Ewe Weight Research Articles

Birth weight responses to shearing ewes in early to mid gestation

AbstractThis study compared the effect on foetal growth of shearing ewes in very early pregnancy (day 50) with the effect of shearing later in pregnancy (day 70 or 100). One hundred and sixty ewes were allocated at day 49 of pregnancy to four ‘time of shearing’ treatments — pregnancy day 50 (P50), P70, P100 (no. = 45 ewes per treatment) and unshorn (shearing of this group occurred 43 days after weaning) (no. = 25); two methods of shearing (by standard comb and cover comb); and two levels (1 or 2) of pregnancy/rearing rank. All ewes had been mated over a 28-day period and grazed pasture throughout the trial. The mid point of lambing was 27 August 1996. Live weights of ewes (corrected for fleece weight) were not influenced by shearing time at any stage except at day 45 of lactation when ewes shorn at P50, P70 or P100 were about 3⋅0 kg lighter than unshorn ewes. Shearing method had no effect on ewe live weight. Time of shearing and shearing method had no effect on ewe greasy fleece production or wool tensile strength. Shearing significantly (P < 0⋅05) influenced the birth weight of single- (by 0⋅7 to 0⋅8 kg) but not twin-born lambs. Maternal plasma triiodothyronine concentration increased proportionately by 0⋅47 to 0⋅85 (P < 0⋅05) and lasted for at least 20 days in response to shearing irrespective of time of shearing. No difference in plasma insulin concentration was detected between shearing groups but plasma glucose concentration proportionately increased by 0⋅06 to 0⋅16 (P < 0⋅05) for 10 to 20 days after shearing. These results indicate that shearing between day 50 and 100 of pregnancy can increase lamb birth weights and that the response is associated with an increase in thyroid hormone concentrations in the maternal circulation.

Continued selection of Romney sheep for resistance or susceptibility to nematode infection: estimates of direct and correlated responses

AbstractDivergent breeding lines of Romney sheep, selected as lambs for consistently high or low faecal worm egg count (FEC) following natural multi-species challenge by nematode parasites, were established in New Zealand at Wallaceville Animal Research Centre in 1979 and at Rotomahana Station in 1985. In 1988 the Rotomahana lines, including an unselected control line maintained under the same management conditions, were transferred to Tokanui Station where they remained for 4 years. In 1993 elite high and low FEC animals from Tokanui, along with the controls, were transferred to Wallaceville, where merged lines have since been managed together. Selection responses from the lines at Rotomahana and Tokanui, and from a further 5 years of divergent selection in the merged lines, are reported here. For the two most recent lamb crops (1996 and 1997 birth years), log-transformed FECs of the high and low lines were 1·27 and -1·46 phenotypic standard deviation units from the control. After back-transformation to the original scale, where the FEC for control line lambs averaged 1255 eggs per g, the means for the high and low lines were 3Ό5 and 0·27 times the control mean. Animal-model restricted maximum likelihood estimates of her it ability and repeatability for single-record FEC (following separate infections) were 0·28 (s.e. 0·02) and 0·42 (s.e. 0Ό1), respectively. Correlated responses in production traits include significantly decreased post-weaning weight gain and increased dags (breech soiling) in lambs, and decreased fleece weight in yearlings and ewes in the low FEC line, compared with those in the high line. However the low FEC line had proportionally 0·11 more lambs weaned per ewe mated than the high FEC line (F < 0·01). It is concluded firstly that selection for high or low FEC in Romney s has achieved an 11-fold difference between the divergent lines. Secondly, it will generally be necessary in a commercial environment to apply index selection for a combination of increased productivity, decreased FEC and possibly decreased dags, when potential candidates are recorded under conditions of nematode challenge.

