Variations During Lactation in Total and Differential Leukocyte Counts,N-acetyl-ß-D-glucosaminidase,Antitrypsin and Serum Albumin in Foremilk and Residual Milk from Non-infected Quarters in the Bovine

Quarter samples of foremilk and residual milk were taken approximately every second week from 2 days post partum (pp) throughout lactation month 9, from 5 dairy cows in their second lactation period. Bacteriologically positive milk samples were excluded. The aim was to study the variation in total and differential leukocyte counts, N-acetyl-ß-D-glucosaminidase (NAGase), antitrypsin (ATR) and serum albumin (BSA) in milk during the lactation period and different stages of oestrous cycle. Also the between milkings variation was studied from lactation month 4 to 9. At 2 days pp, each fraction of milk contained significantly higher numbers of leukocytes and had a higher activity of NAGase and ATR than later in the lactation period. In foremilk the highest content of BSA was also recorded at 2 days pp. From lactation month 2 to 9, stage of lactation had, in general, a slight effect on the variation in the variables measured. The total leukocyte count in residual milk tended to increase as lactation proceeded. The proportion of monocyte-macrophages in foremilk was significantly decreased during the last 4 months. NAGase and BSA in both fractions and ATR in residual milk increased significantly towards the end of the lactation period. From lactation month 4 to 9 the highest recorded ranges of variation between milkings, within quarter and stage of lactation, in the total leukocyte count, proportions of neutrophils, lymphocytes, monocyte-macrophages, NAGase, ATR and BSA in foremilk were 215 × 103ml, 42 %, 34 %, 54 %, 6.68 units, 0.36 units and 0.14 mg/ml respectively. The corresponding figures in residual milk were higher except for the variation in BSA which was slightly lower in residual milk than in foremilk. In residual milk there was a positive correlation between the proportion of neutrophils and the total leukocyte count, when calculated on data from all cows and the entire experimental period. During the oestrous periods, the proportion of neutrophils in residual milk was higher than during the dioestrous periods. Foremilk and residual milk differed in the total as well as the differential leukocyte counts in all the various stages of lactation, whereas the contents of NAGase, ATR and BSA were equal in both fractions. The exception was 2 days pp when the proportions of lymphocytes were equal in both fractions and BSA-significantly higher in foremilk than in residual milk.     

Effect of butaphosphan and cyanocobalamin on postpartum metabolism and milk production in dairy cows

The aim of this study was to determine the effect of butaphosphan and cyanocobalamin (BTPC) supplementation on plasma metabolites and milk production in postpartum dairy cows. A total of fifty-two Holstein cows were randomly assigned to receive either: (1) 10 ml of saline (NaCl 0.9%, control group); (2) 1000 mg of butaphosphan and 0.5 mg of cyanocobalamin (BTPC1 group); and (3) 2000 mg of butaphosphan and 1.0 mg of cyanocobalamin (BTPC2 group). All cows received injections every 5 days from calving to 20 days in milk (DIM). Blood samples were collected every 15 days from calving until 75 DIM to determine serum concentration of glucose, non-esterified fatty acids (NEFA), β-hydroxybutyrate (BHB), cholesterol, urea, calcium (Ca), phosphorus (P), magnesium (Mg), aminotransferase aspartate (AST) and γ-glutamyltransferase (GGT). The body condition score (BCS) and milk production were evaluated from calving until 90 DIM. Increasing doses of BTPC caused a linear reduction in plasma concentrations of NEFA and cholesterol. Supplementation of BTPC also reduced concentrations of BHB but it did not differ between the two treatment doses. Milk yield and milk protein had a linear increase with increasing doses of BTPC. A quadratic effect was detected for milk fat and total milk solids according to treatment dose, and BTPC1 had the lowest mean values. Concentrations of glucose, urea, P, Mg, AST, GGT, milk lactose and BCS were not affected by treatment. These results indicate that injections of BTPC during the early postpartum period can reduce NEFA and BHB concentrations and increase milk production in Holstein cows.     

