Ewe Milk Research Articles

Effect of Milking Vacuum and the Supplementation of Vitamin E and Se in Milk Quantity, Quality, and Hygiene of Mammary gland in Mountainous Greek Sheep.

The aim of this research was to study the effect of two machine milking vacuum levels on the quantitative and qualitative characteristics of milk and mammary gland hygiene of ewes, when vitamin E and Se were administrated supplementarily. The experiment was conducted at the Vlasti Research Station in the Greek province of West Macedonia. Ninety-six ewes of the Mountainous Greek sheep breed were used. Animals were separated in four equal groups of 24 ewes per group. A 2 × 2 factorial design was applied, with two milking vacuum levels (38 kPa and 46 kPa) and two rations, one supplemented with vitamin E (300 I.U.) and Se (3 mg/kg DM feed) and one without any vitamin E and Se supplementation. Six test days were assigned (evening and morning milkings) at 14-day intervals, from April to July. Following milk yield control, milk samples were collected for chemical composition and somatic cell count (SCC) determination. At the end of milking of each lot, the milk from the terminal receiver of the milking machine was received for the evaluation of total bacterial count (TBC). The results revealed that milk yield was improved considerably in the case of 46 kPa vacuum level. Moreover, the chemical composition of milk was not influenced by vacuum level; however, the administration of vitamin E and Se appeared to have a positive effect. Moreover, the addition of vitamin E and Se decreased somatic cell counts (number and log10) at the two assessed machine milking vacuum levels. In reference to TBC and their log10, significant differences were not observed at both milking vacuum levels, regardless of vitamin E and Se administration. Statistical analysis did not indicate any interactions between the factors that were studied. Therefore, it is concluded that the quantity of vitamin E and Se supplemented to the ration has a positive effect on decreasing SCC and consequent positive action in the hygiene of the mammary glands of machine milked ewes.

Identifying the Influence of the Dietary Polyunsaturated Fatty Acid Content on Milk Quality Traits in Najdi Sheep at Different Stages of Lactation

The quality of milk is fundamental to producing safe milk and dairy products that are suitable for consumption. The objective of this study was to determine the influence that the content of dietary polyunsaturated fatty acids (PUFA) has on the total mixed ration (TMR) and lactation stage of milk’s composition and the fatty acid profile (FA) of the dairy Najdi breed. During the lactation period, 48 Najdi ewes used the following four treatments: traditional feed (TR) and three total mixed rations (TMR1, TMR2, and TMR3) with different PUFA content. Milk samples were taken from whole milk in the morning. The chemical composition and FA profile were analyzed. The results show that the ewes fed TMR1 with a PUFA content (25.20%) produced high-quality milk as they contained high levels of polyunsaturated fatty acids (PUSF), linoleic acid (LA), α-linolenic acid (ALA) and omega-3 (n3). On the other hand, the milk of ewes fed TMR2 with PUFA (15.06%) contained high levels of unsaturated fatty acids (USF) and monounsaturated fatty acids (MUFA) and had significantly reduced hypercholesterolemia (HFA). It can be concluded that milk fat, protein, and total solids in the milk of Najdi sheep increased as lactation progressed, while lactose remained constant. Furthermore, as lactation progressed, saturated fatty acids (SFA), stearic acids, and oleic acids (OA) increased while USF and MUFA decreased. TMR diets can directly benefit the producer and livestock by producing high-quality milk while reducing its economic value.

Multidrug Resistance in Enterococci Isolated from Cheese and Capable of Producing Benzalkonium Chloride-Resistant Biofilms.

