Age Of Ewe Research Articles

English

Sheep and goats represent an important component of the farming system by providing about 12% of the value of livestock products consumed and 48% of the cash income generated at the farm level. Although diverse sheep and goats resources are found in Ethiopia, their productivity is low; the sector has not received a great deal of attention from scientists, administrators and legislators. Strategic recording and documentation of the performances of the animals in their native environment under farmer’s condition is very essential. Current survey study was conducted in Dwaro zone, Southern Ethiopia to assess productive and reproductive performance of sheep and goat kept under framers management condition. Primary data were collected from 270 household selected randomly, while secondary data from relevant written documents. Survey result showed that ewes and does were weaned on average at age of 126.2±1.44 and 145.5±1.48 and 249.0±3.10 days in order and weaning age was significantly longer in highland and midland as compared to lowland whereas ewes age at puberty does not vary significantly across agro-ecological zone but does age at puberty is significantly shorter in highland. In addition, the finding indicated that age at first lambing and kidding was 408.0±3.32 and 393.5±3.05 days, respectively. Age at first lambing was not significantly (p>0.05) affected by agro-ecological zones while age at first kidding of does was significantly (p<0.05) longer in lowland (408.6±7.75 days) as compared to midland (385.6±4.31 days) and highland (386.2±0.83 days). Furthermore, survey result revealed that mean kidding and lambing interval was 269.9±3.08 and 269.0±2.89 days, respectively and kidding interval was significantly shorter in highland (263.5±6.0 days) and midland (264.0±5.89 days) relative to lowland (281.7±3.70 days), whereas lambing interval was not affected by agro ecological differences. Furthermore, the survey pointed out that household in the study area slaughtered sheep and goat at mean age of 258.1±4.39 and 255.6±2.49 days in sequence. Lowland household were preferred to slaughter sheep and goat at younger age as compared to midland and highland household for both species that preferred slaughtering of sheep and goat at older age. Feed and other related management improvement and implementing strategic breed improvement is the area that need further work in the future. Key words: Age at first kidding, lambing interval, weaning age, Dawro. &nbsp

Use of autochthonous mesophilic lactic acid bacteria as starter cultures for making Pecorino Crotonese cheese: Effect on compositional, microbiological and biochemical attributes

The use of selected autochthonous mesophilic lactic acid bacteria as starter cultures was investigated according to the traditional protocol for making Pecorino Crotonose (PC). Leuconostoc mesenteroides subsp. mesenteroides 2A, Lactobacillus casei 23C and Lactobacillus plantarum 18C (Autochthonous Starter, AS1) and Leuc. mesenteroides subsp. mesenteroides 2A, and L. casei 25D and 16A (AS2) were isolated and identified from aged ewes' milk PC cheeses, selected based on several enzymatic activities, and used as starter cultures. As shown by the in vitro kinetic of acidification, selected starter cultures had suitable capabilities to acidify. The manufacture of PC cheeses was carried out at an industrial plant scale. A control cheese (CC) was also made, using commercial starters consisting of mesophilic and thermophilic species. Ripening lasted 105 days at 10 °C. A poly-phasic approach was used to compare cheeses during manufacture and ripening, mainly based on pyrosequencing of the 16S rRNA targeting DNA, proteolysis and volatile component analyses. Compared to CC, both autochthonous starter cultures slightly affected the gross chemical composition of PC cheese. The cell density of thermophilic starters of CC progressively decreased throughout ripening. Plate count and RAPD-PCR showed that the cell number of autochthonous lactobacilli cultures of PC cheeses, made with AS1 and AS2, was almost constant throughout ripening and abundantly higher than that observed in CC. As shown by culture-independent analysis, the OTUs found during ripening varied depending on the manufacture with or without autochthonous starter cultures. The major chemical differences among cheeses were the concentration of free amino acids and the synthesis of some key volatile components (e.g., 2-methyl-1-propanol, 2-methyl-1-butanol, isobutyric, isovaleric, and isocaproic acids). Compared to CC, the use of AS1 positively affected the overall cheese quality.