Effects of Short-Term Over-supplementation of Copper in Milk on Hematology,Serum Proteins,Weight Gain,and Health in Dairy Calves

Thirty-six calves were used in the present study. The animals were divided equally into three groups (control, test 1, and test 2). The three groups of calves were homogeneous for parity of dams, sex, and month of birth. From 14 days of age, in the test 1 group copper as copper sulfate (Merck Co, Germany) was added to each meal of milk at a rate of 10 mg/kg of milk for 14 days and in test 2 group copper as copper sulfate was added to each meal of milk at a rate of 20 mg/kg of milk for 14 days. Blood samples were taken by jugular venipuncture using disposable syringes at 14 (before Cu supplementation), 30, 60, and 80 days of age. Anticoagulated blood was used for CBC determination. Plane tubes were used for harvesting of serum and the amounts of total serum protein, albumin, iron, and copper were measured. Calves were weighted at birth and at the end of trial (day 80) and total gain and mean daily gain were calculated. Days of treatment for ill calves were also recorded during experiment. Group (treatment) had no significant effect on the amounts of measured parameters except MCH values (p < 0.05) which were significantly lower in test 1 group than other trial groups. Age (sampling time) had significant effects on the values of most measured parameters (p < 0.05) except WBC, lymphocyte, total protein, and fibrinogen. Significant interactions between sampling time and group were not seen for any of measured parameters. No significant differences were seen for total weight gain and mean daily gain between trial groups. Chi-square test revealed no significant difference for the days of treatment between trials groups.     

Role of dietary phosphorus in the progression of renal failure

Dietary phosphorus is thought to be a factor that impairs the residual renal function in patients with chronic renal failure. To determine the effect of dietary phosphorus on the prognosis of chronic renal failure, low-phosphorus milk was prepared from normal cow's milk using boehmite, a synthetic phosphate-ion absorbent. Regular diet, normal cow's milk, and low-phosphorus milk were then given to 5/6-nephrectomized rats and the serum levels of inorganic phosphorus, calcium, creatinine, and blood urine nitrogen in the rats in each group were compared. The serum levels of inorganic phosphorus and calcium were not different among the groups, despite a significant difference in phosphorus intakes. On the other hand, serum levels of creatinine (Cr) and blood urine nitrogen (BUN) in the rats fed low-phosphorus milk were significantly lower (Cr, 0.54+/-0.054mg/dl; BUN, 29.2+/-3.90mg/dl) than those in the rats fed a regular diet (Cr, 0.64+/-0.057mg/dl; BUN, 37.4+/-3.55mg/dl) or normal milk (Cr, 0.61+/-0.040mg/dl; BUN, 34.5+/-3.59mg/dl). No beneficial effect of protein restriction was observed when residual renal functions in rats fed a regular diet and those fed normal milk were compared. The results suggest that dietary phosphorus plays a major role in the progression of renal failure.     

Influence of testosterone substitution on sperm suppression by LHRH agonists

To investigate the effect of LHRH (GnRH) agonists on sperm suppression, we studied the effect of a depot preparation of D-Trp6 LHRH in 10 normal men for 30 weeks. In addition, to determine the role of androgenic substitution on sperm suppression, the volunteers were divided into two groups: group 1 (n = 5) received a low dose T substitution (125 mg of T enanthate every month), while group 2 (n = 5) received a normal T substitution (120 mg of T undecanoate every day). Four men became azoospermic in group 1 and none in group 2. Moreover, administration of additional T injections in 1 volunteer of group 1 resulted in the reappearance of spermatozoa in the ejaculate. Return to the low dose therapy produced azoospermia. These results suggest that testosterone supplementation supports spermatogenesis.     

Evaluation of Molybdenum Status of Cows: The Use of Blood Plasma and Milk as Indicators Under Semi-Arid Environmental Conditions in Punjab,Pakistan

The present investigation was carried out to determine the molybdenum (Mo) status of blood plasma and milk of lactating cows at the Livestock Experimental Station, Khizer abad, Sargodha, Pakistan. Blood and milk from the lactating cows were sampled periodically after every month during winter so as to examine the effect of sampling intervals on Mo as well as its transfer from various dietary sources to animals during the whole investigation period. The Mo contents of blood plasma and milk except some instances during the study coincided nearly with their respective critical levels. Thus, there is no need of supplementation of Mo in feeds for the cows being reared at the ranch.     

