Investigating the expression of fertility-regulating LncRNAs in multiparous and uniparous Shal ewe's ovaries.

Sheep is the primary source of animal protein in Iran. Birth type is one of the significant features that determine total meat output. Little is known about how long non-coding RNAs (LncRNAs) affect litter size. The purpose of this research is to investigate the DE-LncRNAs in ovarian tissue between multiparous and uniparous Shal ewes. Through bioinformatics analyses, LncRNAs with variable expression levels between ewes were discovered. Target genes were annotated using the DAVID database, and STRING and Cytoscape software were used to evaluate their interactions. The expression levels of 148 LncRNAs were different in the multiparous and uniparous ewe groups (false discovery rate (FDR) < 0.05). Eight biological process terms, nine cellular component terms, 10 molecular function terms, and 38 KEGG pathways were significant (FDR < 0.05) in the GO analysis. One of the most significant processes impacting fertility is mitogen-activated protein kinase (MAPK) signaling pathway, followed by oocyte meiosis, gonadotropin-releasing hormone signaling pathway, progesterone-mediated oocyte maturation, oxytocin signaling pathway, and cAMP signaling pathway. ENSOARG00000025710, ENSOARG00000025667, ENSOARG00000026034, and ENSOARG00000026632 are LncRNAs that may affect litter size and fertility. The most crucial hub genes include MAPK1, BRD2, GAK, RAP1B, FGF2, RAP1B, and RAP1B. We hope that this study will encourage researchers to further investigate the effect of LncRNAs on fertility.

Investigation of phenotypic, genetic and genomic background of Milk spectra in Sarda dairy sheep.

Aim of this study was to analyse the genetic background of milk Fourier transform infrared (FTIR) spectra in dairy sheep. Individual milk FTIR spectra, with 1060 wavenumbers each, were available for 793 adult Sarda breed ewes genotyped at 45,813 SNP. The absorbance values of each wavenumber was analysed using a linear mixed model that included dim class, parity and lambing month as fixed effects and flock-test date and animal as random effects. The model was applied to estimate variance components and heritability and to perform a genome-wide association study for each wavenumber. Average h2 of wavenumbers absorbance was 0.13 ± 0.08, with the largest values observed in the regions associated with the characteristic bonds of carbonylic and methylenic groups of milk fat (h2 = 0.57 at 1724-1728 cm-1; and h2 = 0.34 at 2811-2834 cm-1, respectively). The absorbance values of wavenumbers were moderately correlated with the estimated heritabilities. After the Bonferroni correction, a total of nine markers were found to be significantly associated with 32 different wavenumbers. Of particular interest was the SNP s63269.1, mapped on chromosome 2, that was found to be associated with 27 wavenumbers. Genes previously found to be related to traits of interest (e.g. disease resistance, milk yield and quality, cheese firmness) are located close to the significant SNP. As expected, the heritability estimated for the absorbance of each wavenumbers seems to be associated with the related milk components.

Rumen-protected l-carnitine supplementation during mating period altered metabolic status and reproductive performance of ewes.

Current study hypothesized that dietary l-carnitine (LC) inclusion during the mating period ameliorates both metabolic status and reproductive performance of ewes. Seventy Baluchi ewes (52 ± 4.2 kg of bodyweight and 18 ± 6 months old of age) were enrolled in this study. Animals were randomly allocated into two dietary treatments, control (only basal diet) or basal diet plus supplementation with a rumen-protected LC (Carneon 20 Rumin-pro; 20% LC; Kaesler Nutrition GmbH) at the rate of 10 g/head/day from 21 days before until 35 days after introducing rams to the ewes (MP). Feed intake was monitored by subtracting the ort from feed offered. Blood sample collection was conducted on Days -10, +10 and +20 relative to MP. Pregnancy was confirmed on Day 30 post-MP. Feed intake of the ewes in the LC group was higher than the control (p < 0.05). LC supplementation increased the cholesterol concentration in the ewes (p < 0.05). Blood urea concentration of animals in the LC group was significantly lower than the control (p < 0.05). The mRNA expression of toll-like receptor 4 was evidently lower in animals supplemented with LC than the control (p < 0.05). Both lambing and fecundity rates in the LC group tended to be higher compared with the control. LC supplementation showed potential to alter certain metabolites in the ewes. A tendency for higher lambing rate may partly be driven by dams efficient energy partitioning to support foetal growth and maintaining pregnancy.

