Ewe Productivity Research Articles

A study on the genetic and phenotypic factors affecting specific ewe productivity traits in Sangsari sheep.

The study's objectives were to assess the genetic parameters of reproductive characteristics in Sangsari sheep. A data set of reproductive information with pedigree details from 1995 to 2016 was used. Studied traits were litter size at birth (LSB), litter size at weaning (LSW), litter mean weight per lamb born (LMWLB), litter mean weight per lamb weaned (LMWLW), total litter weight at birth (TLWB) and total litter weight at weaning (TLWW). Test significance of the environmental factors to be included in the model was conducted using the general linear model procedure of the SAS program. All traits were significantly affected by the year of lambing and ewe age at lambing (P < 0.01). The AI-REML procedure of the Wombat program was used to evaluate genetic parameters. A series of bivariate animal models were employed to calculate genetic (rg) and phenotypic (rp) correlations between traits. The total least square means ± standard error of LSB and LSW were 1.04 ± 0.05 and 0.96 ± 0.03, while LMWLB, LMWLW, TLWB, and TLWW were 3.12 ± 0.08, 15.40 ± 0.13, 3.28 ± 0.04, and 19.31 ± 0.16kg, respectively. The estimates of h2 were relatively low (P < 0.01) and ranged from 0.063 ± 0.028 for LSW to 0.181 ± 0.063 for TLWW. Repeatability estimates varied from 0.101 for LSW to 0.241 for TLWW. The sire service effects for LMWLB, TLWB, and TLWW were 0.012 ± 0.004, 0.023 ± 0.006, and 0.039 ± 0.009, respectively. The traits studied showed a greater magnitude of genetic correlation than phenotypic correlation, with values ranging from - 0.59 (LSB-LMWLB) to 0.87 (LMWLB-TLWB). It appears that focusing on TLWW for selection could result in more significant improvements in the reproductive performance of Sangsari ewes.

Evaluation of the slaughter indicators of the Edilbaevsky sheep breed depending on the milk productivity of sheep

Relevance. Increasing the milk productivity of ewes is an important factor for improving the meat qualities of the offspring. The study of the influence of the milk productivity of ewes on the results of the control slaughter of rams of the Edilbaev breed, as well as the morphological and chemical composition of lamb, will allow optimizing the technology of growing and fattening young animals to obtain high-quality meat.Methods. A scientific and economic experiment was carried out. The material for the experiment was sheep at the ages of 4 and 7 months. 3 groups of sheep were formed, obtained from abundant dairy queens with milk productivity per lactation (120 days) — 89.55 liters (group I of sheep), medium-dairy — 71.6 liters (group II), low-dairy — 48.4 liters (group III). To conduct the experiment, in accordance with generally accepted methods, young animals were selected according to the principle of analogues, taking into account gender, age, type of birth (males), and body weight.Results. The results obtained indicate that an increase in the milk productivity of ewes leads to an improvement in the meat qualities of rams of the Edilbaev breed. Lambs born from ewes with high milk productivity have higher slaughter weight, slaughter yield and meat quality compared to rams born from ewes with lower milk productivity. These data can be used to develop optimal technologies for growing and fattening young animals to produce high-quality meat.

Estimation of Genetic Parameters for Litter Size and Growth Traits in a Prolific Line of Tunisian Barbarine Sheep

This study aimed to assess genetic parameters for ewe productivity in a Tunisian Barbarine sheep line. The traits studied were litter size (LS), birth weight (BW), weight at 90 days (W90), and average daily gain between 10 and 30 days (ADG13). A total of 3804 growth and 2726 lambing records were used. Bivariate linear and threshold animal models were fitted and analyzed using the Gibbs sampling methodology. Heritabilities for LS obtained with univariate threshold, bivariate linear, and threshold models were around 0.15, higher than the estimate obtained by a univariate linear model (0.09 ± 0.03). Direct heritability for growth traits remained consistent across models, except for W90 in the bivariate linear threshold model. Maternal heritability for growth traits was higher than direct heritability, ranging from 0.07 to 0.15, except for BW. The covariances between the direct and maternal effects of growth traits were slightly negative. Repeatability oscillated between 0.16 and 0.62. Direct genetic correlations between LS and the other traits were negative, varying from −0.18 (LS-BW) to −0.83 (LS-W90). Our results suggest that the threshold model may be the most appropriate for LS. A selection index including LS and growth traits may be proposed for routine genetic evaluation in this population.

