Rumen-protected choline and vitamin E supplementation in periparturient dairy goats: effects on milk production and folate, vitamin B12 and vitamin E status

We investigated the effects of rumen-protected choline (RPC) and vitamin E (VITE) administration on milk production and status of folate, vitamin B12 and vitamin E during the periparturient period of dairy goats. Forty-eight Saanen multiparous goats were selected for the 72-day experiment, being moved to a maternity pen 30 days before expected parturition and assigned to one of the four experimental groups: control (CTR), no choline or vitamin E supplementation; choline (RPC), supplemented with 4 g/day choline chloride in rumen-protected form; vitamin E (VITE), supplemented with 200 IU/day vitamin E in rumen-protected form; and choline and vitamin E (RPCE), supplemented with 4 g/day RPC chloride and 200 IU/day vitamin E. Supplements were administered individually before the morning feed to ensure complete consumption, starting 30 days before kidding and continuing for 35 days after. During the experiment, milk yield and 4% fat-corrected milk (FCM) yield were, respectively, 210 and 350 g/day higher in RPC-supplemented goats than in non-supplemented goats. Milk fat concentration and fat yield were also increased by RPC treatment. Milk yield and composition were unaffected by vitamin E supplementation. There were no significant interactions between RPC and VITE for any of the variables measured. Plasma metabolites did not differ between treatments before and after kidding except that plasma folate at parturition was higher in RPC-supplemented goats. Neither choline nor vitamin E affected vitamin B12 plasma concentrations, while a time effect was evident after the second week of lactation, when B12 levels in each treatment group started to increase. Vitamin E administration resulted in plasma α-tocopherol levels that were 2 to 2.5 times higher than in non-supplemented goats. Overall, these results suggest that greater choline availability can improve milk production and methyl group metabolism in transition dairy goats.     

Changes in mammary blood flow during the lactation period in goats measured by the ultrasound Doppler principle

1. Mammary blood flow was measured during the lactation period in two low- and two high-yielding dairy goats (peak milk yields approx. 1.5 and 3.6 kg/day respectively), using the ultrasound Doppler principle for determination of blood velocity in both milk veins (subcutaneous abdominal veins) of the animals, and ultrasound scanning for measurement of cross-sectional area of the veins. 2. Milk vein cross-sectional area ranged from 0.11 to 0.38 cm2 in the four goats, with a close to significant (P = 0.06) difference between the veins in the two sides of the animals. Cross-sectional area remained constant during the lactation period. Changes in mammary blood flow was therefore caused by changes in blood velocity. 3. Milk vein blood velocities ranged from 4.4 to 34.7 cm/sec independently of the time of the day, and were of the same magnitude in the two sides of the animals. Except in one goat (P = 0.1), blood velocity decreased significantly (P less than 0.01) with progressing lactation, during which period also milk yield was declining. 4. In the two low-yielding goats, a positive linear relationship (R2 = 0.20) was found between milk yield and milk vein blood velocity, whereas a diminishing exponential relationship (R2 = 0.97) was found in the two high-yielding goats. At a given milk vein blood velocity, high-yielding goats obtained a higher milk yield and also responded to changes in blood velocity (up to approx. 15 cm/sec) with greater increases in milk yield than low-yielding goats.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pseudopregnancy and aseasonal breeding in dairy goats: genetic basis of fertility and impact on lifetime productivity

