity of Hair Sheep Ewes and Lambs in the Tropics