Milk productivity of queens, growth of purebred and crossbred young animals of the southern beef breed

Relevance. The safety of lambs is the most important factor affecting the efficiency of the industry. It is of particular relevance for multiple breeds. The level of dairy productivity of ewes is one of the factors affecting the growth and development of lambs, their safety before weaning. Milk productivity is positively correlated with the dynamics of the live weight of lambs.The aim of the study was to study the milk content of crossbred ( 1/2 southern meat and 1/2 Katum) and purebred (southern meat) ewes, the effect of this indicator on the growth of lambs.Methods. The objects of the study were purebred (n = 46), crossbred ( n = 30) ewes and their lambs. To determine the amount of milk produced by a ewe over 20 days, the increase in live weight of lambs during this period was multiplied by a factor of 5 (on average, up to 5 liters of milk are required for an increase of 1 kg). In multiple-fetal ewes, milk production was determined by multiplying the sum of the growth of all lambs in the litter by 5.Results. The number of lambs in the litter and the genotype of the ewes have a statistically significant effect on the live weight of lambs at birth and the milk production of ewes. Lambs born alone in a litter exceeded double lambs by 18.1% and triple lambs by 22.6% in live weight. Multiple ewes are superior in milk production to ewes with one lamb. In terms of the amount of milk produced in 20 days, ewes with triplets exceeded their peers with one lamb by 2.24 times, and with twins — 1.52 times. Crossbred (1/2 southern meat and 1/2 katumskaya) ewes are higher in milk productivity than the maternal breed.

Effects of rosemary essential oil on the milk production and fatty acid profiles of ewes fed oat hay or silage

Effects of rosemary essential oil on the milk production and fatty acid profiles of ewes fed oat hay or silage

Genetic parameters for ewe lifetime productivity traits in Central Anatolian Merino sheep

Rapidly increasing population size, recent breaks in production and supply chains, due to pandemics, and those further expected because of climate change emphasize the compelling importance of animal productivity. Traits associated with the productivity of ewes have a direct impact on the overall productivity, profitability and efficiency of sheep farms. Therefore, the objective of the current study was to estimate the variance components, heritabilities as well as genetic and phenotypic correlations, for traits associated with the lifetime productivity of Central Anatolian Merino ewes. Birth and weaning records of lambs for each ewe as well as environmental factors such as sex and birth type were utilized for deriving ewe lifetime productivity traits. Genetic parameter estimations involved observations from 3101 Central Anatolian Merino ewes, encompassing mean and total lamb birth weight per ewe (MBW and TBW), mean and total lamb weaning weight per ewe (MWW and TWW), and the mean and total number of lambs weaned (MNLW and TNLW). This analysis utilized a pedigree comprising 13229 animals. Average Information Restricted Maximum Likelihood (AIREML) based Animal Linear Mixed Model estimations for the decomposition of (co)variance components were implemented based on pedigree-derived numerator relationship matrix by also accounting for the number of parities as a fixed factor. Low to moderate heritability estimates, ranging between 0.29 and 0.42, were observed for the lifetime productivity traits of the breed. A wide range of genetic and phenotypic correlations (between −0.56 and 0.99) was observed among the traits of interest. The outcomes of the study are anticipated to significantly enhance the global sheep production systems by uncovering the essential parameters for incorporating ewe’s lifetime reproductive performance and productivity into the selection indices. This will also benefit Central Anatolian Merino farmers, who form a large proportion of sheep producers in Turkey.

Should lambs born to one-year-old ewes and grown to heavy live weights be retained as replacements and mated at seven months of age?

ABSTRACT The lifetime productivity and efficiency of singleton- and twin-born ewe lambs born to one-year-old ewes were compared with twin-born ewe lambs born to mixed-age ewes. Romney ewe lambs either born as twins to mixed-age ewes (Heavier n = 135 and Control n = 135), or to one-year-old ewes as singletons (L1; n = 135) or twins (L2; n = 88) were included. The Heavier ewes weighed 47.9 ± 0.36 kg at ewe lamb breeding while Control ewes weighed 44.9 ± 0.38 kg. The lifetime number of lambs born and weaned, and the lifetime weight of lambs weaned were used to calculate both feed and ewe efficiency. Heavier ewes had greater lamb production as one-year-old ewes than L1, L2 and Control ewes, after which the yearly lamb production and efficiency did not differ between treatments. Heavier ewes had a greater lifetime number and weight of lambs weaned than L1 and L2 ewes but did not differ from Control ewes. The lower lifetime production of L1 and L2 ewes was driven by their low production as one-year-old ewes. Farmers, therefore, could select their replacements from ewes born to one-year-old ewes and have similar lamb production to ewes born to mixed-age ewes, providing they reach recommended pre-breeding live weights.