Until recently, the main selection focus in UK dairy goats has been on milk yield. To develop a selection index suitably weighted for a variety of traits, it is important to understand the genetic relationships between production, health and fertility traits. This study focussed on three aspects of reproduction that are of interest to goat breeders. (1) Out of season (OOS) kidding ability: goats are highly seasonal breeders so achieving consistent, year-round dairy production presents a challenge. It may be possible to select for extended or shifted breeding cycles, however, there are no published studies on the genetic basis of seasonal kidding ability, and a genetic correlation with milk production in dairy goats; (2) age at first kidding (AFK): a reduced AFK offers the opportunity for more rapid genetic improvement, as well as reducing the amount of time and resources required to raise the animals to producing age; (3) pseudopregnancy (PPG): as it is difficult to diagnose pregnancy within 30 days of mating, high herd levels of PPG could add a significant delay in breeding replacement animals, or commencing a new lactation. Using records from 9546 goats, the objective of this study was to investigate the genetic relationships between the reproductive traits described above, and the production traits 520-day milk yield (MY520), lifetime milk yield (MYLife) and lifetime number of days in milk (DIMLife). The ‘out of season’ phenotype was defined as week of kidding relative to the 4 weeks of the year where the highest average number of births occur. Incidences of PPG that occurred during the first lactation were used as cases, while goats with none were assigned as controls. Relevant fixed and random effects were fitted in the models. In line with other reproduction traits, heritability estimates were low ranging from 0.08 to 0.11. A negative genetic correlation was found between AFK and MY520 (−0.22±0.10), whereas a positive genetic correlation was found between PPG and DIMLife (0.58±0.11). Pseudopregnancy and OOS were positively genetically correlated (0.36±0.15). All other genetic correlations were very low. The results of this study indicate that selection for the reproductive traits analysed is feasible, without adversely affecting MYLife.     

Milk fat progesterone concentrations in goats and early pregnancy diagnosis

Blood and milk samples from foremilk during afternoon milking, were simultaneously collected from 285 dairy goats. In experiment 1, fiva cyclic goats were sampled daily for 21 days. In experiment 2, 280 females from 9 flocks were submitted to sampling 21 days after insemination. In addition, some milk samples were divided in two parts, after which one was frozen and the other kept at +4 degrees C until assay. Progesterone concentrations were measured in blood, whole milk and milk fat by radioimmunoassay. No difference in whole milk or fat progesterone levels was found between frozen and refrigerated milk samples. Milk butterfat progesterone concentrations paralleled those in plasma or whole milk throughout the estrous cycle and ranged from about 20 ng/ml at estrus to about 400 ng/ml in mid-luteal phase. The ratio of mid-luteal phase progesterone levels to those seen in the estrous period was over 20 in fat and in blood. This ratio was very much lower in whole milk. Consequently the determination of pregnant and non-pregnant goats from the samples collected 21 days after service was very much easier and accuracy was better when the progesterone content was assayed from milk fat than from whole milk. It was concluded that early pregnancy diagnosis in goats can be done routinely by determination of progesterone levels in milk fat.     

Body condition score and live-weight effects on milk production in Irish Holstein-Friesian dairy cows

The objective of the present study was to quantify the relationships among body condition score (BCS; scale 1 to 5), live weight (WT) and milk production in Irish Holstein-Friesian spring calving dairy cows. Data were from 66 commercial dairy herds during the years 1999 and 2000. The data consisted of up to 9886 lactations with records for BCS or WT at least once pre-calving, or at calving, nadir or 60 days post-calving. Change in BCS and WT was also calculated between time periods. Mixed models with cow included as a random effect were used to quantify the effect of BCS and WT, as well as change in each trait, on milk yield, milk fat concentration and milk protein concentration. Significant and sometimes curvilinear associations were observed among BCS at calving or nadir and milk production. Total 305-day milk yield was greatest in cows calving at a BCS of 4.25 units. However, cows calving at a BCS of 3.50 units produced only 68 kg less milk than cows calving at a BCS of 4.25 units while cows calving at 3.25 or 3.00 BCS units produced a further 50 and 114 kg less, respectively. Cows that lost more condition in early lactation produced more milk of greater fat and protein concentration, although the trend reversed in cows that lost large amounts of condition post-calving. Milk yield increased with WT although the marginal effect decreased as cows got heavier. Milk fat and protein concentration in early lactation also increased with WT pre-calving, calving and nadir, although WT did not significantly affect average lactation milk fat concentration.     

The potential interaction between body condition score at calving and dietary starch content on productive and reproductive performance of early-lactating dairy cows

