Dry Ewes Research Articles

Effects of sheep breed and grass silage quality on voluntary feed intake and enteric methane emissions in adult dry ewes

Forty adult dry ewes in early pregnancy participated in a 2 × 2 factorial design study to investigate the effects of two grass silage qualities (Early vs. Average; 7.12 vs 5.74 MJ of net energy lactation per kg dry matter (DM)) and two breeds (Norwegian White Sheep, NWS; Old Norwegian Spæl, ONS) on voluntary feed intake and enteric methane (CH4) emissions. Ewes of the two breeds were equally mixed in two groups and assigned to Early and Average silage quality for first part of the experiment and switched for the second part of the experiment. Each period of the experiment lasted for three weeks; one week of adaptation and two weeks of measurements. The ewes were housed in individual pens and fed silage ad libitum. Feed intake was continuously logged using the BioControl System. Enteric CH4 was measured for 10 weekdays in Portable Accumulation Chambers in each period. Average body weight (BW) for NWS and ONS were 91 and 60 kg, respectively. ONS had significantly (p < 0.0001) lower daily DM intake (DMI), DMI/kg BW, daily NDF intake, NDF/kg BW, g CH4/day and g CH4/kg BW, compared to the NWS. The Early grass silage (p < 0.0001) resulted in higher daily DMI (kg DMI/day, kg DMI/kg BW), and higher enteric CH4 emissions/kg BW when offered to the ewes, compared to the Average grass silage. Significant interactions (p < 0.05) between breed and grass silage quality were observed for both measures of feed intake and CH4 emission. The results show that breed differences in CH4 emission is strongly linked to DMI, however breed differences were still present after correcting for DMI, which indicated breed differences not explained by BW or DMI. Persistent breed differences after correcting for DMI may be related to contrasts in rumen passage rate, NDF digestibility, rumen microbiome, fermentation rate etc. We conclude that improved grass silage quality may be a potential mitigation option. However, to avoid weight gain in early pregnancy in an ad libitum feeding regime, the practical applicability may be limited to periods with higher feed requirements, such as in late pregnancy and early lactation. The breed differences in enteric CH4 emission need to be related to productivity (e.g., fecundity, lamb growth rate). Potential breed differences not explained by body size and/or DMI need to be further investigated.

The Effect of By-Pass Linseed Oil Supplementation on the Maternal Antioxidant System during the Embryo-Maternal Recognition Period in Ewes.

This study analyzed the effects of dietary supplementation with by-pass linseed oil (LO; rich in α-linolenic acid) on maternal antioxidant systems at Days 14 and 16 of pregnancy in Sarda ewes. This trial used sixteen dry ewes. Eight ewes (CT group) were fed with a control diet without LO, and eight ewes (LO group) were fed with a diet supplemented with LO (10.8 g of α-linolenic acid/ewe/day). Both diets had similar crude protein and energy levels. The experiment included 10 days of an adaptation period and 31 days of a supplementation period. This supplementation period was divided into Period -2 (from Day -15 to -8), Period -1 (from Day -7 to -1; before synchronized mating period/Day 0), Period +1 (from Day +1 to + 7 after mating), and Period +2 (from Day +8 to +15 after mating). Estrous synchronization was induced in all the ewes using an intravaginal sponge (45 mg fluorgestone acetate) for 14 days and equine chorionic gonadotropin (350 UI/ewe) at the end of the treatment. On Days 14 (CT, N = 4; LO, N = 4) and 16 (CT, N = 4; LO, N = 4) after mating, the ewes were slaughtered. Samples of plasma, uterine, and luteal tissues were collected. Thiols, total antioxidant activity (TEAC), superoxide dismutase (SOD) activity, and malondialdehyde (MDA) content were measured. On Day 16, thiol and TEAC in luteal tissues were higher in the LO group when compared with the control one (p < 0.05). Moreover, TEAC was higher for the LO group in uterine tissues on Days 14 and 16 (p < 0.05). SOD activity was higher in the LO group in luteal and uterine tissues on Day 14 and Day 16, respectively (p < 0.001). On Day 16, uterine MDA content was lower for the LO group (p < 0.001). No differences were found between groups at the plasmatic level. However, the by-pass LO supplementation enhanced the analyzed antioxidant parameters in luteal and uterine tissues. In conclusion, these results demonstrate that by-pass LO supplementation exerted a positive effect on antioxidative defenses on maternal structures during the embryo-maternal recognition period in ewes. Thus, this could contribute to improving the maternal environment during the embryo-maternal recognition period in mammals.

