Early Lamb Research Articles

Colostrum traits and newborn body weight and growth: comparison between single and twin underfed sheep pregnancies.

Maternal nutrition during gestation plays an important role in colostrum production, postnatal growth, and survival of newborn lambs, especially in twin gestations. This research aimed to investigate the effects of chronic natural undernutrition on colostrum traits and early lamb's postnatal growth born from single and twin sheep pregnancies developed in a restrictive prairie, representative of southern Patagonia. Single- and twin-bearing ewes (n = 20 per group) were maintained grazing in a natural pasture. At 140 days of gestation, ewes were placed in individual pens for lambing control. Colostrum was collected immediately after delivery and at 12, 24, and 36 h postpartum, for determination of yield and composition. Maternal blood was obtained at 140 days of gestation and at lambing for plasma glucose, progesterone, 17β-estradiol, and IgG determination. Newborn lamb blood for determining glycaemia and IgG was collected at birth and at 12, 24, 36, and 120 h after birth. Lamb mortality and growth was assessed from birth until 30 days of life. No differences were observed in progesterone and 17β-estradiol. There were no differences in colostrum yields and fat components, however single- had higher values of protein and lactose than twin-bearing ewes (p < 0.05 for both). Singletons had higher glycaemia than twins at 12 h postpartum (102.2 ± 32.8 vs. 73.4 ± 29.9 mg/dL, p < 0.05). Colostrum IgG content was similar at delivery but higher in single ewes at 12 and 24 h, reaching a similar values at 36 h (4.7 ± 9.7 and 5.8 ± 7.7 mg/mL in single and twin pregnancies, respectively). Newborn IgG was higher in singletons compared to twins at least until 48 h of life. Lams body weight was always superior in singleton than twins from birth until 30 days of life. Mortality did not differ during the first week of life, but it increased significantly only in twins until day 30 of life. Undernourishment in pregnant ewes affected colostrum quantity and quality, resulting in a lower postnatal growth and a higher mortality in twins. Alternative managements favoring fetal growth, birth weight and neonatal viability in twin sheep pregnancies are needed, when flocks are breed under harsh environments.

Transcriptome and iTRAQ-Based Proteome Reveal the Molecular Mechanism of Intestinal Injury Induced by Weaning Ewe's Milk in Lambs.

Early feeding regime has a substantial lifelong effect on lambs and weaning ewe's milk can lead to the intestinal injury of lambs. To explore the molecular regulatory mechanism of intestinal injury of lambs under weaning stress, the jejunum was conducted transcriptome and then integrated analyzed with our previous proteome data. A total of 255 upregulated genes and 285 downregulated genes were significantly identified. These genes showed low overlapping with differentially expressed proteins identified by isobaric tags for relative and absolute quantification (iTRAQ). However, according to their functions, the differentially expressed genes (DEGs) and proteins with the same expression trend were enriched for the similar Gene Ontology (GO) terms and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, such as intestinal lipid absorption, urea cycle, peroxisome proliferator-activated receptor (PPAR) signaling pathway, and ferroptosis. Furthermore, the DEGs, including FABP2, ACSL3, APOA2, APOC3, and PCK1, might play essential roles in intestinal lipid absorption and immune response through the PPAR signaling pathway and ferroptosis. This study could provide new insights into early lamb breeding at the molecular level.

Effects of parity, litter size and lamb sex on maternal behavior of small Tail Han sheep and their neuroendocrine mechanisms