This study aimed to investigate enterococci recovered from eight Portuguese cheeses made with raw ewe's milk, regarding antibiotic resistance, virulence genes, minimum inhibitory concentration (MIC) of benzalkonium chloride (BAC), biofilm formation capacity, and biofilm eradication (MBEC) by BAC. Antimicrobial resistance against seven antibiotics of five groups was evaluated using the disk diffusion method. The presence of the genes that encode resistance to the antibiotics penicillin (blaZ), erythromycin (ermA, ermB, and ermC), vancomycin (vanA and vanB), aminoglycoside (aac(6')-Ie-aph(2″)-Ia), and β-lactam (pbp5) and the genes that encode virulence factors, frsB, cylA, gelE, esp, and agg, were investigated via multiplex PCR. The susceptibility of planktonic cells to BAC was evaluated by the MIC and MBC values of the isolates, using the broth microdilution method. To assess the biofilm-forming ability and resistance of biofilms to BAC, biofilms were produced on stainless steel coupons, followed by exposure to BAC. The results showed a high resistance to the antibiotics vancomycin (87.5%), erythromycin (75%), tetracycline (50%), and penicillin (37.5%). Multidrug resistance was observed in 68.8% of the isolates. Genes encoding the virulence factors FrsB (frsB) and gelatinase E (gelE) were detected in all isolates. The esp and cylA genes were found in 56.3% and 37.5% of the isolates, respectively. All isolates exhibited a biofilm-forming ability, regardless of incubation time and temperature tested. However, after 72 h at 37 °C, E. faecium and E. faecalis biofilms showed significant differences (p ≤ 0.05). Although most isolates (62.5%) were susceptible to BAC (MIC ≤ 10 mg/L), biofilms of the same isolates were, generally, resistant to the higher concentration of BAC (80 mg/mL) tested. This study using Enterococcus isolates from a ready-to-eat food, such as cheese, reveals the high percentages of vancomycin resistance and multidrug resistance, associated with the presence of virulence genes, in isolates also capable of producing biofilms resistant to BAC, an important active ingredient of many disinfectants. These results emphasize the need for effective control measures to ensure the safety and quality of dairy products.

Occurrence of some probiotic bacteria in ewe's and goat's milk in Assuit City with regarding to genes responsible for production of bacteriocins.

Occurrence of some probiotic bacteria in ewe's and goat's milk in Assuit City with regarding to genes responsible for production of bacteriocins.

Epicoccum sp. as the causative agent of a reddish-brown spot defect on the surface of a hard cheese made of raw ewe milk

Colour defects can affect the appearance of cheese, its flavour, the safety of its consumption, and the price it can demand. This work reports the identification of five fungal isolates from a dairy plant where the surface of most cheeses was affected by patent, reddish-to-brown stains. One of these isolates was obtained from cheese, two from brine, and two from a bulk tank containing ewe milk. Molecular identification by partial amplification, sequencing, and database comparison of the concatenated sequence of the genes coding for the largest subunit of RNA polymerase II (RPB2), β-tubulin (β-TUB), and the large subunit of the rRNA molecule (LSU), plus the internal transcribed sequence (ITS) regions, assigned the isolates to Epicoccum layuense, Epicoccum italicum, and Epicoccum mezzettii. Features of the growth of these different species on different agar-based media, and of the morphology of their conidia following sporulation, are also reported. The strain isolated from cheese, E. layuense IPLA 35011, was able to recreate the reddish-brown stains on slices of Gouda-like cheese, which linked the fungus with the colour defect. In addition, two other strains, E. italicum IPLA 35013 from brine and E. italicum IPLA 35014 from milk, also produced stains on cheese slices. Epicoccum species are widely recognized as plant pathogens but have seldom been reported in the dairy setting, and never as human or animal pathogens.

A Thorough Investigation of the Microbiological, Physicochemical, and Sensory Properties of Ewe's Yoghurt Fermented by a Selected Multi-Strain Starter Culture.