Improving reproductive performance is one of the most important factors affecting the profitability of dairy herds. This study investigated the effect of feeding a high starch (HS) diet and body condition score (BCS) at calving on blood metabolites, fertility and ovarian function and milk production in Holstein dairy cows. One hundred seventy-four multiparous cows were fed common close-up and early lactation diets during the first 15 days in milk (DIM). Cows were randomly assigned to 1 of 2 experimental diets from 16 until 50 DIM (n = 87 per group); normal starch (228 g/kg diet DM; NS) or HS (270 g/kg diet DM; HS) diets. Each treatment group was further subdivided based on BCS at calving as normal BCS (BCS ⩽ 3.5; normal BCS (NBCS); n = 45) or high BCS (HBCS) (BCS ⩾ 3.75; HBCS; n = 42). A significant difference was detected for increased milk production (47.24 v. 44.55 kg/day) and decreased milk fat (33.93 v. 36.33 g/kg) in cows fed HS or NS, respectively. Plasma glucose and insulin concentrations were significantly higher in cows fed the HS compared to the NS diet. Diets significantly affected DIM at first artificial insemination (AI, 79.51 ± 3.83 v. 90.40 ± 3.83 days for cows fed HS and NS diets, respectively). High BCS groups had greater milk fat content and elevated plasma nonesterified fatty acids (NEFA), β hydroxybutyrate (BHB) and bilirubin concentrations. In general, feeding higher starch diets to normal BCS cows during the first 50 DIM improved productive and reproductive performance of early-lactating dairy cows.     

Nutritional regulation of body condition score at the initiation of the transition period in primiparous and multiparous dairy cows under grazing conditions: milk production, resumption of post-partum ovarian cyclicity and metabolic parameters

The objective of this study was to investigate the effect of different body condition score (BCS) at 30 days before calving (-30 days) induced by a differential nutritional management from -100 days until -30 days on productive parameters, the interval to first ovulation and blood parameters in primiparous and multiparous Holstein cows under grazing conditions until 60 days post partum. The experimental arrangement was a randomized complete block design, where cows were blocked according to BW and expected calving date and then randomly assigned to different nutritional treatments from -100 to -30 days relative to calving to induce different BCS. As the assignment of cows to treatments was random, cows had to lose, maintain or gain BCS; thus, different planes of nutrition were offered with approximately 7, 14 or 20 kg dry matter per day. The BCS score was assessed every 15 days and animals were reassigned in order to achieve the desired BCS at -30 days. Only animals that responded to nutritional treatment were considered and this was defined as follows: primiparous and multiparous high cows (PH and MH) had to gain 0.5 points of BCS, primiparous low (PL) had to lose 0.5 points of BCS and multiparous low (ML) had to maintain BCS at least in two subsequent observations from -100 to -30 days. From -30 days to calving, primiparous and multiparous cows (P and M cows) were managed separately and cows were offered a diet once a day. From calving to 60 days post partum, cows of different groups grazed in separate plots a second year pasture. Cows were also supplemented individually with whole-plant maize silage and commercial concentrate. Cows had similar BCS at -100 days and differed after the nutritional treatment; however, all groups presented similar BCS at 21 days post partum. The daily milk production and milk yield at 60 days post partum was higher in M than P cows. The percentage of milk fat was higher in PH cows compared with PL cows. Concentrations of non-esterified fatty acids (NEFA) were affected by the BCS at -30 days within parity, and in PH cows the concentration of NEFA was higher than in PL cows. The concentrations of total protein were higher in M cows. A lower probability of cycling was found in PL than in PH cows (P < 0.05) and in ML than in MH cows (P < 0.05). Treatment affected various endocrine/metabolic profiles according to parity, suggesting that the metabolic reserves signal the productive/reproductive axis so as to induce a differential nutrient partitioning in adult v. first-calving cows.     