The effect of maternal organic manganese supplementation on performance, immunological status, blood biochemical and antioxidant status of Afshari ewes and their newborn lambs in transition period.

It has been documented that adequate maternal manganese (Mn) status is vital for performance and health of ewes and their newborn lambs. However, required level and form of dietary Mn in ruminants are not well defined. The current study was conducted to evaluate the effect of maternal organic Mn supplementation on performance, immunological status, blood biochemical and antioxidant status of Afshari ewes and their newborn lambs in transition period. For this purpose, various organic Mn concentrations were utilized as a supplementary ingredient in formulating the diets of ewes. The ewes were randomly allocated into three groups, fed with 0, and 80 mg/kg organic Mn supplemented diet. At the end of the experiment, the parameters including the performance of newborn lambs, as well as biochemical factors, immune status and antioxidant status in ewes and their newborn lambs were evaluated. The results showed a significant increase in the plasma concentrations of Mn, glucose, insulin, thyroid hormones (T3 , T4 ) and enzymatic antioxidants (SOD, GPX , CAT) in ewes and their newborn lambs that were treated with maternal organic Mn. Moreover, inorganic Mn treatments, the concentration of IgG in newborn lamb's plasma, and colostrum of ewes increased. According to this research, organic Mn acts as a valuable and safe supplementary material that could be exploited for enhancing health of ewes and their newborn lambs.

Effects of pasture management and supplementation on the productive performance of recently lambed ewes.

The hypothesis was tested that the performance of lactating ewes is affected by the supplementation level and pasture management. Two supplementation levels (0.5 and 1.0% of body weight, BW) and two pasture managements (mowed and non-mowed) were tested. Forty adult ewes (2 years old) with an average weight at lambing of 62.97 ± 7.0 kg (day 0) and an average the body condition score of 2.5 points (day 0) were evaluated. Verminosis was monitored with periodic deworming. The number of eggs per gram of feces (EPG) of ewes at lambing was used as a covariate for performance assessments. Ewes lost an average of 7.5 kg over the 90 days post-partum (12% BW). The weaning rate was 53%. The body condition of the ewes was influenced by the post-partum period. The ewes mobilized their body reserves in the first 30 days of lactation. Mowing management negatively affected the nutritive value of the forage. Supplementation with 0.5% BW was sufficient for nutritional management post-partum. Pasture management (mowed vs. not mowed) cannot prevent post-partum weight loss. Supplementation levels and pasture management altered the morphological and chemical components of the pasture.

Performance responses of lactating Rahmani ewes fed diet supplemented with Enterococcus faecium NRC-3 or Lactobacillus rhamnosus.

Production of new types of probiotics for animal nutrition mainly depends on the appropriate bacterial strain and efficient substrate. Therefore, this study aimed to evaluate the impact of two probiotic strains containing 1.2 × 108 (CFU/g), produced on permeate media on performance responses of Rahmani ewes. Thirty early lactating ewes (about 2-3 years old and weighting on average 43.2 ± 0.3 kg) were randomly divided into three groups of 10 animals each using a completely randomized design. The 1st group was fed the basal diet (60% concentrate feed mixture (CFM) + 30% Egyptian clover + 10% bean straw). While the ewes in 2nd and 3rd groups were fed the basal diet + 2 g of Enterococcus faecium NRC-3(EF) and Lactobacillus rhamnosus (LR), respectively for 9 weeks. Ewes' diet supplementation with EF or LR increased (p < 0.05) dry matter, organic matter, crude protein, neutral detergent fiber, acid detergent fiber, and non-structural carbohydrates digestibility compared to ewes of the control group. Glucose, total protein, and albumin concentrations significantly increased in the blood of EF ewes than those of LR and control. Probiotics increased ewes' milk yield as well as milk protein, fat, and lactose yields, but no differences were observed between treatments when milk components were expressed as percentage. Milk fatty acids profile not changed due to EF or LR supplementation. Probiotics (E. faecium and L. rhamnosus) produced on cheese industry waste (permeate) have proven their ability to improve the productive performance of the lactating Rahmani ewes.

