Seasonal variation in in vitro immune activity of milk leukocytes in elite and non-elite crossbred cows of Indian sub-tropical semi-arid climate

Immunity of mammary gland in terms of in vitro activity of milk leukocytes has been evaluated during hot-humid, summer, and winter season in elite (n = 10) and non-elite (n = 10) crossbred cows. Milk samples were collected from all the cows throughout the year at 15-day interval. Milk somatic cell counts (SCC) and differential leukocyte counts (DLC) were evaluated microscopically. Milk neutrophils, macrophages, and lymphocytes were isolated and cultured in vitro. In vitro PI of milk neutrophils and macrophages was evaluated by colorimetric NBT (nitro-blue tetrazolium) reductive assay. Mitogen-induced milk lymphocyte blastogenic response was measured by colorimetric MTT (thiazolyl blue tetrazolium bromide) assay. Milk SCC was found to be significantly (p < 0.01) higher in elite cows compared to non-elite cows irrespective of season. There was significant (p < 0.05) increase in milk SCC during hot-humid season compared to winter season in both the group of the cows. There was no significant difference between group and season in terms of DLC. In vitro phagocytic index of elite cows was significantly (p < 0.01) higher than non-elite cows. The phagocytic index was significantly (p < 0.01) decreased in summer and hot-humid season compared to winter season in both the group of animals. Macrophages isolated from elite cows having significantly (p < 0.01) lower phagocytic index than non-elite cows which significantly (p < 0.01) decreased during summer and hot-humid season compared to winter. In vitro milk lymphocyte proliferative response was significantly (p < 0.01) lower in elite cows. Activity of B-lymphocytes decreased significantly (p < 0.01) during summer and hot-humid season than winter, but activity of T-lymphocytes remains unaltered during different seasons. In conclusion, the mammary immunity in terms of in vitro activity of milk leukocytes is compromised during summer and hot-humid season in elite crossbred cows; therefore, better care and management should be taken in high-yielding cows during summer and hot-humid season to minimize intramammary infections.     

Alterations in the milk yield and composition during different stages of lactation cycle in elite and non-elite Karan-Fries cross-bred cows (Holstein Fresian x Tharparkar)

Alterations in the milk constituents throughout the lactation cycle have been studied in 20 Karan-Fries cross-bred cows (Holstein Fresian x Tharparkar) divided into two groups, viz. elite (n = 10) and non-elite (n = 10). About 100 ml of composite milk samples (from all the quarters) were collected through hand milking in sterile tubes from the day of calving at 15-day interval till 300 days of lactation cycle. Different milk constituents (viz. fat, protein, lactose, Solid not fat) were estimated by automatic milk analyzer. The daily milk yield varied significantly (p < 0.01) between group and different days of lactation cycle. Milk fat percentage of milk did not differ significantly between groups and different days of lactation cycle. Milk protein and lactose percentage did not differ significantly between groups but differed significantly (p < 0.001) between days. Solid not fat (SNF) percentage of milk was significantly (p < 0.01) higher in elite cows compared to non-elite cows and also varied significantly (p < 0.05) during different days of lactation cycle. In both the group of cows, milk protein, fat, and SNF percentage was highest and lactose percentage was lowest up to 1st week of lactation cycle and rapidly declined thereafter due to the transition of the colostrum into milk. After 2nd week of lactation, all the milk constituents under study were almost remained unaltered till the end of the cycle. The above stated investigation not only substantiates the already existing information of lactation stage-specific alteration in milk constituents but also depict the exact point of transition of these constituents during the lactation cycle so the nutritional and managemental interventions could be carried out in proper time.     