Study of some physical wool characterization in Arabi ewes in Erbil Governorate

This study was carried out at Private flock in Murtkah District - Erbil Governorate. Samples of wool were taken from mid-side of 72 Arabi ewes during May, 2017. to study the effect of ewes age and the sex of the lambs on the physical wool characteristics The overall means of raw fleece weight, clean fleece, fiber diameter, crimps, staple length and fiber length were 1653.75 g, 79.06%, 28.24 micron, 1.33 cm, 9.36 cm and 16.03 cm respectively. The percentages of the fibers of each of Fine, Coarse and Kemp were 52.42, 38.89 and 8.68% respectively. and S/P ratio 1.27. Age of ewe effects appeared to be significant on raw fleece weight and coarse fiber (p ≤ 0.05), also on fine fiber and (S/P) ratio (p ≤ 0.01) only, while the effects of sex of lamb were non-significant on all physical wool properties except the percentage of kemp fiber (p ≤ 0.05). Although the maximum R-square increased very little gradually in the equation to predict fleece weight depending on body weight and dimensions, the simplest equation includes body weight could be considered the most significant (P<0.01) and more reliable than others to predict fleece weight (The equation is: fleece weight = 353.41 + 31.84 (body weight). The multiple regression equations were calculated to predict clean wool percentage, staple length, fiber length, crimps, fine fiber percentage, coarse fiber percentage, and S/P ratio from fleece weight, body weight and dimensions and the maximum R-square for all characteristics were very small. Fiber diameter could be predicted using the formula of multiple regression includes body weight and length and chest depth according to the maximum R-square (P<0.01). While Kemp fiber percentage could be predicted using the formula includes body weight, fleece weight and Shoulder height. Only the simple regression equation of Fleece weight on body weight was significant (P<0.01) with R-square (0.19). The correlation coefficient was done among all studied characteristics and ranged between -0.69 (p<0.01) (between fine fiber and coarse fibers) and 0.94 (p<0.01) (between fine fiber and S/P ratio). It was concluded that wool properties of Arabi sheep were not at standard level especially in both fine and Kemp properties and need to be improved

Assessment of circadian rhythm of activity combined with random regression model as a novel approach to monitoring sheep in an extensive system

Sensor-based technologies are becoming increasingly available and can be used to automatically gather long-term data about animal behaviour. With this information, it is possible to assess the circadian rhythm of activity and monitor its response to internal and external factors. Identifying irregularities in this rhythm may indicate animal health and welfare issues. The aim of this study was to collect sensor-based general activity and investigate circadian rhythm of this activity to identify the changes due to weather influences that act on these parameters throughout the year; to identify the differences between individuals; and to assess links between general activity and circadian rhythm of activity with sheep body weight change. In total, 29 Scottish Blackface ewes of different ages and body condition scores were used. The animals were monitored for four consecutive weeks in each of four seasonal periods, in extensive systems on Scottish upland pastures, and without human handling during study periods. Accelerometer-integrated collars were fitted to the animals to collect motion index continuously every minute. These data were used to calculate the percentage of cyclic behaviour that was harmonic/synchronized with the environment (over 24 h period), as Degree of Functional Coupling (DFC). The DFC was shown within rolling seven-day periods. Low DFCs indicate low synchronization. Weather data were collected daily. Random regression models were used to assess between-individual variation. During the winter period, the level of the DFC for the activity of nineteen ewes lowered in response to a period of high level of precipitation combined with low winter temperatures. However, four ewes exhibited a lower level of variation in the DFC values, showing that there were differences between individuals in regard to their response to the precipitation level. The overall mean of the DFC for the general activity was highest in autumn (95.4%, P < 0.001), however, it did not differ between summer and spring (respectively 90.2% and 88.1%, P > 0.05), but was significantly lower during the winter (81.7%, P < 0.001) compared with summer and autumn. Over the spring and summer, variation in DFC was a good estimator of body weight gain. It was concluded that the assessment of circadian rhythms of general activity using the DFC-parameter allows a better understanding of sheep responses to weather influences, compared to the evaluation of general activity alone. The random regression model method was effective in identifying animals that deviated positively or negatively from population responses.

Genetic parameters for ewe reproductive performance and peri-parturient fecal egg counts and their genetic relationships with lamb body weights and fecal egg counts in Katahdin sheep.