Understanding the phenotypic and genetic background of the lactose content in Sarda dairy sheep.

Lactose, the principal carbohydrate found in milk, plays an important role in the physiological processes of milk production because it is related to milk volume, and it is responsible for the osmotic equilibrium between blood and milk in the mammary gland. In this study, factors affecting lactose content (LC) in sheep milk are investigated. For this purpose, 2,358 test-day records were sampled from 509 ewes (3-7 records per animal). The LC and other main milk traits were analyzed using a mixed linear model that included days in milk (DIM) class, parity, lambing month, and type of lambing as fixed effects and animal, permanent environment, and flock test day as random effects. The pedigree-based approach was used to estimate the heritability and repeatability of LC. Moreover, the genomic background of LC was investigated through a GWAS. The LC was affected by all tested factors (i.e., DIM class, parity, lambing month, and type of lambing). Low heritability (0.10 ± 0.05) and moderate repeatability (0.42 ± 0.02) were estimated for LC. High negative genetic correlations were estimated between LC and NaCl (-0.99 ± 0.01) and between LC and somatic cell count (-0.94 ± 0.05). Only 2 markers passed the chromosome-wide Bonferroni threshold. Results of the present study, although obtained on a relatively small sample, suggest the possibility to include LC in the breeding programs, particularly because of its strong relationship with NaCl and somatic cell count.

Gene expression pattern and molecular mechanisms involved in Shal and Sangsari sheep fertility using RNA-Seq.

Ovulation rate and litter size are the main reproductive traits with high economic value in the sheep breeding industry. In this study, three Shal ewes (multiparous) and three Sangsari ewes (uniparous) at the age of 5 were used. The live weight was between 45 and 50 kg at an extremely body condition score of 3. These breeds are marked seasonal reproduction activity and are often bred in semi-closed breeding systems. Total RNAs were extracted from the ovarian tissues, and RNA sequencing was carried out. The DAVID (Database for Annotation, Visualization and Integrated Discovery) database was then used to annotate genes, and the string database and the Cytoscape software were used to investigate their interactions. Then path-act network analysis and gene-act network analysis were investigated. The results indicated that 19,932 genes were differentially expressed. The 5968 differentially expressed genes were identified in Shal ewe's ovarian tissue compared to Sangsari ewes (FDR < 0.05), of which 2921 genes were up-regulated and 3047 genes were down-regulated. Bioinformatics analysis exhibited that most of the biological processes and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways associated with significant DEGs (Differentially Expressed Genes) in the two studied breeds are associated with oocyte maturation and metabolism. MAPK signalling pathways and Ubiquitin-mediated proteolysis are the most important biological pathways associated with reproductive and fertility traits in the Shal breed. AKT3, MAPK8, MAPK9 and RELA genes are also important genes related to the fertility of multiparous sheep. Analysis of ovarian RNA-seq data identified that most of the differentially expressed genes were involved in various reproductive processes including folliculogenesis, ovulation, ovarian and embryonic development. The MAPK signalling pathway had the most interaction with other pathways, and the AKT3 gene could be a powerful candidate gene in the reproduction and fertility of Shal sheep. These results could pave the way for future efforts to address sheep prolificacy barriers.

Early Pregnancy Markers in the Serum of Ewes Identified via Proteomic and Metabolomic Analyses.