Alterations in the relative abundance of Haptoglobin (Hp) transcripts in total milk somatic cells during different stages of lactation cycle in high yielding cross-bred cows

The expression profile of Haptoglobin (Hp) gene in total milk somatic cells (SCC) of high-yielding cross-bred Karan Fries (KF) was studied during early, mid, and late lactation cycle. Milk samples (200 ml/animals) were collected from 10 high-yielding and 10 low-yielding cows throughout the lactation cycle (from day 7 to day 300) with an interval of one month. Relative mRNA expression profiles of Hp by RT polymerase chain reaction was studied in high-yielding cows, whereas low-yielding cows were taken as control. The folds of induction of Hp was significantly (p < 0.001) downregulated by a mean factor of 0.207 in milk SCC during early lactating cows. Whereas, it was significantly (p < 0.01) upregulated by a mean factor of 20.888 during mid lactation. The expression was unaltered during the late lactation. The study demonstrates that Hp is synthesized within the mammary gland and significantly upregulated during mid-lactation period compared to other stages of lactation cycle.     

Infradian rhythmicity in milk leukocyte activity together with plasma cortisol and prolactin levels throughout the lactation period in high-yielding crossbred cows

Infradian rhythmicity in milk leukocyte activity together with plasma cortisol and prolactin levels throughout the lactation period in high-yielding crossbred cows has been studied in 10 high-yielding (milk production: 5000 l per lactation) Karan Fries crossbred (Holstein Friesian × Tharparkar) cows. Milk and blood samples were collected from all the experimental animals. Isolation of milk phagocytes (neutrophils and macrophages) and lymphocytes were done by density gradient centrifugation. In vitro phagocytic index of milk neutrophils and macrophages was performed by colorimetric NBT reductive assay. Mitogen-induced milk lymphocyte blastogenic response was estimated by colorimetric MTT (tetrazolium) assay. Total plasma cortisol and prolactin were estimated by enzyme immune assay. Highest value of plasma cortisol and prolactin was observed at calving which decreased significantly (p < 0.01) on 15th day postpartum for both prolactin and cortisol. Immune activity of milk leukocytes was highest on day 0 colostrum and decreased significantly (p < 0.01) on 7th day postpartum. A significant (p < 0.01) rise of plasma prolactin was observed around 135th and 225th days postpartum, whereas a peak level of plasma cortisol was observed at 105th, 180^th, and 270th days postpartum. Phagocytic index of milk neutrophils and macrophages remains almost in a steady state during mid-lactation period (between 100 and 200 days postpartum). A decline in increasing trend of milk phagocytic activity was observed during late lactation. Mitogen-induced milk lymphocyte blastogenic response was highest on day 0 colostrum which decreased significantly (p < 0.01) on 15th day postpartum. Con A-induced milk lymphocyte blastogenic response showed an increasing trend from 120th to 210th days postpartum. Upon correlation study, it showed that the plasma cortisol has a negative effect on milk leukocyte activity, while prolactin has a positive effect, though the effect is lactation stage specific.     

Infradian rhythm in hematology,cell mediated immunity and serum micronutrient concentration around peripartum periods in high yielding crossbred cows before and after micronutrient supplementation

Alteration in hematology and cell-mediated immunity around peripartum periods before and after micronutrient supplementation was studied in this investigation. Twelve (12) high-yielding cross-bred cows in advanced pregnancy were selected for the experiment and divided into two equal groups viz. supplemented (n = 6) and unsupplemented (n = 6). Supplemented animals were provided with a micronutrient mixture (@ 25 g per cow) as per the recommendation of NRC over the normal feeding. Unsupplemented group of cows were kept as control with standard farm feeding management. Blood samples (15 ml/cow) were collected from all the animals during days 30th, 15th, and 7th before calving, on the day of calving, and during days 7th, 15th, and 30th after calving and analyzed for hematology viz. hemoglobin (Hb), total erythrocyte counts (TEC), total leukocyte counts, and differential leukocyte counts. In vitro phagocytic index (PI) of neutrophils and lymphocyte proliferation response (LPR) were also evaluated. Copper (Cu), zinc (Zn), manganese, and selenium (Se) concentrations in serum were estimated by atomic absorption spectrophotometer. The Hb concentration was found to be significantly (p < 0.01) higher in supplemented group compared to the unsupplemented group of cows. There were no significant differences in Hb concentration during different days of peripartum in both the group of cows. There was a significantly (p < 0.001) higher TEC in supplemented group compared to unsupplemented group of cows, though it did not vary significantly between different days of peripartum in both the group of cows. There was a significantly (p < 0.001) higher PI in supplemented group compared to the unsupplemented group of cows. In both the groups, the PI of blood neutrophils was significantly (p < 0.001) lower during calving. The LPR did not differ significantly between the groups, but it differed significantly (p < 0.01) between different days of peripartum and was lowest on the day of calving in both the groups. The Cu, Zn, and SE concentration was found to be significantly (p < 0.01) higher in supplemented group compared to the unsupplemented group of cows, but remained unaltered throughout the peripartum period. The study indicated that there was a marked immune depression around peripartum (15 days precalving to 15 days postcalving) in terms of in vitro phagocytic activity of blood neutrophils and in vitro LPR. Supplementation of micronutrients improves the hematological status as well as immune status, so it was recommended to supplement these micronutrients for better productivity and disease resistance in high-yielding cross-bred cows around peripartum.     