Performances of composite genotype resulting from crossingbetween local sumatera and hair sheep under confinement condition

Under semi-intensive conditions, the composite genotype (K) (25% Barbados Blackbelly; BB, 25% St. Croix; SC, 50% Sumatra Thin Tail; DETS) showed relatively have similar weaning weight as compared to other contemporary crossbred, therefore under intensive conditions (confined), they are expected to have better performances. The objective of the study are to find performances of the second generation composite genotype lambs and the first generation performances of the ewes, as well as several genetics parameters under intensive conditions, and compared to the Barbados Blackbelly Cross (BC) as contemporary crossbred. The growth of pre- and post-weaning of BB crossbred (BC) and the second generation of composite genotype (K-F2) are relatively the same. Growth curve using Von Bertalanffy model with the equation of Wt (t) = A*(1-B*e**(- K*t)), show that the equation for BC is Wt (t) = 26.8(1-0.92e**(-0.01t) and for K-F2 is Wt(t) = 26.1(1-0.92e**(-0.01t). This equation indicate that the growth of BC and K-F2 is not significantly different. The BC and K-F2 genotype reach maturity at the weight of 26.8 and 26.1 kg, respectively, and both with rate of reaching maturity of 0.01. Mating weight and weight at lambing of those two genotypes are around 29 - 30 kg dan 31 kg, respectively. The mean of litter size of BC and K-F1 are 1.52 and 1.48, respectively or around 1.5. The average litter size at weaning are 1.39 and 1.34, respectively for BC and K-F1. This means that pre-weaning mortality are around 5.37 and 9.76%, respectively for BC and K-F1. The lambing interval of BC and K-F1 are 211 and 223 days, or 0.58 and 0.61 year, respectively. Therefore the reproductive rate (RR) of the respective genotype are 1.39/0.58 = 2.39 and 1.34/0.61 = 2.19, respectively. The average of litter weight at weaning (LWW) of BC x BC, SC crossbred (HC) x BC and K-F1 x K-F1 are 11.62, 12.60 and 11.83 kg, respectively. Therefore based on the ewe genotype the LWW of BC and K-F1 are 11.74 and 11.83 kg, respectively. Flock productivity (FP) for those two genotypes per year are 20.24 and 19.39 kg, respectively for BC and K-F1. Dam productivity index (DPI) that calculated as /ewe weight for those two genotypes are 0.67 and 0.66, respectively for BC and K-F1. Meanwhile, the flock efficiency index (FEI) that calculated as FEI = FP/ewe weight0.75 for the respective genotypes are 1.57 and 1.54 for BC and K-F1. The estimates of repeatability of litter weight at weaning show relatively low value (0,092), therefore the estimate of MPPA (Most Probable Producing Ability) for predicting the future productivity is relatively the same. The estimate of MPPA for litter weight at weaning (LWW) for the respective genotype are 11.79 and 11.81 kg, respectively for BC and K-F1. Results of the study show that performances of composite genotypes (F) and the contemporary crossbred (BC) are relatively similar in the traits of growth, dam productivity and the estimate of MPPA. Key words : Composite sheep, performance of production and reproduction, intensif condition

Effect of Body Weight of Ewes on Birth Weight of Lambs In Rambouillet Breed of Sheep

Effect of Body Weight of Ewes on Birth Weight of Lambs In Rambouillet Breed of Sheep

Estimation of Milk Yield in Suckled Awassi Sheep Under Traditional Feeding Conditions

Said, S.I., Kridli, R.T. and Muwalla, M.M. 1999. Estimation of milk yield in suckled Awassi sheep under traditional feeding conditions. J. Appl. Anim. Res., 16: 163–168. This study was performed to estimate the milk production ability of Awassi ewes using oxytocin-induced hand milking method under traditional feeding. Thirty eight Awassi ewes (2 to 7 years) were used in this study. Milk production and body weight of ewes were estimated once a week throughout the suckling period (8 weeks). Each ewe received 5 i.u. of oxytocin (iv) followed immediately by hand-milking until all the milk was stripped off. Lambs remained in isolation from ewes for 4 hours after which the milking procedure was repeated. Milk obtained at second milking was measured. Twentyfour hour milk production was calculated in relation to the interval between milkings. The least-squares means for daily milk yield in the first eight weeks of lactation (suckling period) were 1.88. 1.60, 1.58, 1.39, 1.30, 1.18, 1.12 and 1.06 kg, respectively. The effect of lamb sex, ewe age, day of measurement and ewe weight on daily milk yeild were generally not significant.