Field outcomes of laparoscopic ovum pick-up combined with in vitro embryo production in sheep: Effects of long-acting recombinant ovine FSH pre-stimulation, collection frequency, and donor breed

Laparoscopic ovum pick-up (LOPU) combined with in vitro embryo production (IVEP) is a technology platform that improves the utilization rate of the elite ewe's ovarian oocytes and increases the number of obtained offspring. This study aimed to evaluate the effects of FSH pre-stimulation, serial oocyte collection, and breed on LOPU-IVEP under field conditions. Donors were randomly assigned to five groups (group A: decreasing doses of pituitary FSH (p-FSH); group B: constant doses of p-FSH; group C: two doses of long-acting recombinant ovine FSH (ro-FSH); group D: single administration of a long-acting ro-FSH in; group E: no FSH stimulation). Oocyte yield following LOPU (average recovered oocytes: 20.9 ± 0.5; average viable oocytes: 17.2 ± 0.4) and oocyte developmental competence (average blastocysts: 7.0 ± 0.2) in group C were significantly better than these of group D and group E, and similar to these of groups A and B. Meanwhile, there were no differences in oocyte yield and developmental capacity using repeated LOPU session at 1-, 2-, and 3-month intervals (p > 0.05). Finally, we compared LOPU-IVEP outcomes among five sheep breeds. The results indicated that East Friesian × Chinese Mongolian crossbred sheep and purebred East Friesian sheep had the more recovered oocytes and viable oocytes compared with the Suffolk, Dorper, and Texel breeds, and average number of blastocysts in East Friesian × Chinese Mongolian sheep group was also highest among the groups (8.1 ±0.3, p < 0.05). In summary, the results of this study indicate long-acting ro-FSH pre-stimulation combined with 12 times LOPU sessions over one year maximizes embryo production of elite donor ewes under field conditions.

PSV-22 Productivity at Weaning of F1 Dorper X Pelibuey Ewes Carrying the Fecge Allele of the Ovine GDF9 Gene

Abstract The FecGE allele of the ovine GDF9 gene has been reported segregating in the Pelibuey hair type breed in México. Homozygous E/E ewes reproduce normally, in contrast to the sterility of homozygous ewes reported for other GDF9 variants. Thus, potential exists to cross homozygous and carrier Pelibuey ewes with meat type rams of low-prolificacy but well-adapted breeds to obtain F1 commercial flock ewes. The aim was to evaluate ewe productivity, as total lamb weight weaned (TWW), of FecGE carrier vs non-carrier F1 Dorper x Pelibuey ewes. Sixty one first lambing ewes (34 carrier and 27 non-carrier) equally served with two Texel rams were used. Management was under feedlot conditions. Genotyping was done by real time PCR (StepOnePlus) using the FAMACTTCAAACAGTTTCTTTTTMGBNFQ and VICTCAAACAGTGTCTTTTTMGBNFQ probes (Applied Biosystems). Type of birth (TB; twins vs single) and weaning (TW) were analyzed with PROC CATMOD of SAS. Fixed effects of ewe genotype (carrier vs non-carrier), contemporary group and ram of service were included in a logistic generalized linear model. Lamb weaning weights were adjusted to a common age of 75 d and by sex. Equivalent to male average birth lamb weight (ABW), average weaning lamb weight (AWW) and TWW per ewe were analyzed with PROC GLM of SAS. Carrier ewes had more twins (P &amp;lt; 0.01) for TB (75 vs 19.4 %) and TW (58.8 vs 21.7 %) than non-carrier ewes. Equivalent to male ABW on carrier ewes was less (P &amp;lt; 0.05; 3.17 ± 0.21 vs 3.97 ± 0.20 kg) than for non-carrier ewes but not difference (P &amp;gt; 0.05) was observed for AWW (21.96 ± 0.85 vs 22.93 ± 0.90 kg). Ewe productivity, as indicated by TWW, was greater (P &amp;lt; 0.05; 33.16 ± 1.78 vs 27.23 ± 1.88 kg) for FecGE carrier ewes than for the non-carrier ones. More research on this topic deserves further attention, especially under range conditions, with multiple parity ewes, different years and reproductive activity seasons, using a larger simple.

