Awassi Ewes Research Articles

Nutritive value of Sesbania aculeata grown on salty soil and its effect on reproductive parameters of Syrian Awassi ewes

Nutritive value of Sesbania aculeata hay was determined by estimating the nutritive components, nitrogen forms, in vitro digestible organic matter (IVDOM), and metabolisable energy (ME). A study was carried out to evaluate the effect of feeding 2 groups of Syrian Awassi ewes with 2 wheat straw-concentrate diets without (control) or with (experimental) added S. aculeata hay on some reproductive parameters of the ewes at different stages. Half of the wheat straw in the daily ration of the experimental group of ewes was replaced by S. aculeata hay (whole plant) grown on salty soil and irrigated by saline water. Daily metabolisable energy and crude protein consumed by the ewes in the 2 groups were the same during the different stages (2.5 months before mating, throughout pregnancy, and during lactation). Crude fibre and cell wall constituents’ values were lower, whereas the values of crude protein and crude ash were higher in leaves and pods than in stalks. The values of IVDOM in S. aculeata hay were 537, 380, and 626 g/kg DM, and of ME were 7.19, 5.43, and 8.58 MJ/kg DM for the whole plant, stalks, and leaves and pods, respectively. The values of buffer soluble nitrogen were 27% or 39% and of buffer soluble non-protein nitrogen were 21% or 35% of the total nitrogen in leaves and pods or stalks, respectively. Feeding with S. aculeata hay had no effects on the liveweight of the ewes during the periods before mating and throughout pregnancy, on mating rate, fertility rate, duration of pregnancy, birth weight, or weaning weight of lambs. Furthermore, feeding with sesbania hay had no effect on either the response of ewes to the oestrous synchronisation programme or on the blood serum concentration and pattern of progesterone during the period extending from the commencement of feeding the ewes sesbania hay (2.5 months before mating) until the time of their lambing.

The effect of water restriction on certain physiological parameters in Awassi sheep

The effect of water restriction was studied on various physiological parameters in Awassi ewes over a 6-week-period (April–May, 2002). Fifteen dry, multiparous Awassi ewes were randomly assigned to three watering regimes of five ewes per group. Group A received water once every 4 days; Group B once every 2 days and Group C was the control, receiving water daily. Group feed intake and weather data were recorded daily, while rectal temperatures and body weight were recorded weekly. Venous blood was sampled weekly and analyzed for pH, electrolytes, packed cell volume (PCV) and hemoglobin, serum glucose, urea, creatinine, total protein, globulin, albumin, cholesterol, and cortisol. A decrease in body weight was recorded in Groups A and B. In addition, Group A showed significantly ( P<0.05) higher blood urea, creatinine, protein, globulin, and cholesterol concentrations than the control. Blood pH and Na + were higher and K + concentrations lower with water restriction than in the control group, while the levels of Cl − and Ca 2+ were similar between treatment groups. Similarly, serum cortisol levels did not differ between treatments over the experimental period. The physiological response to water restriction in Group B was not significantly different from that in the control. This study indicates that dry Awassi ewes can withstand a 2 days water restriction regime for more than 1 month with minimal physiological disturbances, while 4 days water restriction induces physiological changes as reflected by changes in most of the serum components assessed, accompanied by weight loss.

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)

The Effect of Dietary Fat Inclusion on Nutrient Intake and Reproductive Performance in Postpartum Awassi Ewes

