Lactose Percentage Research Articles

Effects of substitution of millet straw for corn silage and alfalfa hay on lactation performance, ruminal fermentation, and blood metabolites in late-lactation Holstein dairy cows

The study was conducted to evaluate the effect of replacing dietary corn silage (CS) and alfalfa hay (AH) with millet straw (MS) on the production performance and the ruminal fermentation patterns of Holstein cows in late lactation. For this purpose, forty-eight multiparous Holstein dairy cows blocked by milk yield (32 ± 3.2 kg/d) and days in milk (179 ± 19 d) were randomly allocated to one of four treatments. The diets were formulated with a forage-to-concentrate ratio of 48:52 [dry matter (DM) basis] and contained the same concentrate mixtures, with different forage sources (on a DM basis): (1) Control (60% CS, 40% AH, and 0% MS; on 100% roughage); (2) LMS (54% CS, 36% AH, and 10% MS), (3) MMS (48% CS, 32% AH, and 20% MS), and (4) HMS (42% CS, 28% AH, and 30% MS). The dry matter intake and milk yield were lower in the HMS diet than those in the Control, LMS, and MMS diets (P < 0.01), whereas there was no difference in the Control, LMS, and MMS diets. Compared with the Control diet, 4% FCM, milk protein yield, and N conversion ratio decreased in the MMS and HMS diets (P < 0.01), whereas no difference between the Control and LMS diets was found. Besides, cows fed the HMS diet had lower milk fat yield, lactose percentage, and feed efficiency than those in the Control and LMS diets (P < 0.05), with no difference between the Control, LMS, and MMS diets. The percentage of milk fat and protein was not affected by the diets. Compared with the Control diet, the total VFA concentration was decreased, whereas the ammonia-N concentration was increased in the HMS diet (P < 0.05), with no difference between the Control, LMS, and MMS diets. The molar proportion of acetate and the ratio of acetate to propionate were lower (P < 0.01), while the molar proportion of propionate was higher in the Control diet than that in the MMS and HMS diets (P < 0.01), with no difference between the LMS and MMS diets. Compared with the Control, the apparent digestibility of DM, CP, NDF, and ADF was decreased, while the blood urea nitrogen concentration was increased in the HMS diet (P < 0.05), with no differences in the Control, LMS, and MMS diets. Thus, it was concluded that it is feasible to use MS as a fiber source for late-lactation dairy cows. However, considering the milk production performance and the feed digestibility, the replacement of CS and AH with MS should not exceed 20% of the roughage.

Effect of lambing season on ewe’s colostrum composition

Colostrum provides newborns with nutrients and immunoglobulins that play a major role in the immune system. In this survey, the immunoglobulin G (IgG) content, gross composition, mineral content, and fatty acid composition were determined in the colostrum of Valle del Belice ewes with the aim of evaluating the effect of lambing of season. In total, we analysed 60 bulk tank colostrum samples taken after lambing during two seasons (summer and winter). The IgG content and Brix mean values were 40.35 g/L and 21.02%, respectively. The colostrum fat, protein, casein, and lactose percentages were 8.01, 12.10, 8.51, and 3.13%, respectively. The lambing season significantly influenced the pH and somatic cell count, with higher values observed in winter than in summer. The most common fatty acids were palmitic (27.75 vs. 24.84 g/100 g), oleic (24.57 vs. 18.15 g/100 g), myristic (12.55 vs. 12.16 g/100 g) and stearic (7.02 vs. 6.16 g/100 g) detected in the summer and winter seasons, respectively. The winter season significantly increased the polyunsaturated fatty acid values (11.18 vs. 6.41). Additionally, the lambing season determined different mineral composition levels in the colostrum, particularly copper (8.50 vs. 5.35 µmol L−1) and manganese (3.35 vs. 0.80 µmol L−1), which were higher in the summer. Based on IgG content, the quality of the colostrum was excellent.

Estimation of genetic parameters and single-step genome-wide association studies for milk urea nitrogen in Holstein cattle.