The diagnosis of ewes' pregnancy status at an early stage is an efficient way to enhance the reproductive output of sheep and allow producers to optimize production and management. The techniques of proteomics and metabolomics have been widely used to detect regulatory factors in various physiological processes of animals. The aim of this study is to explore the differential metabolites and proteins in the serum of pregnant and non-pregnant ewes by proteomics and metabolomics. The serum of ewes at 21, 28 and 33 days after artificial insemination (AI) were collected. The pregnancy stratus of the ewes was finally determined through ultrasound examination and then the ewes were grouped as Pregnant (n = 21) or N on-pregnant (n = 9). First, the serum samples from pregnant or non-pregnant ewes at 21 days after AI were selected for metabolomic analysis. It was found that the level of nine metabolites were upregulated and 20 metabolites were downregulated in the pregnant animals (p < 0.05). None of these differential metabolomes are suitable as markers of pregnancy due to their small foldchange. Next, the proteomes of serum from pregnant or non-pregnant ewes were evaluated. At 21 days after AI, the presence of 321 proteins were detected, and we found that the level of three proteins were upregulated and 11 proteins were downregulated in the serum of pregnant ewes (p < 0.05). The levels of serum amyloid A (SAA), afamin (AFM), serpin family A member 6 (SERPINA6) and immunoglobulin-like domain-containing protein between pregnant and non-pregnant ewes at 21-, 28- and 33-days post-AI were also analyzed via enzyme-linked immunosorbent assay (ELISA). The levels of SAA and AFM were significantly higher in pregnant ewes than in non-pregnant ewes, and could be used as markers for early pregnancy detection. Overall, our results show that SAA and AFM are potential biomarkers to determine the early pregnancy status of ewes.

Milk fatty acids as covariates in multiple regression analysis is a robust approach to model the decrease in milk fat concentration and yield in small ruminants.

Milk fat depression (MFD) syndrome has been associated with the antilipogenic effects of trans-10 fatty acids (FA), such as t10, c12-CLA (CLA) and t10-18:1 (T10). However, these FA alone cannot completely explain the changes in milk fat in small ruminants. Thus, the aim of this study was to use multiple regression analysis to evaluate other FA that may be related to shifts in milk fat, as well as to improve model accuracy when different milk FA are used as covariates in the models. Previously published data were used in multiple regression analysis for goats (n = 106) and ewes (n = 68). Body weight (BW), vaccenic acid (t11-18:1), both trans-10 FA and the major milk FA were tested as covariates to model four response variables associated with MFD: fat concentration (FC), percentage change in milk fat concentration (CFC; %), fat yield (FY; g/d) and percentage change in milk fat yield (CFY; %). All four multiple regression models were significant for both species. When compared with simple regression models, all multiple regression models improved accuracy when estimating MFD. The improvements in model accuracy (lower RMSE) for FC, CFC, FY and CFY were 60.6%, 43.3%, 35.6% and 44.4% for ewes, and 52.1%, 60.1%, 33.6% and 14.9% for goats respectively. Linolenic acid and t11-18:1 were covariates in all models for goats, and palmitic acid and CLA were covariates in all ewe models. These FA should be investigated regarding their direct effect on gene expression associated with milk fat metabolism in the mammary gland of small ruminants. Multiple regression analysis is the most robust approach to account for the variation of milk fat and yield in goats and ewes.

Effect of Saccharomyces cerevisiae supplementation during the suckling period on performance of Awassi ewes.