A new insight about the selection and intake of forage by ewes and lambs in different production systems on pasture

Keeping lambs with their dams and providing concentrate supplement for weaned lambs are two strategies used in lamb meat production systems on pasture that may affect the way that lambs explore, select, and ingest the forage while grazing. Thus, this study aimed to evaluate the selection and intake of forage by ewes and lambs using the continuous bite monitoring method in two pasture-based production systems: non-weaned and non-supplemented lambs (NW); and weaned lambs supplemented with concentrate (WS). Continuous bite monitoring is based on a bite-coding grid that allows the estimation of bite mass, intake rate, selection of plant species and plant parts by grazing animals. Two experiments were carried out during September–November of two subsequent years on a mixed pasture of black oat (Avena strigosa Schreb.) and annual ryegrass (Lolium multiflorum Lam.) established over a perennial Tifton 85 (Cynodon spp.) pasture. On the second year, a third treatment including only the dams of weaned lambs – dry ewes – was also evaluated. In the WS system, lambs were supplemented with concentrate feed at 2% of body weight (BW)/day on a dry matter (DM) basis. Both experiments lasted 46 days, and a continuous stocking management with the forage allowance maintained at 16% BW in DM/day for all treatments. There was a high degree of variability on botanical and morphological composition of forage that was ingested by lambs and ewes, with ranges of 3–14 and 8–11 bite categories for NW lambs and ewes, respectively; 12–15 bite categories for WS lambs, and 8 bite categories for dry ewes. There was similarity between the forage ingested by lambs and ewes in the NW system, except for inflorescences of black oat and annual ryegrass, that were ingested in greater proportions by ewes. WS lambs ingested the most diverse forage diet, which appeared to explore the superior strata of pasture (above 10–15 cm of height) more frequently, and grazed inflorescences and senescent material in higher proportions than NW lambs. Dry ewes showed higher intake of Paspalum spp., Kikuyu grass and other voluntary species and weeds compared to NW ewes. These results suggest that the production system affects the way that lambs explore the pasture and compose their forage diet, with WS lambs ingesting the most diverse diet. The increased intake of inflorescence and, eventually, voluntary species and weeds may be a strategy used by lactating and dry ewes to extend the vegetative stage of high-quality forage species and reduce the population of low-quality plant species on pasture.

Efficiency of Artificial Insemination at Natural Estrus in Organic Churra Ewes.

Simple SummaryHormonal treatments used to synchronize estrus in sheep artificial insemination procedures can cause several physiological problems that can affect negatively fertility and animal health; however, alternative protocols based on the detection of natural estrus offer a more sustainable option while reaching successful fertility results. Therefore, in this study, an artificial insemination protocol at natural estrus in organic Churra sheep was performed. In the protocol design phase, 125 ewes were exocervically inseminated, and their fertility was assessed based on the number of inseminations, physiological state, body condition, estrus detection–insemination interval and vaginal fluids in cervix. That protocol was repeated in six consecutive years. In all ewes, fertilities based on the timing of insemination after estrus detection were very high. Lactating ewes produced better results than did dry ewes, which was probably because of the better feeding of the former. In addition, double insemination increased the fertility of ewes, whose estrus was detected within 16 h of onset. Body condition and amount of vaginal fluid were correlated with fertility. In conclusion, exocervical inseminations at natural estrus can produce acceptable fertility and prolificity in Churra ewes, avoiding physiological problems derived from the use of hormonal treatments.Hormonal treatments used in the artificial insemination (AI) of sheep can cause several physiological problems that can affect negatively fertility and animal health; however, AI protocols based on the detection of natural estrus offer a more sustainable option and can achieve high fertility. In this study, an AI protocol at natural estrus in organic Churra sheep was performed. In the first phase (AI protocol development), 125 ewes were exocervically inseminated, and their fertility was assessed based on the following factors: number of AI, physiological state, body condition, estrus detection–AI interval, and vaginal fluids in cervix. That protocol was repeated for six consecutive years. In all individuals, fertilities based on the timing of insemination after estrus detection were very high. Lactating ewes produced better results than did dry ewes, which was probably because of the better feeding of the former. In addition, double insemination increased the fertility of ewes whose estrus was detected within 16 h of onset. Body condition and amount of vaginal fluid were correlated with fertility. Exocervical inseminations at natural estrus can produce acceptable fertility and prolificity in Churra ewes.