The objective of this study was to evaluate the effect of dietary fat inclusion on nutrient intake, body weight, milk production, return to estrus, pregnancy and lambing of winter-lambing, postpartum Awassi ewes. Thirty multiparous, winter-lambing Awassi ewes (body weight=51′7.0 kg) were randomly assigned to three dietary treatments (n=10) for 62 days using a completely randomized design. Experimental diets were isonitrogenous, and were formulated to contain 0 (CON), 2.5 (MF), and 5% (HF) added fat, and 33% of the dietary crude protein (CP) as undegradable intake protein (UIP). On day 26 postpartum (day 0=parturition), ewes and their lambs were housed in individual pens for 28 days. Feed offered and refused was recorded daily. At the end of this period, ewes and their lambs within each treatment were combined into one group and fed their respective diet ad libitum. One fertile Awassi ram fitted with a marking harness was allowed with each group for 34 days. No significant (p>0.05) differences in dry matter intake, organic matter intake, and crude protein intake were observed for ewes fed the three experimental diets. No difference was observed in metabolizable energy intake (MEI) for ewes fed the CON and the MF diets (average 8.3 Mcal/d) diet. However, ewes fed the HF diet had greater (p<0.05) MEI compared with the rest of the treatments. Ewe body weights increased throughout the study, unaffected by the experimental diets. No significant differences in milk production were found among ewes fed the three experimental diets. No significant differences were observed in pregnancy rate (6/10, 5/10, 6/10 for CON, MF and HF diets, respectively), lambing rate and the number of lambs per ewe among the three treatments. These results indicate that fat inclusion to high concentrate diets does not improve postpartum reproductive performance of well-fed, winter-lambing Awassi ewes.

Impact of feeding saltbush ( Atriplex sp.) on some mineral concentrations in the blood serum of lactating Awassi ewes

This study was conducted to assess mineral status in the blood serum of lactating Awassi ewes fed saltbush plants and concentrate rations. Twelve lactating Awassi ewes were randomly selected, and divided into two equal groups. Ewes in the first group (control) were fed the traditional ration usually fed to ewes at the station, consisting of concentrate and shredded straw of lentil (tibin). Ewes in the second group were fed a mixture (1:1) of two saltbush species ( Atriplex halimus and Atriplex nummularia) to replace roughage content in the experimental diet. Feeding saltbush to ewes lead to a decrease ( P<0.05) in Ca level in ewes after the fourth week of the experiment. Phosphorus level in the blood serum was higher ( P<0.05) in ewes fed saltbush than in ewes fed the traditional ration. However, blood serum of both groups contained lower Ca and P levels than normal. Although saltbush contained high levels of Cu, feeding saltbush did not lead to differences ( P>0.05) in Cu level in the blood serum of ewes in both groups. The high Mo content in saltbush resulted in an increase of Mo level in the blood serum of ewes fed saltbush compared to ewes fed the traditional ration. There was no difference ( P>0.05) in Zn level in the blood serum of both groups. Manganese level was higher ( P<0.05) in ewes fed saltbush than in ewes fed the traditional ration after the sixth week of the experiment. Selenium level in the blood serum (13.79–35.93 μg/dl) was higher ( P<0.05) in ewes fed saltbush than in ewes fed the traditional ration (10.08–13.08 μg/dl). Selenium levels of ewes in group 2 after the sixth week of the experiment were above than normal Se level (10–20 μg/dl). The results of this experiment suggest that saltbush might lead to a decrease in Ca level and an increase in P, Mo and Mn levels in the blood serum. Selenium level in the blood serum of ewes fed saltbush might exceed normal levels and therefore special attention should be taken when feeding saltbush to lactating Awassi ewes for long periods.

Estrus Synchronization in Awassi and Red Karaman Fat Tailed Ewes

Emsen, E., Bilgin, O.C., Yaprak, M. and Ockerman, H.W. 2003. Estrus synchronization in Awassi and Red Karaman fat tailed ewes. J. Appl. Anim. Res., 24: 153–158. To evaluate the efficacy of estrus synchronization procedures 60 Awassi and 44 Red Karaman ewes were equally divided into 2 groups each. To synchronize estrus sheep in one group from each breed (group 1 and 2) were injected intramuscularly with PGF2 α (1 ml) 10 days intervals, other two groups (group 3 and 4) ewes were treated with intravaginal sponges containing fluorogestone acetate (FGA; 40 mg) for 14 d. On the day of the PGF2 α injection or at sponge removal, rains were placed with the ewes. The variability (standard deviation) of hours to estrus synchronization was significantly (P<0.01) different for both breeds within treatment groups (PGF2 α and sponges). The time of the estrus was significantly (P<0.01) shorter in group 3 and 4 than in group 1. The number of ewes in estrus was greater (P<0.05) in groups 3 and 4 than in groups 1 and 2. The time taken for onset of estrus for group 1, 2, 3 and 4 was 48.05±0.32, 45.45±0.17, 41.02±1.11 and 41.44±3.75 h, respectively. Estrus was induced with sponge withdrawal in almost 100 per cent sheep while about 80 per cent of ewes had been observed in estrus after the PGF2 α injection within 3 d. It is concluded that Progestagen was better than PGF2 α for synchronization of estrous in Awassi and Red Karaman ewes.