This study estimated genetic parameters for ewe reproductive traits [number of lambs born (NLB) and weaned (NLW) per ewe lambing] and fecal egg counts (FEC) during the peri-parturient rise (PPR) for use in genetic evaluation of Katahdin sheep. Data included NLB and NLW for 23,060 lambings by 9,295 Katahdin ewes, 1,230 PPR at lambing (PPR0) for 750 ewes, 1,070 PPR at approximately 30 d postpartum (PPR30) for 611 ewes, BW at birth, weaning, and (or) post-weaning for 12,869 lambs, and FEC at weaning and (or) post-weaning for 4,676 lambs. Direct additive, permanent environmental, and residual (co)variances were estimated in univariate and bivariate animal models. Fixed effects included effects of ewe management group and ewe age for all traits, and, for PPR, a continuous effect of days between lambing and measurement. Effects of litter size on PPR0 and number of lambs suckled on PPR30 were included in univariate models but excluded from bivariate models for PPR and NLB or NLW. Heritability estimates in univariate models for NLB, NLW, PPR0, and PPR30 were 0.09 ± 0.01, 0.06 ± 0.01, 0.35 ± 0.06, and 0.24 ± 0.07, respectively. Estimates of permanent environmental variance as a proportion of total phenotypic variance were 0.02 ± 0.01 for NLB, 0.03 ± 0.01 for NLW, 0.05 ± 0.06 for PPR0, and 0.13 ± 0.07 for PPR30. Direct additive, phenotypic, permanent environmental, and residual correlations between NLB and NLW were 0.88 ± 0.03, 0.74 ± 0.004, 0.54 ± 0.15, 0.74 ± 0.003, respectively; corresponding correlations between PPR0 and PPR30 were 0.96 ± 0.07, 0.46 ± 0.03, 0.98 ± 0.50, 0.18 ± 0.05, respectively. The additive genetic correlation (rd) between ewe reproductive traits and PPR ranged from 0.12 to 0.18. Estimates of rd between lamb BW and subsequent ewe NLB and NLW ranged from 0.07 to 0.20, and those between PPR and lamb BW ranged from -0.03 to 0.29. The rd between ewe reproductive traits and lamb FEC ranged from 0.27 to 0.40, and those between PPR and lamb FEC ranged from 0.56 to 0.77. Correlations between maternal additive effects on BW and direct additive effects on PPR were low (-0.08 to 0.10), and those between maternal additive effects on BW and direct additive effects on ewe reproductive traits were variable (-0.36 to 0.11). We conclude that FEC in growing lambs and peri-parturient ewes are controlled by similar genes and that modest, but manageable, genetic antagonisms may exist between FEC and ewe productivity.

Impact of the ovarian cycle and pregnancy on plasma chemistry values in ewes.

Normative data for plasma chemistry values in pregnant and non-pregnant reproductive age ewes are scant. Availability of data would aid monitoring of ewe health for both research and veterinary medicine. We determined specific plasma chemistry 95% confidence reference intervals (RIs) in non-pregnant and pregnant ewes. Mixed Western-breed ewes were grouped based on phase of ovarian cycle: luteal ( n = 15), follicular ( n = 17), or late-gestation pregnant ( n = 102). Plasma samples were collected for analysis on a commercial biochemical analyzer. For RIs, chemistry panels for the 3 groups of ewes included nutrients and metabolites (glucose, triglycerides, cholesterol, urea, creatinine, total protein, albumin, and bilirubin), enzymes (lactate dehydrogenase, aspartate transaminase, gamma-glutamyl transferase, alanine aminotransferase, and alkaline phosphatase [ALP]), and micronutrients (calcium, phosphorus, iron, sodium, potassium, and chloride). Sample chemistry values for glucose and total protein in pregnant ewes were lower than in follicular ewes; cholesterol was lower in pregnant and luteal ewes than in follicular ewes. In addition, total bilirubin in pregnant ewes differed from that in luteal ewes, and that in follicular ewes also differed from luteal ewes. ALP in pregnant ewes was higher than other groups; phosphorus in pregnant ewes was lower than in luteal ewes. Iron was higher in pregnant ewes than in luteal ewes, with iron in luteal ewes lower than in follicular ewes. These data provide clinical RIs comparing pregnant and non-pregnant ewes for use in monitoring ewe health in both human research and veterinary medicine.

Molecular detection of Brucella melitensis, Coxiella burnetii and Salmonella abortusovis in aborted fetuses of Baluchi sheep in Sistan region, south-eastern Iran.