Determination of maintenance energy requirement and responses of dry ewes to dietary inclusion of lucerne versus concentrate meal

An accurate value for metabolizable energy (ME) requirement for maintenance (MEm) is essential to enable sheep husbandry practice to reach its potential. The objectives of the study were to use calorimetry chamber data of dry ewes (Hu × thin-tail Han F1 crossbred) to develop updated MEm, examine effects of substituting concentrate feed with lucerne hay on energy partitioning, and explore the relationships between energy utilization and fasting heat production (FHP). Data were collected from three experiments. In Exps. 1, 2a and 2b, lucerne hay was used to replace concentrates in three levels (0:40%, 15:25% and 30:10%), with diets containing 60% maize stover (Exp. 1), fresh rye forage (Exp. 2a) or dry rye forage (Exp. 2b). Within each experiment, diets were isoenergetic (digestible energy, DE) and isonitrogenous. Exp. 3 aimed at evaluating effects of three BW levels on nutrient utilization of dry ewes offered diets containing 60% maize stover, 15% lucerne hay and 25% concentrates. Energy metabolism data were measured using the respiration calorimeter chamber technique in all three experiments, followed by the measurement of FHP in Exps. 1, 2b and 3. The MEm derived from the linear regression between energy balance (EB) and ME intake was 0.440 MJ/kg BW0.75. The average FHP was 0.326 MJ/kg BW0.75. The fasting metabolism, net energy requirement for maintenance (NEm) and MEm were estimated to be 0.336, 0.359 and 0.511 MJ/kg BW0.75, respectively, through adjustment of FHP using fasting urinary energy output, activity allowance and efficiency of ME use for maintenance. The FHP was negatively correlated to EB/metabolic BW, ME/gross energy (GE), ME/DE, EB/GE intake and EB/ME intake, while positively correlated to HP/GE intake, HP/ME intake and CH4-E/GE intake. Compared to zero lucerne hay diet, the 15% lucerne hay intake decreased HP (MJ/d), and had no negative effects on EB (MJ/d) or energy utilization efficiencies. The results indicate that nutrient requirement standards currently used across the world are likely to underestimate MEm for dry ewes, and the selection of low FHP ewes for breeding has the potential to improve sheep production efficiency.

Effects of feeding level on enteric methane emissions and utilisation of energy and nitrogen in dry ewes of two genotypes offered fresh ryegrass

The objective of the present study was to evaluate the effect of feeding levels on enteric methane (CH4) emissions and nitrogen (N) and energy utilisation efficiencies of ewe sheep offered fresh ryegrass. Twenty-four dry ewes (16 mo old and 47.6 ± 5.1 kg body weight) were used in a factorial design study, with 2 genotypes (12 ewes/genotype, Belclare vs. Lleyn) × 3 feeding levels (maintenance level vs. ad libitum vs. intermediate level (targeted level = 1.5 maintenance)). All sheep were offered fresh grass harvested daily in the morning from the second regrowth sward. All animals were housed in individual pens for 19 d and then in individual respiration chambers for further 5 d with feed intake, faeces and urine outputs and CH4 emissions measured during the final 4 d. There was no significant interaction between genotype and feeding level on any variable evaluated, except for CH4 emissions with which the interaction was significant (P < 0.01). Sheep offered diets at the maintenance level had significantly higher digestibilities of dry matter (DM), organic matter (OM), neutral detergent fibre, acid detergent fibre and energy than those given at intermediate level or ad libitum (P < 0.001). However, increasing feeding level significantly decreased CH4 emissions as a proportion of nutrient intake (DM, OM, digestible DM and digestible OM) or energy intake (gross energy (GE), digestible (DE) and metabolisable energy (ME)), and N loss in urine and manure as a proportion of N intake (P < 0.01). Belclare ewes had greater ME/GE and ME/DE and lower CH4 energy/ME intake, urine N/N intake and manure N/N intake than Lleyn ewes (P < 0.05). The present data were also used to develop a range of prediction equations for CH4 (R2 = 0.274 to 0.800, P < 0.001) and manure N (R2 = 0.410 to 0.915, P < 0.001) emissions using feed intake. The present result indicates that optimizing grazed grass intake is an effective mitigation strategy to reduce the environmental footprint of grazing sheep production in term of per unit of feed intake.