Behavior and Performance of Dairy Cows After Transfer from Tied to Cubicle Housing

Behavior and performance changes when tied dairy cows were moved to a loose housing system in a cubicle system were investigated. Behavioral observations were made for 3 consecutive days in 3 periods after transition. The cows (n = 105) were observed on 18 sampling occasions for 1 month. Recordings were made of body positions and general and social behaviors. Monthly milk records were collected 1 year before and 1 year after transition. Cows walked more during the 1st observation period than during the other periods (p < .05). Walking activity also differed between days when nested to period (p < .05). During the 1st period, cows ruminated while standing more than during the 3rd period (p < .05). Cows ate and groomed less and vocalized more during the 1st period (p < .05). It was concluded that after transition from a tied to a cubicle system, several behaviors were affected during the 1st days, and milk production of multiparous cows was negatively affected, although this effect was not long-term.     

Investigations on the effect of a niacin supplementation to three diets differing in forage-to-concentrate ratio on several blood and milk variables of dairy cows

The objective of this study was to investigate the influence of a niacin supplementation to three diets with different forage-to-concentrate ratios on blood and milk parameters. Seven midlactation (102 ± 18 days in milk) and three dry cows of the Holstein-Friesian breed, equipped with cannulas in the dorsal sac of the rumen and proximal duodenum, were used. On a dry matter basis the rations applied consisted of either ? concentrate and ? forage (LC), ½ concentrate and ½ forage (MC), or ? concentrate and ? forage (HC). They were fed for one period without and in the following with a supplementation of 6 g niacin (nicotinic acid) per cow per day. The basal niacin content was 35.0 mg/kg for LC, 34.6 mg/kg for MC and 34.4 mg/kg for the HC diets on a dry matter basis. Blood was sampled before, then three and six hours after first morning feeding from the vena jugularis externa. Milk samples were obtained on two days. Niacin feeding enhanced concentrations of glucose and urea in serum (p < 0.05). No effect of supplemental niacin was seen on serum non-esterified fatty acids or ß-hydroxybutyrate concentrations. Increasing the proportion of concentrate and niacin supplementation enhanced serum nicotinamide concentration (p < 0.01). Nicotinamide concentrations or amounts excreted via milk were influenced by forage-to-concentrate ratio (p < 0.05), but not by niacin supplementation. Milk fat composition showed an effect of additional niacin, as the proportion of oleic acid increased in milk of niacin supplemented cows (p = 0.04). For all parameters analysed, no significant interaction between forage-to-concentrate ratio and niacin supplementation was found.     