• Parity, litter size, and lamb sex affect the maternal behavior of Small-tailed Han sheep. • Multiparous ewes, twin-lamb ewes, ewes with female lambs seemed to have better maternal behavior. • Our findings provide a theoretical basis for the further improving the survival rate and welfare of lambs. The high mortality of lambs has always restricted the development of Small-tailed Han sheep breeding, causing serious economic losses and welfare problems in the sheep breeding industry. Stable and good-quality maternal behavior is critical for the survival of offspring, and given the importance of maternal behavior on early lamb survival, improving maternal behavior in ewes seems to be an effective way to improve lamb survival rates. Thus, exploring the factors that influence maternal behavior is a good place to begin. Therefore, in this study, we investigated the effects of parity, litter size, and lamb sex on the maternal behavior of Small-tailed Han sheep. The neuroendocrine mechanism involved in regulating maternal behavior were also analyzed. Primiparous and multiparous ewes, ewes with different litter sizes, and ewes with different lamb sexes were selected, and their maternal behaviors, including lactating, grooming, following, looking, and udder refusal, were observed and analyzed using scanning and sampling methods during the first 7 days after parturition. The lambs’ body weights were recorded for the first 35 days after birth. The concentrations of estradiol, oxytocin, norepinephrine, dopamine, NO, and γ-aminobutyric acid (GABA) of ewes were measured with ELISA kits for 35 days after parturition. The results showed that the looking and udder refusal behavior of multiparous ewes was significantly lower than primiparous ewes (P = 0.004 and P = 0.036). The grooming behavior was significantly higher in both primiparous and multiparous ewes at Day 0 than at Day 1∼7 after parturition (P < 0.05). Ewes with two offspring expressed significantly more lactating behavior than ewes with single lambs in the first 3 days after parturition (P < 0.05). The looking behavior was significantly lower in twin-lambing ewes than in single-lambing ewes at Day 7 postpartum (P = 0.031). The grooming behavior was significantly higher in both single and twin lambing ewes at Day 0 post parturition than at Day 1∼7 post parturition (P < 0.05). Lactation behavior was significantly higher in ewes producing female lambs than in ewes producing male lambs at Day 2 after parturition (P = 0.018). When a female lamb was born, the looking behavior of ewes was significantly higher than ewes with male lambs on Day 3 after parturition (P = 0.01). The grooming behavior and the udder refusal behavior of male lambing ewes were significantly higher at the Day 0 after parturition than at the Day1∼7 after parturition, similar temporal trend was observed in female lambing ewes (P < 0.05). The body weight of lambs was higher in the multiparous ewes group. This was especially significant at Day 0 and Day3 after birth (P = 0.045 and P = 0.007). Single lambs seemed to have higher birth weights than twin lambs; however, the differences were not significant (P > 0.05). Male lambs were significantly heavier than female lambs at Day 0 and Day 7 after birth (P = 0.044 and P = 0.048); thereafter, the lambs of the two groups showed no significant difference in body weight. The level of oxytocin in multiparous ewes was significantly higher than that of primiparous ewes (P < 0.05). The levels of oxytocin, norepinephrine, dopamine, NO, and GABA in ewes with twin lambs were significantly higher than those of ewes with single lambs (P < 0.05). Ewes with female lambs had a significantly higher level of oxytocin than ewes with male lambs at Day 0 (P = 0.024). In conclusion, multiparous ewes exhibited better quality maternal behavior than primiparous ewes, and this was associated with the level of oxytocin in the serum. Ewes with twin lambs exhibited better quality maternal behaviors than the single lamb group, and this was related to the levels of oxytocin, norepinephrine, dopamine, NO, and GABA. Oxytocin was also found to be associated with the improved ewe maternal behavior with female lambs. Altogether, ewes with better maternal behavior have a higher level of oxytocin and noradrenaline. Moreover, the expression of maternal behavior in ewes is positively correlated with lamb weight. Our findings contribute the understanding of the neuroendocrine mechanisms of maternal behavior in Small-tailed Han sheep and provide a theoretical basis for the further exploration of artificial methods to improve ewe maternal behavior, and ultimately improve the survival rate and welfare of lambs.

Efficacy of early administration of liposomal amphotericin B in patients with septic shock: A nationwide observational study

IntroductionLiposomal amphotericin B (L-AMB), a broad spectrum anti-fungicidal drug, is often administered to treat invasive fungal infections (IFIs). However, the most suitable time to initiate treatment in septic shock patients with IFI is unknown. MethodsPatients with septic shock treated with L-AMB were identified from the Japanese Diagnosis Procedure Combination national database and were stratified according to L-AMB treatment initiation either at septic shock onset (early L-AMB group) or after the onset (delayed L-AMB group) to determine their survival rates following septic shock onset and the shock cessation period. ResultsWe identified 141 patients administered L-AMB on the day of or after septic shock onset: 60 patients received early treatment, whereas 81 patients received delayed treatment. Survival rates after septic shock onset were higher in the early L-AMB group than in the delayed L-AMB group (4 weeks: 68.4% vs 57.9%, P = 0.197; 6 weeks: 62.2% vs 44.5%, P = 0.061; 12 weeks: 43.4% vs 35.0%, P = 0.168, respectively). The septic shock cessation period was shorter in the early L-AMB group than in the delayed L-AMB group (7.0 ± 7.0 days vs 16.5 ± 15.4 days, P < 0.001), with a significant difference confirmed after adjusting for confounding factors with propensity score matching (7.1 ± 7.2 days vs 16.7 ± 14.0 days, P = 0.001). ConclusionEarly L-AMB administration at septic shock onset may be associated with early shock cessation.