The main objectives of this study were to estimate genetic parameters for milk urea nitrogen (MUN) in Holstein cattle and to conduct a single-step (ss)GWAS to identify candidate genes associated with MUN. Phenotypic measurements from 24,435 Holstein cows were collected from March 2013 to July 2019 in 9 dairy farms located in the Beijing area, China. A total of 2,029 cows were genotyped using the Illumina 150K Bovine Bead Chip, containing 121,188 SNP. A single-trait repeatability model was used to evaluate the genetic background of MUN. We found that MUN is a trait with low heritability (0.06 ± 0.004) and repeatability (0.12). Considering similar milk production levels, a lower MUN concentration indicates higher nitrogen digestibility. The genetic correlations between MUN and milk yield, net energy concentration, fat percentage, protein percentage, and lactose percentage were positive and ranged from 0.02 to 0.26. The genetic correlation between MUN and somatic cell score (SCS) was negative (-0.18), indicating that animals with higher MUN levels tend to have lower SCS. Both ssGWAS and pathway enrichment analyses were used to explore the genetic mechanisms underlying MUN. A total of 18 SNP (located on BTA11, BTA12, BTA14, BTA17, and BTA18) were found to be significantly associated with MUN. The genes CFAP77, CAMSAP1, CACNA1B, ADGRB1, FARP1, and INTU are considered to be candidate genes for MUN. These candidate genes are associated with important biological processes such as protein and lipid metabolism and binding to specific proteins. This set of candidate genes, metabolic pathways, and their functions provide a better understanding of the genomic architecture and physiological mechanisms underlying MUN in Holstein cattle.

Effect of dietary supplementation of Shatavari on productive performance andfertility of crossbred cows

The aim of the present study was to demonstrate the effect of dietary supplementation of Shatavari (Asparagus racemosus) on milk yield, raw milk constituent indices and fertility of crossbred cows. Twenty healthy lactating crossbred cows with a close date of calving were randomly divided into two equal groups for control group (CG; n = 10) and supplemented group: Shatavari root powder 50 gm/cow/d (SG; n = 12) from 7days post partum (dpp) until 90 dpp. Statistically analyzed data revealed that significantly (P&lt;0.005) higher fortnightly milk yieldfrom 45 to 90 dpp was found in the SG (10.735 to 12.396 kg/day)compared to the CG (9.802 to 10.541 kg/day). Differences in the fortnightly raw milk composition related to percent of milk fat, milk protein and milk lactose of both CG and SG cows were non-significant (P&gt;0.005), but only fortnightly percent of milk solid not-fat from 45 to 90 dpp in SG cows (9.254 to 9.446%) than over to CG cows (8.877 to 8.999%) and percent of milk total solids from60 to 90 dpp cows in SG (13.078 to 13.727%) than that cows in CG(12.617 to 12.648%) were significantly (P&lt;0.005) higher. Occurrence of first post partum estrus interval was reduced significantly (P&lt;0.005) in supplemented Shatavari group (SG: 52dpp) compared to control group (CG: 77 dpp) cows. In this study, it was observed that the overall conception rate was higher(P&lt;0.005) in SG: 60% (cows pregnant: 6/10) than CONT-group:20% (cows pregnant: 2/10). The results of this study indicated that dietary supplementation of Shatavari (Asparagus racemosus)increased the milk yield, raw milk solid not-fat, milk total solids and improved fertility of crossbred cows.

Effect of Asparagus racemosus Supplementation on Milk Yield and Composition During Summer Stress in Jersey Crossbred Cows

The experiment was conducted at the Livestock Farm Complex, Veterinary College and Research Institute (VCRI), Tamil Nadu Veterinary and Animal Sciences University (TANUVAS), Orathanadu, Thanjavur, India to study the impact of Asparagus racemosus supplementation on milk yield and composition in Jersey crossbred cows during April–May, 2020 was studied. Twelve lactating crossbred cows were randomly assigned into two groups, as control and experiment. Experimental animals were given 200 mg kg-1 body weight of Asparagus racemosus root powder. The research carried out for the period of 30 days. The amount of milk produced was recorded daily. The composition of each animal’s milk was analysed on weekly basis. The overall mean milk yield 6.38±0.13, 7.73 ±0.17 L, mean fat percentage 3.88±0.07, 4.68±0.12, mean protein percentage 3.46±0.02, 3.64 ±0.03, mean lactose percentage 3.65±0.04, 3.74±0.04, and mean solid non-fat percentage 7.73±0.06, 8.09±0.06 were obtained for control and experimental group respectively. The mean milk yield, fat percentage, milk protein percentage, lactose percentage and Solid Not Fat percentage were highly significant (p&lt;0.01) in the experimental group as compare to control group. Supplementation with Asparagus racemosus substantially improved milk yield and milk composition in the present study. It can be used to alleviate the environmental heat stress in lactating Jersey crossbred cows.