This work was carried out with the aim to investigate the microbiological, physicochemical, and sensory properties of an innovative yoghurt produced from ewe's milk. Experimental yoghurt productions were performed with a commercial freeze-dried starter preparation and a natural milk starter culture (NMSC) of Streptococcus thermophilus and Lactobacillus delbrueckii. The two yoghurts did not differ for colour parameters, showing an average value of lightness, redness, and yellowness of 94.99, -3.74, and 9.37, respectively. The yoghurt produced using the NMSC as a fermenting agent was characterised by a significantly lower fat percentage and a higher antioxidant potential than commercial starters. Microbiological analysis confirmed the safety of the final product and a level of living lactic acid bacteria of 108 CFU/g. Sensory analysis revealed some differences among yoghurts regarding unpleasant odour, homogeneity, and persistence in the mouth, but the yoghurt processed with NMSC was more appreciated. Thus, the production of ewe's yoghurt fermented by a selected multi-strain starter culture represents an interesting strategy to enlarge the functional ovine dairy product portfolio.

Valorization of Olive Mill Byproducts: Recovery of Biophenol Compounds and Application in Animal Feed.

This study aimed to recover the phenols from olive oil mill wastewater, a major pollutant of the oil industry, by using spray-drying technology to produce a new feed with a nutraceutical value for animal feed supplementation and to evaluate its effect on the productivity and nutritional quality of ewe milk. Forty-five Sarda ewes in late lactation (150 ± 2 d) and with homogeneous live weight (52 ± 1.5 kg) were randomly allotted into three groups and fed with three dietary treatments containing increasing levels of polyphenols: 0% (C), 0.1% (T0.1), and 0.2% (T0.2) of dry matter. No effect of the dietary treatments was found on the milk yield and composition. Interestingly, milk urea content (p < 0.0001) and somatic cell counts (p < 0.001) decreased as the level of polyphenols inclusion in the diet increased. The inclusion of phenols (0.2% of dry matter) in the diet of sheep was effective in increasing the vaccenic (C18:1 trans-11) and rumenic acid (C18: cis-9 trans-11) levels, which are beneficial for human health. Finally, the recovery of polyphenols via spray-drying technology and their incorporation into a new fortified feed can be a valid strategy for naturally improving the nutritional value of milk while valorizing an oil industry byproduct, reducing environmental impact, and promoting waste reuse that is in line with circular economy principles.

Occurrence of Hydroxytyrosol, Tyrosol and Their Metabolites in Italian Cheese.

Tyrosol (T) and hydroxytyrosol (HT) are phenyl alcohol polyphenols with well-recognized health-promoting properties. They are widely diffused in several vegetables, especially in olive products (leaves, fruits and oil). Therefore, they could be present in food produced from herbivorous animals such as in milk and cheese. In this study, an analytical method to determine T, HT and some of their phase II metabolites (sulphates and glucuronides) in cheese was developed and validated. Samples were extracted with an acidic mixture of MeOH/water 80/20 (v/v) and, after a low temperature clean-up, the extracts were evaporated and injected in a liquid-chromatography coupled with high resolution mass spectrometry (LC-Q-Orbitrap). A validation study demonstrated satisfactory method performance characteristics (selectivity, linearity, precision, recovery factors, detection and quantification limits). The developed protocol was then applied to analyze 36 Italian cheeses made from ewe, goat and cow milk. The sum of detected compounds (T, tyrosol sulfate, hydroxytyrosol-3-O-sulfate and hydroxytyrosol-4-O-sulfate) reached as high as 2300 µg kg-1 on a dry weight basis, although in about 45% of cow cheeses it did not exceed 50 µg kg-1. Ewe cheeses were significantly richer of polyphenols (sum) as well as HT sulfate metabolites than cow cheeses. In conclusion, results shows that cheese cannot be considered an important dietary source of these valuable compounds.