The Expression of Maternal Behavior in Chinese Hu Sheep and its Effects on Lamb Survival and Body Weight

Background: The difference in the maternal behavior expression of sheep can affect the early growth and development as well as the survival of lambs. The characteristics of maternal behavior in primiparous and multiparous ewes were observed to reveal the expression of maternal behavior in Chinese Hu sheep and its effects on early lamb survival and body weight.Methods: In total 527 pregnant ewes with delivery were selected, including 246 primiparous ewes and 281 multiparous ewes. The observation record of maternal behavior began from 10 days before delivery to 3 days after delivery by video recording. The behaviors of ewe to the lamb included licking, suckling, seeking lambs, denial of suckling after delivery, butting and trampling lambs, abandoning lambs, and stealing lambs. Body weight of lambs were recorded including newborn, 7-day-old, 14-day-old and 35-day-old (weaning).Result: There were significant differences in the incidence rate in lamb abandonment and stealing between primiparous and multiparous ewes (P less than 0.05), namely the primiparous ewe group had the higher incidence of undesirable behaviours. However, there were no significant differences in seeking, licking and trampling behaviors between two groups (P greater than 0.05). Lamb survival within 7 days after delivery of multiparous ewes was greater than primiparous ewes (P less than 0.05). The body weights of newborn and 7-day-old lambs in the multiparous ewe group were significantly higher than the primiparous group (P less than 0.05). This study demonstrates that limited significant differences exist between primiparous and multiparous ewes in several aspects of maternal behavior in Chinese Hu sheep. Ewe behavioral expression associated with the birth and care of the neonatal lambs are essential for the survival and growth of the offspring.

The production and composition of colostrum from ewes supplemented with niacin (vitamin B3)

Context Twin-bearing ewes may be unable to produce enough colostrum following birth to support the survival of two lambs. This causes the newborn lambs to be at risk of death due to starvation, mismothering, cold exposure and infection. Niacin has previously been demonstrated in cattle to increase immunoglobulin concentrations in colostrum, possibly due to niacin increasing blood flow, allowing the greater accumulation of nutrients and immunoglobulins in colostrum. High producing animals, such as the late gestation twin-bearing ewe, may not be able to produce enough niacin to meet their production requirements. Aims This experiment evaluated whether supplementation of niacin (vitamin B3) to late gestation twin-bearing ewes would increase colostrum production and composition (concentration of fat, lactose, protein and immunoglobulin G), and postnatal lamb growth. Methods A total of 24 artificially inseminated Merino ewes were weighed, body condition scored, aged and randomly allocated to a treatment – control treatment or with 5 g/day niacin supplemented for 2 weeks before lambing until 2–8 days post-lambing. Key results Colostrum production and immunoglobulin G concentration were similar between treatments (P > 0.05). Ewes supplemented with niacin produced significantly higher (P = 0.039) colostral protein at 12.54% compared with the control group ewes at 11.78%. Early lamb growth rates were unaffected (P > 0.05) by treatment. Conclusions Supplementation of ewes with 5 g/day niacin is not recommended to increase the production of colostrum and immunoglobulin G or to increase lamb growth rates following birth. Implications Further research into niacin supplementation, supplementation time and supplementation amount for production effects in late gestation ewes is warranted.