PSIII-8 Late-Breaking: Effect of Feed Additives in Protein Supplements on Reproductive Performance in Young Postpartum Range Cows

Abstract Optimizing reproductive efficiency is crucial in sustaining a successful cattle operation. However, optimizing reproductive performance in young range beef cows is often not captured due to an inability to meet the increased physiological demands. The objective of this study was to determine the impact of feed additives on reproductive performance, cow body weight (BW), body condition score (BCS), and calf growth in young, range beef cows. Data were collected from 2- and 3-year-old range cows (n = 189) from the March-calving herd at the University of Nebraska Gudmundsen Sandhills Laboratory (GSL) located near Whitman, NE over a three-year period (2019-2021). Cows were individually supplemented 908 g/d with one of two 30% crude protein supplement treatments with the addition of either: 1) 160 mg·cow-1·d-1 of rumensin (MON; Elanco Animal Health) or 2) 40 g·cow-1·d-1 of propionate salt (CAP; NutroCal 100; Kemin Animal Nutrition and Health). Supplementation was initiated approximately 7 d after calving and continued for an average of 70 d. Cow BW and BCS were collected weekly from calving to the start of breeding and then again at weaning. On approximately d 60 postpartum, milk production was measured by a modified weigh-suckle-weight technique. Cows were exposed to fertile bulls for a 45-d breeding season starting in June of each year. Cow BW (P ≥ 0.19) and BCS (P ≥ 0.11) were not affected by postpartum supplementation during the study. However, cows receiving CAP did lose more BW (P = 0.04; -7 vs -2 kg for CAP and MON; respectively) from calving to breeding than their counterpart. Calf BW at birth, weaning, or 205-d weight were not impacted (P ≥ 0.68) by the postpartum supplementation strategy. Twenty-four-hour milk production and milk components (fat, solids-non-fat, urea nitrogen) were not influenced (P &amp;gt; 0.21) by postpartum supplementation strategy. However, cows receiving CAP supplement had an increase (P = 0.04; 5.40 vs 5.31% for CAP and MON; respectively) in milk lactose percentage and tended (P = 0.06; 2.56 vs 2.68% for CAP and MON; respectively) to have lower milk protein percentage than their counterpart. Cows receiving CAP supplementation had an increase (P = 0.04; 89 vs 80% for CAP and MON; respectively) in overall pregnancy rate. This study implies that young postpartum cows fed additional glucogenic precursors in the form of propionate salts may increase reproductive efficiency without impacting a change in body weight or body condition score.

PSVI-15 Effects of Different Dietary Sources of Lipids for Lactating Ewes

Abstract The aim of this study was to evaluate the effects of diets with fatty acid profiles on lactation performance and milk composition of ewes. Dorper vs. Santa Inês ewes (n=40; 54.9 ± 8.3 kg BW and 14 days in milk) were penned individually and used in a randomized complete block design. Ewes were fed a basal diet (19.87 ± 0.62% CP) containing 70% concentrate and 30% coastcross hay, and no added oil (CON). The remaining diets were added with 4.0% of soybean oil (SO), calcium salts of palm fatty acids (CSPF), or calcium salts of soybean fatty acids (CSSF) (DM basis). Ewes were fed the diets from the week 2 to 10 of lactation. Milk production was determined every 7 days during the experiment. Ewes were separated from their lambs and mechanically milked for emptying of the mammary gland. After 3 hours, using the same procedure, milk production was recorded and samples collected for milk composition analysis. The addition of SO decreased (P&amp;lt; 0.001) DM intake, with no difference between the other treatments. Milk production, as well as the production of fat, protein, lactose and total solids (g/3 hours) were not affected by the treatments. Regarding milk composition, the percentage of milk fat and total solids increased (P&amp;lt; 0.0001) with CSSF. The percentage of protein was less (P&amp;lt; 0.001) in the milk from ewes that received the diet containing CSPF, with no difference between the other diets. Finally, the percentage of lactose was less (P&amp;lt; 0.001) for ewes fed the diet containing calcium salts of palm fatty acids. In conclusion, soybean oil had the greatest negative effect on dry matter intake. All the oil sources modulated the milk composition, with better results in this regard for the calcium salts of palm fatty acids, considering that it increased the fat and total solids content of the milk.