Effect of feeding cellulase enzyme on productive responses of pregnant and lactating ewes and goats

An experiment was conducted to study the effect of supplementing the diets of Awassi ewes and Shami goats with exogenous fibrolytic enzyme on birth and weaning weight of lambs and kids and on milk production of dams in the first 60 days of lactation. Two groups of ewes (30 each) and two groups of goats (30 each) were used. One group of each species was supplemented with the fibrolytic enzyme during the last 2 months of pregnancy and the first 60 days of lactation. Birth and weaning weights for lambs and kids were recorded and analyzed, while milk production was measured daily and two milk samples were collected weekly from each dam and analyzed for milk composition. The results showed that treatment had no effect on birth weight, but it increased ( P<0.05) the weaning weight of both Awassi lambs and Shami kids. The treatment resulted in increased ( P<0.05) milk production of both Awassi ewes and Shami goats, with no effect on feed intake. The milk fat and protein percentages in treated Awassi ewes were higher ( P<0.05) than those for untreated ones, while no effect was observed on milk of treated goats. Total solids were higher ( P<0.05) in milk of treated groups of both species than the untreated ones. In conclusion, these results showed that using fibrolytic enzyme treatment improves growth of suckling lambs and kids and improves milk production, though the response may differ between sheep and goats.

Replacing soybean meal with sunflower seed meal in the ration of Awassi ewes and lambs

Three experiments were conducted to evaluate sunflower seed meal (SFM) as a substitute for soybean meal (SBOM) in rations of fattening Awassi lambs and milking ewes. In the first experiment, 12 Awassi lambs were assigned into four groups to measure the digestibility of the SFM and experimental rations. The control group ration (1) contained SBOM while in the other two rations, SFM replaced SBOM at a level of 50% (2) and 100% (3), respectively. The fourth group was fed only SFM. No significant differences were observed between lambs fed the experimental rations in digestibilities of DM, OM, CP, CF, NDF, ADF or N balance. NFE had a higher ( P<0.05) digestibility for ration 1 than ration 2. In the second experiment, the voluntary feed intake was measured for the Awassi ewes during milking and dry period using 36 Awassi lactating ewes. For the two stages there were no significant differences between rations in voluntary intake. Milk yields (kg/herd per day), milk fat (%) and milk total solids (%) were not different among groups. In the third experiment, 42 lambs (males and females) were divided randomly into three treatment groups. Rations were the same experimental rations in the digestibility study. There were no significant differences in the average final BW, ADG and average feed conversion ratios (FCR) among the treatments. These experiments showed that SFM could replace SBOM as a protein source in rations of fattening Awassi lambs and milking Awassi ewes.