Filíocht Nua: New Poetry

Filíocht Nua:New Poetry Noel Monahan child and lamb I found an early lamb in Tully's fieldCaught in a briary ditch and I rescued him,Carried him home bouncing and bleating.A robin in the bushes took note, the other sheep stared.Back in the kitchen I tied his feet with twine,Placed him in a cardboard box before the cooker.My mother loved him. She was going on aboutHis loaf white fleece, his angel eyes . . . but he doesn't belong here. You stole a lamb from our neighbours, my father said.Because my father was the greatest man then,I agreed to return the lamb the next morning.Sadly, I watched him drift away with his motherThrough a gap into the next field. Then I turned awayTo think of something else to do that day. [End Page 57] where the wind sleeps Something will come to you in your dreams thatWill help you find your way in abandoned places.Here the wind sleeps with nettles and briarsIn half-empty walls and the owl hatchesHer chicks in the belfry. Here an apparitionOf monks in off-white habits sleepwalkHolding empty skulls in their hands and listeningTo the slow noise of old ways dying.Each in his solitude finds dereliction,Prayer that does not rest on words but livesIn darkness and out of the depths of nightHeaven falls like snow on a linen altar,Two candles burn, carnations as white asChildren's teeth are little nails of glory and grief. [End Page 58] aphrodite in the snow I awaken to the surprise of seeing youStretched naked outside my window,Your ivy hair full of snowflakes,Earrings of frozen ice, blizzard of pearl powderFor your face. Fresh snow begins to blowAcross your navel, curves about your pubic bones,Lodges between your thighs. I know you drifted here.The wind shaped your limbs, your snow white girdleAnd now the wind of forty voices sings:Spem In Alium in the snow,Choral whispers of hope in the singing bowl of winter.A car passes with head-lights on, someone is scraping a drivewayAnd I'm not sure whether I'm looking at the evening or morning star. [End Page 59] famine times A stooped croneLeans on a stick,Her face a famine, withered breasts,Foul breath, sunken eyes. She kisses the clayThe hunger-worm wrigglesFrom drill to furrow,Blight clouds gather. She knows what little remains,Begs God for favours,Prayer makes her tired, [End Page 60] prairie mother She continues to survive out here in the Midwest,Sheltering in the cornstalks of the prairies.Unknowingly, her heart throbs within usTo remind us of who she once was and whereShe is going. She hides in tangled rootsWhen fire strikes. She's the rain afterThe long dry spell, the coneflowers,The purple prairie clover . . . She's a tree-houseTo draw us back to childhood, a prairie windTo brush the old man's whiskers,By night she sleeps with the bees and starsIn the honey hive moon. She's a memoryThat lives in our forgetfulness.Clay holds her soul. [End Page 61] god man We buried our deadPerformed rituals.The gods worried usAs much as they cheered us. When the gods needed food We fed them our children. When the gods needed shelter We built stone circles, temples . . .Later on, we abandoned the caves,Dropped our flint knives and spears on the floorDaubed and wattled our homesSettled for a plough,Bred black headed cattle,White cows with bracelets, necklaces . . . We complained about all the work, Argued and fought, Small-talked about a girl, Found face down in a bog.Many blamed the old gods.Time on our handsWe turned our backs on themAnd found a New One. [End Page 62] pull down the house Break down the doors and windowsLet the jackdaws fly out from the chimneys,The mice leave their nestsUnder the floorboards. Tear the wallpaperIn the bedrooms, pluck the weeds from the gutters,Knock all...

GROWTH CHARACTERISTICS AND SURVIVAL RATE OF PUREBRED AND CROSSBRED LAMBS UNDER UNLIMITED SUCKLING REGIME

Seventy purebred and crossbred lambs were used in this study to investigate the effect of some factors affecting growth traits, daily gains and survival rates of lambs under unlimited suckling regime. Ewes in the flock were not milked and lambs were subjected to unlimited suckling regime without weaning. Results showed that, variation among breed groups were significant (P<0.01) in birth, 6, 9 months and yearling weights, as well as, at 3rd months was a significant (P<0.05). Male born lambs were significantly heavier (P<0.01) than females except at 3rd months. Type of birth or the ages of dam have no significant effect on body weights in all ages except at birth, where it was significant. Breed of lambs have a significant effect on the average daily gains, while there was no significant effect of sex, type of birth or age of dam, except at the period from 3rd to 6th months. The superiority of crossbreed lambs over their parental breeds from birth to yearling age ranged between 2.18 and 1.65 % from birth to yearling. Likewise, the daily gain of crossbred lamb groups during the four periods studied, have the same results. Breed of lambs have a significant effect (P<0.05) on the survival rate of lambs, since the survival rate of Rahmani lambs was higher at the early stages of life while the crossbred lambs showed superiority in survival rate with advancing age. Sex did not have any significant effect on the survival rate, except at birth. Type of birth and the age of ewes had a highly significant effect on survival rates in all periods studied except at the age of a year. It is concluded that Chios breed could be an appropriate breed for terminal sire crossbreeding to improve both Rahmani ewe's productivity and early lamb growth under Upper Egypt conditions system.