Nutrient intake, digestibility, and serum metabolites in dairy cows fed diets differing in starch concentration with palmitic acid or stearic acid supplementation postpartum.

The present study determined the effect of supplementing palmitic acid (PA) and stearic acid (SA) on the nutrient intake, digestibility, and serum metabolites of dairy cows fed two different starch levels during the postpartum period. Forty-four multiparous Holstein cows were used in a completed randomized block based on their parity and previous milk yield. Dietary treatments were arranged in a 2 × 2 arrangement with two dietary starch levels (HS: 260g/kg of diet dry matter (DM) vs LS: 210g/kg of diet DM) and two fat supplements rich in PA or SA at 15g/kg of diet DM. Increasing the starch concentration of the postpartum diet improved organic matter (OM), ether extract (EE), crude protein (CP), and starch intake. Moreover, HS diets resulted in higher apparent digestibility of OM and CP but lower starch digestibility than LS diets. Feeding HS diets increased fecal starch output compared with LS diets. There was starch levels and FA supplements interaction for serum albumin and total antioxidant capacity (TAC), with higher concentrations in HSSA and LSPA compared to HSPA and LSSA. Significant correlations between performance and blood metabolites were observed in weeks 3 and 4. In week 3, a negative correlation was observed between serum TAC with milk protein (r = - 0.51) and lactose percentage (r = - 0.49) in the HS diet. However, non-esterified FA was correlated with the fat to protein ratio in the LS diet (r = 0.54). Moreover, in week 4, serum TAC was negatively related to the body condition score of the cows fed LS diet(r= 0.50), while there was no relationship for cows fed HS diets. In conclusion, feeding HS diets to postpartum cows increased nutrient intake and the digestibility of OM and CP compared with LS diets. The addition of SA to the HS diet may be morebeneficial than PAin improving the oxidative status of dairy cows in the postpartum period.

Using Elisa and nested PCR for detection of the toxoplasmosis in milk and the influence of infection and some factors on milk composition in the Iraqi local and Shami goats

This study concluded detection of Toxoplasma gondii in milk, immunologically by using Elisa and nested PCR)nPCR (based on B1 gene, also to investigate the effect of toxoplasmosis, parity, breed and flock on some milk composition in the Iraqi local and Shami goats in the middle of Iraq. A total of 80 milk samples of the lactating goats were collected. Results of this study showed the prevalence of Toxoplasmosis was 21.25% and 28.75% by Elisa and nPCR respectively without significant differences. The sensitivity of Elisa was a low (30.43%) whereas the specificity was a high (82.45%). The degree of agreement estimated by Kappa coefficient revealed a slight agreement (0.14) between two methods. The results indicated that goats infected with toxoplasmosis have significantly (P&lt;0.05) higher in protein and lactose percentage whereas the effect was not significant for each of fat, SNF and pH. On the other hand, the effect of parity was significant (P&lt;0.05) on fat, protein, lactose, solid nonfat and non-effect on PH. As well as effect of breed and flock was significant (P&lt;0.05) on protein, lactose and solid nonfat without significant effect on fat and PH.

Effects of supplementary inulin on ewes milk composition and rumen fermentation parameters.

This experiment aimed to investigate the effects of inulin supplementation on milk production and composition, feed intake, nutrient digestibility and rumen fermentation parameters in lactating ewes. The experimental treatments were (1) control group (basal diet), (2) basal diet plus 2% inulin (w/w) and (3) basal diet plus 4% inulin (w/w). The experiment was carried out for 21 d in a fully randomized design involving eighteen Ghezel ewes. Production and composition (percentages of fat, protein, lactose and fat-free solids and fatty acid profiles) of milk were measured. Faeces were collected in the last 3 days of the experiment to determine digestibility. On the last day of the experiment, rumen fluid samples were taken from the esophagus 3 h after feeding and fermentation parameters (pH, ammonia nitrogen (N-NH3), volatile fatty acids (VFA) and protozoal population) were examined. Daily milk production was not significantly affected by inulin supplementation, but the fat and protein content of the milk was increased whilst urea nitrogen (MUN) and unsaturated fatty acids were decreased (P < 0.05). The dry matter (DM) intake results showed that there was no significant difference between different diets. The highest digestibility of DM and NDF belonged to the inulin fed group (P < 0.05). Inulin consumption numerically increased the pH of the rumen fluid of the animals and significantly decreased the rumen N-NH3 value (P < 0.05). Inulin supplementation also significantly increased total VFA, acetate, and butyrate levels (P < 0.05). In general, it can be concluded that inulin supplementation can improve rumen fermentation, DM and NDF digestibility,as well as compositional aspects of the ewe's milk production.