This study aimed to investigate the impact of supplementing two levels of Saccharomyces cerevisiae (SC) during suckling period on performance and serum metabolites of Awassi ewes. The study comprised two experimental periods, for experimental period 1, 30 nursing Awassi ewes with their single lambs were randomly assigned to one of three equal treatment groups: a control diet (CON; n=10), low SC (LSC) diet (0.4 g SC/head/day; n=10), and high SC (HSC) diet (0.8 g SC/head/day; n=10) with 9-week experimental periods including 1 week for dietary and pen adaptation and 8 weeks for data and sample collection. For experimental period 2, 4 ewes from each group were randomly selected and were individually housed in metabolism crates with 7-day experimental periods including 3 days for crate adaptation and 4 days for data and sample collection. The results showed that the supplementation of SC improved dry matter (DM) intake of ewes (P = 0.03). Digestibility of DM was higher (P < 0.05) for SC treatment groups. The SC treatment groups had a tendency improvement in digestibility of crude protein, neutral detergent fiber, and acid detergent fiber. Addition of SC improved (P < 0.05) N balance parameters of ewes. A significant increase was observed for the rumen fluid pH of lactating ewe supplemented with SC. No difference was detected in the live weight change of lactating ewes in all treatment groups. The final body weight of the lambs tended to be greater for SC treatment groups vs CON group but average daily gain and total weight gain were significantly higher (P = 0.05) for SC treatment groups. Lactating ewes in the SC treatment groups produced more milk per day (P ≤ 0.05) than those in the CON diet. Milk fat % and yield in the SC treatment groups were also greater (P = 0.05). No differences were found in % of milk protein, lactose, and solid-not-fat (SNF) between all groups (P > 0.05) while lactose and SNF yields were greater (P < 0.05) for SC treatment groups. However, % of the total solids (TS) of milk was higher for HSC diet compared to LSC and CON diets (P < 0.05) while TS yields were significantly higher for SC treatment groups. Energy-corrected milk values were greater (P < 0.05) in HSC diet compared to LSC and CON diets. With the exception of aspartate aminotransferase and alkaline phosphatase, no differences were detected in all other serum metabolite concentrations of lactating ewes in between treatment groups. In conclusion, this study indicates that SC supplementation with varying levels in the diet had a similar positive effect on some performance and physiological parameters of lactating Awassi ewes and their lambs.

Effects of adding rumen-protected palm oil in diet on milk fatty acid profile and lipid health indices in Kivircik ewes.

This study aimed to determine the effect of the addition of rumen-protected palm oil making up 3% of the ration on lipid health indices and milk fatty acid composition of Kivircik ewes'. Kivircik ewes at two years of age, the same parity, lactation stage, and the same bodyweight (52.57 ± 5.80 kg) were chosen for this purpose. Two groups were formed, in which the control group was fed a basal diet without feed supplementation, whereas the treatment group received rumen-protected palm oil which corresponded to 3% of the ration. In order to protect palm oil, it was coated with calcium salts. Treatment increased the palmitic acid (C16:0) content of milk compared to the control group (P < 0.05) and tended to increase saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) (P = 0.14). An increase in SFA and MUFA was attributed to an increase in palmitic acid and oleic acid (C18:1), respectively (P < 0.05). Results indicated that the omega-6/omega-3 ratio (n-6/n-3) ranged between 0.61 and 2.63. The inclusion of palm oil in the diet tended to increase desirable fatty acids (DFAs) regardless of the week of milk sampled (P = 0.42). Treatment did not improve the atherogenicity index (AI), thrombogenicity index (TI), health-promoting index (HPI), and hypocholesterolemic/hypercholesterolemic (h/H) ratio. Results showed that adding rumen-protected palm oil is a plausible method to meet the energy intake of ewes required during lactation without negatively affecting lipid health indices.

Lemongrass supplementation to Farafra ewes improved feed utilization, lactational performance and milk nutritive value in the subtropics.

Application of phytogenic feed additives in livestock production is a sustainable practice and the search for more phytogenic options continues. This study was conducted to investigate the impact of lemongrass supplementation on nutrient utilization, rumen fermentation and milk production and composition. Thirty gestating Farafra ewes were randomly assigned to three experimental treatments of control (without a supplement), or with the supplementation of 5 g (LEM5 treatment), or 10 g of lemongrass/ewe/d (LEM10 treatment) for 12 weeks. Lemongrass supplementation at both doses did not influence ( p > 0.05) nutrient intake, but improved nutrient digestibility (p < 0.05). Furthermore, LEM5 and LEM10 treatments improved (p ≤ 0.001) ruminal total volatile fatty acids, acetate and propionate. Blood glucose was increased (p < 0.05) and cholesterol was decreased in ewes supplemented with lemongrass at both doses. Milk yield, energy corrected milk yield, and milk component were improved (p ≤ 0.001) in ewes supplemented with lemongrass at 5 and 10 g while the feed efficiency was decreased. Lemongrass supplementation at both doses increased (p = 0.040) the proportion of milk total conjugated linoleic acid without affecting other milk fatty acids. In most of the parameters evaluated, there was no significant difference between LEM5 and LEM10. Therefore, lemongrass supplementation at 5 g/ewe/d can be used in dairy production with positive impacts.