Milk fatty acid profile of Peruvian Criollo and Brown Swiss cows in response to different diet qualities fed at low and high altitude

Two identical experimental protocols were followed at 200 and 3,600 m above sea level (a.s.l.) determining the changes of the milk fatty acid (FA) profile of Brown Swiss (BS) and indigenous Peruvian Criollo cows (CR) as a response to diets which were designed to cover the variation in feed quality caused by season. At each site (altitude), six BS and six CR cows, adapted to >3,500 m a.s.l., were fed three dietary treatments (DS, dry-season forage; RS rainy-season forage; OC, diet optimised to meet the cow's requirements) in a 2 × 2 × 3-factorial arrangement. Intakes of FA and milk yield increased from diet DS (low quality diet) to RS and OC (high quality diet) for both cow types. Milk fat proportions of conjugated linoleic acid (CLA), C18:3 c9,c12,c15, total n-3 and polyunsaturated FA (PUFA) were highest (p < 0.05) with diet OC and higher in the lowlands than in the highlands. Low intakes of diet DS obviously resulted in a ruminal energy deficiency and body lipid mobilisation. The ruminal energy deficiency with diet DS was especially pronounced in BS, apparently reducing biohydrogenation rate and leading to lower proportions of C18:0 and higher proportions of C18:3 c9,c12,c15 in milk fat (p < 0.05). Especially C18:3 c9,c12,c15 intake did not concur with its proportion in milk fat, suggesting a strong dependence on energy status. Milk yield and FA excretion with milk were higher for BS than for CR (p < 0.05) with all three diets although milk fat content was lower (p < 0.05) for BS than CR. Milk fat of BS was richer in CLA and PUFA than milk fat of CR (p < 0.05). The desaturase indices for 18 FA were also higher for BS than CR (p < 0.05), suggesting a slightly higher Δ9-desaturase activity for BS, especially with diet DS. Milk fat content was generally higher at the high altitude than at the lowland site (p < 0.05), whereas the FA profile was unexpectedly similar across sites. Various interactions were found among diet type, cow type and altitude (site) indicating that a combination of these factors contributes to the characteristic FA profile of the respective milk.     

Effects of partially replacing barley or corn with raw and micronised CDC SO-I oats on productive performance of lactating dairy cows

Recently, a new genotype of oat (cv. CDC SO-I, containing low-hull lignin and high-fat groat), has been developed. The objective of this study was to determine the effects of partially replacing barley and corn with the new oat and its micronisation on lactating performance of dairy cows. In a double 4 × 4 Latin square design, eight lactating dairy cows (732 ± 46 kg body weight [BW]; parity 4 ± 2) received total mixed rations with a forage-to-concentrate ratio of 50:50 (DM basis). The four treatments were: T1, barley only (control); T2, raw oat, replacing 42% barley of T1; T3, micronised oat, replacing 42% barley of T1; and T4, raw oat and corn blend, replacing 100% barley of T1. The results showed that dairy cows fed the new oats (T2, T3) produced more fat (p < 0.05) and more fat corrected milk (p < 0.10) than cows fed barley only (T1). The performance of cows fed the new oat and corn blend (T4) was not significantly different from other treatments. The micronisation significantly reduced protein degradability (74 vs. 63%, p < 0.05), but increased starch degradability (87 vs. 93%, p < 0.05) of the new oat. However, the overall results suggested that micronisation did not show a significant impact on milk production. The newly developed CDC SO-I oat can replace 42% barley (in T1) as a concentrate supplement in dairy total mixed rations with an increased yield of milk fat and fat corrected milk.     

Influence of feeding whole sunflower seed and extruded linseed on production of dairy cows,rumen and plasma constituents,and fatty acid composition of milk