Effect of supplementation of probiotics and rumen buffer on performance of lactating buffaloes

The study involved 12 Murrah buffaloes which were divided into two groups of six each viz. Control (T0) and Treatment group (T1). The buffaloes from Group T0 received standard concentrate mixture and roughages as per the routine practice of the farm. Whereas Group T1 received same ration as that of Group T0 along with supplement containing probiotics like yeast (Saccharomyces cerevisiae), bacteria (Bacillus subtilis, Bacillus pumilus and Bacillus amyloliquifaciens) and rumen buffer 10 g/day/animal. The experiment lasted for 91 days. The average daily milk yield and FCM yield, DMI, TDN and DCP intake of buffaloes from Treatment group (T1) was significantly (P˂0.01) higher than Control group. The efficiency of feed utilization in terms of dry matter required per kg of FCM yield produced was significantly (P˂0.01) better in Group T1 than Control group. The average milk fat, protein, total solids, SNF and lactose percentage of Group T1 was significantly (P˂0.01) higher than Control group. The average somatic cell count of milk of buffaloes form Group T1 was significantly (P˂0.05) lower than Control group. The economics of the study showed an extra profit of ₹ 25.20 in Supplemented group over Control group.

FASN gene polymorphism and its relationship with milk yield and Composition in the Iraqi Awassi sheep

This study was conducted at the Barakat Abu Fadl al-Abbas (peace be upon him) sheep breeding station / Al-Kafeel General Investment Company in Karbala Governorate for the period from 1/12/2020 to 1/6/2021, with the aim of determining the Frequency of Alleles and Genetic Manifestations of the FASN gene and its relationship to milk production and its main components from The percentage of fat, protein, lactose and non-fat solids in Iraqi Awassi sheep, 51 female Awassi sheep were used in this study. The percentage of distribution of genotype for the FASN gene in the studied Awassi sheep sample was 7.84, 21.57 and 7.59% for each of the structures AA, AC and CC, respectively, and the two alleles were A and C, with a frequency of 0.19 and 0.81. respectively, significant differences were found in total milk production. As for the milk components, only the protein percentage was affected significantly by the different genotype, and there was no significant effect for the other components by the different genotype of the FASN gene. From the results of the current study, it can be concluded that the FASN gene can be adopted as an important indicator in the development of genetic improvement strategies for Awassi sheep to maximize the economic return from breeding projects by selecting and cross-breeding the genotypes that achieved the best productive performance.

Effect of cumin (Cuminum cyminum) seed supplementation on production performance, nutrient digestibility and haemato-biochemical profile of Mehsana goats

A study was carried out to investigate the effect of supplementation of cumin (Cuminum cyminum) seed (CS)on the production performance, nutrient digestibility and hemato-biochemical profiles of lactating Mehsana goats.Twenty lactating Mehsana goats (7 days post-partum) were assigned randomly into two groups (10 animals ineach), control (CON: fed basal diet without supplement) and treatment (CS: basal diet supplemented with10 g/animal/d of CS) for the duration of 60 days. The final body weight was significantly higher (38.09 vs. 34.04kg) in the animals of CS group than the CON group. Feeding of cumin seed to the lactating goats did not influencedaily dry matter intake. However, cumin seed supplementation increased milk yield (985 vs. 859 g/d), 4% FCM(818 vs 623 g/d) and ECM (952 vs. 742 g/d) as compared to the CON group. The percentages of milk fat, SNF, totalsolids and lactose were also improved by the supplementation of cumin seed. Apparent digestibility of dry matterwas comparable in CON and CS groups. However, the digestibilities of crude protein (58.19 vs. 66.97%), crude fibre(47.05 vs. 55.28%), ether extract (67.00 vs.75.82%) and nitrogen free extract (65.25 vs. 75.32%) were significantlyimproved in cumin supplemented group. There was no effect on haematological parameters between the CON andCS groups. The supplementation of cumin has significantly improved glucose concentration in CS group whencompared to the CON group. The concentrations of other estimated blood metabolites were not affected by thecumin supplementation in lactating goats. Based on the results of the present study, it can be concluded that cuminsupplementation in the diet of lactating Mehsana goats at the rate of 10 g/d improved milk yield, nutrient digestibility and feed efficiency without any adverse effect on haemato-biochemical parameters