Lamb and milk production traits of Serrai sheep in Greece

This study is based on data from 1238 lambings, 1516 lambs and 979 lactation records from Serrai ewes. Litter size averaged 1.25 lambs at birth, 1.23 lambs born alive and 1.17 lambs at weaning. Lambs weighed 4.3 kg at birth and 13.5 kg at weaning (42 days). Milk production averaged 70.7 kg in a lactation length of 157 days. Month of lambing influenced litter size, lamb birth and weaning weight, milk yield and lactation length ( P < 0.05). Lactation number influenced litter size, lamb weaning weight, milk yield and lactation length ( P < 0.05). There was a significant effect of litter size on lamb weight at birth and weaning and on milk production. The ewe weight at lambing had a significant effect on weights of lambs at birth and weaning and on milk production.

Introduction of East Friesian dairy sheep into the Norwegian sheep population

The litter size in the Norwegian crossbred (NC) sheep population has increased considerably in recent years and consequently there is a need to improve maternal ability. East Friesian (EF) dairy sheep were introduced by artificial insemination with semen from four Swedish pure-bred rams into two research flocks of the Agricultural University of Norway in 1985. The flocks differed in producing level. Different breed combinations of lambs (1/2 EF, 3/8 EF, 1/4 EF, 1/8 EF, 1/16 EF) with various degrees of EF in the dam (0 EF, 1/8 EF, 1/4 EF, 1/2 EF) were produced and compared to NC lambs for live weight, ultrasonic-scanning results and carcass traits. Ewes of 1/2 EF, 1/4 EF and 1/8 EF were compared to NC ewes for litter size, mature and fleece weights. The groups varied considerably in size. Data from 1988 to 1992 were used, and a least square analysis was carried out in order to test for significant differences. The direct effect of growth reduced as the proportion of EF increased in the crosses. This was seen in the lamb weights and in the mature weight of ewes. A moderate degree of EF in the dam (1/8) seemed to have a positive effect on lamb growth and litter size, indicating that maternal ability in EF is beneficial in improving productivity. An optimal degree of EF in lambs and in dams was observed where the advantage of the superior maternal ability, higher fertility and lower ewe weights of the EF could be exploited without reducing the direct growth capacity and muscling of the lambs very much. This optimal level of EF seems to be higher in lower producing flocks then in high producing flocks.

Estimates of genetic and phenotypic correlations for ewe productivity traits of three breeds under 8-month breeding cycles and artificial rearing of lambs

Paternal half-sib estimates for genetic and phenotypic correlations for ewe productivity of three synthetic sheep breeds (Canadian, Outaouais and Rideau Arcotts) were based on 11 106 ewe records from 3528 ewes and their 814 sires collected over 8 years (1983–1990) and 24 lambings in 8-month breeding cycles. Two separate flocks of ewes, housed indoors year-round in a controlled environment, were mated to lamb alternately at 4-month intervals, at the end of a period of short days, in February, June and October. Artificial lighting regimens and exogenous hormones were used to synchronize estrus. All lambs were raised on milk replacer diets from birth to weaning at 21 days of age. Genetic and phenotypic correlations based on mixed model methodology were estimated by breed and involved ewe weight at breeding, reproduction (prolificacy, multiple birth and fecundity) and total lamb weights (at birth, 21 and 91 days of age). Ewe weight at breeding was found to have neither genetic nor phenotypic relationships with the reproductive traits. Prolificacy was associated, both genetically (0.50–0.80) and phenotypically (0.77–0.79), with total lamb weight at birth for the three breeds. However, genetic correlations between prolificacy and total lamb weights at 21 days (0.85) and 91 days (0.94), important ( P<0.05) in the Outaouais breed, failed to demonstrate significance in the Canadian and Rideau breeds. Estimates of genetic correlations between fecundity and total lamb weights (0.88–0.96 at birth, 0.67–1.06 at 21 days, and 0.72–1.06 at 91 days) were always significant for the three breeds, suggesting that selection for fecundity would result in correlated genetic improvement of ewe productivity. Within total lamb weight, the genetic and phenotypic relationships between weights at birth and either 21 days or 91 days were similar. Corresponding estimates between 21 and 91 days of age tended to be larger. The magnitude of the phenotypic and environmental correlations were alike. In general, genetic and phenotypic correlations based on least squares analysis, maximum likelihood and restricted maximum likelihood procedures were similar, however, there may be some cause for concern in the absence of associated standard errors. The results provide estimates of genetic and phenotypic correlations for ewe productivity traits in the three Arcott sheep breeds developed in Canada under conditions of an 8-month breeding cycle when lambs were fed with a milk replacer diet and raised artificially in a controlled environment.