The effect of the addition of a companion forage to a perennial ryegrass sward on ewe and lamb performance

Ireland's competitive advantage in sheepmeat production is based on the efficient and cost effective production and utilisation of pasture. The objective of this study was to assess the influence of binary mixtures of perennial ryegrass (Lolium perenne L.) plus a companion forage on ewe and lamb performance at pasture. Five sward mixtures were compared, namely; i) perennial ryegrass (Lolium perenne L.;PRG), ii) PRG plus white clover (Trifolium repens L.;PRG + WC), iii) PRG plus red clover (Trifolium pratense L.;PRG + RC), iv) PRG plus plantain (Plantago lanceolate L.;PRG + Plan) and v) PRG plus chicory (Chicorium intybus L.;PRG + Chic). Five farmlets with one sward treatment assigned to each were established which 23 ewes plus their lambs grazed from March to December for the years 2018 to 2021 inclusive. Farmlets were rotationally grazed, stocked at 11.5 ewes/ha and received 130 kg nitrogen/ha/year. Lambs were weaned on average at 15 weeks of age. Post-weaning a leader-follower grazing system was implemented with lambs grazing ahead of the ewes. Post weaning, lambs were weighed fortnightly and drafted at a live weight of 42 kg in June and increasing by 1 kg per month thereafter to produce a target carcass weight of 20 kg. Results show that lamb lifetime average daily gain (ADG) was greater for lambs grazing all binary sward mixtures relative to grazing PRG. Relative to PRG, lamb lifetime ADG was increased by between 17 g/day (PRG + Plan; P < 0.01) to 31 g/day (PRG + RC, and PRG + Chic; P < 0.001) and subsequently the number of days required to reach slaughter (DTS) was reduced by between 15.8 days (PRG + Plan; P < 0.01) to 28.6 days (PRG + RC; P < 0.001) with the addition of a companion forage. As a result of lower DTS, the average total number of anthelmintic treatments administered per lamb was significantly reduced for lambs grazing on all of the binary sward mixtures relative to PRG (P < 0.001). Scanned litter size and ewe milk yield were similar across all sward types as were ewe body weight (BW) and body condition score (BCS) from mating up until 6 weeks post-lambing (P > 0.05). Of the ewes retained from one production year to the next, those grazing PRG + WC, PRG + RC and PRG + Plan had a greater BW than those grazing PRG at the second mating event (P < 0.05), whilst, PRG + RC, PRG + Plan and PRG + Chic ewes had a greater BCS than PRG ewes (P < 0.05). These results suggest the suitability of binary sward mixtures under an intensive sheep grazing system to improve ewe and lamb performance at pasture.

Mastitis in a flock of milking sheep.

Determination of somatic cell counts (SCC) becomes more and more important also for ewe's milk. SCC can be a useful indicator of milk quality for milk processors while it can be a mastitis indicator for sheep keepers and an important selection criterion for breeders. The objective of our study was to acquire basic information about factors influencing SCC variability in lambing ewes of the Tsigai (T) and Improved Valachian (IV) breeds. Somatic cell counts (SCC) were determined in 866 milk samples in 2017 and 2018, during lamb sucking and during milking period. An instrument Fossomatic 90 (Foss Electric, Hillerød, Denmark) was used for analysis. Average SCC varied from 270 to 1897 × 103 cells/ml during lamb sucking and from 268 to 2139 × 103 cells/ml during milking period. Differences between the sampling periods were statistically significant in 2017. An increase in SCC was observed at the end of both sucking and milking periods. An overall evaluation of lactation brought about the average SCC at 364 × 103 cells/ml in 2017 (log(10) SCC - 2,25) and at 1,091 × 103 cells/ml in 2018 (log(10) SCC - 2,68). The indicator log(10) was significantly influenced by breed in 2017 (T - 2,61; IV - 2,75). The effect of lactation number and number of sucking lambs did not have any significant influence on SCC.