Feasibility of Supplying Ruminally Protected Lysine and Methionine to Periparturient Dairy Cows on the Efficiency of Subsequent Lactation.

The objective of this study was to evaluate the effects of supplying ruminally protected Lys (RPL) and ruminally protected Met (RPM) to transition cows' diets on the efficiency of subsequent lactation. A total of 120 prepartum Holstein cows were assigned into four treatments blocked by the anticipated calving date, previous lactation milk yield, number of lactations, and body condition score and fed either RPL, RPM, or the combination (RPML) or control diet (CON) throughout the transition period (3 weeks before till 3 weeks after calving). From 22 to 150 days in milk (DIM), all animals (100 cows) were fed a combination of RPM and RPL (0.17% RPM and 0.41% RPL of DM; n = 25 cows/treatment) as follows; CON–RPML, RPM–RPML, RPL–RPML, and RPML–RPML. Milk production and dry matter intake (DMI) were measured daily; milk and blood samples were taken at 21, 30, 60, 90, 120, and 150 DIM. Supplemented amino acids (AA) were mixed with the premix and added to the total mixed ration during the experiment. DMI (p < 0.001) and energy-corrected milk (ECM, p = 0.04) were higher for cows that were fed RPML–RPML than other cows. Compared with CON–RPML, yields of milk total protein, lactose, and nitrogen efficiency were increased (p < 0.01), whereas milk urea nitrogen (MUN; p = 0.002) was decreased for other treatments. However, supplemental AA did not affect milk lactose percentage, fat yield, feed efficiency, or serum total protein concentration (p > 0.10). Transition cows that consumed AA had a greater peak of milk yield (p < 0.01), as well as quickly reached the peak of milk (p < 0.004). There were differences in β-hydroxybutyrate concentration during the early lactation, with a lower level for AA groups (p < 0.05), and the difference faded with the progression of lactation (p > 0.10). Fertility efficiency as measured by pregnancy rate was improved by supplemental AA during the perinatal period (p < 0.05). In conclusion, transition cows consumed RPM and RPL, increased post-calving DMI, milk production, milk protein yield, nitrogen efficiency, and improved fertility performance.

Supplementing Ruminally Protected Lysine, Methionine, or Combination Improved Milk Production in Transition Dairy Cows.

The objectives of this study were to evaluate the effects of dietary supplementation of ruminally protected lysine (RPL), or methionine (RPM), and their combination (RPML) on the production efficiency of transition cows. A total of 120 pre-partum multiparous Holstein cows were assigned to four treatments based on previous lactation milk production, days (d) of pregnancy, lactation, and body condition score (BCS). Cows were fed a basal diet [pre-calving: 1.53 Mcal/kg dry matter (DM) and post-calving: 1.70 Mcal/kg DM] with or without supplemental ruminally protected amino acids (RPAA). Treatments were the basal diets without supplemental amino acids (CONTROL, n = 30), with supplemental methionine (RPM, pre-calving at 0.16% of DM and post-calving at 0.12% of DM, n = 30), with supplemental lysine (RPL, pre-calving at 0.33% of DM and post-calving at 0.24% DM, n = 30), and the combination (RPML, pre-calving at 0.16% RPM + 0.33% RPL of DM and post-calving at 0.12% RPM + 0.24 % RPL DM, n = 30). The dietary content of lysine was balanced to be within 6.157.2% metabolizable protein (MP)–lysine and that of methionine was balanced within 2.1–2.35% MP-methionine. Dry matter intake (DMI) was measured daily. Milk samples were taken on d 7, 14, and 21 days relative to calving (DRC), and milk yields were measured daily. Blood samples were taken on d −21, −14, −7 before expected calving and d 0, 7, 14, and 21 DRC. Data were analyzed using SAS software. There were significant Trt × time interactions (P < 0.01) for DMI pre- and post-calving period. The CON cows had lower DMI than RPM, RPL, and RPML, both pre-calving (P < 0.01) and post-calving periods (P < 0.01). Energy-corrected milk (P < 0.01), milk fat (P < 0.01), protein (P = 0.02), and lactose (P < 0.01) percentage levels were greater for RPM, RPL, and RPML cows compared to CON. Supplementing RPAA assisted in maintaining BCS post-calving than CON (P < 0.01). Blood concentrations of β-hydroxybutyrate decreased with RPM or RPL or the combination pre-calving (P < 0.01) and tended to decrease post-calving (P = 0.10). These results demonstrated that feeding RPL and RPM improved DMI and milk production efficiency, maintained BCS, and reduced β-hydroxybutyrate concentrations of transition cows.