Effect of Adding Omega-3 to Ration on Production and Physiological Performance of Awassi Ewes during Winter Season

Effect of Adding Omega-3 to Ration on Production and Physiological Performance of Awassi Ewes during Winter Season

Reproductive performance and productivity of local and Dorper x local crossbred ewes under community-based management system, Ethiopia

This study evaluated the reproductive and productivity of local and Dorper crossbred ewes in a community-based management system. We analyzed data collected from 2013 to 2021, taking into account different factors such as dam-breed, location, type of birth, season, and year of lambing. Lambing was observed all year-round, but the majority (35%) occurred in September, October, and December. This suggests that pasture availability, which is influenced by climatic-factors, may play a role in the seasonality of lambing. Litter-size at birth and weaning did not show any significant difference. Age at first lambing varied between breeds (P < 0.001), while lambing-interval and annual reproductive rates were unaffected by dam-breed (P > 0.05). The annual number of lambing per year significantly varied based on location and lambing seasons (P < 0.001), with a higher frequency during the major rainy-season compared to the dry-season (1.58vs1.42), highlighting the influence of feed availability. Productivity indices of ewes were calculated. Location and season of lambing had a significant impact on annual ewe productivity, while the ewe genotype showed no significant influence on productivity indices, except for the weight of lambs produced per kilogram of metabolic weight (0.84vs0.72 lambs per kg ewe and year; P < 0.01: 2.02vs1.77 kg lamb per kg0.75 ewe and year), where local ewes outperformed Dorper crossbred ewes. The difference in annual-productivity indices between local and Dorper crossbred ewes was more evident when considering the postpartum weight, as the ewes exhibited higher postpartum weights. However, both ewe genotypes produced comparable lamb weights per year (20.91vs20.16 kg lamb weaned per ewe and year for local and Dorper crossbred ewes, respectively). In summary, under low-input conditions, Dorper crossbred ewes demonstrated comparable reproductive performances and productivity traits to local ewes. Nevertheless, breed and environmental factors identified in this study should be taken into account to enhance sheep productivity in both local and Dorper crossbred ewes.

Characteristics of lambs and milk productivity of Tsigay breed ewes and F1 and F2 crosses with Assaf dairy sheep

This article presents data on the growth and development of lambs from birth until weaning, from their mothers of the Tsigay breed, as well as crossbreeds F1 ♀Tsigay X ♂Assaf, F2 ♀ Tsigay 25% X ♂Assaf 75%, and F3 ♀Tsigay 12.5% X ♂Assaf 87.5%. The measurements of udder size, udder volume, milk productivity for twenty days after lambing, fostering and milking periods, and overall lactation were recorded. Additionally, the average daily milk yield, milk composition, fat, and protein content in the milk were analyzed. The average weaning weight of F3 lambs from their mothers was 32.81±0.99 kg, F2 was 29.40±1.78 kg, which is 3.41 kg lower, and F1 was 28.56±1.11 kg, significantly lower (P ≤ 0.01) by 4.25 kg. In the first 20 days after lambing, the milk productivity of F2 ewes was 64.09±7.85 kg, higher compared to F1 ewes by 15.41 kg and by 27.87 kg (P ≤ 0.01) compared to purebred Tsigay ewes. The largest udder volume was found in F2 ewes, measuring 2275.20±257.90 cm3, which is 785 cm3 less than in F1 ewes and 943 cm3 less than in purebred Tsigay ewes. The difference between the two groups is statistically significant (P ≤ 0.05). Over 208 days of lactation, crossbred F2 ewes produced 268.38±33.67 kg of milk, which is 62 kg more than F1 ewes, who produced 206.00±26.86 kg in 207 days, and 126 kg more than purebred Țigay ewes, who produced 141.72±13.83 kg in 198 days. The difference is statistically significant (P ≤ 0.01). Regarding the chemical composition, there were slight differences between purebred Tsigay ewes and F1 ♀Tsigay X ♂Assaf crossbreeds, while the fat and protein percentages were the same (9.03 and 8.91, respectively). In F2 ♀ Tsigaiy25% X ♂Assaf 75%, fat, protein, and fat +protein content was higher.