Effect of royal jelly and GnRH on the estrus synchronization and pregnancy rate in ewes using intravaginal sponges

The influence of natural royal jelly (RJ) paste and gonadotropin releasing hormone (GnRH) on reproductive responses of Awassi ewes was evaluated. In May 1998, 20 Awassi ewes (aged 2–5 years and weighing 52 kg) were treated with 40 mg fluorogestone acetate (FGA) impregnated intravaginal sponges for a period of 12 days. Half of the ewes were administered orally a total of 3 g RJ paste in 12 equal doses of 250 mg per day starting at FGA sponge insertion while the remaining half received no RJ paste. Ewes were exposed to two fertile Awassi rams from the time of FGA sponge removal (0 h, 0 day). Blood samples were drawn on alternate days from days 0 to 19. Five ewes per group (RJ and control) were randomly selected to receive a 50 μg GnRH injection 28 h post-sponge removal. No interactions were detected between RJ and GnRH. Incidence of estrus was greater (8/10 versus 4/10) in RJ-treated than in control ewes and intervals from 0 h to detected estrus were similar (45±4.1 h versus 55±6.7 h, respectively). Progesterone concentration increased on days 5–7 in all ewes and remained elevated through day 19 in 60% of the RJ-treated and 20% of the control ewes. These ewes lambed on average 149 days later and the number of lambs born was similar between the two groups of ewes. Regardless of RJ treatment, GnRH administration decreased ( P<0.05) the interval from cessation of treatment to estrus. The first rise in plasma progesterone occurred on day 5 in GnRH-treated compared with day 7 for non-GnRH-treated ewes ( P<0.05). The results demonstrate that RJ treatment in conjunction with a source of exogenous progesterone can be used to induce estrus and increase first service conception rate in sheep. Administration of GnRH reduced the interval to estrus and advanced plasma progesterone elevation.

Period prevalence and etiology of subclinical mastitis in Awassi sheep in southern Jordan

To investigate the period prevalence, etiology and some epidemiological features of subclinical mastitis in Awassi ewes from the southern part of Jordan, milk samples from 318 lactating ewes were aseptically collected for bacterial and somatic cell counts (SCC) tests. Milk samples were collected at monthly intervals. The period prevalence of subclinical mastitis was 18.3% and the prevalence within each flock remained relatively constant throughout the study period. A significant association ( P<0.001) was observed between the occurrence of subclinical mastitis and the age of ewe. Presence of teat lesions has no impact on the prevalence of subclinical mastitis. The prevalent bacterial species isolated from mammary glands with subclinical mastitis were Staphylococcus aureus (39%), Streptococci (25%), Escherichia coli (19.6%) and coagulase-negative Staphylococci (17.9%). Coagulase-negative Staphylococci were the most prevailing isolates from samples that showed negative SCC results.

Reproductive responses following royal jelly treatment administered orally or intramuscularly into progesterone-treated Awassi ewes

An experiment was conducted to determine whether natural royal jelly (RJ) paste administered orally or intramuscularly (i.m.) in conjunction with exogenous progesterone is associated with improved reproductive responses in ewes. Thirty 3–6-year-old Awassi ewes were randomly allocated into three (RJ-capsule, RJC; RJ-injection, RJI and control, CON) groups of 10 ewes each. All ewes were treated with intravaginal progesterone sponges for 12 days. Ewes in the RJC and RJI were administered orally or i.m. with a total of 3 g of RJ given in 12 equal doses of 250 mg per ewe per day starting at the time of sponge insertion. At the time of sponge withdrawal (day 0, 0 h), ewes were exposed to three rams and checked for breeding marks at 6-h intervals for 3 days. Blood samples were collected from all ewes for analysis of progesterone concentrations. Pretreatment progesterone levels were <0.5 ng ml −1 in 16/30 and >1.3 ng ml −1 in the remaining ewes indicating luteal function and cyclicity. Similar reproductive responses and progesterone levels occurred in ewes of the RJC and RJI; therefore, data of the two groups were pooled. Following sponge insertion, progesterone levels increased rapidly and reached maximum values of 5.8±0.2 ng ml −1 within 2 days among ewes of the three groups, and then declined gradually to day 0 values of 1.6±0.1 and 1.9±0.1 ng ml −1 for the RJ-treated and CON ewes, respectively. The rate of progesterone decline was greater ( P<0.001) in RJ-treated than in CON. Mean progesterone levels during the 12-day period were lower ( P<0.001) in RJ-treated than in CON (2.8±0.2 ng ml −1 versus 3.3±0.2 ng ml −1). Treatment with RJ resulted in greater ( P<0.05) incidence of oestrus and shorter ( P<0.05) intervals to onset of oestrus than CON. Based upon progesterone levels, ovulation occurred following day 0 in all ewes. Progesterone increased on day 3 in RJ-treated and on day 4 in CON ewes. Progesterone remained elevated through day 18 in 8/20 RJ-treated and 1/10 CON ewes ( P=0.09). All pregnant ewes exhibited oestrus 14 h earlier ( P<0.02), ovulated approximately 1 day earlier and had higher ( P<0.001) luteal phase progesterone levels than non-pregnant ewes. Non-pregnant had higher ( P<0.04) body weights than pregnant ewes. In conclusion, results demonstrate that both RJ treatments in conjunction with exogenous progesterone were equally capable of improving oestrus response and pregnancy rate.