Evaluation of Different Chemical and Physical Components of Milk in Cows, Buffalos, Sheep, and Goats.

In recent years, the consumption of milk and dairy products has dramatically increased in several parts of the world. Different livestock plays an essential role in global milk production. This study was designed to evaluate different chemical and physical components of milk in four groups of livestock, including cows, buffalos, sheep, and goats. To this end, 200 raw milk samples were collected from cows, buffalos, sheep, and goats (n=50) across Dhi-Qar Governorate, Iraq, for a period of one year (from 01.10.2018 to 01.06.2019). The findings showed sheep and buffalos' milk samples had a significantly higher percentage of total solids (TS%), compared to cows and goats' milk samples (P<0.05). However, there were no significant differences in the TS% between sheep and buffalos' milk samples. Furthermore, the mean TS% values in cows, buffalos, sheep, and goats' milk samples were determined at 11.14%, 12.87%, 13.26%, and 11.33%, respectively. As for fat percentage (F%), buffalos' milk samples had significantly higher F% (4.80%), compared to milk samples of cows, sheep, and goats (P<0.05). Additionally, sheep's milk samples had significantly higher F% (P<0.05) than cows and goats' milk samples determined at 2.78%, 4.20%, and 2.98%, respectively. The findings showed the percentage of solids not fat (SNF%) was significantly higher in sheep's milk (8.97%), compared to milk samples of cows, buffalos, and goats (P<0.05). Additionally, it was found that the SNF% was significantly higher (P<0.05) in Buffalos' milk samples, compared to cows and goats' milk samples determined at 8.36%, 8.60%, and 8.35%, respectively. Moreover, the results revealed that the percentage of milk protein content in sheep's milk was significantly higher than the cows, buffalos, and goats' milk (P<0.05). Recorded data also showed no significant differences in the percentage of milk lactose among cows, buffalos, sheep, and goats' milk samples (P<0.05). Furthermore, the findings illustrated that the percentage of milk ash (Ash%) in sheep's milk samples was significantly higher than the cows, buffalos, as well as goats' milk samples (P<0.05), and no significant differences were observed among cows, buffalos, and goats' milk samples in the Ash% (P<0.05). In addition, there were no significant differences in the specific gravity among different milk samples (P<0.05). Finally, the results displayed no significant differences between cows and goats' milk samples in all the studied traits (P<0.05).

Chemical evaluation of donkey milk yoghurt mixed with milk from different animal species

The objective of this study was to prepare three donkey milk yoghurt formulations mixed with goat, cow and buffalo milk. The formulations were developed with 50% donkey milk and 50% cow, buffalo or goat milk. Concentrated mango pulp was added for flavouring. An evaluation was performed on the chemical composition of each milk sample and the formulated yoghurts. The donkey milk showed the lowest values for fat, protein, casein, total solids and non-fat solids. In turn, goat milk reached higher levels of fat and total solids. Furthermore, buffalo milk stood out with the highest values of protein and non-fat solids. Yoghurt made with donkey and buffalo milk showed higher concentrations of protein, lactose, total solids and non-fat solids. In contrast, the yoghurt that contained donkey and cow milk in its formulation obtained a higher fat percentage and a lower percentage of lactose, total solids and non-fat solids. The low content of fat and total solids in donkey milk, in addition to the structure of the casein micelles and small fat globules favor low consistency in fermented products. Thus, mixing donkey milk with milks from other animal species can result in better chemical composition and better consistency.