Net mineral requirements of dairy goats during pregnancy

Mineral requirements of pregnant dairy goats are still not well defined; therefore, we investigated the net Ca, P, Mg, Na and K requirements for pregnancy and for maintenance during pregnancy in two separate experiments. Experiment 1 was performed to estimate the net Ca, P, Mg, Na and K requirements in goats carrying single or twin fetuses from 50 to 140 days of pregnancy (DOP). The net mineral requirements for pregnancy were determined by measuring mineral deposition in gravid uterus and mammary gland after comparative slaughter. In total, 57 dairy goats of two breeds (Oberhasli or Saanen), in their third or fourth parturition, were randomly assigned to groups based on litter size (single or twin) and day of slaughter (50, 80, 110 and 140 DOP) in a fully factorial design. Net mineral accretion for pregnancy did not differ by goat breed. The total daily Ca, P, Mg, Na and K requirements for pregnancy were greatest in goats carrying twins (P<0.05), and the requirements increased as pregnancy progressed. Experiment 2 was performed to estimate net Ca, P, Mg, Na and K requirements for dairy goat maintenance during pregnancy. In total, 58 dairy goats (Oberhasli and Saanen) carrying twin fetuses were assigned to groups based on slaughter day (80, 110 and 140 DOP) and feed restriction (ad libitum, 20% and 40% feed restriction) in a randomized block design. The net Ca, P and Mg requirements for maintenance did not vary by breed or over the course of pregnancy. The daily net requirements of Ca, P and Mg for maintenance were 60.4, 31.1 and 2.42 mg/kg live BW (LBW), respectively. The daily net Na requirement for maintenance was greater in Saanen goats (11.8 mg/kg LBW) than in Oberhasli goats (8.96 mg/kg LBW; P<0.05). Daily net K requirements increased as pregnancy progressed from 8.73 to 15.4 mg/kg LBW (P<0.01). The findings of this study will guide design of diets with adequate mineral content for pregnant goats throughout their pregnancy.     

Efficiency of donor cell preparation and recipient oocyte source for production of transgenic cloned dairy goats harboring human lactoferrin

The objective was to investigate the effects of the transgenic donor cell synchronization method, oocyte sources, and other factors, on production of hLF-gene nucleus transfer dairy goats. Three transfected cell lines from ear biopsies from three 3-mo-old Saanen dairy goats (designated Number 1, Number 2, and Number 3, respectively) were selected as karyoplast donors for somatic cell nuclear transfer (SCNT) after detailed identification (including PCR and sequencing of PCR products). In donor cell cycle synchronization studies, the apoptosis rate of hLF transgenic fibroblasts was not different (P > 0.05) after 3 days of serum starvation or 2 days of contact inhibition. Additionally, there was no effect (P > 0.05) on developmental capacity of reconstructed embryos; however, the kidding rate of recipients in the serum starvation group was higher than that in the contact inhibition group (18 vs. 0%, respectively). The production efficiency of the transgenic cloned goats using donor cells from the Number 1 dairy goat cell line was higher than those using the Number 2 and the Number 3 cell lines (kidding rates were 18, 2, and 0%, respectively, P < 0.05). The oocyte source did not significantly affect the pregnancy rate of hLF-transgenic cloned dairy goats, but more fetuses were aborted when using in vitro matured oocytes compared to in vivo matured oocytes. In summary, utilizing transfected 3-mo-old dairy goat fibroblasts as donor cells, seven live offspring were produced, and the hLF gene was successfully integrated. This study provided additional insights into preparation of donor cells and recipient oocytes for producing transgenic cloned goats through SCNT.     

Insulin-like growth factor I (somatomedin C) in goats during normal lactation and in response to somatotropin treatment

1. Two experiments were performed. In Experiment 1, IGF-I concentrations in serum were followed in four lactating dairy goats during normal lactation and before, during and after 14 days of daily administration of 10 IU recombinant bovine somatotropin, starting 10 weeks post-partum. In Experiment 2, IGF-I was measured in single blood samples obtained from 40 dairy goats in the first part of lactation. 2. Measured IGF-I concentrations ranged from 4.4-9.0 nM. Concentrations varied during the day with coefficients of variation from 8.9 to 18.4% in the four goats in Experiment 1. There were no systematic trends in the diurnal variations (P greater than 0.75). 3. Concentrations of IGF-I remained fairly constant in all goats in Experiment 1 during the lactational period, and were not related to the changes in milk yield (P greater than 0.65). Similarly, no relationship was found in Experiment 2 between level of milk production and IGF-I concentration in serum. 4. Somatotropin treatment stimulated milk yields by 14 +/- 2.9% (P less than 0.05) and IGF-I concentration by 27.9 +/- 6.7% (P less than 0.05). 5. IGF-I is the most likely factor which increases mammary gland synthetic capacity in response to somatotropin treatment, and thus is responsible for the galactopoietic effect of this hormone being exerted. 6. However, serum IGF-I may primarily be involved in regulation of nutrient partitioning during normal lactation, but a paracrine synthesis with local effect on the mammary gland cannot be ruled out.     

Pregnancy-specific protein B and progesterone concentrations in French Alpine goats throughout gestation.