The requirements of calcium by Awassi ewes at early lactation

The proper development and growth of the fetus and newborn lambs requires an adequate transport of nutrients across the placenta during late gestation and the mammary gland during early lactation. The effect of calcium (Ca) supplementation as calcium carbonate (CC) and injection of Vitamin AD 3E (75 000 IU) on Awassi ewe productivity at early lactation and the growth of newborn lamb was studied. Forty Awassi ewes, 3.5±1 years old, weighing 61±6.4 kg BW at parturition were selected and assigned randomly to four treatment groups based on ration supplementation and vitamin injection: group 1 received 1.4% CC in the ration; group 2 received 2.4% CC in the ration; group 3 received 1.4% CC in the ration plus two intramuscular doses of Vitamin AD 3E; group 4 received 2.4% CC in the ration plus two intramuscular doses of Vitamin AD 3E. Vitamin injections in groups 3 and 4 were given 15 and 30 days postpartum. The experiment started in January and ended in March. Blood and milk samples were collected from dams and lambs every 20 days and the animals were weighed every 15 days. Milk and blood samples were prepared and analyzed for Ca concentrations by atomic absorption spectrophotometry (AAS). Ca concentrations in blood serum of ewes and newborn lambs for group 4, at 60 days postpartum were higher (8.9 and 9.6 mg/dl; P<0.10) compared to other groups. A significant ( P<0.05) increase in lambs average body weight gain (g per day) was detected during the last 15 days before weaning in groups 2 and 4 (268.3 and 269.7 g per day, respectively) compared to groups 1 and 3 (230.1 and 21 6.4 g per day, respectively). Moreover, a significant ( P<0.05) increase in milk ash percentage was observed 60 days postpartum in groups 2 and 4 (1.23 and 1.1%, respectively) compared to groups 1 and 3 (1.02 and 0.96%, respectively). No significant differences were detected on milk yield and body weight between the four ewe groups as a result of treatments. Results indicated that feeding 2.4% CC with or without Vitamin AD 3E to Awassi ewes at parturition improved their blood serum Ca and the average body weight gain of their lambs.

Reproductive Responses of Awassi Ewes Treated with either Naturally Occurring Progesterone or Synthetic Progestagen