Holstein cows were fed total mixed rations (TMR) supplemented with protected palm fat (PPF), whole sunflower seed (WSS) or extruded linseed (ELS) for 100 days. Percentage of dietary crude fat was 5.3, 5.1 and 5.1, respectively. Diet had no (p > 0.05) effect on feed intake, milk yield or milk protein content. Percentage of milk fat and yield of fat – corrected milk were significantly increased when diets were supplemented with WSS and ELS. Feeding PPF resulted in the lowest (p < 0.05) ruminal concentration of volatile fatty acids. No significant dietary effect on plasma characteristics was observed. Concentration of polyunsaturated fatty acids (PUFA) was higher (p < 0.05), and PUFA n-6/n-3 ratio lower (p < 0.05), in the milk fat from cows fed ELS compared to WSS. Supplementation of TMR with oilseeds compared to PPF increased the content of CLA in milk fat (p < 0.005) and decreased its atherogenicity, primarily due to a significant reduction of palmitic acid concentration. Both oilseeds significantly improved the spreadability index of manufactured butter. ELS, but not WSS, increased the susceptibility of milk fat to oxidation (p < 0.05). It can be concluded that feeding of oilseeds to dairy cows improved nutritional quality of milk fat, with supplementation with ELS producing an even more desirable milk fatty acid profile than WSS supplementation.     

Feeding dried distillers grains with solubles to lactating beef cows: impact of excess protein and fat on cow performance,milk production and pre-weaning progeny growth

Multiparous Angus×Simmental cows (n=54, 5.22±2.51 years) with male progeny were fed one of two diets supplemented with either dried distillers grains with solubles (DDGS) or soybean meal (CON), from calving until day 129 postpartum (PP) to determine effects of excess protein and fat on cow performance, milk composition and calf growth. Diets were formulated to be isocaloric and consisted of rye hay and DDGS (19.4% CP; 8.76% fat), or corn silage, rye hay and soybean meal (11.7% CP; 2.06% fat). Cow–calf pairs were allotted by cow and calf age, BW and breed. Cow BW and body condition score (BCS; P⩾0.13) were similar throughout the experiment. A weigh-suckle-weigh was performed on day 64 and day 110±10 PP to determine milk production. Milk was collected on day 68 and day 116±10 PP for analysis of milk components. Milk production was unaffected (P⩾0.75) by dietary treatments. Milk urea nitrogen was increased at both time points in DDGS compared with CON cows (P<0.01). Protein was decreased (P=0.01) and fat was increased (P=0.01) in milk from DDGS compared with CON cows on day 68 PP. Compared to CON, DDGS decreased medium chain FA (P<0.01) and increased long chain FA (P<0.01) at both time points. Saturated FA content of milk was decreased (P<0.01) at both time-points in DDGS compared with CON cows, which resulted in an increase (P<0.01) in monounsaturated and polyunsaturated FA, including cis-9, trans-11 conjugated linoleic acid. Daily gain of the DDGS calves was increased (P=0.01) compared with CON calves, resulting in heavier BW on day 129 (P=0.01). Heavier BW of DDGS calves was maintained through weaning (P=0.01). Timed-artificial insemination (TAI) rates were greater for cows fed DDGS compared with cows fed CON (P<0.02), but dietary treatment had no effect on overall pregnancy rates (P=0.64). In summary, feeding DDGS to lactating beef cows did not change cow BW or BCS, but did improve TAI rates and altered milk composition compared with CON. As a result, male progeny from cows fed DDGS during lactation had greater average daily gain and were heavier at day 129 and at weaning compared with male progeny from cows fed a control diet.     

Colostrum and milk selenium,antioxidative capacity and immune status of dairy cows fed sodium selenite or selenium yeast

Dietary selenium (Se) can be supplemented from organic or inorganic sources and this may affect Se metabolism and functional outcome such as antioxidative status and immune functions in dairy cows. A feeding trial was performed with 16 Holstein-Friesian dairy cows fed with a total mixed ration (0.18 mg Se/kg dry matter (DM)) either without Se supplement (Control, n = 5), or with Se from sodium selenite (Group SeS, n = 5) or Se yeast (Group SeY, n = 6). In Groups SeS and SeY, the Se supplementation amounted to an additional intake of 4 mg Se and 6 mg Se/d during gestation and lactation, respectively. The effect of both Se sources was characterised by milk Se and antioxidant levels, and the phenotyping and functional assessment of phagocytic activity of milk immune cells. Se yeast has been found to increase (p ≤ 0.001) the milk Se and antioxidant levels markedly compared to the control group. The experimental treatment did not affect the immune parameters of the cows. Lymphocyte subpopulations and phagocytosis activity of neutrophilic granulocytes were affected neither by the Se intake nor by the two different dietary supplements. It can be concluded that sodium selenite and Se yeast differ considerably in their effects on antioxidant status in dairy cows. However, the basal dietary Se concentration of 0.18 mg/kg DM seemed to be high enough for the measured immune variables.     