156 The Impact of Sire Parasite Resistance on Offspring Gastrointestinal Nematode Indicators, and Relative Impact of Lamb Breeding Values on sale Value of Ram Lambs

Abstract Genetic selection of sheep for resistance to gastrointestinal nematodes (GIN) has become a priority for pasture-based production of lambs to minimize the need for deworming. The first objective of this experiment was to determine the impact of sire weaning or post-weaning fecal egg count (FEC) estimated breeding value (EBV; WFEC and PFEC, respectively) from the National Sheep Improvement Program (NSIP) on GIN infection in Katahdin lambs born in fall (Oct – Nov; n = 459) or winter (Jan – Feb; n = 378) of 2018 through 2021 at the USDA Agricultural Research Service (ARS). FAMACHA scores were determined, and blood samples and feces were collected from the lambs to determine packed cell volume (PCV), and FEC at 60, 90, 120, and 150 days of age, and lambs were selectively dewormed if anemic. Data were analyzed using mixed models. The offspring FEC was positively (P &amp;lt; 0.001) and the PCV negatively (P &amp;lt; 0.001) related to the sire WFEC and PFEC. This implies that offspring parasitism would be less and survival greater from highly resistant sires. A second objective was to examine effects on sale prices of breeding-quality ram lambs from four farms, including ARS, of lamb EBV for WFEC and ewe productivity trait (EPT) designed to identify ewes with superior maternal ability. Sale price effects were dominated by sale type with a premium of $1,086/animal relative to direct sales from the farm for animals in NSIP or specialty sales. EPT EBV was impactful yielding a-SD increase of 2.3 units or an extra $39/animal. WFEC had no effect on sale value. Thus, while more parasite-resistant sires produced offspring with decreased FEC, the sale value of these ram lambs appeared to have been more strongly associated with EPT, or with a desire to obtain ram lambs with balanced EBV rather than elite EBV for parasite resistance.

Longitudinal assessment of the impact of aging on wastage, productivity and welfare of ewes

Retention of aging ewes is a strategy producers may use to maintain or increase flock size. Older ewes can have a higher risk of mortality and health issues, but these may be minimised with early intervention and culling. This retrospective study examined the incidence and causes of mortality and culling in a flock of Merino ewes as they aged from 4.5 to 5.5 until 9.5 to 10.5 years. The annual rate of ewe mortality ranged from 6.2% to 9.9%, with lambing complications being the major source of reported loss. Annual culling rates ranged from 1.6% to 42.8%, the larger rates reflecting opportunistic replacement with younger ewes rather than essential culling to maintain welfare and productivity. The major reasons for culling were low condition score, worn or missing teeth or faulty udders. The incidence of other faults was low. Only 18.3% of ewes remained when aged 9.5-10.5 years and these were fertile (89% pregnant) with a high proportion of multiple fetuses (52%) in their final year, although fleece weight had declined. Younger ewes born in 2004/2005 tended to have lower annual mortality rates than the aged ewes, but 8%-12% were still culled annually. It is concluded that an annual inspection pre-joining of all ewes and preventative culling for health issues is necessary to minimise any increase in mortality and risk to ewe welfare from retaining aging ewes. More frequent inspection will be required as potential health issues develop during the year, as these may not be evident pre-joining.

Metabolic profile of transition period in ewes and its influence on passive immunity transference in lambs.