The 34 French Alpine dairy goats originated from a single flock and were artificially inseminated 44 h after synchronization of oestrus. They were bled daily at the jugular vein from 15 to 27 days after AI. An early pregnancy diagnosis by RIA of progesterone concentration was performed 21 days after AI. In pregnant goats (greater than 1.5 ng progesterone/ml) daily sampling was extended until 30 days after AI and, from those, 9 were bled every 2 weeks until the end of pregnancy and at 50 and 63 days post partum. Pregnancy-specific protein B (PSPB) was also assayed. The kidding rate was 67.6% (23/34). PSPB concentrations (ng/ml) in pregnant goats were significantly different from those of non-pregnant goats at 24 days after AI (0.82 +/- 0.18 vs 1.78 +/- 0.19; mean +/- s.e.m.) and rose to 40 ng/ml at the end of pregnancy. From Day 25 and throughout gestation, females with 2 fetuses had higher PSPB concentrations than did those with a single fetus (P less than 0.05). In the 2 goats exhibiting late embryonic mortality according to progesterone concentrations, one had a PSPB profile very similar to those of pregnant goats until 30 days while the other did not show any elevation of PSPB concentration. It is concluded that PSPB profiles in goats are similar to those found in cows throughout pregnancy and that PSPB RIA may be useful for pregnancy diagnosis or diagnosis of late embryonic mortality.     

Effects of varying the level of palm oil on feed intake, milk yield and composition and postpartum weight changes of Red Sokoto goats

Twenty-five pregnant Red Sokoto goats (average liveweight, 33.14 ± 1.75 kg) were used from the last month of pregnancy until 118 day of lactation to evaluate the effect of varying the level of palm (Elaeis guineensis, Jacq.) oil (PO) in concentrate supplement on lactation performance. The goats were fed one of five iso-nitrogenous (16% CP) supplements containing 0% PO (control), 4% PO, 8% PO, 12% PO or 16% PO to a basal diet of Wooly finger grass (Digitaria smutsii, Stent) hay. Average consumption of concentrate was 400 g/goat/day, representing 48% of total dry matter intake. Daily dry matter intake decreased linearly with increasing levels of palm oil. The 4% PO concentrate elicited the highest milk production and was the most cost-effective, while improving daily milk production by 29% compared with the control. Milk composition and postpartum weight changes of the goats were not significantly affected by the concentrate supplements but milk fat percent was generally increased by inclusion level of palm oil in the supplement. It is concluded from this study that the concentrate supplement containing 4% palm oil can increase milk yield in Red Sokoto goats without adversely affecting dry matter intake.     

Lactation influences the serum level of leptin and growth hormone during the daily bathyphase in ewes

The aim of the study was to investigate the influence of early lactation on leptin and growth hormone (GH) during bathyphase. Forty lactating Sarda ewes were divided into two equal groups on the basis of their milk production levels: HIGH (>1100 g/day) and LOW (<900 g/day). From the 5th to the 110th day after lambing, every 15 days, body condition score (BCS) was recorded and milk samples were collected. At the same data point, blood sampling was performed and leptin, GH and, Non-Esterified Fatty Acids (NEFA) were assessed. On milk, fat and proteins were determined. Statistical differences were observed in BCS, leptin, GH, NEFA and fat concentration in milk between the two groups. BCS was lower in high group and decreased from the 20th to the 90th day of lactation. Leptin was higher in low group and increased from the 50th and the 65th day of lactation, in low and high groups, respectively. GH and NEFA were higher in high group and decreased from the mild lactation. In high group, BCS and milk yield were negatively correlated and leptin was negatively correlated with GH and NEFA. In low group, leptin was positively correlated with BCS and negatively correlated with the all studied parameters. GH and NEFA were positively correlated with both groups. In conclusion, milk yield had an effect on the leptin and GH plasma values recorded during their bathyphase.     