Produção de cordeiros da raça Suffolk em dois sistemas de manejo reprodutivos

Foram utilizadas 32 ovelhas Suffolk por dois anos, em dois sistemas de monta, com acasalamentos a cada oito meses (alternativo) ou a cada doze meses (tradicional), visando a reduzir a estacionalidade da disponibilidade de animais para abate. Não foram observadas diferenças (P&gt;0,05) na fertilidade e prolificidade dos animais, sendo no sistema alternativo, 66,7% e 110,4% e no tradicional 78,1%; 103,1% , obtendo-se 53 e 33 crias nascidas no período, respectivamente. Para a mortalidade das crias, observou-se, respectivamente, 28,3% e 6,1% (P&lt;0,01). O peso médio das crias ao nascerem foi de 3,46 e 4,45kg. (P&lt;0,05) e ao desmame (60 dias) foi de 18,73 e 18,86kg (P&gt;0,05) e o peso da ovelha à parição foi de 68,06 e 71,05kg (P&gt;0,05), para o sistema alternativo e tradicional, respectivamente. Conclui-se que o sistema de monta alternativo possibilita a obtenção de maior número de cordeiros, sem prejuízo no desempenho ponderal das ovelhas e dos cordeiros, bem como uma melhor distribuição na produção de cordeiros para abate durante o ano.

Effect of feeding level in late pregnancy and early lactation and fibre level in mid lactation on body mass, milk production and quality in Awassi ewes

AbstractIn west Asia, it is traditional for sheep to gain body condition when low-cost native pastures are available and to mobilize reserves thus built up at other times. With diminishing shares of native pasture, crop by-products and food grains are increasing in sheep diets, and facilitate feeding for constant body condition.In a 2 × 2 × 2 factorial experiment, 48 Awassi ewes were individually fed indoors, nursed single lambs for 42 days, and were hand-milked from day 29 after lambing. Dietary treatments were imposed at different times: level of feeding (i) in the last 24 days of pregnancy (Lconstv. Lmob), (ii) in days 18 to 60 after lambing (Lconstv. Lmob), and (iii) level of fibre in days 60 to 102 after lambing (Fhighv. Flow). RationsPconst, Lconst, Flowand Fhighwere calculated to maintain body condition. Fhighprovided the calculated maximum ingestible quantity of barley straw and Flowprovided 0·08 kg barley straw per kg diet. Live weights (M) of ewes and lambs, milk yield and milk quality were recorded.WithPconst, andPmob(0·51 and 0·33 MJ metabolizable energy (ME) per kg M0.75per day), M gains were 140 and 23 g/day (P&lt; 0·001). Lamb birth mass and subsequent maternal milk yield were not affected. WithLconstandLmob(0·81 and 0·61 MJ ME per kg M0.75 per day), M changes were -28 and -70 g/day (P&lt; 0·001) and milk yields (calculated in part from lamb growth) were 1042 and 892 g/day (P &lt; 0·01). Fhighand Flow(385 and 170 g acid-detergent fibre per kg dry matter) were compared in a two-period change-over design experiment. Milk yields were similar (414 and 427 g/day), milk fat concentrations were 64·8 and 72·9 g/kg (P &lt; 0·001) and milk fat yields were 26·5 and 31·1 g/day (P &lt; 0·001) but solids-not-fat and protein yields were not affected.There were benefits and costs in manipulating body reserves in Awassi sheep. M at lambing affects milk yield and body condition around mating is known to improve lambing rate. The existence of body reserves also allows body condition to be lost in late pregnancy and early lactation without affecting health or apparent welfare, which simplifies management of pregnant ewes, permits feeding of milk-fat-increasing high-fibre diets but the ME to maintain increased body reserves must not be ignored.