Effects of dry period length on milk production and energy balance in two cow breeds

Shortening the dry period (DP) has been proposed as a strategy to improve energy balance (EB) in cows in early lactation. This study evaluated the effects of shortening the DP on milk yield (MY), EB and residual feed intake (RFI) in two breeds; Swedish Red (SR) and Swedish Holstein (SH). Cows were blocked by breed and parity and then randomly assigned to one of two treatments; short DP of 4 weeks (4W, n=43) or conventional DP of 8 weeks (8W, n=34). Cows were kept and fed under the same conditions, except for the 4 weeks when the 4W group were still lactating prepartum and thus kept with the lactating cows. Milk yield and BW were recorded and body condition score (BCS) was rated from 10 weeks prepartum to 12 weeks postpartum. Dry matter intake (DMI) was recorded for lactating cows postpartum. Milk yield was reduced by 6.75 kg/day during the first 12 weeks postpartum (P<0.001) for the 4W cows compared with 8W cows, but there was no significant difference in total MY (3724 kg compared with 3684 kg, P=0.7) when the milk produced prepartum was included. Protein content was higher in 4W cows (3.42%) than in 8W cows (3.27%) (P<0.001) postpartum. In the 8W group, cows lost more BCS after calving (P<0.05). Cows of SR breed had higher BCS than cows of SH breed (SR=3.7, SH=3.2, P<0.001), but no differences in BW were found between breed and treatment. Energy balance was improved for cows in the 4W group (P<0.001), while feed efficiency, expressed as RFI, was reduced for 4W cows than for 8W cows (5.91 compared with −5.39, P<0.01). Shortening the DP resulted in improved EB postpartum with no difference between the breeds and no milk losses when including the milk produced prepartum.     

The functional dynamics of neutrophils during different seasons in zebu cattle

The present study was conducted in Hariana and Sahiwal cows to study neutrophil functional dynamics during different seasons (summer, rainy and winter) in terms of expression of toll like receptor 2 & 4, neutrophils’ apoptosis in terms of caspase 3, 7 activities, and transmembrane mitochondrial potential. Blood samples were collected from Hariana (n = 10) and Sahiwal cows (n = 10) throughout the year to evaluate the effects of season on neutrophil dynamics. In each season, eight blood samples were collected from each animal (twice in each month). Toll-like receptor 2 and 4 expressions were significantly (p < 0.05) decreased in neutrophils during summer season as compared to rainy and winter seasons. Significantly, (p < 0.05) higher caspase 3 & 7 activities and significantly higher per cent of neutrophils with low transmembrane mitochondrial potential indicating its enhanced apoptosis were found during extreme summer and lowest during winter. Both Sahiwal and Hariana breeds exhibited similar trends in neutrophil apoptosis. The results of the study evidently indicate that neutrophil competence varies from season to season in zebu cattle and could determine the possible incidences of infections in these cows. Hot-humid season could be conducive for microbial infections owing to accelerated apoptosis of neutrophils and down regulation of TLR2 and TLR4 of immune cells of zebu cattle.     