Index selection in terminal sires improves early lamb growth1

The use of terminal sires (TS) for crossbreeding is integral to the UK sheep industry where approximately 71% of market lambs are sired by TS rams. Early growth of these crossbred lambs affects profitability. The objectives of this study were i) to evaluate the effectiveness of index selection among TS on BW and ADG of their crossbred offspring; and ii) to compare the efficacy of that selection within TS breeds. The most widely used TS breeds in the United Kingdom are Charollais, Suffolk, and Texel. These participated in sire referencing schemes in which they were evaluated on a lean growth index designed to increase carcass lean weight at a given age. From 1999 to 2002, approximately 15 high and 15 low lean growth index rams per breed (93 in total, differing in index on average by 4.6 SD) were selected from within their sire referencing schemes and mated to Welsh and Scottish Mule ewes. Their crossbred offspring were reared commercially on 3 experimental farms in England, Scotland, and Wales. A total of 6,515 lambs were born between 2000 and 2003. Lambs were weighed at birth (BWT), 5 wk (5WT), and 10 wk (10WT), and their ADG from birth to 10 wk was calculated. Lambs sired by high index rams were on average, across breeds, heavier at all ages (P < 0.01) with 0.07 ± 0.03, 0.3 ± 0.1, and 0.4 ± 0.1 kg greater BWT, 5WT, and 10WT, respectively. Their ADG was 5.1 ± 1.9 g/d greater than low-index-sired lambs (P < 0.01). Suffolk-sired lambs were on average heavier at all ages, with greater ADG, whereas Charollais-sired lambs were lightest with smallest ADG. Overall, there was no significant interaction between sire index and sire breed (P > 0.10). Within Suffolk-sired lambs, there was little difference between high and low index sires for the traits studied (P > 0.3). High and low index Charollais-sired lambs differed in BWT (0.09 ± 0.04 kg) and 5WT (0.3 ± 0.1 kg), and Texel-sired lambs differed in 5WT (0.5 ± 0.1 kg), 10WT (0.9 ± 0.2 kg), and ADG (10.2 ± 3.3 g/d; P < 0.01). Lambs from Scottish Mule dams were heavier, with greater ADG, than lambs born to Welsh Mules (P < 0.01). Lambs reared in Scotland were heavier at all ages (P < 0.01). The results suggest that using index selection in TS can improve the growth of their commercial offspring reared on grass.

Genetic parameters for early lamb survival and growth in Scottish Blackface sheep1

The objectives of this study were 1) to estimate the heritability of lamb survival and growth in the Scottish Blackface breed; 2) to examine the relationship between lamb survival and live BW; and 3) to investigate the possibility of using lamb survival in a breeding program for this breed. The data used for the analyses contained information about survival and live BW at different ages on 4,459 animals. The records were collected from 1988 to 2003 in a Scottish Blackface flock. Live BW was recorded every 4 wk from birth to 24 wk. Survival was defined either by perinatal or postnatal mortality (up to weaning at 12 wk), or as cumulative survival to 1, 4, 8, and 12 wk. The pedigree file comprised 1,416 dams and 178 sires. A sire model was used to estimate genetic parameters for binary survival traits. Heritabilities of BW traits, and phenotypic and genetic correlations between BW and between survival and BW were estimated by fitting an animal model. Further, correlations of survival with live BW were estimated by using a Markov chain Monte Carlo threshold model, implemented by Gibbs sampling. The heritability estimates for cumulative lamb survival declined from birth onward (from 0.33 to 0.08), and postnatal survival had a heritability of 0.01. The direct and maternal heritabilities for BW traits ranged from 0.08 to 0.26 and from 0.06 to 0.21, respectively, whereas the maternal environmental component was between 0.04 and 0.16. The genetic correlations between BW traits at different ages were high. The genetic and phenotypic correlations between survival and BW were always positive (ranging from 0.04 to 0.54), so there was no antagonism between these traits. Therefore, it is possible to simultaneously improve both survival and live BW in a breeding program for this breed.