孟鲁司特与糠酸莫米松鼻喷剂联合治疗儿童变应性鼻炎的近期疗效观察

目的：评价口服孟鲁司特和糠酸莫米松鼻喷剂联合治疗儿童变应性鼻炎的近期疗效,以优化儿童变应性鼻炎的治疗方案。方法：选择2011年4月-2012年4月在潍坊市人民医院耳鼻喉科就诊并确诊为变应性鼻炎的患儿48例,随机分为联合用药组（MM组,24例）和糠酸莫米松组（MS组,24例）。MM组患者给予糠酸莫米松喷鼻（早晨喷鼻1次,每次2喷）,孟鲁司特片口服（5mg／次,1次／天,睡前30分口服）;MS组患者给予糠酸莫米松喷鼻（早晨啧鼻2次,每次2啧）。两组的治疗疗程均为3个月,治疗后观察和比较两组患者鼻塞、鼻痒、流清涕、喷嚏等,临床症状及鼻内镜的检查结果。结果：治疗1个月后,两组治疗总有效率的差异无统计学意义（P〉0．05）;治疗3个月后,两组症状评分的改善高于1月朱（P〈0．05）;治疗3个月后,MM组的治疗总有效率显著高于MS组（P〈0．05）。结论：糠酸莫米松与孟鲁司特联合治疗儿童常年性变异性鼻炎的临床疗效优于单用糠酸莫米松治疗,且不良反应少。对于常年性变应性鼻炎患儿的治疗应以序贯性和个体化治疗为原则,最大程度发挥糠酸莫米松与孟鲁司特间的相互协同作用。     

Milk ceruloplasmin and its expression by mammary gland and liver in pigs

Concentrations of ceruloplasmin and copper in milk and blood plasma, the nature of milk ceruloplasmin, and the effects of lactation and gestation on these parameters, as well as the expression of ceruloplasmin mRNA by the mammary gland, were examined in pigs. As seen previously in humans, ceruloplasmin and copper concentrations in sow milk were much higher a few days after birth than 1 month later, averaging 26.5 and 6.6 mg ceruloplasmin/L (by immunoassay) and 1.67 and 0.34 mg total Cu/L, on days 3 and 33 postpartum, respectively. Values for ceruloplasmin oxidase activity (measured with p-phenylene diamine) were 7.8 and 1.3 nmol/min/L, respectively. Daily milk ceruloplasmin production went from 61 to 22 mg/day and daily copper output from 38 to 12 mg/day. In contrast, there was little or no variation in serum ceruloplasmin concentration during lactation or gestation, although total plasma copper was high at the end of gestation. Milk ceruloplasmin was of the same apparent size as serum ceruloplasmin, as determined by SDS-PAGE and immunoblotting, and ceruloplasmin mRNAs of liver and mammary gland were indistinguishable by Northern analysis and RT-PCR of the various exons. Expression of total RNA and ceruloplasmin mRNA, as detected in biopsies of mammary gland, increased markedly upon onset of lactation and then declined during the next month in conjunction with a drop in milk ceruloplasmin production. The results indicate that milk ceruloplasmin, while being the same protein as in plasma, is not derived from the plasma but is produced by the mammary gland.     

A reappraisal of protein turnover values in neonates fed human milk or formula

We investigated the effect of human milk feeding on the nitrogen metabolism of appropriate-for-gestational age infants of birth weight 1.5-2.0 kg. Eight infants received pooled mature human milk. The remaining 20 were divided into two equal groups, who received one of two low-protein, milk-based formulae. The formulae were identical in composition except for the protein source, which was either casein- or whey-predominant. The three diet groups received similar total nitrogen (390 mg N.kg-1.d-1) and energy (500 kJ.kg-1.d-1) intakes. The human-milk-fed group, however, received a significantly higher intake of nonprotein and urea nitrogen and a significantly lower true protein nitrogen. Nitrogen metabolism was studied using a modified constant infusion of [15N]glycine, mixed with the feeding every 2-3 h. Urine was collected in approximately 3-h aliquots and analysed for total ammonia and urea nitrogen. Excretion of the 15N label was measured in urinary urea and ammonia. No differences were seen between the three diet groups in total [15N]urea or [15N]ammonia urinary excretion. However, the concentration of 15N in urinary urea in the human-milk-fed group was lower than in the two formula-fed groups. This reduction in concentration appeared due to a higher dietary intake of urea among the human-milk-fed group, and the consequent dilution of the label in the urine. As a result, protein turnover rates calculated from the [15N]urea end product were artificially raised in the milk-fed group, and were significantly higher than those in the formula groups.(ABSTRACT TRUNCATED AT 250 WORDS)     