Mammary Specific Transgenic Over-expression of Insulin-like Growth Factor-I (IGF-I) Increases Pig Milk IGF-I and IGF Binding Proteins,with no Effect on Milk Composition or Yield

IGF-I regulates lactation by stimulating mammary mitogenesis, inhibiting apoptosis, and partially mediating the effects of growth hormone on lactogenesis. Herein, lactation performance during first and second parity was assessed in transgenic swine (TG) that over-expressed human IGF-I in milk under the control of the bovine α-lactalbumin promoter, regulatory regions and signal peptide coding sequence. Milk samples were collected throughout lactation (farrowing to d24) from TG sows and non-transgenic littermates (CON) and IGF-I, IGF-II, and IGFBP determined. Colostral (<24 h postpartum) IGF-I content was 26-fold greater (p < 0.001) in TG sows (949 ± 107 μg/L; range 228–1600 μg/L) than CON (36 ± 17.8 μg/L) and was 50- to 90-fold greater (p < 0.001) in mature milk (d2-24 postpartum). There was no effect of parity on milk IGF-I content. Milk IGF-II concentration was unaffected by IGF-I over-expression. Low molecular weight IGFBP (IGFBP-2 and -5) in the milk of TG sows were higher (p = 0.02) than CON in the early postpartum period, but did not differ in mature milk. Milk yield, determined by weigh-suckle-weigh, was similar in TG and CON as was litter weight gain. Milk nutrient composition was not significantly affected by IGF over-expression. Thus, mammary specific transgenic over-expression of IGF-I significantly increased milk IGF-I and IGFBP content, but did not impact lactation performance in swine.     

Effects of a plant product consisting of green tea and curcuma extract on milk production and the expression of hepatic genes involved in endoplasmic stress response and inflammation in dairy cows

During the periparturient phase, cows are typically in an inflammation-like condition, and it has been proposed that inflammation associated with the induction of stress of the endoplasmic reticulum (ER) in the liver contributes to the development of fatty liver syndrome and ketosis. In the present study, the hypothesis that supplementation of dairy cows with a plant product consisting of green tea (95%) and curcuma extract (5%) rich in polyphenols attenuates inflammation and ER stress in the liver during early lactation was investigated. Twenty-seven cows were assigned to two groups, either a control group (n = 14) or a treatment group (n = 13). Both groups of cows received a total mixed ration, and the ration of the treatment group was supplemented with 0.175 g of the plant product per kg dry matter from week 3 prepartum to week 9 postpartum. Dry matter intake and energy balance during week 2 to week 9 postpartum were not different between the two groups. However, cows supplemented with the plant product had a greater amount of energy-corrected milk during week 2 to week 9 postpartum and lower concentrations of triacylglycerols and cholesterol in the liver in week 1 and week 3 postpartum than cows of the control group (p < 0.05). Cows supplemented with the plant product showed a trend towards a reduced mRNA concentration of haptoglobin (p < 0.10), while relative mRNA concentrations of eight genes of the unfolded protein response considered in the liver were not different between the two groups of cows. Relative hepatic mRNA concentration of fibroblast growth factor, a stress hormone induced by various stress conditions, was reduced at week 1 and week 3 postpartum in cows supplemented with the plant product (p < 0.05). Overall, the data of this study suggest that – although there were only minor effects on the occurrence of ER stress and inflammation – a supplementation of polyphenols might be useful to improve milk yield and prevent fatty liver syndrome in dairy cows.     

Effects of dietary energy intake during gestation and lactation on milk yield and composition of first,second and fourth parity sows

Abstract

In order to determine the effects of a varied level of dietary energy intake during pregnancy and lactation on milk yield and composition, first, second and fourth parity sows (Large White × German Landrace) were provided with energy at a level of either: (i) 100% of ME requirement (MEreq) during pregnancy and lactation, (ii) 120% MEreq during pregnancy and 80% during lactation, and (iii) 80% MEreq during pregnancy and 120% during lactation. In spite of equal target levels feed analysis revealed that gestating first parity sows with 120/80 treatment combination and lactating sows of 80/120 treatment combination received 25, and 11 – 17% more digestible N than in the respective 100/100 treatment combination. Irrespective of this 120/80 sows responded with the highest milk DM, fat, and energy contents, and the lowest lactose concentrations whereas protein levels where not affected, irrespective of parity (p < 0.05). Milk yield of sows in 1st and 4th lactation was 85 and 106% of that in 2nd lactation, respectively. Average milk composition was 18.1% DM, 4.9% protein, 6.8% fat, 5.6% lactose, and 0.8% ash. Milk composition changes ceased at day 7 of lactation with a reduction of milk GE and protein, and an increase of lactose content. Concentrations of threonine, arginine, valine, leucine, tyrosine, phenylalanine, cystine, and tryptophan, as well as stearic, oleic, and linoleic acid were higher in colostrum than in milk at later lactation stages. In contrast, laurine, myristic, palmitic, and palmitoleic acids were lower concentrated in colostrum. In conclusion, these results illustrate the importance of body reserve mobilization for milk production in sows and indicate that low energy supply during gestation cannot be compensated by higher energy supply during lactation.     