The objective was to identify the appropriate form of progesterone, which exhibits compact reproductive responses in Awassi ewes during mid to late seasonal anestrous period. Forty-eight Awassi ewes were randomly allocated into four groups to be treated with 60 mg medroxyprogesterone acetate (MAP), 30 mg fluorogestone acetate (FGA), 40 mg FGA, or 600 mg progesterone sponges. After a 12 day period, sponges were removed and ewes were administered i.m. with 600 IU PMSG (d 0, 0 h). Five harnessed Awassi rams were turned-in with the ewes to detect heat. Ewes were checked for breeding marks at 6 h intervals for 5 days. Blood samples were collected from all ewes for analysis of progesterone concentrations. Pretreatment (d -13 and -12) progesterone concentrations were ≤0.2 ng/mL among all ewes and were indicative of seasonal anestrous period. On d 0, progesterone concentrations were elevated to 1.4±0.1 ng/mL in ewes received progesterone sponges only and were higher (p 0.1) among all ewes. Incidence of estrus was similar (p>0.1) among the four groups and occurred in 75% (9/12), 82% (9/11), 67% (8/12) and 58% (7/12) of the ewes receiving MAP, 30 mg FGA, 40 mg FGA and progesterone sponges, respectively. Estrous responses occurred 14.7, 20 and 13.6 h earlier in progesterone-sponge-treated ewes than those of MAP- (p 0.1) among ewes of the four treatment groups. Ewes that returned to estrus 16 to 20 days following d 0 were 5/12, 5/11, 6/12 and 4/12 ewes treated with MAP, 30 mg FGA, 40 mg FGA and progesterone sponges, respectively, and all lambed 169 days later. Overall lambing rates were 75% (9/12), 82% (9/11), 75% (9/12) and 58% (7/12) ewes treated with MAP, 30 mg FGA, 40 mg FGA and progesterone sponges, respectively. Results demonstrate that applications of MAP, 30 mg FGA, 40 mg FGA and progesterone sponges Awassi ewes were equally effective in induction of estrus and tended to favor both types of FGA and MAP in overall lambing rates over progesterone sponges during the seasonal anestrous period. (Asian-Aust. J. Anim. Sci. 2002. Vol 15, No. 9 : 1257-1262)

Protocols for Estrus Synchronization in Awassi Ewes under Arid Environmental Conditions

In July, three trials were conducted to evaluate the best sponge type and optimum PMSG dose to be administered to sheep under the Jordanian Badia (arid) conditions. In trial 1, three flocks (n=77, n=18 and n=47 for flocks 1, 2 and 3, respectively) were administered with 40 mg fluorogestone acetate (FGA) intravaginal sponges for 12 days before receiving 600 IU of PMSG at the time of sponge removal. In trial 2, 95 ewes were assigned to 4 groups to receive 300 (n=25), 450 (n=27), 600 (n=22) or 750 (n=21) IU of PMSG following a 12 d FGA 40 mg sponge insertion period. In trial 3, 60 ewes were assigned to 3 groups (n=20) to receive either FGA 30 mg, FGA 40 mg or medroxyprogesterone acetate (MAP) 60 mg intravaginal sponges all followed by an administration of 600 IU of PMSG at sponge removal. In all trials, rams were isolated 1 day before sponge insertion and were allowed back with the ewes at sponge removal. Estrual responses and lambing data were collected. The effects of treatment, milking status and face color on estrual responses and lambing data were examined. In trial 1, greater first cycle conception rate (p0.05). Despite low lambing rate in trial 2, ewes receiving 600 IU of PMSG had greater (p3.1, 493.1 and 493.1 h post sponge removal in ewes receiving MAP 60 mg, FGA 30 mg and FGA 40 mg sponges, respectively). Other parameters were not influenced (p>0.05) by sponge type, milking status and face color. Data show that a 600 IU dose of PMSG tends to give the best lambing results. In addition, results indicate that the use 60 mg MAP sponges for estrus synchronization may be more appropriate under the Jordanian Badia conditions during late seasonal anestrus.

Partial purification and characterization of proteins with growth promoting activities from ovine mammary gland secretions