Essential trace elements in milk and blood serum of lactating donkeys as affected by lactation stage and dietary supplementation with trace elements

The aim of this trial was to study the concentration of zinc (Zn), iron (Fe), copper (Cu), manganese (Mn), selenium (Se), cobalt (Co) and iodine (I) in milk and blood serum of lactating donkeys, taking into account the effects of lactation stage and dietary supplementation with trace elements. During a 3-month period, 16 clinically healthy lactating donkeys (Martina-Franca-derived population), randomly divided into two homogeneous groups (control (CTL) and trace elements (TE)), were used to provide milk and blood samples at 2-week intervals. Donkeys in both groups had continuous access to meadow hay and were fed 2.5 kg of mixed feed daily, divided into two meals. The mixed feed for the TE group had the same ingredients as the CTL, but was supplemented with a commercial premix providing 163 mg Zn, 185 mg Fe, 36 mg Cu, 216 mg Mn, 0.67 mg Se, 2.78 mg Co and 3.20 mg I/kg mixed feed. The concentrations of Zn, Fe, Cu, Mn, Se, Co and I were measured in feeds, milk and blood serum by inductively coupled plasma-MS. Data were processed by ANOVA for repeated measures. The milk concentrations of all the investigated elements were not significantly affected by the dietary supplementation with TE. Serum concentrations of Zn, Fe, Cu Mn and Se were not affected by dietary treatment, but TE-supplemented donkeys showed significantly higher concentrations of serum Co (1.34 v. 0.69 μg/l) and I (24.42 v. 21.43 μg/l) than unsupplemented donkeys. The effect of lactation stage was significant for all the investigated elements in milk and blood serum, except for serum manganese. A clear negative trend during lactation was observed for milk Cu and Se concentrations (−38%), whereas that of Mn tended to increase. The serum Cu concentration was generally constant and that of Co tended to increase. If compared with data reported in the literature for human milk, donkey milk showed similarities for Zn, Mn, Co and I. Furthermore, this study indicated that, in the current experimental conditions, the mineral profile of donkey milk was not dependent on dietary TE supply.     

Effect of a supplement rich in linolenic acid added to the diet of post partum dairy cows on ovarian follicle growth, and milk and plasma fatty acid compositions

The objective of this study was to determine the effect of a linseed supplement on follicle growth, progesterone concentrations and milk and plasma fatty acids in dairy cows post partum. Sixteen Holstein cows were given a basal total mixed diet plus one of two supplements: control (C; extruded soybeans; n = 8) or linseed (L; extruded linseeds; n = 8). One month after calving oestrous cycles were synchronised (PRID). Follicle growth and milk progesterone concentrations were measured every 2 d over the induced oestrous cycle. Milk production characteristics were unaffected by treatment. The L cows lost significantly more BCS than the C cows (P < 0.01). Plasma insulin, glucose and urea were unaffected by the treatment. Plasma NEFA tended to be affected by the treatment (L > C, P = 0.08). The proportions of 18:3n-3 in milk and plasma were increased by L compared to C (P < 0.001 and P < 0.01, respectively). There was an effect of dietary supplement on the numbers of small follicles (L < C, P < 0.05). Milk progesterone was unaffected by treatment. In conclusion, the increased supply of 18:3n-3 to the cows had only a modest effect on follicle populations and corpus luteum activity was unchanged.     