Factors associated with lamb mortalities in Muzaffarnagari sheep

The Muzaffarnagari sheep, a mutton-producing breed of India, is generally known for its fast growth rate and high feed conversion efficiency. The study identified the causes of perinatal and postnatal deaths and factors contributing to the cause of mortalities in lambs. Data were recorded for 4628 lambs born to Muzaffarnagari ewes in single-sire matings from 165 rams, between 1978 and 2002. The least-squares means for overall lamb mortality from birth to 1 year of age in the flock was 12.6% (582/4628), while the overall pre- and post-weaning mortality rate averaged 6.6% and 6.0%, respectively. The mortality rate of the lambs declined as the lambs grew older. The major causes associated with lamb losses were pneumonia (31.4%), digestive disorders (14.6%), starvation (9.6%), endoparasitism (5.0%), septicaemia and toxaemia (10.1%), accidental (2.1%) and undetermined causes (27.2%), respectively. The main causes of early lamb mortality (within 15 days of birth) were pneumonia followed by starvation. The highest lamb mortalities occurred within the first 15 days of life. The year of birth of the lamb significantly affected ( P < 0.01) the cumulative lamb mortality rate at all ages. The sire of the lamb also had a significant ( P < 0.01) effect on lamb mortality rate at all ages. Lambs reared under an intensive feeding management system had a remarkably ( P < 0.01) lower mortality rate than lambs maintained under a semi-intensive management system, at 3 months of age and later. The lamb losses were significantly ( P < 0.01) higher in ram lambs than in females during the post-weaning stages. The linear regressions of lamb birth weight and dam weight at lambing were highly significant ( P < 0.01) with lamb mortality rate during pre- and post-weaning stages. Logistic regression analyses revealed lambs maintained under a semi-intensive system, to be at a greater risk of dying from all ailments than lambs maintained under intensive feeding systems. Male lambs had greater risk of death from respiratory, digestive and other causes, compared to their female counterparts. The findings of this study revealed causes of pre-weaning lamb mortalities to be mainly due to a low birth weight and non-parasitic diseases (predominantly pneumonia). These factors must be considered in any lamb production system.

Genetic analysis of early lamb survival in extensively reared lambs

RiassuntoAnalisi genetica della sopravvivenza in agnelli allevati in condizioni estensive. La sopravvivenza degli agnelli è uno dei caratteri economici più importanti nell’allevamento ovino. A questo scopo sono state esaminate 4.583 osservazioni di agnelli Scottish Blackface di cui erano noti i dati ripetuti di sopravvivenza (nascita, 1, 4, 8 e 12 settimane) e di peso (nascita, 4, 8, 12, 16, 20 e 24 settimane). Sono stati utilizzati un sire model per la stima dei parametri genetici della sopravvivenza e un animal model per la stima delle correlazioni genetiche tra la sopravvivenza e gli incrementi ponderali degli agnelli. Le ereditabilità stimate sono risultate più alte di quelle riportate in bibliografia e le correlazioni genetiche tra la sopravvivenza e gli incrementi ponderali sempre positive e moderate (in media 37,5%), confermando la possibilità di inserire la sopravvivenza degli agnelli nei programmi di selezione della razza Scottish Blackface.

Body Weight Change, Milk Production and Reproductive Parameters in Suckled vs. Non-suckled Awassi Ewes