Developmental regulation of growth promoting activities in mammary secretions of pregnant Awassi ewes was defined, and growth factors contained in these secretions were partially purified and characterised. Mammary secretions from pregnant ewes enhanced fibroblast cell (AKR-2B) and mammary cell (CID-9 cell strain) proliferation to levels comparable to that induced by 10% Foetal calf serum. Major milk proteins in mammary secretions collected from pregnant ewes one month prior to lambing up to one week after lambing, were resolved by SDS-PAGE, while gelatinases were resolved by zymography. Gelatinase activity was noted prior to P134 and decreased thereafter to reach a minimum during lactation. This decrease was concomitant with the onset of casein production. It is during this critical developmental period that highest growth promoting activity in mammary secretions was detected. Secretions with highest growth promoting activity were fractionated by ion exchange and gel filtration chromatography. Two heat-resistant, trypsin/chymotrypsin sensitive, growth-promoting activities were characterised. The first, designated ovine mammary derived growth factor-1 (oMDGF-1), had around a 30 kDa molecular weight and eluted at 0.65 M NaCl gradient on cation ion exchange chromatography. The second, oMDGF-2, eluted under gel filtration conditions at a molecular weight of 50 kDa and 150 kDa. oMDGF-1 induced changes in Connexin 43, but not in β-casein mRNA expression by CID-9 mammary cells. In conclusion, growth factor activities in ewe mammary secretions peak during gestation at a period that overlaps maximal gelatinase expression and precedes milk protein synthesis. The factors modulate mammary cell function and may play a role in mammary gland development.

A genetic analysis of complete lactation milk production in Improved Awassi sheep

Monthly test-day records of milk production comprising 3740 lactations, collected between 1993 and 1999 from 1360 fully pedigreed Improved Awassi ewes of the Kibbutz Ein Harod Israel, were analyzed. In this flock, ewes were milked from lambing until milk production dropped to 0.5 l/day, with no suckling period. Lactation curves were fitted and a number of parameters of the lactation curves were calculated. Genetic models were fitted to the different lactation parameters. Additive genetic, permanent environmental, maternal genetic and residual variances were estimated and used to calculate the heritability, repeatability and maternal components of 13 traits of lactation. The heritability of total milk yield throughout the lactation (TMY) was 0.10±0.036 and the repeatability 0.46±0.042. The repeatability was reduced to 0.44 when lactation length was used as a covariate. A maternal genetic effect of 4% (TMY) was found and the heritability of TMY of first lactation records alone was 0.13±0.081. For other lactation parameters, the heritability and repeatability were: 0.03 and 0.08 (day of peak yield), 0.12 and 0.36 (peak yield), 0.09 and 0.16 (increase in milk production per day) and 0.11 and 0.15 (persistency of lactation), respectively. The level of the additive genetic variance for TMY and the other lactation parameters was low in this improved Awassi population. Permanent environmental effects, which may include dominance and epistasis, have a profound contribution to the total variance of milk yield traits in this population.

Weaning and the ram-effect on fertility, serum luteinizing hormone and prolactin levels in spring rebreeding of postpartum Awassi ewes

Spring rebreeding activity was investigated in 44 multiparous Awassi ewes allocated to one of three treatments. The first treatment entailed ewes suckling lambs for 45 days and then continuously exposed to fertile rams (Group 1); ewes of the second group were weaned at 14 days of age and then were either exposed continuously (Group 2) or intermittently (Group 3) to rams. Time of weaning and type of exposure to the ram did not influence the reproductive performance in terms of fertility and prolificacy in postpartum Awassi ewes. Time of weaning did not influence serum LH concentrations monitored at 3 h intervals in Groups 1 and 2. However, serum prolactin (PRL) concentrations were significantly higher in Group 1, compared to Group 2 of ewes. Serum LH levels at weaning were significantly higher in ewes that conceived and lambed, compared to ewes that did not. It was concluded that spring rebreeding of postpartum Awassi ewes did not respond to ram presence and/or early weaning in terms of improved reproductive performance. The lack of reproductive response was further reflected in LH and PRL profiles.

Oestrous synchronisation and twinning rate of Syrian Awassi ewes treated with progestagen and PMSG during the breeding season