Effect of rumen fluke on feed digestibility and methane emissions in sheep.

Thirty-six ewes aged 18 months were assigned to one of three groups (n = 12) on the basis of faecal egg count (FEC) for rumen fluke; C: control (FEC = 0-5 epg), T: affected (FEC ≥ 6 epg) and treated, NT: affected (FEC ≥ 6 epg) and not treated. T ewes were treated with oxyclozanide 14 days prior to the trial commencing. Ewes were fed grass silage ad libitum. Digestibility crates and respiration chambers were used to measure feed digestibility and methane production. Dry matter intake (DMI), feed digestibility and CH4/DMI did not differ (P > 0.05) between treatments. However, CH4/live weight (LW) was significantly greater (P < 0.001) for NT ewes, while that of C and T ewes were similar. This study indicates that a high rumen fluke burden can increase methane emissions but only when expressed on a body weight basis (per kg LW). As the link between rumen fluke infection and methane production has not previously been investigated within the literature, these findings demonstrate the need for further research to better understand these relationships.

Comparison of GnRH and hCG effects on oestradiol, progesterone and premature luteolysis in Ovsynch-synchronized ewes.

The purpose of this study was to ascertain whether premature luteolysis can be alleviated by substituting the ovulation inducing agent hCG for GnRH. Seventy-two hours after the end of artificial insemination (AI), pluriparous Awassi ewes were randomly assigned to one of three treatment groups of 13 ewes each. First group received 37.5 µg of the GnRH analog Lecirelin, the second 1000 I.U hCG and the third group served as a control (received 1 ml of physiological saline solution). Blood samples were collected at daily intervals after GnRH treatment and analysed for plasma oestradiol and progesterone concentrations. Ovarian follicles were monitored ultrasonically at the time of GnRH administration, 60 hr and 84 hr later. Pregnancy was diagnosed ultrasonically at Day 35 after AI. Number and size of ovarian follicles did not differ (p > .05) among treatment groups. Onset and duration of oestrus were not affected by treatment (p > .05). No significant differences (p > .05) were recorded in oestradiol and progesterone concentrations between the treatment groups during the inspection period. Premature luteolysis became evident in ewes with longer oestrous durations by Day 6.25 after AI and amounted to 7.69%, 18.18% and 23.07% in GnRH, hCG and Control groups respectively. Pregnancy rates increased to 92.31% and 81.82% in GnRH and hCG groups, compared to 76.92% in the Control group. The results indicate that GnRH was more effective in reducing premature luteolysis than hCG. Substituting hCG for GnRH as an ovulation inducing agent was of no avail.

Comparison of four strategies of ram management in a semen collection centre.

Thirty Merino rams were used to determine the effect of four management systems of rams on semen quality during the anoestrous season. Animals were divided into four groups: Artificial-Photoperiod group (AP; n = 8), which were isolated from females and exposed to artificial long days (16 hr/d) from 1 Feb to 15 Mar; Natural-Photoperiod (NP; n = 8), isolated from females and exposed to the natural photoperiod throughout the experiment; Oestrous-Ewe group (EE; n = 7), housed in a pen adjacent to another pen that housed three ewes in oestrus, and Anestric-Ewe group (AE; n = 7), housed adjacent to another pen that housed three ovariectomized ewes. From 20 Mar to the end of May (10 weeks), semen samples were collected weekly, and blood samples were collected to determine plasma testosterone concentrations. Mean plasma testosterone concentrations, ejaculate volume and reaction time were not affected either by treatment or week. There was a significant effect (p < .01) of ram treatment on sperm concentration, and both TM y PM, and their interaction, were significantly affected by group and week (p < .001). Rams exposed to ewes in oestrus presented the largest sperm concentration (p < .05) compared with the other three groups, although they had the lowest total and progressive motilities (p < .01). In conclusion, management strategy in spring affects semen quality of rams, with the presence of ewes in oestrus being the best plan to increase sperm concentration.