10.4314/sajas.v40i5.65265

This study was conducted to evaluate the effect of breed types and lactation status on reproductive performance of hormonally-treated Awassi ewes. A total of 282 ewes were treated with intravaginal progestagen sponges and equine chorionic gonadotropin. Ewes were mated with fertile rams following sponge removal. Lambing rate was similar between brown- and black-faced ewes, while the percentage of multiple births, fecundity and prolificacy were greater in black-faced ewes. Lambing rate and the percentage of multiple births were similar between lactating and dry ewes. Fecundity tended to be greater in lactating ewes, while prolificacy was similar regardless of lactation status. Results of the present study indicate that black-faced Awassi ewes respond better to hormonal treatment than brown-faced ewes while the lactation status does not appear to influence the ewes’ response to hormonal treatment.

Assessment of the Welfare of Extensively Managed Autochtonous Sheep Breed Vlasicka Zackel using Animal-Based Measurements

AbstractIn the Balkan region, the state of sheep welfare is little known. In this context, the assessment of sheep welfare is important for the identification of health and behavioral problems that affect these animals, along with the deficiencies present in the environment. The study was conducted during the winter season on a farm of 220 autochthonous breed Vlašićka Zackel sheep reared in extensive systems on the mountain regions of Bosnia and Herzegovina. A total of 65 ewes, aged 2–4 years, were observed. The welfare assessment was performed according to the AWIN protocol for sheep. The authors found the following issues: dry ewes were significantly fat (p&lt;0.001) in regard to pregnant and lactation ewes; 42.11% of pregnant ewes were thin while 31.25% of dry ewes were fat; most of the assessed animals (78.46%) had dry or damp, slightly soiled fleece; 32.31% of animals had lesions on face/muzzle while ocular discharge, respiratory problems, mild mastitis and minor lameness were present in 16.92%, 4.62%, 15.38% and 7.69% sheep, respectively. All animals showed a negative relationship with humans. Using this methodology, the welfare problems in animals may be detected, and thus certain segments in the production cycle may be improved. The on-farm welfare assessment is highly recommended for emphasizing the key points in improving sheep welfare in Balkan countries.

Fermentative Quality and Animal Acceptability of Ensiled Persimmon Skin with Absorbents for Practical Use in Ruminant Feed.

Simple SummaryAlthough persimmon skin (PS) has a high nutrition content, it loses much of its nutrient value through effluent, which hampers its use as a feed. To reduce effluent production during ensiling, we tested three kinds of moisture absorbents (kraft pulp, wheat bran, and beet pulp). We evaluated five types of table scale silages: persimmon skin only, persimmon skin plus Lactobacillus buchneri inoculum, and persimmon skin plus L. buchneri plus each absorbent in turn. We observed low effluent and gas loss in absorbent-treated groups, implying a positive contribution of these absorbents to fermentation quality. Further, we performed an in vitro culture test of PS silage supplemented with an absorbent mixture. The proportion of methane to total gas decreased in the ensiled group compared with that in the other groups. Finally, we conducted a preliminary feeding experiment on dry ewes to assess the palatability of PS with a partial substitution of up to 20% dry matter, and found no adverse effect on feed intake and acceptability. Our results highlight the potential use of PS as a part of ruminant feed.Persimmon skin (PS), while representing an attractive feed source, requires an appropriate preservation procedure to increase its shelf life. We assessed the fermentation quality, in vitro ruminal incubation, and intake of persimmon skin silage ensiled with different dry absorbents. We prepared the silage on a table scale (Experiment 1) and evaluated five different mixtures: PS without an additive, PS plus Lactobacillus buchneri inoculum (LB), and PS plus LB plus each of the absorbents kraft pulp, wheat bran, or beet pulp. We opened the laboratory bags, kept at 25 °C, at 0, 14, 28, and 60 days for fermentation quality and chemical analysis (n = 3 for each measurement). Further, with an in vitro rumen simulated cultivation study (Experiment 2), we evaluated the fermentation pattern of PS with a mixture of two absorbents (kraft pulp and wheat bran) either raw (no fermentation) or ensiled (n = 4 for each treatment). Finally, we conducted an in vivo experiment using six dry ewes assigned based on their body weight to two experimental groups in a crossover design of two periods (Experiment 3). We fed a control group a 100% basal diet (tall fescue hay and concentrate mixture) and ensiled PS (PSS) group, a 20% dry matter substitution of tall fescue with PS silage mixed with kraft pulp as the sole absorbent. The results of Experiment 1 show, regardless of the absorbents used, the effluent volume of the lab bags was lower in absorbent-treated groups (p < 0.001). In Experiment 2, the condition of the PS with absorbents (raw or ensiled) did not affect the total gas production (p > 0.05), but we observed an increased propionate proportion in PSS with absorbents compared to basal diet (p = 0.019). The proportion of methane to the total gas in PSS group was considerably reduced compared with that in the other groups (p < 0.001). As we did this incubation study with a single run, a more detailed evaluation in the future would verify these observations. In the animal trial (Experiment 3), dry matter intake was similar between groups (p > 0.05), but ewes spent a shorter time eating in the PSS-fed group (p = 0.011). Here we present the practical use of PSS as part of ruminant feed in which dry absorbents prevented dry matter loss.