A comparison of chopped/un-chopped big bale silage, pit silage and hay when offered with concentrates to twin bearing ewes

Big bale silage has become increasingly popular on many livestock farms in Ireland yet there is limited information on its use for sheep. The objective of this experiment was to compare the effects of feeding chopped or unchopped big bale silage, pit silage and hay when supplemented with either a barley or a molassed sugar beet pulp based concentrate when fed to ewes in late pregnancy on feed intake, ewe weight and body condition score changes, gestation length, lamb birth weight and colostrum yield.Sixty four mature lowland cross ewes (8/treatment) were oestrus synchronised in October and mated to terminal sire breeds (Suffolk, Texel or Charollais). The ewes were housed, winter shorn and pregnancy scanned in December, following which twin bearing animals were allocated to a 4 x 2 factorial experiment and individually fed either un-chopped or chopped big bale silage which had been wilted for 36-48 hours as is usual for this type of forage, pit silage, which had been wilted for 18-24 hours or hay.

クリープフィーディングが子羊の反すう胃の発達に及ぼす影響

The effects of creep feeding on the growth of body weight and the development of ruminoreticulum were investigated during 3 months of nursing period.Eight Suffolk ewes and their lambs (two single born lambs and six twins) were used for this study. Three twins were fed creep feed from 2 weeks of age. The data for ram lambs only were used for this study.Ewes and their lambs were kept in pen of 4-5 m2 each. Ewes were fed at 8 : 30 and 17 : 00. Creep feed for lambs was given once a day in the adjoining pen. The residues of creep feed was measured at the next feeding. Body weight of ewes and lambs were measured once a week. After the weaning at 3 months of age, lambs were slaughtered, then the weight of ruminoreticulum, omasum and abomasum was measured, and the length of papillae was measured. Difference between means were tested for significance by two sample t-test. The twin lambs fed creep feed showed satisfactory growth until weaning. However, the growth rate of the other lambs decreased after 7-8 weeks of age. The mean body weight at weaning and the daily gain from birth until weaning of the twin lambs fed creep feed were 1.48 times and 1.53 times bigger than the means of the other twins, respectively (P < 0.05). In the case of the single born lambs, those means were intermediate values between the means of the twin lambs fed creep feed and the other twins.The mean weight of ruminoreticulum, omasum and abomasum of the twin lambs fed creep feed were 1.54 times, 1.60 times and 1.54 times bigger than the means of the other twins, respectively (P< 0.05). In the case of the single born lambs, those means were intermediate values between the means of the twin lambs fed creep feed and the other twins.The ratio of the weight of ruminoreticulum to the body weight, the metabolic body size and the weight of abomasum at weaning did not show significant difference between the values of the twin lambs fed creep feed and the values of the other lambs. These results showed that ruminoreticulum, omasum and abomasum were developed simultaneously with the increase of body weight by creep feeding.The twin lambs fed creep feed showed higher development of papillae than the other lambs (P< 0.05).

Effects of Ad Libitum Silage Feeding Systems on Ewe Performance and Floor Wastage

Two experiments were conducted to investigate how silage intake, ewe weight gains, lambing performance and floor wastage of feed were affected by ad libitum silage feeding systems differing with respect to feeder space allowance, feeding frequency and feeder design. In Experiment 1, 162 ewes of the Icelandic sheep breed were divided into three treatments. Feeding twice a day in a conventional feeder type (A) for loose silage with 0.40 m feeder space per animal (Treatment 1-1) was compared with feeding whole round bales in a new feeder type (B) with an average space of 0.11 m per animal, and also with two different leftover allowances at feeding: approximately 5 and 15% in Treatments 1-2 and 1-3, respectively. In Experiment 2, 168 ewes of the Icelandic sheep breed were divided into three treatments. Treatment 2-1 was as Treatment 1-1 in Experiment 1, but here it was compared with feeding round bales cut in half in a third type (C) of feeder, with two different levels of feeder space allowance: average 0.11 m (Treatment 2-2) and 0.09 m (Treatment 2-3) per ewe. In Experiment 1, no significant differences in ewe weight gains or lambing performance were found between treatments. However, the silage intake was, on average, 10 and 20% higher in Treatments 1-2 and 1-3, respectively, than in Treatment 1-1. In Experiment 2, ewe weight gains differed significantly (P<0.05) between treatments, being 13.1, 11.5 and 9.6 for Treatments 2-1, 2-2 and 2-3, respectively, which parallels the trend found for intake in the treatments. The feed wastage on the floor was about 0, 4-5 and 1% for feeders A, B and C, respectively. It is concluded that when ewes are fed round bale silage ad libitum, continuous access feeding regimes with restricted feeder space allowance can be an interesting alternative, especially on farms where labour is a limiting factor on productivity.