Fertility prediction in dairy goats from Murciano-Granadina breed: The role of sperm evaluation and female traits

Fertility is one of the most economically important traits in farm animals, due to the direct and indirect costs associated to low pregnancy rates. Thus, one of the priority goals in animal reproduction is to predict the performance that the semen doses will have in vivo based on the quality values obtained in laboratory assays. Attempts have been made for getting a predictive model of fertility of frozen-thawed sperm in dairy goats, but similar studies have not been conducted for chilled goat buck sperm doses that are mostly used for artificial insemination in many countries including Spain. We study how parameters of in vitro sperm quality and characteristics of Murciano-Granadina dairy goats may affect the in vivo fertility obtained after artificial insemination with semen doses chilled at 4 °C. Moreover, this information was used for obtaining predictive models of the fertility. Sixty-three ejaculates from 13 males were used to prepare chilled doses for the insemination of 495 goats over 13 sessions. Fresh and chilled sperm were evaluated for motility and plasma membrane integrity with a computer-assisted sperm analysis system and flow cytometry, respectively. Fertility was determined at parturition, according to the kidding goats. Overall fertility was 59.6%. Pearson’s correlation coefficients between in vivo fertility and quality variables of fresh sperm were not significant and were low (below 0.34 in absolute value) for chilled sperm. Females’ characteristics had a low negative impact on fertility (correlation coefficients of ?0.19 with age, ?0.20 with parturitions and ?0.11 with total milk yield obtained in the best lactation). Fixed and mixed logistic regression procedures were used trying to explain the fertility results. None of the models accurately predicted fertility, but the best models included the percentage of total motile sperm or average path velocity from fresh semen, age of the females and the session effect (uncontrolled environmental effects). These analyses showed that primiparous goats were 2.42 times more likely to get pregnant than goats that had kidded four or more times. Our field assay data on fertility in Murciano-Granadina dairy goats highlighted the importance of making quality controls of sperm, of choosing the doses presenting high percentages of motile sperm exhibiting regular trajectories and of selecting the youngest goats for AI, after their first kidding. Efforts should continue to obtain better predictive models for improving fertility in goat dairy herds.     

Factors affecting goat milk production and quality

Differences between production systems based on grazing and browsing vs. use of harvested feedstuffs in confinement largely depend on specific feedstuffs and plants available and being consumed. Low forage nutrient ingestion should have relatively greater impact on tissue mobilization than milk production in early than later periods of lactation, with a transition to proportionally greater change in milk production in late lactation. However, low body condition at kidding would limit tissue energy mobilization and restrict impact of level of nutrient intake to milk yield and, likewise, tissue mobilization would be less with one vs. two or three milkings per day. As lactation advances after freshening, fat and protein levels decrease with increasing milk yield, and when production declines in mid- to late lactation, fat and protein concentrations increase. Milk production generally peaks at a parity of 3 or 4, thereafter declining slowly. Elevated somatic cell count alone in dairy goats is not a valid indication of mammary infection. Extended lactations offer opportunities to minimize or avoid seasonal fluctuations in milk production and lessen production costs. If differences in performance between suckled and machine-milked dairy goats occur, they may be restricted to or of greater magnitude during the suckling period compared with post-weaning, and differences in milk yield will either be absent or less with one kid compared with greater litter sizes. The magnitude of effects of milking frequency on milk yield is less for goats of low vs. high production potential and with low vs. high diet quality. Likewise, the effect of milking frequency is greater in early and mid-lactation when yield is higher than in late lactation, along with a shorter period of peak production with one vs. two daily milkings. Physical form of the diet can affect production and composition of goat milk, although effects appear of smaller magnitude than in dairy cattle. When tissue is mobilized to support milk production in early lactation, levels of C18:0 and C18:1 cis in milk increase and levels of medium-chain fatty acids decline. Effects of elevated levels of dietary fatty acids on specific long-chain fatty acids in milk and milk products vary with the fatty acid profile of fat sources used.     

Leukocyte Populations in Human Preterm and Term Breast Milk Identified by Multicolour Flow Cytometry

Background

Extremely preterm infants are highly susceptible to bacterial infections but breast milk provides some protection. It is unknown if leukocyte numbers and subsets in milk differ between term and preterm breast milk. This study serially characterised leukocyte populations in breast milk of mothers of preterm and term infants using multicolour flow cytometry methods for extended differential leukocyte counts in blood.

Methods

Sixty mothers of extremely preterm (<28 weeks gestational age), very preterm (28–31 wk), and moderately preterm (32–36 wk), as well as term (37–41 wk) infants were recruited. Colostrum (d2–5), transitional (d8–12) and mature milk (d26–30) samples were collected, cells isolated, and leukocyte subsets analysed using flow cytometry.