Abortion in sheep and goats causes enormous economic losses. This study revealed the epidemiology of abortion caused by Brucella melitensis, Coxiella burnetii and Salmonella abortusovis in Baluchi sheep in Sistan region. In the autumn of 2015 and winter of 2016, a total of 78 aborted sheep fetuses were collected from all over the Sistan region. Risk factors, including location of livestock, history of abortion, gender of fetus, age of fetus, age of ewe and parity were obtained using a questionnaire. The results showed that 27 fetuses (35%) were infected with these organisms. Infection with B. melitensis, C. burnetii and S. abortusovis were identified respectively in 15 (19.2%), 13 (16.6%) and 1 (1.3%) fetus. Logistic regression analysis showed that infection with B. melitensis in male fetuses is higher than females (OR=3.73, P=0.040), also infection with C. burnetii in ≤2 years' ewes (OR=0.047, P=0.009) and 2-5 years' ewes (OR=0.197, P=0.069) is lower than ≥5 years' ewes.

Estimates of genetic parameters for growth traits of local Hamra breed threatened with extinction in southwestern arid rangeland of Algeria

The data base for body weights and growths of 411 Hamra lambs were used to estimate genetic parameters. These lambs were obtained from 31 rams and 493 ewes between 2012 and 2017. Traits analysed were weights at birth (BW), 30 days (W30), 90 days (W90) of age, and average daily gains from 10 to 30 (ADG10-30) and30-90 (ADG30-90) days. REML estimates of variance and covariance components were obtained assuming animal models that included the fixed effects for year-type of birth (2012 single, 2012 twin, . ., 2017 single, 2017 twin), sex (male, female), and ewes age at lambing (&lt; 18, 18-30, 30-42, 42-54, &gt;54 months). Heritabilities were 0.12, 0.06 and 0.11 respectively for BW, W3Oand W90and the average daily gains were 0.05 and 0.17 for ADG0-30and ADG30-90. The estimates of genetic correlations showed no genetic antagonisms among the growth traits. The genetic correlations estimated were positive and medium to high, except those between ADG30-90 and ADG0-30 and between ADG30-90 and W30 which were slightly negative. Phenotypic correlations were positive and ranged from 0.12 to 0.85. They were high between adjacent weights and between ADG and their corresponding weights.

Effect of mother’s age on body weight of lambs from birth to weaning in various strains of domestic sheep Pramenka

This study has been conducted on the domestic sheep Pramenka that is a dominant breed in Serbia. The purpose is to determine the effects of mother?s age on suckling and growth of lambs, and to find out at which week the lambs are normally weaned. Research was carried out on 1800 lambs of four strains (Svrljiski, Pirotski, Sjeni?ki, Sarplaninski) of sheep Pramenka (450 lambs per strain) for body weight. The weight of lambs was measured at the time of birth, 30, 60 and 90 days after birth during three years of experiment (2011-2013). Obtained results refer to variability of body weight of lambs at the time of birth, 30, 60 and 90 days after birth depending on mother?s age within each of four strains of Pramenka sheep. At the time of birth, the highest average weight (3.79 kg) of lambs was found in second age group of Pirotska genotype, while the highest average weight in third age group was found in remaining three Svrljiska (3.91 kg), Sjeni?ka (3.74 kg) and Sarplaninska (3.97 kg) strain of Pramenka sheep. Thirty days after birth the highest average weight of lambs was found in the second age group of Pirotska genotype (9.36 kg), in the first age group in Svrljiska (9.89 kg), while the highest average weight in third age group was found in remaining two Sjeni?ka (9.51 kg) and Sarplaninska (9.41 kg) strain of Pramenka sheep. Sixty days after birth, the highest average weight of lambs was found in third age group of Pirotska genotype (15.85 kg), in second age group in Svrljiska (15.51 kg) and Sjeni?ka (15.50 kg) genotypes, while the highest average weight in first age group was found in Sarplaninska (14.45 kg) strain of Pramenka sheep. Ninety days after birth, the highest average weight of lambs was found in second age group of Pirotska (20.58 kg) and Sarplaninska (20.45 kg) genotype, while the highest average weight in first age group was found in Svrljiska (24.38 kg) and Sjeni?ka (23.76 kg) strain of Pramenka sheep. The variability in body weight of lambs at birth, as well at different stages of growth after weaning at early growth stages is influenced by direct maternal genotype, strains of Pramenka sheep and age of ewes.