Analysis of cow factors influencing conception rates after two timed breeding protocols

The objective of this study was to determine cow factors that influence conception rates after timed artificial insemination (TAI) on a commercial dairy farm. In Trial 1, 197 cows were synchronized by an administration of 25 mg of dinoprost between Days 48 and 54 post partum and again 14 days later. Cows were inseminated 66 and 90 hours after the second treatment. In Trial 2, 186 cows were treated with an Ovsynch protocol consisting of an administration of 0.02 mg of buserelin between Days 62 and 68 post partum, a treatment with 0.75 mg of tiaprost 7 days later and a second treatment with buserelin 48 h later. Cows were bred 16 to 20 hours after the last treatment. Cows with abnormal vaginal discharge at the time of insemination were excluded from AI. Lactation number, milk yield, fat and protein content of milk, signs of endometritis at an examination 14 to 20 days post partum and month of breeding were included as potential factors influencing conception on TAI. Conception rates after timed breeding were 32.0% and 30.6% in Trials 1 and 2, respectively. Logistic regression revealed that neither milk production parameters nor endometritis at post partum examination influenced conception rates in either of the two timed breeding protocols. Only parity showed an effect (P=0.012) in Trial 2. Primiparous cows were more likely to conceive after timed breeding than older cows (43.5 vs. 23.1%). An effect of parity, however, was not observed in Trial 1. It can be concluded that neither milk production nor endometritis at an examination 14 to 20 days post partum influence conception rates after TAI if cows with abnormal vulval discharge at the designated time of AI are excluded from breeding.     

Use of cow-side progesterone tests to improve reproductive performance of high-producing dairy cows

This study evaluated the effectiveness of the cow-side ELISA milk progesterone test in improving postpartum reproductive performance in the Dordt College dairy herd. Cows that produced more than 18,500 lb of milk per lactation were assigned to the high production group (40 cows), while cows that produced less than 18,500 lb of milk (42 cows) were assigned to the low production group. Twenty-one cows in the high production group and 19 cows in the low production group received no ELISA testing (untreated controls), while the remaining cows in each group were evaluated by ELISA test every 7 d beginning on Day 27 post partum (treated cows). A sequence of 2 high progesterone tests and 1 low test indicated the cows were cycling normally. Cows that had low milk progesterone levels (<5 ng/ml) for 3 consecutive tests were assumed to have follicular cysts and were treated with 2 ml GnRH (Cystorelin, 50 mug/ml). Cows that had 3 consecutive high tests (>5 ng/ml) were assumed to have persistent corpora lutea (CL) and were treated with 5 ml PGF(2)alpha (Lutalyse, 5 mg/ml). In both the high and low production groups, treated cows had higher (P < 0.08) pregnancy rates by Day 210 than the untreated controls (63.2 vs 38.1% and 56.5 vs 42.1%, respectively). The days open were reduced (P < 0.05) for the treated animals by 41.6 d compared with the controls. The treated cows produced a net savings of $70.42 (US) per cow assuming a $3.00 savings/day open.     

AluI polymorphism of the bovine growth hormone (GH) gene, resumption of ovarian cyclicity, milk production and loss of body condition at the onset of lactation in dairy cows

Relationships among GH genotype (AluI polymorphism), parity, metritis and interval from calving to first ovulation, milk production and body condition score (BCS) loss were determined in dairy cows (n = 307) on four large-scale farms in Hungary. Cows with systemic signs of puerperal metritis or mastitis were excluded. Time of the first postpartum (PP) ovulation was obtained from milk progesterone profiles. Based on GH genotype determination, groups of leucine homozygous cows (n = 246) and valine allele carriers (n = 61) were formed. All animals became cyclic during the study period. The average interval to first ovulation was 27.6 ± 0.69-d PP (mean ± S.D.). Genotype had no effect on the commencement of ovarian cyclicity. First ovulation occurred sooner after calving in pluriparous than in primiparous cows. The greater BCS loss cows had during the first 30-d PP, the longer they took to resume cyclic ovarian function. The interval from calving to first ovulation was substantially affected by farm, but not by mild cases of puerperal metritis. Genotype was not related to cumulative 30-d milk yield or BCS loss after calving. Primiparous cows had lower milk yield than pluriparous ones. Cows with metritis lost more body condition than healthy individuals in the first month postpartum. We concluded that, under field conditions, AluI polymorphism of the bovine GH gene had no effect on the interval from calving to first ovulation and could not be directly related to differences in milk yield and to the extent of BCS loss during the first month after calving in Holstein-Friesian cows.     