Milk-clotting activity of recombinant bovine and camel chymosin for cow’s, goat’s and ewes’ milk

Goats and sheep were domesticated during the Neolithic Revolution. Since then, various breeds of goats and sheep have been bred, including dairy ones. In this work, we tested the milk-clotting activity of recombinant bovine (Bos taurus) and camel (Camelus bactrianus) chymosins in cow, goat, and ewe milk. The milk-clotting activity of recombinant bovine chymosin for cow’s, goat’s and ewes’ milk was 12 854 ± 0,61, 5385 ± 0,25 and 14 811 ± 0,72 U/mg. The activity of recombinant camel chymosin was higher by 29%-46% and amounted to 16 590 ± 0,82, 7850 ± 0,34 and 20 700 ± 0,85 U/mg. Proteolytic activity was 1679.97 ± 9.54 and 10 767 ± 54.56 U/mg for recombinant camel and bovine chymosins, respectively. With the recombinant camel chymosin, cheeses were obtained from cow’s, goat’s and ewes’ milk. The yield of cheese from cow’s, goat’s and ewes’ milk was 18.0%, 17.3% and 15.3%, respectively. The results indicate the prospects for the use of recombinant camel chymosin as the coagulation enzyme in the processing of cow’s, goat’s and ewes’ milk to cheeses.&#x0D; &#x0D;

Artisanal cheeses relying on spontaneous fermentation as sources of unusual microbiota – The example of the Bulgarian ‘mehovo sirene’ skin bag cheese

The Bulgarian ‘mehovo sirene’ cheese is a type of regional artisanal cheese prepared from raw ewe milk in a skin bag relying on spontaneous fermentation. A metagenomics study revealed an unusual microbiome comprising beneficial bacteria such as Staphylococcus equorum, Lactococcus lactis, Streptococcus thermophilus, Lactobacillus delbrueckii, Lactobacillus kefiranofaciens, Lactococcus raffinolactis, Lactiplantibacillus plantarum, Limosilactobacillus fermentum and Loigolactobacillus coryniformis. Our findings suggest that ‘mehovo sirene’ could have some functional food properties and is a source of beneficial microorganisms.

Reduction of Beta Cyclodextrin by Curd Washing in Low-Cholesterol Manchego Cheese.

Beta-cyclodextrin (β-CD) is a cyclic oligosaccharide consisting of seven glucose units. β-CD is increasingly used in food research to reduce cholesterol due to its affinity for non-polar molecules such as cholesterol and as a natural additive. The purpose of this study was to evaluate the effect of curd washing in ewe's milk cheese on the reduction in cholesterol by β-CD from pasteurized ewe's milk Manchego cheese and the characteristics of its main components: milk, lipids, and flavor. An approximately 98.45% cholesterol reduction was observed in washed experimental cheeses that were treated by using β-CD. The remaining residual β-CD from the effect of curd washing was 0.15% in mature cheese, of the initial 1% β-CD treatment of the milk. The chemical properties (fat, moisture, and protein) did not change as a result of the curd washing with or without β-CD. The curd washing with or without β-CD on the levels of the various lipid fraction (fatty acids, triglycerides, and phospholipids) were comparable in treated and untreated cheeses. The effects of curd washing and the β-CD treatment did not significantly affect flavor components or short chain free fatty acids. The β-CD molecules were edible and nontoxic; as a result, they could be used safely in cholesterol removal processing in cheese manufacturing, improving the reduction in residual β-CD by curd washing by 85%. Therefore, the present study suggests that curd washing combined with β-CD is an effective process for cholesterol removal in Manchego cheese, preserving its desirable properties.

Effect of the Onset of Intramammary Infection on the Electrical Conductivity of Ewe's Milk and Study of Various Algorithms for Its On-Line Detection.