The intensification of ewe production, focusing on increasing prolificity, results in a higher incidence of metabolic disorders, especially in the transition period, which can lead to production losses with consequences for the health of the animals. The objective of this study was to evaluate the metabolic profile in transition period Lacaune ewes according to the parity and litter size born and its influence on the transference of passive immunity. Nineteen Lacaune ewes, with initial mean body weight of 76.36 ± 10.37kg (SD), kept in a semi-extensive system and receiving the same diet, were used. Ewes were classified according to parity (primiparous and multiparous) and the litter size born at parturition (1, 2, and 3). On days - 14, - 7, and - 4 of the expected date of parturition and on days 1, 4, 7, and 14days postpartum, blood sampling, the evaluation of the body condition score (BCS), and the weighing of animals were performed. Blood samples were taken from the lambs 48h after birth. Colostrum was collected up to 6h postpartum to determine the brix percentage. Serum concentrations of total plasma proteins (TPP), albumin, aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), beta-hydroxybutyrate (BHB), non-esterified fatty acids (NEFA), paraoxonase (PON1), calcium (Ca), and magnesium (Mg) were evaluated. In lambs, the blood parameters evaluated were TPP, albumin, GGT, and PON1. Lamb plasma was used to estimate colostrum efficiency, brix percentage immunity, and total plasma protein (PPT). Productive data, pre- and postpartum metabolic variables for ewes, lambs, and those related to colostrum brix were analyzed. The BCS had a reduction (p < 0.0001) in the postpartum period, which is evidenced on days 7 and 14 (2.88 and 2.73, respectively). Serum concentration of BHB presented the highest concentrations in the prepartum period for ewes that gave birth to triplets, from day - 14, and for ewes that gave birth to twins on day - 4 (p = 0.0245). Serum concentration of NEFA demonstrated the highest value on day 14 in primiparous (1.07; p = 0.0402). Calcium had the lowest concentrations on day 1 (8.85mg/dl, p < 0.0001) and magnesium on day 3 (1.79mg/dl, p < 0.0001) postpartum. The multiparous with two lambs had higher brix percentages (30.5%), and the lowest value was observed in primiparous ewes that gave birth to a single lamb (27.06%; p = 0.0395). Triplet lambs had the lowest weight (3.73kg, p = 0.0007), and the best brix percentage in plasma was observed in twins (10.29%, p = 0.0174). Regardless of the parity, the ewes that presented the greatest metabolic challenge were those that gave birth to triplets, and these lambs presented the worst immunity and the lowest live weight. The quality of colostrum was influenced by the parity, and multiparous ewes that gave birth to triplets had the lowest brix percentage in the colostrum.

O-140 Effect of injectable eprinomectin on milk production and quality of dairy ewes reared semi-intensively and naturally infected with gastrointestinal nematodes

O-140 Effect of injectable eprinomectin on milk production and quality of dairy ewes reared semi-intensively and naturally infected with gastrointestinal nematodes

Evaluation of the Crossbreeding Scheme and Farmers’ Perception of Awassi and Dorper Crossbred Sheep

The objectives of this study were to characterize the performance of crossbred sheep and crossbreeding scheme and to solicit farmers’ opinions about crossbred sheep. A total of 238 respondents were selected from five districts and data were collected through a personal interview, focus group discussion, measurement of animals, and field observation. Continuous type of data were analyzed using different procedures of SAS, while the estimated breeding value (EBV) for distributed rams was estimated by the WOMBAT software fitting animal model. The findings showed that sheep were the most significant species and that they were primarily raised for meat consumption and income generation. The proportions of crossbred sheep were 79.6% in Angot, 61.3% in Dessie zuria, 64.2% in Gazo, 80.6% in Legambo, and 27.5% in the Kobo area. The sheep crossbreeding program was constrained by feed shortage, lack of improved genotype, and diseases. The ongoing sheep crossbreeding program lacks a proper recording scheme, rams were not selected based on genetic merit, not exchanged in time, lack periodic importation of genetically unrelated rams, and lacks fixing the maximum exotic gene level suitable for the production system. The EBVs of Dorper crossbred rams for birth weight and weaning weight were 0.007 kg and 0.273 kg, respectively. Tikur sheep had an earlier age at first lambing (AFL) than Awassi x Tikur sheep. Likewise, the indigenous Wollo sheep had earlier AFL, short lambing interval, and produced a large number of lambs per lifetime than their Awassi crossbreds. Dorper crossbreds were preferred (9.30 - 72.2 times greater and P &lt; 0.001 ) for their growth rate, physical appearance, preference in the market or price, and milk production of ewes compared with indigenous Tumele sheep. The Awassi crossbred sheep were preferred (odds ratio = 12.7– 90.0 and P &lt; 0.001 ) due to their good physical appearance, fast growth rate, wool yield, milk yield, and better preference in the market compared with Tikur and Wollo sheep breeds. The implementation of the crossbreeding program needs some sort of revision, monitoring, and periodic evaluation. Besides, it must be accompanied by improved management to exploit the expected benefits from the crossbreeding program in the low-input production system.