Effects of exogenous ovine growth hormone on reproduction, serum hormone profiles and milk characteristics in early-postpartum fine-wool ewes nursing single or twin offspring

After parturition (Day 0), 31 mature spring-lambing, fine-wool ewes were randomly allotted to one of six groups. Treatments were lambs suckled (one or two) and ovine growth hormone (oGH; 0, 5 or 10 mg). Growth hormone was administered subcutaneously daily from Days 6 to 25. Milk characteristics were determined on Day 26. Ewes were observed for estrus beginning on Day 27. Serum insulin did not differ (P > 0.10) between suckling intensity before or after oGH treatment on Days 6, 15 or 25. Likewise, no difference (P > 0.10) in serum insulin was detected among ewes receiving 0, 5 or 10 mg oGH. Ewes suckling twins had higher (P < 0.05) serum growth hormone on Day 6 (before beginning oGH treatment) than ewes suckling single lambs. In ewes receiving 0, 5 and 10 mg oGH, serum growth hormone differed (P < 0.01) in a linear fashion 1 h after treatment was initiated on Day 6 and continued through Hour 6. Serum growth hormone on Days 15 and 25 differed among groups both before and after oGH was administered (P < 0.01). Suckling intensity did not affect (P > 0.10) milk or milk protein and fat yields; however, oGH increased (linear, P < 0.05) fat but did not affect milk or protein yields. Interval from parturition to estrus did not differ (P > 0.20) in ewes suckling single or twin offspring. Likewise, no differences (P > 0.20) in interval length were noted in ewes receiving 0, 5 or 10 mg oGH. Suckling intensity and oGH administration for 20 d had little effect on postpartum interval or milk characteristics during the first 30 d after lambing in fine-wool ewes.     

Levels of cytokines (IL-1beta, IL-2, IL-6, IL-8, TNF-alpha) and trace elements (Zn, Cu) in breast milk from mothers of preterm and term infants

It has been well documented that human milk contains several immunomodulator components which are important during infant period when the newborn's immune system is still under development. In this study, we aim at examining levels of cytokines, zinc (Zn), and copper (Cu) in milk from mothers of premature and mature infants, and comparing changes during lactation periods consequently. Milk was collected from total of 40 mothers (group M: mothers of mature infants, n = 20; group PM: mothers of premature infants, n = 20) from four lactation stages: colostrum (0-7 days), transitional (7-14 days), mature milk (21 days), and mature milk (2nd month). Levels of cytokines (interleukin [IL]-lbeta, IL-2, IL-6, IL-8, tumor necrosis factor-alpha [TNF-alpha]) were determined by chemiluminesence method, whereas atomic absorption spectrophotometer was used for the determination of Zn and Cu levels. Cytokine levels were determined to be high in colostrum and transient milk from mothers of full-term infants, whereas their levels were reduced drastically in the 21st day and the 2nd month milk (P < .01, P < .001). Similar trends were observed in milk from mothers of premature infants, but cytokine levels were significantly lower in colostrum compared to colostrum from mothers of mature infants (P < .01). The differences in cytokine levels were continuous in transient milk (P < .05) and mature milk (21 days) (P < .05), whereas there was no statistically significant differences between milk from both groups of mothers in the 2nd month (P > .05). Zn levels in milk from mothers of premature infants were significantly lower compared to the ones from mothers of mature infants (P < .01) and these differences continued through the 2nd month. Although Cu levels were lower in milk from mothers of premature infants, there was no statistically significant difference except colostrum (P > .05). Our results clearly demonstrate that the level of immunomodulating agents such as cytokines and trace elements in milk from mothers of premature infants is less than the level of the same agents in milk from mothers of full-term infants. Although there are commercially available products for infant feeding, human milk is still the best natural nutrient for newborns. Therefore, when premature infants are breastfed, necessary precautions such as supplemantary diets must be considered for possible infections and risks related with immune system deficiency.     