Fleece Yield and Same Characteristics of Karadi Sheep

This research was carried out to investigate fleece yield and characteristics of karadi sheep in Hasar village of Kirkuk/Iraq. Fifthy eight ewes and four rams were used in this study. Greasy fleece yield (GFY), breaking strength (BS), fiber elasticity (FE), fiber diameter (FD), fiber length (FL) and clean fleece percentage (CFP) and effects of some environmental factors on the these characteristics have been also studied. Least squares means for body weight at shearing (BWS), GFY, BS, FE, FD, FL and CFP were 52.28kg, 1.65 kg, 21.74 cN/tex, 31.58 %, 36.10 µm, 18.33 cm and 67.98 %, respectively. Effects of ewe age on BS, FE and CFP was statistically significant (P<0.05), but on the other characteristics were not significant. The effect of BWS was statistically insignificant on all characters. From sortiman value (44'S) calculated, it was concluded that Karadi breed could be evaluated in the class of carpet wool fleece sheep.

Husbandry procedures at the point of lambing with reference to perinatal lamb mortality

Perinatal mortality reduces the number of lambs sold per ewe and consequently impacts negatively on the economic sustainability of sheep farming. Figures quoted for the incidence of perinatal lamb mortality...

Farklı Yetiştirici Koşullarında Norduz Koyunlarının Kırkım Sonu Canlı Ağırlığı ve Kirli Yapağı Verimi

In this study, the live weight after shearing, the greasy wool weight and, the clean fleece percentage of Norduz ewes in different breeding conditions were investigated. The animal material consisted of a total of 260 head of Norduz ewes including 52 head ewes at the different flocks raised in Dolayli (farm 1), Gecerli (farm 2), Geziyurt (farm 3), Oguldami (farm 4) and, Tasinacak (farm 5) neighbourhoods of Gurpinar province in Van city. Norduz ewes were sheared using shearing scissors between end of June and beginning of July. After shearing, ewes were weighted by using electronic digital weighing scale. Then, the sampling for clean fleece percentage were performed from area of the last rib on the right shoulder of 12 head of ewes in each flock. When all the farms were generally evaluated, the effect of live weight after shearing on the greasy wool weight was statistically significant (p<0.01). Least squares means for greasy wool weight at farm 1, farm 2, farm 3, farm 4 and, farm 5 were 2.03, 2.05, 2.05, 2.06 and, 2.06 kg, respectively. When all the farms were generally evaluated, the effect of age of ewe and farm on the live weight after shearing was statistically significant (p<0.01) in Norduz ewes. Least squares means for live weight after shearing at Dolayli, Gecerli, Geziyurt, Oguldami and, Tasinacak neighbourhoods were 53.21, 54.30, 51.25, 55.08 and, 54.93 kg, respectively. Means of clean fleece percentage were 64.25%, 67.76%, 63.50%, 66.68% and, 64.06% for Dolayli, Gecerli, Geziyurt, Oguldami and, Tasinacak neighbourhoods, respectively.

Factors affecting conception rate of hair ewes after laparoscopic insemination with chilled semen under tropical conditions

The objective was to evaluate the effect of some factors on the conception rate of hair ewes using laparoscopic intrauterine insemination with chilled semen under tropical conditions. Data on 1200 inseminations carried out in Pelibuey, Blackbelly, Katahdin and Dorper ewes from 19 farms were used. Estrous was synchronized using vaginal sponges or a controlled intravaginal drug release (CIDR) device by 12days. At the withdrawal of the device (sponge/CIDR) 200 or 250 IU of equine chorionic gonadotropin (eCG) was applied. Insemination was carried out 54–56h after withdrawal of the device using chilled semen with 150 million spermatozoa per dose. Ultrasound conception diagnosis was carried out 35–40 d after insemination. The effects of ewe breed, age of ewe (1–4 years), body condition score (low, middle and high), type of device (sponge and CIDR), dose of eCG (200 and 250 IU), year of insemination (2010–2012), season (hot-dry, hot-humid; fresh-humid), inseminator (5 inseminators) and simple interactions on conception rate were determined using binary logistic regression. The overall conception rate was 66.4%. There was not significant interactions of main effects. Only breed, body condition score (BCS) and year of insemination influenced (P<0.05) conception rate. Blackbelly (73.1%) and Pelibuey (68.9%) ewes had the highest conception rates as compared to Dorper (61.4%) and Katahdin breeds (62.4%). The conception rate was better in the ewes of middle body condition (68.1%) than ewes of low BCS (64.2%). Under the conditions of this study, the conception rate of ewes, using laparoscopic intrauterine insemination with chilled semen was influenced by ewe breed, BCS and year of insemination.