The objective of this study was to identify the effect of early weaning on body weight change, milk production and the return to estrus in Awassi ewes. Twenty multiparous winter-lambing Awassi ewes were randomly assigned to either suckled (S, n=10) or non-suckled (NS, n=10) groups in a completely randomized design. Lambs in the NS group were removed from their dams on day 2 postpartum (PP). Animal body weights (BW) and body condition scores (BCS) were recorded at the beginning of the study and every 3 weeks thereafter until the end of the experiment. Milk production was estimated by machine milking at weekly intervals for 4 weeks beginning on d 11 PP. Blood samples were collected from each ewe every third day for 4 weeks beginning on day 15 PP. Initial body weight was similar for both treatments. By the end of the experiment, NS ewes gained an average of 1.8±1.0 kg while S ewes lost an average of 7.0±1.0 kg (p<0.001). Body condition scores followed a trend similar to that observed for BW and was greater (p<0.001) in the NS ewes. Significant correlation existed (p<0.01) between BW and BCS (r=0.77). The first milk production recording for both suckled and non-suckled was similar. Later recordings, however, showed that the S group had greater milk production (p<0.01) compared with the NS group. Lambs in the NS group were heavier (p<0.05) than those in the S group on d 10 PP. By the end of the study, lamb weights in the NS group were significantly lower (p<0.001) when compared with S group. The first rise in plasma progesterone (P4) occurred earlier (p<0.05) in the NS than S ewes (day 27.0±2.2 vs. 34.0±2.2 postpartum, respectively). All of the NS ewes (10/10) and 60% (6/10) of the S ewes expressed estrus following ram introduction (p<0.05). Results of the current study indicate that non-suckled ewes gained more weight and displayed ovarian activity earlier than suckled ewes. Early lamb removal can be used to obtain biannual lambing in Awassi sheep. (Asian-Aust. J. Anim. Sci. 2004. Vol 17, No. 9 : 1236-1240)

Economic Assessments of Hormonal and Nutritional Treatments for Improvement of Awassi Sheep Production in Jordan

The animal production sector in Jordan is characterized by shortages of locally produced feedstuffs derived from rangeland, forage plants or from human food crops as by products. This is exacerbated by insufficient rainfall, overgrazing, early grazing and high stocking rate. Thus, subject to these constraints, other technological improvements are highly desirable to meet the needs of crop growth and animal production. Alternative adapted technologies are also desirable in order to meet the increased demand for red meat in relation to population growth along with the changes in the price subsidy for feedstuff. The technologies are those, which have been introduced to the animal production sector, obtained in agricultural research stations besides on-farm demonstrations. They include technologies suited for increasing birth and twining rates, synchronizing the mating period, introducing the early weaning method, and animal feed and sheep production. Economic assessments conducted in this study demonstrate promising results of hormonal and nutritional practices in improving production efficiency of Awassi sheep in Jordan. Jordanian published data between 1991 and 1998 were used. The examined practices were: 1) use of PMSG in estrus synchronization in ewes, 2) introduction of early lamb weaning program, 3) supplementation with AD 3 E for ewes and 4) the use of agro-industrial feed block as a feed supplement for grazing lambs. Production data were then subjected to partial budgeting for economical evaluation. The use of PMSG outperformed the control groups in fertility and net returns per ewe by US$ 8.36/ewe. The early weaning of lambs increased the net returns by US$ 3.90/lamb. The injection with vitamin AD 3 E showed an average additional net return of US$ 5.66/ewe. Feeding agriculture by-product blocks improved weight gain in the feed block groups and resulted in additional net returns of US$ 3.5/lamb. The economic viability and reproductive performance indicators demonstrate that efforts should be undertaken to disseminate these new practices in the development program.

The inheritance of traits describing early lamb performance in Scottish Blackface sheep

Ewe prolificacy, lamb survival and early lamb growth are economically important traits, playing a major role in determining the profitability of hill sheep farms (Coningtonet al., 2000). In currently advocated selection strategies these traits are usually expressed as traits of the dam, however, relatively low heritabilities limit the genetic progress achievable (Coningtonet al., 2001). An alternative approach is to treat these traits, where appropriate, as traits of both the ewe and lamb. This study investigates reparameterisation of these traits as joint expressions of both lamb and ewe genotype, and considers the impact of the results on currently-advocated selection strategies.