Iodine and selenium carry over in milk and cheese in dairy cows: effect of diet supplementation and milk yield

Iodine and selenium are essential trace elements involved in the regulation of thyroid metabolism and antioxidant status. Two experiments were undertaken on lactating cows to determine the milk concentrations of iodine and selenium, carry over (CO) in milk, the fraction in curdle portion and how milk yield affects the milk iodine and selenium concentrations and CO. Sources of elements were potassium iodide and sodium selenite. In Experiment 1, 12 cows were randomly allotted to three diet groups in a completely randomized design: control group (CTR) - total mixed ration (TMR) containing 1.71 and 0.08 mg/kg dry matter (DM); Group 1 (T1) - TMR plus 23.8 and 2.2 mg; Group 2 (T2) - TMR plus 45.5 and 4.3 mg, respectively, for iodine and selenium. In Experiment 2, 30 cows were allotted to three groups according to milk yield: high (H), average (A) and low (L). Within each group, cows were randomly assigned two levels of iodine and selenium: Level 1: TMR containing 1.55 and 0.15 mg/kg DM; Level 2: TMR plus 47.2 mg and 8.0 mg, respectively, iodine and selenium. In both experiments, individual milk samples were collected and analyzed for iodine and selenium contents. In Experiment 1, Grana Padano cheese was obtained at lab scale and the iodine and selenium fractions in the curd were measured. In Experiment 1, the iodine intake increased (P < 0.001) the concentration and total excretion in milk. The CO increased (P < 0.05) from 16 (CTR) to 27 (T1) and 26% (T2); the sampling time was significant (P < 0.05) with no interaction with treatments. Concentration of selenium in milk was increased (P < 0.05) by treatment and CO decreased (P < 0.01) from 26 (CTR) to 12 (T1) and 9% (T2). The iodine showed a mild enrichment factor in the curdle (about 1.7-fold), whereas selenium enriched five- to sevenfold. In Experiment 2, the level of iodine supplementation affected (P < 0.05) the concentration and total excretion in milk. No effects on milk iodine concentration were related to milk yield or milk yield × treatment interaction; however, the iodine excretion in milk was major (P < 0.05) in higher yielding groups. The iodine CO was affected (P < 0.05) by the milk yield in supplemented groups. The selenium milk concentration and excretion were affected (P < 0.01) by the milk yield, whereas the CO was affected (P < 0.05) by the milk yield and selenium supplementation. Results highlight the possibility of fortification with iodine in milk and selenium in cheese through animal feeding.     

Microencapsulated sodium selenite supplementation in dairy cows: effects on selenium status

The objective of this study was to compare the efficiency of transfer of selenium (Se) to plasma and milk from inorganic sodium selenite, either free or microencapsulated, and from selenized yeast in dairy cows. The study consisted of an in situ-nylon bags incubation, and in an in vivo experiment to compare the Se status of cows supplemented with either sodium selenite, microencapsulated sodium selenite, or Se yeast. Thirty dairy cows, divided in five groups, were fed the following diets: the control group (CTR) received a total mixed ration supplemented with sodium selenite in order to have 0.3 mg/kg DM of total Se; 0.3M and 0.5M groups received the same control diet supplemented with lipid microencapsulated sodium selenite to provide 0.3 and 0.5 mg/kg DM of total Se, respectively; 0.3Y and 0.5Y groups received selenized yeast to provide 0.3 and 0.5 mg/kg of total Se, respectively. Cows were fed the supplements for 56 days during which milk, blood, and fecal samples were collected weekly to conduct analysis of Se and glutathione peroxidase (GSH-px) activity. Se concentration in the nylon bags was assessed to 72%, 64%, and 40% of the initial value (time 0) after 4, 8, and 24 h of incubation, respectively. In vivo, cows supplemented with 0.3 mg/kg of microencapsulated Se had higher milk Se concentration compared to CTR. The increment was more pronounced at the highest inclusion rate (0.5 mg/kg, 0.5M group). GSH-px activity was not significantly affected by treatments. The results indicate that lipid microencapsulation has the potential to protect nutrients from complete rumen reduction and that Se from microencapsulated selenite is incorporated in milk more efficiently than the free form. Microencapsulated sodium selenite was shown to be comparable to Se-yeast in terms of availability and incorporation in milk when fed at 0.3 mg/kg DM, whereas the inclusion in the diet at 0.5 mg/kg DM resulted in higher plasma and milk concentrations than selenized yeast.     