The nutrition of grazing ewes during pregnancy and lactation: relationships between herbage, supplement and milk intakes, and ewe and lamb liveweight and body composition

This paper reports results from a study of ewes in pregnancy and lactation, during which times they grazed at a high versus medium stocking rate and either received or did not receive a pelleted supplement. We measured ewe liveweight, condition score and body composition; intakes by ewes of pasture and supplementary feed; milk production by ewes, and; birthweight, milk intake, liveweight gain and body composition of single and twin lambs. Ewes grazing at the medium stocking rate consumed more pasture in late pregnancy and the intake of supplement significantly reduced pasture intake. Nevertheless, total intakes of organic matter or digestible organic matter were unaffected by supplementation and were significantly higher at the medium stocking rate. Effects of stocking rate on intake persisted into early and mid-lactation, but supplement intake did not affect pasture intake in lactation. Pasture intakes in pregnancy were not markedly different between twin-bearing and single-bearing ewes, nor were pasture intakes in lactation affected by the number of lambs suckled. Ewes suckling twins produced much more milk. There were significant effects of birth type, ewe stocking rate and supplementation on lamb milk intake and liveweight gain. The data were reanalysed by regression, to explore the effects of actual herbage masses and ewe intakes, and the possible effects of non-treatment terms such as ewe age, condition score and dentition score at allocation. These analyses confirmed the above effects of treatment, but also demonstrated that ewes in better condition at the start of the experiment ate less pasture in both pregnancy and lactation, and produced significantly less milk. Ewe organic matter intakes in pregnancy were not related to dentition score at allocation, but in early and mid-lactation were reduced by ~170 g organic matter/day and 280–380 g organic matter/day, respectively, per unit increase in dentition score. There was no significant effect of ewe dentition score on lamb milk intake, but there was a significant penalty of ~19 g lamb liveweight gain/unit increase in ewe dentition score at allocation. Future studies of this kind thus need to include estimates of the condition score and dentition score of ewes when they commence the experiment.

Factors affecting fecal egg counts in periparturient Katahdin ewes and their lambs.

Selection for low fecal egg counts (FEC) can be used to genetically enhance resistance to gastrointestinal nematode parasites in growing lambs, thereby reducing the frequency of use of anthelmintics, facilitating marketing of organic lamb, and reducing the risk of development of anthelmintic resistance by the parasite. Recording of FEC in lambs has, therefore, been incorporated into several national sheep genetic evaluation programs. Ewes in late gestation and early lactation are also vulnerable to parasite infection and commonly experience a periparturient rise in FEC. This study was designed to assess factors associated with the periparturient rise in FEC in Katahdin ewes and associated changes in FEC in their lambs. Data came from 1,487 lambings by 931 Katahdin ewes from 11 farms in the Eastern United States. Fecal egg counts were measured in ewes at approximately 0, 30, and 60 d postpartum and in their lambs at approximately 60, 90, and 120 d of age. Approximately 1,400 lambs were evaluated at each measurement age. Data were analyzed separately for ewes and lambs and also initially analyzed separately for each measurement time. Repeated-measures analyses were then used to evaluate responses across measurement times. In ewes, FEC peaked at approximately 28 d postpartum, and we concluded that informative periparturient FEC could be obtained from 1 wk before until approximately 5 wk after lambing. Yearling ewes had higher FEC than adult ewes ( < 0.01), and ewes that nursed twin or triplet lambs had higher FEC than ewes that nursed single lambs ( < 0.01). In lambs, FEC increased through approximately 120 d of age. Lambs from yearling ewes and lambs nursed in larger litters were, like their dams, at greater risk of parasitism ( < 0.05). Ewes and lambs in these groups would benefit from enhanced monitoring of parasite loads at lambing and in early lactation. Correlations () between FEC in lambs at 90 d of age and FEC in ewes at 0, 30, and 60 d postpartum of 0.05 to 0.09 ( ≤ 0.05) support the presence of a genetic relationship between these 2 indicators of parasite resistance.