An experiment was conducted on Awassi ewes, during the breeding season, to evaluate the effectiveness of intravaginal sponges for oestrous synchronisation and the effect of pregnant mare serum gonadotropin (PMSG) on twinning rate. Thirty intact ewes with an average live weight of 3.1 ± 9.1 kg were divided into 3 equal groups. Sponges containing 60 mg of medroxy‐progesterone acetate (MAP) were inserted for 13 days in ewes in groups Tl and T2. Ewes in the latter group (T2) were injected intramuscularly, at the time of sponge withdrawal, with 500 i.u. of PMSG. The third group (C), received no treatment and served as a control. The mean interval to onset of oestrus was 2.0 days (range: 1.2–3.0 days) and 2.1 days (range: 1.0–3.9 days) after sponge withdrawal for ewes in groups Tl and T2, respectively (P > 0.05). In the control group (C), time of onset of oestrus was more variable (mean: 4.2 days, range: 1–14 days). Differences between the treated and the control animals in the time of onset of oestrus were significant (P < 0.05). The mean concentration of progesterone at sponge withdrawal was 0.16 and 0.08 and at mating was 0.11 and 0.10 nmol 1‐1 for groups T1 and T2, respectively. The treatments had no effect on duration of pregnancy, lamb birth weight, or lamb weaning weight. Using PMSG at sponge withdrawal increased twinning rate from 20% in groups T1 and C to 50% in group T2. It is concluded that intravaginal sponges (MAP) can be used for oestrous synchronisation in local Awassi ewes during the breeding season and that treatment with PMSG at the end of MAP treatment increases twinning rate.

Effects of Haemoglobin and Transferrin Polymorphisms on the Performance of Awassi and Crossbred Ewes Under Subtropic Environment

Darcan, N. and Güney, O. 2000. Effects of haemoglobin and transferrin polymorphisms on the performance of Awassi and crossbred ewes under subtropic environment. J. Appl. Anim. Res., 19: 187–192. Performance (lactation milk yield, prolificacy, fertility and litter size) and polymorphisms of two biochemical systems (haemoglobin and transferrin) of pure Awassi and Çukurova Assaf (Ç. Assaf, 5/8 Awassi + 3/8 East Friesian) and influences of Hb, Tf titred groups on performances of two genotypes were examined. Performance of Awassi and Ç. Assaf ewes were significantly different. Furthermore, there was significant difference between lamb weights at birth and weaning (P<0.01), while no significant differences between haemoglobin and transferrin types of pure Awassi and Ç. Assaf (P>0.05) were found. It was confirmed that haemoglobin and transferrin polymorphisms were found to be effective on the performances of Awassi and Çukurova Assaf breeds.

Nutritive value of lentil and vetch straws as compared with alfalfa hay and wheat straw for replacement ewe lambs

The objective of this study was to compare the nutritive value of lentil straw (LS) and vetch straws (VS) with alfalfa hay (AH) and wheat straw (WS). Forty Awassi ewes (body weight (BW)=56.2 kg) were assigned randomly to four dietary treatments (10 ewes per treatment) for 6 weeks using a complete randomize design. In each dietary treatment, ewes were fed 550 g per day of concentrate mix formulated to supply 40% of the metabolizable energy requirement. After the consumption of the concentrate mix, ewes had ad libtum access to AH, LS, VS, or WS. Forage intake, total dry matter intake (DMI), and organic matter intake (OMI) were higher for AH and LS and lowest for WS. Final weight of ewes fed AH and LS diets were higher ( P<0.05) than VS and WS diets. However, ewes fed VS diet gained more weight (2.5 kg) than ewes on WS diet (0.2 kg). Dry matter digestibility was higher for the AH and LS diets (59.4%), and lowest for WS diet (49.6%). The VS diet had an intermediate value (54.4%). Ruminal passage rate was higher for AH and LS (3.4% per hour) compared with WS (1.9% per hour). Eating time for the AH diet was lowest compared with the rest of the forages. Eating time, expressed as minutes per kilogram NDF intake, was highest for WS and VS diets (680 min) compared with AH and LS diets (535 min). WS diet required more time for rumination (395 min per day) compared to AH, LS, and VS diets. However, ewes on VS diet spent more time ruminating per kilogram NDF consumed (954 min) compared with WS, LS, and AH diets (901, 617, and 597 min, respectively). These results were significant and demonstrate that the nutritive value of LS is greater than VS and close to the nutritive value of AH. VS nutritive value is slightly greater than WS.