Effect of the amount of body condition loss from the dry to near calving periods on the subsequent body condition change, occurrence of postpartum diseases, metabolic parameters and reproductive performance in Holstein dairy cows

We investigated the effect of body condition loss from the dry to near calving periods on the subsequent body condition change, the occurrence of postpartum diseases, the serum metabolic parameters total cholesterol, triglyceride, glucose, and urea nitrogen and the number of days to first breeding after calving in Holstein dairy cows. Body condition scoring (using a 5-point scale with quarter-point divisions) was performed on 67 pregnant Holstein dairy cows. Cows were scored once for body condition during the dry period (prepartum day 35 +/- 16), near calving (postpartum day 5 +/- 4), and subsequently at months 1 (+/- day 4), 2 (+/- day 5), 3 (+/- day 5), and 4 (+/- day 4) of lactation. At the same time, blood samples were collected to evaluate serum total cholesterol, triglyceride, glucose and urea nitrogen concentrations. Cows were categorized based on body condition loss from the dry to near calving periods into two groups: the moderate condition loss group (0-0.75 points, n=41), or the marked condition loss group (1.0-1.5 points, n=26). Regular reproductive health examination was conducted by the same investigator once a week. The marked condition loss group lost more body condition (P<0.01) than the moderate condition loss group consistently until month 1 of lactation. The recovery of body condition in the marked condition loss group was more delayed (P<0.01) than in the moderate condition loss group from months 1 to 4 of lactation. The occurrence of metritis and metabolic diseases (including abomasal displacement, milk fever, ketosis) was greater (P<0.01) in the marked condition loss group (62 and 23%) than in the moderate condition loss group (27 and 2%), respectively. The total cholesterol concentration was lower (P<0.05) in the marked condition loss group (167 +/- 5.3 mg/dl) than in the moderate condition loss group (183 +/- 5.8 mg/dl) at month 1 of lactation, however, the cholesterol levels at the other periods were not different (P>0.05) between the two groups. The triglyceride, glucose, and urea nitrogen concentrations were not different (P>0.05) from the dry period to month 4 of lactation between the two groups. The number of days to first breeding after calving was longer (P<0.05) in the marked condition loss group (103 +/- 7.8 day) than in the moderate condition loss group (87 +/- 5.3 day). We conclude that marked body condition loss from the dry to near calving periods results in the increased occurrence of postpartum metabolic and reproductive diseases, decreased serum total cholesterol concentrations at month 1 of lactation and a longer interval to first breeding after calving in Holstein dairy cows, probably due to the more severe energy deficit reflected by unfavorable body condition score change during early lactation.     

Effect of timing of first clinical mastitis occurrence on lactational and reproductive performance of Holstein dairy cows

Objectives of this study were to determine the influence of timing of first clinical mastitis case occurrence on lactational and reproductive performance in high producing lactating dairy cows during the first 320 days in milk (DIM). Holstein cows, 1001, from two commercial dairy farms in California were retrospectively divided into four treatment groups according to timing of first clinical mastitis case caused by environmental pathogens: control with no recorded clinical cases of mastitis (C; n=501); first clinical mastitis prior to first postpartum AI (MG1; n=250); first clinical mastitis between first postpartum AI and pregnancy diagnosis (MG2; n=147); and first clinical mastitis after diagnosed pregnant (MG3; n=103). Clinical cases of mastitis were identified at every milking by the herd personnel based on abnormal milk or swelling of the mammary gland. A fore sample of milk was aseptically collected from every clinical case for microbiological culture. Mastitis decreased yields of milk, 3.5% fat-corrected milk, and milk components, but the effect was only observed for MG1 and MG2. Cows in the control group had lower linear somatic cell count (SCC) score throughout the lactation. Culling was increased by mastitis, and cows in the mastitis groups left the study earlier than controls. Conception rate at first postpartum AI and pregnancy rate at the end of the study were both decreased by mastitis prior to or after first AI, and MG1 and MG2 cows had extended days open. Furthermore, cows experiencing mastitis during lactation had a higher incidence of abortions. The negative effects of mastitis on reproduction were observed regardless of clinical case being caused by either Gram positive or negative bacteria. Mastitis either prior to or after first postpartum AI impairs lactation performance, increases culling, and decreases reproductive efficiency in high producing Holstein dairy cows.