160 A comparison of body temperature among pregnant, non-pregnant and lactating hair sheep ewes in the tropics

Abstract St. Croix White hair sheep are well adapted to the tropics. The objective of this study was to evaluate the impact of pregnancy on body temperature of hair sheep. Multiparous St. Croix White ewes (n = 9) were evaluated over 4 d at 128 d of gestation (PREG) and 45 d postpartum (PP) while lactating. A set of non-pregnant, non-lactating (DRY) ewes (n = 9) were also evaluated at each time. Temperature data loggers recorded vaginal temperature (VT) at 10-min intervals for 96 h. Ewes were kept in a 0.6 ha pasture. Data were analyzed using GLM procedures of SAS for repeated measures with pregnancy status and time of day in the model. Mean temperature and solar radiation were 26.3 °C and 212.3 W/m2, respectively. Ewe VT was lowest (P &amp;lt; 0.0001) between 0 and 0700 h and greatest between 1400 and 1900 h (38.21 ± 0. 02 vs 39.11 ± 0.02 °C, respectively). Ewe VT was lowest (P &amp;lt; 0.004) in PREG ewes compared to DRY or PP ewes (38.38 ± 0.02 vs 38.76 ± 0.02 vs 38.77 ± 0.02, °C, respectively). The VT of PREG ewes was lower than that of DRY ewes (P &amp;lt; 0.0001) during 0 to 0480 and 1920 to 2400 h, but there was no difference (P &amp;gt; 0.10) between 0480 and 1920 h. There was no difference in VT between PP and DRY ewes at any time of the day (P &amp;gt; 0.10). The VT of PREG ewes was lower than that of PP ewes (P &amp;lt; 0.0001) during 0 to 0480 and 1920 to 2400 h, but there was no difference (P &amp;gt; 0.10) between 0480 and 1920 h. The lower VT of PREG ewes compared to PP and DRY ewes may be a protective mechanism for the developing fetus.

Apelin system detection in the reproductive apparatus of ewes grazing on semi-natural pasture

Apelin (APLN) is an adipokine with pleiotropic effects involved in the regulation of metabolic, cardiovascular, immune, and electrolyte balance function. Recent studies demonstrated a pivotal role in the regulation of male and female reproduction. APLN and its receptor (APLNR) were found in the hypothalamic-pituitary-gonad axis tissues, regulating gonadotropin release and steroidogenesis. However, to date, there are no studies that describe APLN system in the reproductive apparatus of the sheep.The study was performed on 10 Comisana x Appenninica adult dry ewes reared in a semi-natural pasture. Organ samples were collected from five animals in the two pasture functional phases: after maximum pasture flowering (Group 1) and after maximum pasture dryness (Group 2). Experiments were devised to characterize the gene expression and protein localization of the APLN/APLNR system in ewe reproductive apparatus; in addition, the concentration of plasma APLN was evaluated during the trial.Through immunohistochemical analysis, a positive staining for APLN was observed in the large luteal cells, in the epithelial cell coat of the ampulla, in the uterus epithelial lining and in the uterine glands. APLNR was observed in the granulosa cells, in the large luteal cells, in the secreting cells of the ampulla, in the uterus epithelial lining and uterine glands. The transcripts for APLN and APLNR were evidenced in all organ tissues examined. The highest level of APLN mRNA was detected in the Group 2 ewes in the luteal phase of the ovarian cycle compared to Group 1 ewes in the anestrous one. The relative content of APLN transcript was respectively twofold higher in the ovary (P < 0.05) and uterus (P < 0.05) and threefold higher in the ampulla (P < 0.05) in the Group 2 vs Group 1. The same trend of APLN transcript was evaluated for APLNR mRNA in uterus (P < 0.05) and ovary (P < 0.05). No difference was evidenced between Group 1 and Group 2 for APLNR mRNA levels. The plasma APLN level was fairly constant during the trial period.In conclusion, the present data suggest that the apelinergic system is involved in the reproduction function of ewes, being differentially distributed and expressed in the organs of the reproductive apparatus of ewes; these variations could be related to the sexual cycle and to the cyclic activity of the reproductive apparatus.