Fermentation Parameters of Suero Costeño Elaborated with Lactic Acid Bacteria Strains

Studying the fermentation parameters of "Suero Costeño" was the focus of this research, considered a traditional product in the Caribbean region of Colombia, inoculated with lactic acid bacteria Lactococcus lactis subsp. Lactis (ATCC29146) and Lactobacillus paracasei subsp. paracasei (ATCC 334). It was found that the percentage of lactose decreased progressively during the hours of fermentation, with a minimum lactose value of 3.1% at 15 h for the samples of Suero Costeño with L. lactis, while for L. paracasei the percentage of lactose was 3.4%. L. paracasei the percentage of lactose was 3.4%; on the other hand, the pH, which is a limiting factor in the fermentation process, was reported to have a considerable reduction in the samples with L. lactis in comparison with L. paracasei, at the end of the fermentation process at 15 h, with values of 4.3 and 4.5, respectively. Finally, the sensory evaluation allowed establishing that the Suero Costeño with L. lactis obtained similar values to that produced in a traditional way, and therefore its use can be recommended in this type of dairy products as a starter culture.

The influence of crossbreeding and LPL genotype on the yield, composition and quality of goat milk

The aim of this study was to investigate the influence of crossbreeding and the LPL genotype on goat milk yield, composition and quality indicators. This research was carried out in a herd of pure-breed Saanen, Anglo-Nubian, and crossbred Saanen and Anglo-Nubian goats (n=137) in Lithuania. Saanen x Anglo-Nubian crossbred goats and Saanen had a significantly (P&lt;0.05) higher (34.91% and 16.03%, respectively) milk yield compared to Anglo-Nubian goats. The highest (P&lt;0.05) fat and protein and the lowest (P&lt;0.05) lactose percentages and somatic cell count were found in the milk of Anglo-Nubian goats, compared to Saanen x Anglo-Nubian crossbreds and Saanen goats. The highest (P&lt;0.05) milk yield was determined in the CC genotype of the LPL gene (on average 20.08% higher than in the CG and GG genotypes) of goats. However, the milk yield of the CC genotype was characterised (P&lt;0.05) by the lowest fat, protein and milk urea levels, and the highest amount of lactose compared to the milk of the GG genotype. The study showed that breed and LPL genotype affected goat milk yield and composition and appear to be the valuable biomarkers of the goat selection process.

Association of genetic variants in STAT5B gene with milk performance and mastitis related traits in dairy cattle

Udder performance and health are important traits in dairy cattle worldwide. The present study aimed to explore the association of single nucleotide polymorphisms (SNPs) in the STAT5B gene in dairy cattle with milk performance and mastitis related traits. The study included 201 cows of three pure breeds (i.e. Holstein Friesian, Jersey and Achai) and two crossbred cattle at four established dairy farms in Khyber Pakhtunkhwa, Pakistan. The milk samples were analysed for somatic cell count (SCC) and milk composition (i.e. fat , protein and lactose percentages). The generalized linear model was deployed for association analysis using SAS. The pool DNA sequencing showed four (three synonymous and a 3/ UTR) SNPs in STAT5B. These SNPs were further validated in all DNA samples using SNaPshot assay. The breed-wise analysis showed that most of the SNPs were consistent with Hardy-Weinberg equilibrium (P&gt;0.05). The association analysis revealed a significantly higher protein percentage in TT genotype and lower SCC in CC genotypes of SNP 1 (exon 2, C&gt;T), whereas in SNP 2 (exon 16, T&gt;C) the TT genotypes revealed significantly lower SCC and SCS compared with other genotypes (P&lt;0.05). SNP 4 (3/ UTR, C&gt;T) showed significantly lower SCC and frequency of clinical mastitis in the heterozygous (CT) genotype compared to the homozygous genotypes. The in silico predictions revealed changes in the RNA secondary structure for SNP 2 and SNP 3. The study suggests that STAT5B should be considered as a candidate gene, and the variants identified as useful genetic markers for improved milk composition and udder health.