Effect of selenium in soluble glass bolus on selenium content of milk and blood of goats

Soluble glass bolus (SGB) with selenium (Se) was administered intraruminally to Se-deficient Philippine does to determine its effect on milk Se and to correlate the Se contents of does' milk and blood of does and kids. Five months after the Se administration, the does in the treated group (n=14) had higher (p<0.01) Se content in their blood (62.2 vs 25.7 μg/L) and milk (5.1 vs 2.5 μg/L) than does in control group (n=13). Consequently, the blood Se of the kids (n=14) from the treated does was higher (p<0.05) than those kids (n=13) in the control group (28.0 vs 5.1 μg/L). Blood and milk Se of does and blood Se of their kids correlated (p<0.01) with each other. The increased Se level of does' milk because of Se supplementation was not regarded as a health hazard to humans.     

Diurnal rhythm in the counts and types of milk somatic cells,neutrophil phagocytosis and plasma cortisol levels in Karan Fries cows during different seasons and parity

Chances of mammary infections are comparatively higher in high producing cows during harsh environmental conditions and are usually characterised by changes occurring in various somatic cells secreted in the milk and their activities. The present study was conducted to record diurnal rhythmicity in milk somatic cell counts (SCC), neutrophil: macrophage (N: M) ratio, phagocytic activity (PA) of milk neutrophils and plasma cortisol concentrations during different seasons and parity in high producing Karan Fries cows. Values of milk SCC, N: M ratio and plasma cortisol levels were lowest during thermoneutral (TN), intermediate in winter and highest during the summer season. Diurnal rhythm in the milk SCC and N: M ratio was noticed in the summer while plasma cortisol exhibited diurnal rhythm in both winter and summer seasons. Milk SCC, N: M ratio and plasma cortisol increased in multiparous cows, but diurnal variation was noticed only in the N: M ratio and plasma cortisol in cows having more than four parity. Phagocytic activity of milk neutrophils was highest during TN, intermediate in winter and lowest during the summer season. Phagocytic activity was higher and similar in cows up to fourth parity but decreased in subsequent lactation cycles. Diurnal rhythm in the PA was noticed in winter and summer seasons and in cows having more than four parity where morning samples showed higher phagocytosis as compared to the evening samples. These results can be used for immunomodulatory interventions and therapeutic approaches in treating mastitis of crossbred cows reared under tropical conditions.     

Effect of switch trimming on udder and teat hygiene of dairy cows

The study objective was to determine the effects of trimming the switch of dairy cows on teat-end bacterial counts and udder hygiene scores. Cows (n = 102) were blocked by days in milk, milk production, and parity and then assigned to (a) treatment (trimming of their tail switch using a commercially available trimmer), or (b) control (unaltered tails). Udder hygiene was recorded for cows on Days 0 (initiation of treatment), 32, and 64. A subset of cows (n = 21) was used to assess Streptococci and coliform bacterial populations on teat ends. Samples were collected by swabbing the left front teat end before milking on Days 0, 32, and 64 and were cultured within 24 hr of sampling. The GLIMMIX and PROC Frequency (SAS Version 9.3) were used to analyze data. There were no treatment effects of switch trimming on hygiene scores or bacterial counts. These findings suggest that udder hygiene may not be driven by tail status. Environmental and management factors, such as cleanliness, stall bedding, and stall design, may be more important contributing factors in maintaining udder health.