Maternal serum progesterone concentration during pregnancy and lamb birth weight at parturition in Javanese Thin-Tail ewes with different litter sizes

Pregnant ewes, ( N=38), with similar body weight and age (19, 13 and 6 carrying 1, 2 and 3 fetuses, respectively) were used to study the relationship between maternal serum progesterone concentration during pregnancy and lamb birth weight at parturition. Average maternal serum progesterone concentration in the ewes carrying 1, 2, and 3 fetuses was: 5.3±0.3, 6.2±0.7 and 6.6±0.5 ng/ml, during weeks 0 to 7 of gestation; 16.9±1.4, 25.3±1.5, and 26.8±2.5 ng/ml, during weeks 8 to 20; and 13.2±1.0, 18.7±1.0, and 19.8±1.7 ng/ml, during the entire gestation period respectively. Total lamb birth weight in ewes carrying 1, 2, and 3 fetuses was 1.9±0.1, 3.2±0.2, and 4.2±0.4 kg, respectively. In the respective litter sizes, ewes with higher mean serum progesterone concentration during the whole pregnancy gave birth to lambs with higher birth weight ( r 2=0.76, 0.42 and 0.46, for ewes carrying 1, 2 and 3 fetuses, respectively). The results of the study indicated that prenatal growth could probably be improved by increasing endogenous secretion of maternal progesterone during pregnancy.

Effect of strategic supplementary feeding on ewe productivity under range conditions in North Kordofan, Sudan

Strategic supplementary feeding practices were imposed on ewes prior to mating (flushing) and during late pregnancy (steaming-up) at two locations in North Kordofan, Sudan. The objective was to improve ewe reproductive performance and increase lamb birth weight. A completely randomized block design was used and the results analyzed from the economic point of view. Strategic supplementary feeding of ewes increased conception and lambing rates ( P<0.01), reduced abortions ( P<0.01), and resulted in higher lamb birth weights ( P<0.05). The treatment also reduced ewe weight loss ( P<0.05) and caused no ewe mortality. Respective lambing rates for the supplemented and control ewes were 91.7 and 41.7%. Strategic supplementary feeding was economically more advantageous and could accrue up to 382540 additional Sudanese pounds (US $273.24) in returns. It was concluded that steaming-up and flushing are essential for improving ewe reproductive performance, increasing lamb birth weights, and minimizing pregnancy stress of ewes. Hence, the practice is recommended in similar ecological zones to improve productivity of desert sheep.

Body weight, oestrous and ovarian activity in local Burundian ewes and goats after parturition in the dry season.

To compare body weight losses and post-partum anoestrus, twelve local Burundian ewes and twelve goats which had lambed or kidded at the middle of the dry season were followed from parturition until eight months. Each dam was weighed every month and bled three times a week to assess the ovarian activity resumption by plasma progesterone (P4) profiles. For the two species, the body weight decreased significantly (P < 0.05) compared to the body weight at parturition. The mean time during which the body weight decreased was longer (P < 0.05) for the ewes (3.2 +/- 1.2 months) than for the goats (2.3 +/- 1.4 months), however, the relative body weight losses did not significantly differ. The time to oestrous and ovarian activity resumption was highly correlated to the body weight losses for the ewes (r = 0.81; P < 0.01 and r = 0.58; P < 0.05) not for the goats. The first oestrus preceded the first ovarian activity by 4 days in the goats, but occurred 36 days later in the ewes. Nevertheless, after the first luteal function, the subsequent ovarian activity was regular and normal in the ewes but not in the goats and in some cases a return to anoestrus could be observed. These data indicate that in the ewe, not in the goat, the body weight losses are one of the major limiting factors of the oestrous and ovarian resumption after parturition during the dry season. Moreover, the occurrence of luteal function does not initiate a regular reproductive cyclicity in the goat in contrast to the ewes.