Effects of short and long milking intervals on milking characteristics and changes of milk constituents during the course of milking in crossbred Istrian × Awassi × East-Friesian ewes.

The main objective of this experiment was to evaluate the effects of two milking intervals (8 and 16 h) on milk constituents (fat, protein, lactose, dry matter, and log10 SCC) of nineteen Istrian × Awassi × East-Friesian crossbred ewes in different milk fractions (0-25, 25-50, 50-75 and 75-100%) during the course of milking and in machine stripping (MS) milk. Furthermore, we sought to determine the effect of the two milking intervals on milking characteristics (average milk flow rate, peak milk flow rate, machine-on time, total milk yield, and milk production rate) and whether each milk constituent within each milking interval is best described by a linear, quadratic, or cubic function. Average milk flow rate and milk yield per milking decreased in the 8 h milking interval compared to the 16 h milking interval (P < 0.05). Peak milk flow rate, machine-on time, and milk production rate were not different between the two milking intervals. Overall, milk fat content, dry matter content, and log10 SCC increased in the 8 h milking interval compared to the 16 h milking interval (P < 0.05). Milk protein content did not change through the main milk fractions at either milking interval. Milk lactose content did not change through the milk fractions at the 8 h milking interval, whereas it decreased in the 75-100% and stripping milk fractions at the 16 h milking interval (P < 0.05). The 0-25% and stripping milk fractions contained the highest log10 SCC compared to all other milk fractions (P < 0.05). Changes of milk fat and dry matter content throughout milking were best described by quadratic functions, whereas milk protein content, milk lactose content, and log10 SCC were best described by different functions depending on the milking interval. These results demonstrate that milking interval influenced all milk constituents in various milk fractions during the course of ewe milking. Moreover, milking characteristics such as average milk flow and total milk yield, and the appropriate mathematical function to characterize milk constituents throughout a milking, were affected by milking interval.

Factors affecting the lactation curve parameters of crossbred dairy ewes in a flock of the highlands of Mexico.

Sheep milk production is incipient in Mexico with scarce knowledge on the performance of dairy ewes from different breeds. The objective of this study was to evaluate the effect of breed (Awassi (Aw), East Friesian (EF) and other (Ot)), parity number (1, 2 and 3 or more (+ 3)), litter size (1 and 2 or more (+ 2)) and lambing season (spring-summer (SS) and autumn-winter (AW)) on day of peak yield (DP), peak yield (PY), persistency (P), total milk yield (TMY), 305-day milk yield (TMY305d), 150-day milk yield (TMY150d) and lactation length (LL) of crossbred dairy ewes in a flock of the central highlands of Mexico. A total of 4312 weekly milk yield records collected from 2014 to 2015 were used to model 133 lactations using a random regression model with a fifth-order orthogonal polynomial. Flock mean values of curve parameters were 42 days at DP, 1.2 kg/day at PY, - 3.5 g/day of P, 190 kg TMY, 189 kg TMY305, 124 kg TMY150 and 269 days of LL. Multiparous ewes had significantly higher (P < 0.05) PY and TMY than primiparous ewes. Ewes that lambed in AW had 15% higher PY and produced 14% more TMY than ewes that lambed in SS (P < 0.05). Correlations among curve parameters were significant except for the correlation between PY and LL and between P and TMY150d. TMY was strongly correlated with LL (0.91). Predominantly Awassi crossbred ewes had lower curve parameter values than predominantly East Friesian and other crossbred ewes.

The effects of feeding chickpea grains on the lactating performance and blood metabolites of ewes.