Differentiation of vulnerability to parasitic infections in various breeds of sheep in the Lubelskie region

The aim of the study was to compare the prevalence and intensity of parasitic invasions between Uhruska sheep (a local breed protected in a genetic resources protection program) and two synthetic sheep lines: BCP and SCP. The sheep were kept in the same flock in a combined indoor-pasture management system with unified feeding and environmental conditions. The observed farm is located in south-east Poland. The study animals were 210 mother ewes of similar age (Uhruska breed – 70 sheep, synthetic prolific-meat BCP line – 70 sheep, SCP synthetic line – 70 sheep). The study material was faeces collected from the rectum of every mother ewe in autumn (November), winter (January), spring (April) and summer (June). On the basis of the obtained results, the following parasites were detected: Eimeria spp. and nematodes from the family Trichostrongylidae, as well as the genera Capillaria and Nematodirus. It was shown that in almost all cases the invasion intensity was similar, while the prevalence of parasitic invasion was significantly lower in local Uhruska breed sheep than in synthetic lines. This could stem from the better adaptation of the animals to the environmental conditions. The results of the observations indicate a need for further studies on the resistance of local breeds to parasitic invasions. The use of resistance breeds may be helpful in effective breeding work aimed at reducing the risk of infection. Such activity could lead to better growth and fewer deaths, which would certainly contribute to an improved profitability of sheep production.

Sonographische Trächtigkeitsuntersuchung und Bestimmung von Anzahl und Alter der Feten beim Schaf

The aim of the present study was to evaluate accuracy of transabdominal ultrasonography for pregnancy diagnosis, determination of fetal number and estimation of gestational age in ewes. A total of 1068 ewes from 8 different flocks (Swiss White Alpine n=379, Swiss Black- Brown Mountain n=189, Oxford-type n=164, Ostfriesian n=154, Texel n=104, Lacaune × Osfriesian crossbred n=78) was investigated using an Ovi-ScanTM ultrasound scanner with a 3.5 MHz 170° mechanical axial probe (BCF Technology Ltd., Bellshill, Great Britain). Scanning was performed transabdominally at the right inguinal region in ewes restrained in standing position. Sonographic findings were compared with lambing data recorded by the farmers. Included in the analysis were all ewes that, at the time of examination, were not pregnant and those that were pregnant between 26 and 110 days with a known lambing date and number of lambs born (n=882). The sensitivity of pregnancy diagnosis was 97.8% and the specificity 97.6% (overall accuracy 97.8%, n=853). Sensitivity and specificity for discrimination between single and multiple pregnancies was 95.8% and 90.5% (overall accuracy 93.9%, n=752), respectively, when multiples were defined as positive. Discrimination between twins and triplets reached a sensitivity of 86.0% and a specificity of 99.5% (overall accuracy 98.0%, n=458) when triplets were defined as positive. Considering a gestation period of 150 days, the mean deviation of the estimated to the effective day of gestation at examination was 5.6±5.0 days (n=781). The correlation between estimated and true gestational age was very high (r=0.936, P<0.0001). In conclusion, a highly accurate and efficient diagnosis of pregnancy with reliable estimation of fetal number and age is possible using an Ovi- ScanTM ultrasound scanner by an experienced examiner.

Impact of young ewe fertility rate on risk and genetic gain in sheep-breeding programs using genomic selection

Genomic selection could be useful in sheep-breeding programs, especially if rams and ewes are first mated at an earlier age than is the current industry practice. However, young-ewe (1 year old) fertility rates are known to be lower and more variable than those of mature ewes. The aim of the present study was to evaluate how young-ewe fertility rate affects risk and expected genetic gain in Australian sheep-breeding programs that use genomic information and select ewes and rams at different ages. The study used stochastic simulation to model different flock age structures and young-ewe fertility levels with and without genomic information for Merino and maternal sheep-breeding programs. The results from 10 years of selection were used to compare breeding programs on the basis of the mean and variation in genetic gain. Ram and ewe age, availability of genomic information on males and young-ewe fertility level all significantly (P &amp;lt; 0.05) affected expected genetic gain. Higher young-ewe fertility rates significantly increased expected genetic gain. Low fertility rate of young ewes (10%) resulted in net genetic gain similar to not selecting ewes until they were 19 months old and did not increase breeding-program risk, as the likelihood of genetic gain being lower than the range of possible solutions from a breeding program with late selection of both sexes was zero. Genomic information was of significantly (P &amp;lt; 0.05) more value for 1-year-old rams than for 2-year-old rams. Unless genomic information was available, early mating of rams offered no greater gain in Merino breeding programs and increased breeding-program risk. It is concluded that genomic information decreases the risk associated with selecting replacements at 7 months of age. Genetic progress is unlikely to be adversely affected if fertility levels above 10% can be achieved. Whether the joining of young ewes is a viable management decision for a breeder will depend on the fertility level that can be achieved in their young ewes and on other costs associated with the early mating of ewes.