Assessment of different supplemental feeding strategies including cactus (Opuntia ficus-indica) to enhance sheep productivity in Chakwal, Pakistan

In arid and semiarid areas, livestock production is faced with a challenge of uncertain feed supply which limits the quantity of forage available to animals either from natural grazing or crop residues. The current study compared the effect of three different supplemental feeds including oat (Avena sativa L.), lucerne (Medicago sativa L.) and spineless cactus [Opuntia ficu-sindica (L.) Mill.] in addition to a control treatment (farmer practice without supplementation) on sheep productivity, over a 60-day period in Chakwal, Pakistan. The common ingredients of the three diets were maize grain, barley grains, wheat bran, canola meal, groundnut hay and wheat straw. Eighteen ewes of similar age and weight were allocated to each treatment, with measurements of live-weight gain recorded at 15-day intervals. Lactating ewes fed oat (0.076 kg day‑1) and lucerne (0.064 kg day‑1) supplements showed similar average daily gain (ADG) compared with cactus- and control-supplemented ewes, with the same trend observed for dry ewes. The ADG for lambs fed cactus and lucerne was greater (at 0.083 kg day‑1 for both), compared with those fed oats and the control treatment. Weight changes of lactating ewes fed with different supplement feeds were not significantly different over the course of the experiment. Dry ewes supplemented with cactus had greater weight gains (54 kg at 15 days of supplementing and 57 kg at 60 days of supplementing) compared with oat-supplemented dry ewes (46 and 50 kg) from the first weighing interval until the end of the experiment. Based on these results, it can be concluded that supplementing sheep with cactus has a positive impact on live-weight gain, compared with solely grazing under poor rangeland conditions. Therefore, it is important to develop rations that maximize the full potential of this low-nitrogen, yet water- and carbohydrate-rich alternative feed source.

Characteristics of romanov breed locus bmp-15, responsible for prolificacy of the sheep

The article deals with the actual problem, the diagnostics of the prolificacy gene in sheep of the Romanov breed. The new method for the diagnostics of the polymorphic gene of the bone morphogenetic protein 15 (BMP-15), which causes the multiple pregnancy in the Romanov sheep, has been proposed based on the carried out surveys. The frequencies of occurrence of the normal (wild type) and mutant alleles responsible for the multiple pregnancy-related locus and the genotypes in the sheep are present. The economic indicators including the numbers of newborn lambs, the lambs at winning, and the dry and culled ewes were recorded with taking into consideration the genotypes of the BMP-15 locus. The relationships between the frequency of occurrence and the number of the produced posterity and between the dry and culled Romanov ewes were ascertained. It was proved that the highest percentage of the lamb output at birth to weaning was typical for the ewes homozygous (MM) for a mutant allele. The animals referred to as heterozygous genotypes (WM) appeared to be in the second position. With respect to the wild genotype, the highest percentage of the culled and dry ewes was recorded in the carriers of the WW homozygote. The obtained results allow us to conclude that the genotype frequency at the BMP-15 locus should be taken into account while estimating the fertility of the ewes. Therefore, the further researches into the determined phenomena in the Romanov sheep are required to improve this item, since the multi-fetal pregnancy is recorded in some ewes of group WW.

Alleviation of reproductive seasonality in Barki ewes using CIDR-eCG with or without melatonin