Effects of dietary vitamin E supplementation during late pregnancy on lamb mortality and ewe productivity

Objective To determine the effect of feeding vitamin E to ewes during late pregnancy on lamb mortality and ewe productivity. Design Prospective study. Animals 1,302 mature Rambouillet and Targhee ewes. Procedure During a 3-year period, approximately 430 ewes/y were randomly allocated to 2 groups; supplement-group ewes were fed additional vitamin E and control-group ewes were not. Beginning approximately 3 weeks before the first expected lambing date, ewes were fed 2.3 kg (5 lb) of alfalfa-grass hay/d and 0.23 kg (0.5 lb) of barley-based pellets/d with or without supplemental vitamin E. Pellets that were supplemented contained 1,450 mg of dl-α-tocopherol acetate/kg (658 mg/lb) of feed and provided an additional 330 IU of vitamin E/ewe/d. Selenium was incorporated into a trace mineral salt and fed free choice to all ewes throughout pregnancy. Results Supplemental vitamin E had no effect on ewe weight, body condition score, fertility, or prolificacy. In ewes that lambed in the early part of the lambing season, vitamin E supplementation significantly reduced lamb mortality, compared with no supplementation (12 vs 17%, respectively). Consequently, supplement-group ewes had significantly greater total body weight of lambs per ewe at the time of weaning, compared with control-group ewes. Differences were not observed between ewe groups in lamb mortality or total body weight of lambs per ewe at the time of weaning when ewes lambed during the late part of the lambing season. Clinical Implications If ewes are fed additional vitamin E 3 weeks before parturition, those that lamb in the early part of the lambing season may have low lamb mortality and, thus, higher total body weight of lambs per ewe at the time of weaning. (J Am Vet Med Assoc 1998;212:997–1000)

Milk composition, postpartum reproductive activity and growth of lambs in Pelibuey ewes fed calcium soaps of long chain fatty acids

Seventeen 3-year-old multiparous Pelibuey ewes were used to determine the effects of including calcium soaps of fatty acids (CSFA; 50 g ewe −1 day −1) in diets with 14 or 16% crude protein (CP) on milk composition, body weight of ewes and their lambs, fat metabolites, and reproductive performance. Ewes (40 kg) were fed, from 8 days before lambing to 75 days after lambing, one of the following diets: 14% CP, no CSFA; 14% CP with CSFA; 16% CP, no CSFA and or 16% CP with CSFA. Diets were isoenergetic (ME = 5.2 Mcal day −1). Feeding CSFA increased milk fat percentage from 3.3 to 5% ( P < 0.05) in ewes receiving the 16% CP diet, but not those receiving the 14% CP diet ( P > 0.05). Body weight of ewes fed diets with 16% vs. 14% CP was greater at 60 days (43.9 ± 0.9 vs. 48.6 ± 0.8 kg; P < 0.05) and at 75 days postlambing (44.0 ± 0.9 vs. 48.5 ± 0.8 kg; P < 0.05). Feeding CSFA increased ( P < 0.05) serum concentration of total cholesterol (CHOL), high density lipoprotein-cholesterol (HDL), very low density lipoprotein-cholesterol (VLDL) and triglycerides (TG). Days to conception in ewes fed CSFA were lower ( P < 0.05) than in those not fed CSFA (41.5 ± 3.8 vs. 53.8 ± 4.0 days). Feeding CSFA to Pelibuey ewes increased serum fat metabolites and reduced days to conception without effects on serum concentrations of P 4. The CSFA treatment did not have an effect on milk protein percentage, body weight of lambs at birth and weaning, days from lambing to first increase in serum P 4, serum concentrations of low density lipoprotein-cholesterol (LDL) and days to first detected estrus. Diets with 16% CP improved postpartum body weight in Pelibuey ewes after the peak of milk production than those with 14% CP.