Productive traits of sheep of Prikatun breeding type under the conditions of the Altai Republic

The main number of sheep in the Russian Federation is currently concentrated in peasant (farmer) and personal farms, where the level of breeding work is often very low. Despite this, there is a huge reserve of mutton production in these categories of farms. The purpose of the work was to study the productive traits of sheep of Prikatun breeding type of Mountain Altai breed under the conditions of peasant (farmer) farms in the Altai Republic. The experimental part of the research was carried out on the basis of the farm “Usoltseva N. A.” in the Ust-Kansky area in the Altai Republic. The object of the study were the mature ewes sheep of Prikatun breeding type of Mountain Altai breed, their off spring aged from birth, 4 and 6 months, before slaughter, as well as carcasses obtained during slaughter. Under the conditions of the Altai Republic with year-round pasture content in sheep of Prikatun breeding type of Mountain Altai breed a complex study of milk productivity and the chemical composition of sheep’s milk was carried out. New data on the eff ect of age, live weight, prolifi cacy, polymastia, off spring sex and morphometric measurements of the udder on the milk production of sheep have been obtained. The infl uence of the level of milk content of sheep of Prikatun breeding type of Mountain Altai breed on the growth, development and meat productivity of lambs has been studied. It was found that lambs received from mothers with high milk capacity had a higher growth rate in all the studied age periods. The young animals of this group were characterized by better meat productivity and as a result had a higher level of profi tability, which amounted to 53,35 %. Taking into account the infl uence of the level of milk production of ewes of Prikatun breeding type on the growth and development of lambs, we recommend that peasant (farmer) farms of the Altai Republic, in order to increase the production of mutton, select ewes for the fi rst 20 days of lactation with a milk yield of at least 21 kg of milk.

Composição em ácidos graxos no leite de vacas e ovelhas suplementadas com extrato tanífero de acácia negra

ABSTRACT: This study evaluated the effects of Acacia mearnsii tannin extract on milk fatty acid profile of dairy ewes and cows. In experiment 1, twenty-four Lacaune ewes received one of the following dietary treatments: control (no tannin extract added to the diet), T30 (30 g tannin extract/kg concentrate), and T40 (40 g extract/kg concentrate). In experiment 2, thirty Jersey cows received either a control diet (no tannin extract added to the diet) or the same diet containing 40 g tannin extract/kg concentrate (T40). Dry matter intake, milk production and milk solids content of ewes and cows were unaffected by tannin supplementation. The cis-9, trans-11 conjugated linoleic acid (CLA) content increased linearly by 21% in milk fat from ewes fed tannin extract, while the C18:2 n-6 (linoleic acid) content tended (P = 0.051) to increase by 13% in cows fed TE. The supplementation with black wattle tannin extract improves the nutritional quality of milk fat of ewes and cows to a small extent, with no adverse effects on performance or gross milk composition.

Age at weaning of lambs raised in an intensive production system

Context Early weaning is an alternative that may shorten the production time, and improve growth, and carcass quality. Aims The effects of different weaning ages on growth performance and carcass characteristics of Dorper × Santa Inês lambs were evaluated. Methods Initially, 33 crossbred lactating ewes Dorper × Santa Inês with initial bodyweight (BW) of 53.16 ± 9.17 kg (mean ± s.d.) were penned individually with their lambs (nine females and 36 males; 6.59 ± 0.30 kg of initial BW and 10 ± 2.22 days of age) 10 days after birth and used in a randomised complete block design (three treatments and 11 blocks). Each pen was individually equipped with a creep feed system for the lambs. The lambs received the initial diet, and the ewes were confined and received a diet with 400 g/kg of roughage and 600 g/kg of concentrate. Lambs were weaned at ages of either 45 days (W45), 60 days (W60) or 75 days (W75). At weaning, the ewes were removed from the pens and the lambs remained in the same pen for 15 days, receiving the initial diet. After 15 days of weaning, only the males continued received the finishing diet until 165 days of life. After the finishing period, the lambs were slaughtered to measure the carcass characteristics. Key results There was no influence of weaning age on BW, body condition score, dry-matter intake, and milk production and composition of ewes. Additionally, there was no effect of treatments on the lambs‘ performance. Conclusion In an intensive production system, weaning at 45, 60, and 75 days provided similar growth performance and carcass characteristics. Implications Therefore, weaning at 45 days may be an option for farmers.