This study was conducted to evaluate the efficiency of CIDR-eCG protocol with or without melatonin (MEL) on reproductive performance in Barki ewes during non-breeding season. A total of sixty multiparous Barki ewes were divided into two groups, thirty lactating and thirty dry ewes. In each group, animals were allocated randomly into two sub- groups (15 ewes each). In the first sub-group, ewes received a single 18 mg melatonin implant for 42 days followed by controlled internal drug release (CIDR) device for 14 days in conjunction with intramuscular 500 IU equine chorionic gonadotrophin (eCG) at day of CIDR removal. The second sub-group received CIDR combined with eCG in parallel with the first sub group. Melatonin implantation increased (P < 0.05) number of corpora lutea (CLs) and serum glucose concentration, but non-implanted ewes recorded greater (P < 0.05) concentration of estradiol. Regardless of treatment, dry ewes showed lower (P < 0.05) concentration of serum total protein and higher (P < 0.05) concentrations of triiodothyronine (T3) and serum glucose compared to lactating ewes. All ewes exhibited estrus after CIDR removal with greater estrus duration in dry ewes. Prolificacy of melatonin implanted dry ewes was greater (P < 0.05) compared to lactating implanted ewes. In conclusion, Using CIDR-eCG protocol and CIDR-eCG preceded with melatonin successfully induced estrous behavior in anestrus Barki ewes. Melatonin implantation in conjunction with CIDR-eCG protocol enhanced prolificacy in dry ewes during non-breeding season.

Apelin System in Mammary Gland of Sheep Reared in Semi-Natural Pastures of the Central Apennines.

Simple SummaryGrazing activity is fundamental to natural grassland biodiversity preservation. Increasing summer aridity decreases the grassland pastoral value, negatively affecting animal morpho-functional features and production with detrimental effects on the extensive sheep farming sustainability. Since adipokines represent a link between a subject’s energy availability and tissue metabolism, we investigated the presence and distribution of the system composed of the adipokine apelin and its receptor in the mammary gland of sheep during the period between maximum flowering and maximum dryness of the pasture, providing a group of sheep with food supplementation. This work represents a part of a wider study aimed to buffer the negative effects of increasing summer drought stress on farm income and to maintain the grassland biodiversity. Our findings improve the knowledge of apelin/receptor system function on the sheep mammary gland and this could be a useful tool in the farm management practices.Sheep are the most bred species in the Central Italy Apennine using the natural pastures as a trophic resource and grazing activity is fundamental to maintain the grassland biodiversity: this goal can be reached only ensuring an economical sustainability to the farmers. This study aimed to investigate the apelin/apelin receptor system in ovine mammary gland and to evaluate the differences induced by food supplementation, in order to shed light on this system function. A flock of 15 Comisana x Appenninica adult dry ewes were free to graze from June until pasture maximum flowering (MxF). From this period to pasture maximum dryness (MxD), in addition to grazing, the experimental group (Exp) was supplemented with 600 g/day/head of cereals. Apelin and apelin receptor were assessed by Real-Time PCR and immunohistochemistry on the mammary glands of subjects pertaining to MxF, MxD and Exp groups. They were detected in alveolar and ductal epithelial cells. The pasture maximum flowering group showed significant differences in apelin expression compared with experimental and MxD groups. Apelin receptor expression significantly differed among the three groups. The reduced apelin receptor expression and immunoreactivity levels during parenchyma involution enables us to hypothesize that apelin receptor plays a modulating role in the system control.

Variation in methane production over time and physiological state in sheep

Livestock produce 10% of the total CO2-equivalent greenhouse gases in Australia, predominantly as methane from rumen fermentation. Genetic selection has the potential to reduce emissions and be adopted in Australian grazing systems. Developing a breeding objective for reduced methane emissions requires information about heritability, genetic relationships, when best to measure the trait and knowledge of the annual production of methane. Among- and within-animal variation in methane production, methane yield and associated traits were investigated, so as to determine the optimal time of measurement and the relationship between that measurement and the total production of methane. The present study measured 96 ewes for methane production, liveweight, feed intake, rumen volume and components, and volatile fatty acid (VFA) production and composition. Measurements were recorded at three ages and different physiological states, including growing (12 months), dry and pregnant (21 months) and dry (non-pregnant, non-lactating; 28 months of age). The single biggest determinant of methane production was feed intake, but there were additional effects of age, proportion of propionate to (acetate+butyrate) in rumen VFA, total VFA concentration and CO2 flux. Rumen volume and pregnancy status also significantly affected methane production. Methane production, CO2 flux, liveweight, feed intake and rumen volume had high repeatability (&amp;gt;65%), but repeatability of methane yield and VFA traits were low (&amp;lt;20%). There were no interactions between sire and age (or pregnancy status) for methane traits. This suggests that methane could be measured at any time in the production cycle. However, because MY is reduced during pregnancy, it might be best to measure methane traits in dry ewes (neither pregnant nor lactating).