Effects of service ram on litter size in Romanov sheep

The objective of the present study was to examine and quantify the effects of factors acting during the mating period (service ram, mating group) on subsequent litter size in the highly prolific Romanov breed of sheep and to propose models for the potential inclusion of this effect in mixed model equations for breeding value estimation. A dataset of 4412 lambings of purebred Romanov sheep in a performance test program from 1998 to 2013 was used in analyses. The basic model fitted to litter size was a single-trait repeatability animal model with fixed effect of ewe age and random effects of contemporary groups of ewes during lambing, direct additive genetic effect of ewe, permanent environmental effect of ewe and random residual. Eight modifications of the basic model examined various combinations of mating effects, contemporary group of ewes during mating (harem), and additive genetic and permanent environmental effect of service ram. When the service ram effect was analyzed without inclusion of the population relationship matrix in the model, the proportion of variance attributable to service ram was 0.081. When the relationship matrix was included in the analysis, however, service ram heritability estimates varied from 0.046 to 0.10, depending upon whether raḿs permanent environmental effect, a harem effect or both were included in model. Models containing the additive genetic effect of service ram had slightly lower proportions of residual variance than models lacking this effect. Including effects of mating (service sire, harem, and/or raḿs permanent environmental effect) in the model favourably decreased deviance information criterion. Means of estimated BVs by year of birth increased across the 22 years from about 0.45–0.60 lambs per litter for female fertility and from 0.55 to 0.59 lambs per litter for BV male contribution on litter size, with only small differences among models. Results from present study demonstrate that service rams in Romanov sheep have a clearly detectable influence on litter size of their mates. Genetic parameter estimates indicate that direct selection on the service ram effect could increase litter size and achieve genetic gain through ram selection.

Replacement of mustard oil cake by urea in short-term strategic feeding of cull ewes to improve body condition and carcass traits

Strategic short-term feeding of culled Malpura ewes (age &gt;6 years, average liveweight 26.8 ± 0.96 kg) was aimed at improving their body condition and increase marketability of their carcass following slaughter. Randomly, 8 out of 40 ewes were slaughtered to study initial (Day 0) carcass traits and the remaining ewes were equally divided into two groups: mustard cake (Control) and urea. They were stall fed with ad libitum guar straw (Cyamopsis tetragonoloba) and concentrate mixture at 25 g/kg liveweight after 4 h of morning grazing in the pasture. The Control group was offered concentrate with solvent extracted mustard cake whereas it was replaced on an equivalent nitrogen (N) basis with urea in the concentrate offered to the other group. Daily feed intake and weekly change in ewe liveweight and body condition score were measured during the 91 days of the experiment. There was no significant (P &gt; 0.05) difference in digestibility of nutrients between the groups. Both groups had similar dry matter and metabolisable energy intake, but the mustard cake group recorded higher (P &lt; 0.05) cumulative weight gain and body condition score. Ruminal fluid samples and blood biochemical measurements were analysed periodically (0, 45 and 91 days), with ruminal fluid samples during the post-feeding hours also analysed. There was periodic variation in rumen pH (P = 0.013), volatile fatty acid (P = 007), total N (P = 0.001) and ammonia-N (P = 0.025) concentration in both groups. Higher post-feeding volatile fatty acid (P = 0.031) and total N (P = 0.003) values were observed in the mustard cake group. Ruminal ciliate protozoal population showed a quadratic response over time after feeding with an initial decline post-grazing, but was not affected by treatment. Similar significant (P &lt; 0.05) improvements in haemoglobin, glucose, total protein, urea and cholesterol levels were evident in both groups at 91 days. Both treatments showed similar improvement in carcass composition, distribution of fat and chemical composition of Longissimus dorsi after 91 days of realimentation compared with initial values. Short-term pre-slaughter feeding of cull ewes improved body condition, carcass traits and composition. Replacement of costly mustard cake with urea in the diet of cull ewes could be a means to improve profitability of this strategic feeding protocol, as well as enhancing their market value.