Application of the theory of linear elastic materials with voids to NDT of interfaces of bilaminates

Non-destructive testing (NDT) of interfaces in composite structural elements is mandatory in several industries. This calls for modeling of composite interfaces incorporating real world conditions of imperfect bonding. Theories of materials that modern continuum mechanics offer can be profitably employed to develop these models. For instance, distributed voids are often present in the adhesive zone of a structural element and these voids may lead to a failure of the element due to the imperfect bond. As the theory of linear elastic materials with voids (LEMV) provides a model for solids with properties akin to viscoelastic materials, it is employed in the present work to represent the thin adhesive viscoelastic layer with its minutes pores spread over the interface region of a symmetric bilaminate. The bilaminate is assumed to be insonified in water and the governing leaky Lamb wave (LLW) frequency equation is derived. The dispersion and attenuation of LLWs in an Al/adhesive/Al bilaminate are graphically-presented for various porosity-coupling parameter values and are compared with those in perfectly-bonded Al plates. The results presented in this paper showing the influence of pore-infested adhesive layer on the early leaky Lamb modes promises to be useful in identifying interfacial porosity.

Learning of olfactory cues is not necessary for early lamb recognition by the mother

Ewes identify their young through the use of different sensory modalities. Olfactory recognition, which mediates selective acceptance at the udder, is established at 4 h postpartum (pp). Visual and auditory cues are involved in recognition at a distance, which is evident at 12 h pp. This study investigates whether anosmic ewes are able (a) to develop visual and auditory recognition and (b) to restore selective acceptance of their lamb at the udder. Visual and auditory recognition was assessed in anosmic and intact ewes at 12 h and 24 h pp by a test of two choices: their own and an alien lamb. Selectivity at allowing suckling was tested by presenting successively an alien and the familiar lamb at 4 h, 3 days, and 1 month pp. In the two-choice recognition test, at both 12 h and 24 h pp, anosmic as well as intact ewes showed a preference for their familiar lamb. Although anosmic ewes showed no difference in their acceptance of alien and familiar lambs for suckling at 4 h and 3 days pp, they nursed the alien lamb less at 1 month pp and showed more rejection behaviors toward it. Thus, visual, auditory, or both those types of recognition can be rapidly established, independent of olfactory recognition. Moreover, differential behavior of anosmic ewes toward their own versus an alien lamb at the udder at 1 month suggests that vision and audition may compensate to some extent for the loss of olfaction.

A comparison between ARC (1965) and AFRC (1991) phosphorus requirements for ewes

Beef cows given a diet severely inadequate in phosphorus (P) from 16 weeks before calving maintained appetite until 3-6 weeks after calving when plasma P concentrations were below 1.0 mmol/1 (Bass et al. 1981). The objective of this experiment was to compare the adequacy of ARC (1965) and AFRC (1991) dietary P inputs for ewes in relation to dry matter (DM) intake, plasma P concentration and early lamb growth.Blackface ewes (˃ 3 lambings, n=87, mean liveweight (LW) 53.9, s.d. 5.1kg)) were mated to Border Leicester rams and then randomly allocated to three equal groups according to LW and expected lambing date.

A comparison between ARC (1965) and AFRC (1991) phosphorus requirements for ewes

Beef cows given a diet severely inadequate in phosphorus (P) from 16 weeks before calving maintained appetite until 3-6 weeks after calving when plasma P concentrations were below 1.0 mmol/1 (Bass et al. 1981). The objective of this experiment was to compare the adequacy of ARC (1965) and AFRC (1991) dietary P inputs for ewes in relation to dry matter (DM) intake, plasma P concentration and early lamb growth.Blackface ewes (˃ 3 lambings, n=87, mean liveweight (LW) 53.9, s.d. 5.1kg)) were mated to Border Leicester rams and then randomly allocated to three equal groups according to LW and expected lambing date.

An intraruminal soluble glass bolus containing melatonin — a potential system for early lamb production

Seasonal changes in daylength (photoperiod) are effectively monitored by the eye transmitting a neural signal to the pineal gland which responds by secreting a hormone, melatonin, during the hours of darkness. Decreasing daylength is accompanied by an increase in the duration of melatonin secretion and stimulates breeding activity in sheep.It has been demonstrated that both timed (afternoon feeding and injection) and continuous (subcutaneous and vaginal implant) administration of supplementary melatonin to ewes in mid-summer mimics the effect of short or decreasing photoperiod and can advance the onset of breeding activity. Such treatments can also increase relative fecundity at early mating by phase-advancing the mid-breeding season peak in ovulation rate. As the U.K. is not sufficient in lamb production and bearing in mind the economic pressure for early lamb marketing, effective melatonin treatment offers considerable potential for commercial application.