Results

The major CD45+ leukocyte populations circulating in blood were also detectable in breast milk but at different frequencies. Progression of lactation was associated with decreasing CD45+ leukocyte concentration, as well as increases in the relative frequencies of neutrophils and immature granulocytes, and decreases in the relative frequencies of eosinophils, myeloid and B cell precursors, and CD16- monocytes. No differences were observed between preterm and term breast milk in leukocyte concentration, though minor differences between preterm groups in some leukocyte frequencies were observed.

Conclusions

Flow cytometry is a useful tool to identify and quantify leukocyte subsets in breast milk. The stage of lactation is associated with major changes in milk leukocyte composition in this population. Fresh preterm breast milk is not deficient in leukocytes, but shorter gestation may be associated with minor differences in leukocyte subset frequencies in preterm compared to term breast milk.     

Echium oil reduces plasma lipids and hepatic lipogenic gene expression in apoB100-only LDL receptor knockout mice

We tested the hypothesis that dietary supplementation with echium oil (EO), which is enriched in stearidonic acid (SDA; 18:4 n-3), the product of Delta-6 desaturation of 18:3 n-3, will decrease plasma triglyceride (TG) concentrations and result in conversion of SDA to eicosapentaenoic acid (EPA) in the liver. Mildly hypertriglyceridemic mice (apoB100-only LDLrKO) were fed a basal diet containing 10% calories as palm oil (PO) and 0.2% cholesterol for 4 weeks, after which they were randomly assigned to experimental diets consisting of the basal diet plus supplementation of 10% of calories as PO, EO or fish oil (FO) for 8 weeks. The EO and FO experimental diets decreased plasma TG and VLDL lipid concentration, and hepatic TG content compared to PO, and there was a significant correlation between hepatic TG content and plasma TG concentration among diet groups. EO fed mice had plasma and liver lipid EPA enrichment that was greater than PO-fed mice but less than FO-fed mice. Down-regulation of several genes involved in hepatic TG biosynthesis was similar for mice fed EO and FO and significantly lower compared to those fed PO. In conclusion, EO may provide a botanical alternative to FO for reduction of plasma TG concentrations.     

The economics of fibre and meat on Norwegian dairy goats

Seasonal variations in the volume of milk in Norwegian goat dairy farming complicate the production of brand goat cheeses. In the specialised goat dairy farming system most kids are culled shortly after birth without utilising the meat. In this paper the farm economics of an alternative system with altered period of kidding (currently from January to March) combined with the production of meat and cashmere fibre, is examined. May kidding combined with raising the kids for 8 or 20 months yielded the most promising economical return. Raising the kids for 1 year is also profitable when kidding takes place in February while December kidding seems to perform best with the present system of culling the kids right after birth. Cashmere fibre production seems to be profitable on Norwegian dairy goat farms and fibre and meat could become an option in countries seeking to improve incomes on dairy goat farms. Compared to the present system the changes would also be favourable from an animal welfare point of view.     

Consumption of milk from transgenic goats expressing human lysozyme in the mammary gland results in the modulation of intestinal microflora

Lysozyme is a key antimicrobial component of human milk that has several health-promoting functions including the development of a healthy intestinal tract. However, levels of lysozyme in the milk of dairy animals are negligible. We have generated transgenic dairy goats that express human lysozyme (HLZ) in their milk in an attempt to deliver the benefits of human milk in a continual fashion. To test the feasibility of this transgenic approach to achieve a biological impact at the level of the intestine, feeding trials were conducted in two animal models. Pasteurized milk from HLZ transgenic animals was fed to both kid goats (ruminant model) and young pigs (human model), and the numbers of total coliforms and Escherichia coli present in the small intestine were determined. Data from this proof-of-principle study demonstrate that milk from transgenic animals was capable of modulating the bacterial population of the gut in both animal models. Pigs that consumed pasteurized milk from HLZ transgenic goats had fewer numbers of coliforms and E. coli in their intestine than did those receiving milk from non-transgenic control animals. The opposite effect was seen in goats. Milk from these transgenic animals not only represent one of the first transgenic food products with the potential of benefiting human health, but are also a unique model to study the development and role of intestinal microflora on health, well-being and resistance to disease.