An experiment was conducted to see how replacing soybean meal with chickpea grains (CHPE) affected the performance, milk production, digestibility, nitrogen (N) balance, and blood metabolites of Awassi ewes. Thirty Awassi ewes with an initial body weight of 53.2 ± 2.31 kg and aged between 4 and 5 years were selected and randomly assigned to different feeding treatments (10 ewes per diet). Dietary dry matter (DM) was (1) 0 g/kg CHPE (CON); (2) 150 g/kg CHPE (CHPE150); and (3) 300 g/kg CHPE (CHPE300). The costs of these diets were determined using current ingredient prices. The experiment lasted 9 weeks. During the trial, ewes and their lambs were kept in individual pens. Daily nutrient intake was monitored. Every 2 weeks, the body weight (BW), milk output, and composition of the ewes were measured. In comparison to the CON diet, adding the CHPE to the experimental diets lowered feed costs (US$) per ton by 11% for CHPE150 and 21% for CHPE300. The CHPE300 group had a lower (P < 0.05) consumption of neutral detergent fiber (NDF) than the CHPE150 group, while the CON group had the highest (P < 0.05) intake of NDF. The intake of ether extract (EE) (g/d) was higher (P < 0.05) in the ewes fed the CHPE300 compared to the ewes fed CHPE150, and it was lowest in ewes fed the CON diet. When the ewes were fed the CHPE300 and the CHPE150 diets, the total solids (g/kg) in each kg of milk produced per day was higher (P < 0.05) than when they were fed the CON diet. The cost per kg of milk produced by the ewes was lowered (P < 0.05) when the CHPE was added to their diets. When the ewes on the CHPE300 and the CHPE150 diets were compared to the ewes on the CON diet, crude protein (CP) digestibility was higher (P < 0.05). The EE digestibility was higher (P < 0.05) for the CHPE300 group, while the CHPE150 group had an intermediate outcome. The CHPE300 group had lower amounts of N in their feces and urine (P < 0.05) than the other groups. The retention of N (g/100 g) in the ewes fed the CHPE300, and the CHPE150 diets was higher (P < 0.05) than in the ewes fed the CON diet. As a result, the current research demonstrates that part of soybean meal and barley grain could be replaced with chickpeas in the diets of lactating Awassi ewes.

Effects of rosemary (Rosmarinus officinalis) by-products and linseed (Linumusitatissimum) intake on digestibility, body weight gain, and estimated tissular composition in cull fat-tailed ewes.

The aim of this study was to evaluate the effect of rosemary (Rosmarinus officinalis) residues (RR) as dietary supplement in association with linseed (Linumusitatissimum) on digestive aspects and body weight (BW) gain in fat-tailed Barbarine ewes. To achieve this, 24 cull ewes (BW: 33 ± 2.7 kg) were divided into four groups receiving a basal diet composed of 500 g of straw for two groups (S) and 300 g of straw in addition to 200 g of RR for two other groups (R). All animals received 750 g of concentrate; the usual concentrate (UC) was offered for one S (S-UC) and one R group (R-UC); the linseed concentrate (LC) was also offered for one S (S-LC) and one R group (R-LC). The fattening and digestibility trials lasted 90 days. The dry matter (DM) intake and digestibility were similar across the groups. However, the crude protein (CP) intake and digestibility and the neutral detergent fiber intake were significantly affected by the treatments (P > 0.05). The nitrogen intake (NI), the fecal, and retained nitrogen were significantly affected by the regimen (P < 0.05); however, the urinary nitrogen was unchanged. The nitrogen balance was positive for all groups averaging 60% of the NI. The ruminal pH, ammonia nitrogen, and protozoa concentration were not affected by the RR intake and linseed supply; however, the control time affected significantly these parameters. Final BW, the average daily gain, the muscle, and fat contents were neither affected by the basal diet nor by the concentrate type (P > 0.05). In conclusion, the RR intake in association with linseed did not alter the animal's performances by improving their productive characteristics and consequently, the commercial value of this sheep's category.