The aim of this study was to determine the effect of the onset of intramammary infection (IMI) on the electrical conductivity (EC) of ewe milk and assess the detection capability of various algorithms based on daily glandular milk EC measurement. An experiment was carried out with 26 Manchega sheep located at the farm of the Miguel Hernández University, Elche, Spain. The variables in milk from the gland (production, EC) were monitored daily for 2 weeks during the morning and evening milking; once infection was established in the gland, the variables were measured for a further 4 weeks. In addition, the SCC, sodium, potassium, chloride and milk macro-compositions were analysed. The sensitivity, specificity and positive and negative predictive values for IMI detection of different algorithms were calculated using the EC variable. It was observed that the onset of IMI resulted in an increase in SCC and a significant decrease in yield, and EC rose significantly when infection occurred bilaterally. The best results for IMI detection were obtained with the algorithm that detected deviations greater than 3σ of the conductivity ratio between collateral glands with respect to a moving average calculated with a time horizon of 10 days (50% sensitivity and 100% specificity).

Evaluation of the adulteration of camel milk by non-camel milk using multispectral image, fluorescence and infrared spectroscopy

In the present study, the focus was to evaluate the potential of three spectroscopic techniques (Mid Infrared -MIR-, fluorescence, and multispectral imaging -MSI-) to check the level of adulteration in camel milk with goat, cow, and ewe milks. Camel milk was adulterated with goat, ewe, and cow milks, respectively, at 6 different levels viz. 0.5, 1, 2, 5, 10, and 15%. After preprocessing the data with standard normal variate (SNV), multiplicative scattering correction (MSC), and normalization (area under spectrum = 1), partial least squares regression (PLSR) and partial least squares discriminant analysis (PLSDA) were used to predict the adulteration level and their belonging group, respectively. The PLSR and PLSDA models, validated using external data, highlighted that fluorescence spectroscopy was the most accurate technique giving a R2p ranging between 0.63 and 0.96 and an accuracy ranging between 67 and 83%. However, no technique has allowed the construction of robust PLSR and PLSDA models for the simultaneous prediction of contamination of camel milk by the three milks.

A new insight into the polar lipid composition in mature breast milk and ewe milk with comparative lipidomics analysis

Polar lipids play essential biological functions in energy storage, both as structural components of cell membranes and as signaling molecules. In this study, a comprehensive UHPLC-QTRAP-MS-based lipidomic analysis of mature breast milk (BM) and ewe milk (EM) was conducted. Through the analysis, a total of 362 polar lipid species from 14 subclasses were characterized, including 60 phosphatidylethanolamines (PEs), 59 phosphatidylcholines (PCs), 38 phosphatidylinositols (PIs), 35 sphingomyelins (SMs), and 34 ceramides (Cers). Of these, 139 lipid molecules were screened as significantly differentially expressed polar lipids (SDPLs) between the two kinds of milk based on the following criteria: a variable importance in projection (VIP) value > 1.0, a false discovery rate-adjusted P-value < 0.0001, and a fold change (FC) of either > 2.0 or < 0.5; these included 111 upregulated and 28 downregulated SDPLs in EM compared to BM. Among these SDPLs, the content of PE (16:1_18:0) was found to be significantly higher in EM compared to BM (FC = 69.5853, P < 0.0001). Moreover, sphingolipid metabolism and glycerophospholipid metabolism were determined to be vital metabolic pathways. This was derived from the finding that PE, PC, SM, and PI were key lipid metabolites in the two kinds of milk that were related to these two metabolic pathways. This study provides new insights into the characterization of SDPLs in mammalian milk, and also provides a theoretical basis for optimizing infant formula.

Effect of weaning system on lamb growth, mammary gland development and ewe milk production in dairy sheep managed in an outdoor pasture-based commercial farming system

The objective was to merge science and practice to determine the feasibility of a mixed suckling and milking system compared with a traditional exclusive suckling management system on the production performance of dairy sheep and their progeny in an outdoor pasture-based farming system at commercial scale. At 14 d postpartum, twin- and triplet-bearing mixed-age East Friesian ewes were randomly allocated to either a mixed system of once-a-day milking,suckling and early weaning (MS, n=61) or control with exclusive suckling and later weaning (Ctrl, n=57) using a randomised block design. MS lambs had lower live weight at weaning (14.6 vs. 16.7 kg; P&lt;0.001) but 3-5weeks post-weaning average daily gain and mammary gland mass was similar between groups. Ewe lamb mammary mass was positively associated with post-weaning but not pre-weaning live weight gain (P&lt;0.01). Weaning system influenced the percentage of protein, total solids and fat (MS &gt; Ctrl) while milk yield, somatic cell count and lactose levels were not different. This study highlighted that the MS comparedwith Ctrl system had no negative effects on dam or progeny performance.