18週齢時に屠殺した舎飼いサフォーク種雌および雄子羊の枝肉成績

Carcass characteristics and carcass class were compared in 24 entire male (ram) and 14 female (ewe) Suffolk lambs. Lambs were fed concentrate and hay in confinement, and slaughtered at 18 weeks of age. The means (±s. d.) for body weight at slaughter of ram and ewe were 57.2±3.5 and 48.6±3.1 kg, respectively. Carcass class were assessed by the lamb carcass classification of Japan Sheep Breeders Association.Although cold-carcass weight of ewe were lower than that of ram (24.2±2.5 v. 27.0±2.1 kg; P<0.01), dressing percentage of ram was lower than that of ewe (52.0±1.7 v. 53.6±2.1%; P<0.05). Kidney fat percentage of ewe was higher than that of ram (2.9±0.8 v. 2.0±0.7%; P<0.01), but no significant difference was seen in back fat depth between sexes. Longissimus dorsi area of ram was higher than that of ewe (17.1±1.7 v. 15.5±1.4 cm2; P<0.01).In the ewe carcasses, 8 out of 14 (57%) were classified into M2, the most desired class in Japan, ranged in carcass weight from 20 to 25 kg and in backfact depth from 4 to 7 mm. Five out of 14 ewe carcasses (36%) were classified into thicker backfat depth class. In contrast with ewe, 4 out of 24 ram carcasses (17%) were classified into M2. Although 13 out of 24 ram carcasses (54%) were classified into desired backfat depth class, 19 out of 24 (79%) were classified into heavier carcass weight class.

Genetic and phenotypic parameters of body weights, average daily gains and first shearing wool yield in Muzaffarnagri sheep

Data on 953 Muzaffarnagri lambs, progeny of 41 rams, born between 1987 and 1993 at the Central Institute for Research on Goats, were utilized to estimate genetic and phenotypic parameters for BW at birth, 3 and 6 months, first-shearing wool yield and average daily gain (ADG) for the periods 0–3 (ADG1), 3–6 (ADG2) and 0–6 (ADG3) months of age. The effects of sire, year of birth and type of management on weight at birth, 3 and 6 months, first-shearing wool yield and ADG were all appreciable. Season of birth affected BW at 6 months, ADG2 and ADG3. Sex of lambs affected all traits except birth weight. The linear regression effect of age of ewe at lambing was significant for birth weight, ADG2 and ADG3, while linear and quadratic regression effects of weight of ewe at lambing were significant for all traits studied, except ADG3. Least squares means were 3.48 ± 0.07, 16.82 ± 0.37, 25.16 ± 0.41 kg and 511.0 ± 11.9 g for weight at birth, 3 and 6 months and first-shearing wool yield, respectively. The mean values for ADG1, ADG2 and ADG3 were 148.2 ± 3.9, 92.5 ± 3.2 and 120.5 ± 2.3 g, respectively. Male lambs attained heavier weights and grew faster than females; similarly, lambs maintained in feedlot had better ADG and higher weights than those kept in group. Heritability estimates for weight at birth, 3 and 6 months of age and wool yield were 0.32 ± 0.10, 0.43 ± 0.12, 0.27 ± 0.09 and 0.15 ± 0.07, respectively. The h 2 of ADG1, ADG2 and ADG3 was 0.44 ± 0.12, 0.34 ± 0.10 and 0.29 ± 0.10, respectively. Birth weight had low to moderate phenotypic ( r p ) and genetic ( r g ) correlations with other traits, while standard errors of r g were high. BW at 3 months was highly and positively correlated with 6-month weight and wool yield, both at genetic and phenotypic scales. The r p between 6-month BW and wool yield was 0.354 and the r g with ADG2 was 0.14 ± 0.30. ADG1 had negative genetic and phenotypic correlations with ADG2, indicating that lambs growing faster from 0 to 3 months grew at a slower rate from 3 to 6 months. High heritability of BW at 3 months and ADG2, and their high and positive correlations with 6-month weight indicated that selection for BW could be practised at 3 months of age or these traits could be included in an index for improving 6-month weight and wool yield.