Ewe culling and retention strategies to increase reproductive rates in Merino sheep

The present empirical study of data from three Merino resource flocks of varying genetic backgrounds run in different environments investigated the impact of various selection strategies aimed at culling poor performers (‘passengers’) or retaining good doers (‘performers’) longer, or both, on the flock reproductive performance. Four strategies were investigated and applied either individually or in combination, to quantify their impact on the litter size, rearing type and breeding efficiency (number of lambs weaned per ewe per year) of the whole flock. The main benefit from implementing any of the strategies was a decrease in the proportion of dry ewes in each flock (1–7%). There was little difference between the single strategies of culling twice-dry ewes or culling ewes that twice lambed and lost their lambs. When retaining a cohort of older ewes, it was more efficient to select these on the basis of their lifetime reproductive performance. There was only a marginal benefit gained by combining strategies and, in some cases, a single strategy was still better in terms of breeding efficiency. Commercial producers can improve the reproductive rate of these flocks by culling twice-dry ewes on the basis of their pregnancy scan data.

Effect of Geographic Location and Age on Levels of Some Biochemical Parameters of Ewes in Southern of Iraq

A total of one hundred and ten healthy dry ewes of Arabi sheep diffusive in three geographic locations in the north of Basrah (AL-Qurna, Al-Midaina and Al-Uazair) were divided into three different age groups: 3 years old, to investigate the influence of geographic location and age on the concentration of some biochemical parameters of sheep in the south of Iraq. The results showed significant (P < 0.05) changes among geographic locations in some bio-chemical parameters such as cholesterol, glucose, estridol and growth hormone concentrations. No significant differences were presented in concentrations of total protein, albumin, Fe, phosphorus, ascorbic acid, LH, T3 and T4 hormones in the blood of ewes in different geographic locations. The concentrations of cholesterol, T3 and T4 hormones decreased significantly (P < 0.05), while, the concentrations of glucose and estradiol hormone increased significantly (P < 0.01) in adult ewes compared with younger ewes.

Haematology values and effect of age and reproductive stage on haematological parameters of Chios sheep

The main aim of the present study was to determine the values of the haematological parameters of dairy sheep reared under intensive and semi-intensive conditions, as well as to test for the effects of age and reproductive stage of the animals on the values of these parameters. In total, 200 clinically healthy Chios sheep from 10 farms of Central Macedonia were used in the study. For the determination of the effect of age 150 sheep were assigned in three groups. Group A consisted of 50 lambs aged 3-6 months (meantSD: 4.45±1.22 months), group Β of 50 non-pregnant ewes into lactation aged 1-3 years (meantSD: 2.18±0.74 years) and group C of 50 non-pregnant ewes into lactation aged more than 3 years (meantSD: 5.88±1.87 years). For evaluating the effect of reproductive status 50 pregnant ewes in dry period were used, 15-30 days before the expected day of lambing (group D), along with the 100 non-pregnant ewes into lactation of groups Β and C (group E). Blood sampling was performed once, in dry ewes from December to January, and in lambs and lactating ewes from March to May. The mean values of the determined haematological parameters were within the range provided by the literature, except for red blood cells count of ewes. The results also showed that haematocrit, haemoglobin concentration and red blood cells, white blood cells, neutrophils, lymphocytes, eosinophils and platelets count were significantly affected by the age; only monocytes and eosinophils count by the reproductive stage of the animals.

Comparison of a non-contact infrared thermometer with a rectal digital thermometer for use in ewes

The aim of this study was to assess the accuracy of measuring body temperature in sheep using a noncontact infrared thermometer on the inguinal area and the eye cornea in comparison with a rectal digital thermometer. The trial for the first comparison was conducted in the milking parlor in 52 ewes in full lactation and 15 dry ewes and for the second one in 51 ewes. The body temperature measured with the noncontact infrared thermometer in the inguinal area, although significantly lower, was strongly linearly correlated with that of the rectal digital one in both ewes in full lactation and dry ewes. In lactating ewes, besides the high precision, the highest accuracy was also recorded and the plotted differences were within clinically insignificant levels. The corneal temperatures were highly correlated but were significantly lower compared to the rectal ones. Due to these differences the cut-off point of 37.9°C was estimated to be adopted for the detection of the hyperthermic animals when noncontact infrared thermometers are applied to the eye cornea for the measurement of body temperature. In conclusion the inguinal area of the dry ewes and the eye cornea cannot be recommended as appropriate sites for body temperature measurement because the temperatures recorded are biased by external factors. The noncontact infrared thermometer evaluated is sufficiently accurate for the measurement of body temperature in sheep only when applied in the inguinal area of sheep in full lactation.