Influence of dietary grape pomace supplementation on chemical and sensory properties of ewes' cheese

The nutritional and sensorial properties of Pecorino cheese made from milk of ewes fed a diet formulated with grape pomace (GP), a winemaking by-product, were evaluated. Dietary inclusion of GP (GP+) did not influence cheese moisture or total lipid content; however, a significant reduction of C14:1 cis-9 was noted, assumed to be a dietary effect on stearoyl-CoA desaturase function. The amount of β-casein was increased in GP+ samples, but total and TCA soluble fraction nitrogen did not indicate any marked effect on the proteolytic processes. Analysis of volatile compounds showed lower relative percentages of aldehydes, ketones, esters and lactones in GP+ cheeses, indicating improved oxidative stability during ripening. There was a marked decrease of lightness and an increase of hardness, gumminess and resilience (Young's modulus) in the GP+ samples. Sensory analysis of 120-day ripened cheeses confirmed these findings, and highlighted an increase in odour intensity and saltiness.

Effects of BLG polymorphism and dietary supplementation with carob pulp on ewe milk traits and fatty acid composition

The current study examined the effect on milk traits and composition of the replacement of barley grain with carob pulp as a supplement for grazing ewes with different genotypes at the β-lactoglobulin (BLG) locus. Forty-six Valle del Belìce lactating ewes were chosen for the feeding trial and split into control and carob groups based on the BLG p.Tyr38His polymorphism. The carob group received a supplement of 250 g/d of carob pulp, whereas the control group received 250 g/g of a barley whole grain-based concentrate. There were no milk yield or gross composition variations related to the BLG genotype. Nevertheless, milk fatty acid composition was influenced by the BLG polymorphism. Compared to the AB genotype, milk from BB sheep had higher concentrations of linoleic, linolenic acids, and total polyunsaturated fatty acids. The addition of carob pulp did not significantly modify fat and protein-corrected milk, whereas reduced protein and urea concentration, increased the fat content but worsened the milk quality in terms of fatty acid composition, increasing saturated and medium chain fatty acids. The genotype × feed interaction had no appreciable effect on milk composition or quality. HIGHLIGHTS Diet, genotype, and their interaction affect the milk traits and quality. Carob pulp reduced protein, urea and worsened fat quality. The genotype positively influenced the milk fat quality.

The Influence of the Lambing Season on Awassi Sheep Milk Quality, Milk Productivity, and Biochemical Traits

The current study was carried out from October 15, 2021, to June 15, 2022, in the area of animal production at the Agricultural Technical College, Northern Technical University, Mosul, Iraq. 24 Awassi ewes between the ages of 2-3, were employed in the study and split into two groups. In the first group, 12 ewes had winter lambs in December–January and 12 ewes had spring lambs in March–April. This was required to determine how the season affected some productive and biochemical blood features. The milk yield and its components of Awassi sheep, and some biochemical characteristics, as well as the number of somatic cells in milk, the estrus of the ewes were standardized using vaginal sponges. The season had a noticeable effect on milk production, as ewes with spring births produced significantly more milk in the second, fourth, eighth, and tenth weeks after birth. In the eighth and tenth week of the experiment, non-fat solids were consumed. Except for the fourth week of the trial, the number of somatic cells in the milk of spring-born ewes increased significantly (P0.05) in all other weeks of the study. The proportions of fat, protein, and solid non-fat percentages increased significantly. In addition to an increase in the number of somatic cells increased significantly and the incidence of mastitis in the milk of ewes with spring births.