Milk production, milk composition, and reproductive function of dairy cows fed different fats

Feeding Flaxseed and Lupins during the Transition Period in Dairy Cows: Effects on Production Performance, Fertility and Biochemical Blood Indices

Flaxseed and lupin seed were offered as an alternative dietary approach in dairy cows, through the partial substitution of soybean meal. Milk production and fertility traits were investigated. A total of 330 animals were allocated into two groups, treated (n = 176) and control (n = 154). From each group, 30 animals were selected for hematological and cytological studies. The experimental feeding period lasted for 81 days (25 days prepartum and 56 days postpartum). The control ration (group C) contained corn, barley, soybean meal, rapeseed cake, corn silage and lucerne hay; whereas, in the treatment group (group T), 50% of the soybean meal was replaced by an equal mixture of flaxseed and lupins. The two rations were formulated to be isonitrogenous and isoenergetic. Milk samples were analyzed for chemical composition, somatic cell count (SCC) content and total colony forming units (CFU). Blood samples were collected, and serum was analyzed for non-esterified fatty acids (NEFA), acute phase proteins (haptoglobin and serum amyloid) and lipid oxidation indices, namely thiobarbituric-acid-reactive substances (TBARS) and catalase activity. To assess polymorphonuclear neutrophils (PMN) numbers, endometrial samples from each cow were collected on days 21 and 42. No difference was recorded between groups in milk yield (p > 0.05). In multiparous cows, NEFA (mMol/L) concentrations were significantly lower in group T than in group C on day 14 (p > 0.009) and on day 42 (p = 0.05), while no difference was detected in the group of primiparous cows. At all time points, serum TBARS and catalase values were similar in both groups (p > 0.05). Multiparous cows in group T expressed the first postpartum estrus and conceived earlier than cows in group C (p ≤ 0.05). Between days 21 to 42 postpartum, the PMN reduction rate was higher in group T animals (p ≤ 0.05). Acute phase protein levels were in general lower in group T animals, and at specific time points differed significantly from group C (p ≤ 0.05). It was concluded that the partial replacement of soybean meal by flaxseed and lupins had no negative effect on milk yield or milk composition, and improved cow fertility; which, along with the lower cost of flaxseed and lupins mixture, may increase milk production profitability.

The effect of different processing methods of linseed on growth performance, nutrient digestibility, blood parameters and ruminate behaviour of lambs

BACKGROUND

Oilseeds such as linseed, canola and sunflower contain unsaturated fatty acids that play important functions in the body. The aim of this study was to assess the effects of different levels of processing linseed on growth performance, nutrient digestibility, blood parameters and ruminate behaviour of lambs.

METHODS

Fifty-six Moghani male lambs (3 months of age, initial average body weight = 28 ± 1.2 kg) were allocated to seven experimental diets in randomized design (eight lambs per each treatment). The experimental diets were as follows: (1) control diet (without linseed), (2) 5% raw linseed, (3) 10% raw linseed, (4) 5% micronized linseed, (5) 10% micronized linseed, (6) 5% extruded linseed and (7) 10% extruded linseed. Lambs were fed ad libitum a basal diet as total mixed ration consisting of 25% concentrate and 75% hay.

RESULTS

The results showed that linseed level and processing method had no significant effect on dry matter intake. Average daily gain, final body weight and feed conversion ratio (FCR) in lambs were affected by experimental diets. The use of 10% micronized linseed and 10% of extruded linseed in the lambs' diet improved dry matter and crude protein digestibility significantly (p < 0.001). Blood glucose concentration observed for lambs fed 10% of micronized or extruded linseed (LS) was not different from that observed in other groups, only from the values shown by lambs fed diets 1 (control) and 2 (5% raw LS). The lowest cholesterol and the highest blood urea nitrogen concentrations were related to lambs fed the control diet (p < 0.001). Feeding processed linseed relative to control diet had no effect on feeding behaviour in lambs.

CONCLUSION

Results of this research showed that the use of extruded and micronized linseed at the level of 10% can improve FCR, nutrient digestibility, and blood parameters.

Dietary n-3 PUFA augments pre-ovulatory follicle turnover and prolificacy in well-fed ewes

The present study evaluated the effect of dietary supplementation with n-3 polyunsaturated fatty acids (PUFA) on preovulatory follicle (POF) turnover, prolificacy, and endocrine and metabolic milieu in Malpura sheep. Fifty cyclic ewes with 3-3.5 body condition scores on a five-point scale were allocated equally to two groups (n = 25) following estrus synchronization and were supplemented with 0.6 mL/kg body weight of n-3 PUFA-rich fish oil (FO) or palm oil (PO) as control, for 60 d following an acclimatization period of 7 d. All ewes were mated with sexually active rams at the end of the supplementation period. On ultrasonographic ovarian scanning at the last fourth estrus, the mean number of POFs was 77.8% greater (P < 0.01) in FO ewes than in the PO ewes. The proportion of ewes with multiple ovulations two months after the beginning of supplementation was 56% in the FO group as compared to 8% in the PO group. The number of fetuses was 46% higher (P < 0.01) in the FO than in the PO ewes at d 45 of gestation. At lambing, the twinning percent in the FO ewes was three times greater than in the PO ewes (27.3 vs. 9.1%). Plasma cholesterol, estradiol, and insulin concentrations were lower (P < 0.01) in ewes fed with FO than those offered PO group at the end of the feeding period. It was concluded that the dietary supplementation of n-3 PUFA-rich FO in well-fed Malpura ewes improved the number of follicles and ovulation rate which led to an increased prolificacy, accompanied by a reduction of plasma cholesterols, estradiol, and insulin.

Flaxseed Oil and Heated Flaxseed Supplements Have Different Effects on Lipid Deposition and Ileal Microbiota in Albas Cashmere Goats

Simple Summary

With the grassland desertification intensified, pasture carrying capacity decreased, and grass seasonal changed, stall-feeding fattening has become an effective means to protect the natural environment. The stall-feeding fattening increased the cashmere goats’ weight but reduced the meat quality and increased the saturated fatty acids content in muscle and fat tissue of cashmere goats. Supplementing flaxseed and flaxseed oil rich-in linolenic acid (ALA) to diet to improve meat quality is an effective nutritional regulation means. Previous research results of our team showed that compared to diet supplemented with flaxseed oil, added flaxseed increased linoleic acid biohydrogenation by reducing the Ruminobacter relative abundance and increasing the relative abundance of Prevotellaceae_UCG-001 and Fretibacterium in rumen, protected ALA away from biohydrogenation, and more n-3 polyunsaturated fatty acids entered the post-intestinal tract. Based on the previous research, this study explored whether the ALA flowing into the posterior intestine can reduce fat deposition and blood lipid by affecting intestinal microbiota. The results showed that adding flaxseed grain to diet decreased the growth performance, lipid deposition, and blood lipid content of goats by regulating the blood lipid-related enzyme activity, which positively associated with [Eubacterium]_coprostanoligenes_group, but negatively associated with unclassified_f_Peptostreptococcaceae, Intestinibacter, and Ruminococcus_2.

Abstract

The present study investigated the effect of flaxseed grain or flaxseed oil on ileal microbiota and lipid deposition of cashmere goats. Sixty kid goats (average body weight 18.6 ± 0.1 kg) were allocated to three treatments, fed for 90 days, with control treatment: basal diet (CON, total-mixed ration), experimental treatment: basal diet with added flaxseed oil (LNO), experimental treatment: basal diet with added heated flaxseed grain (HLS). The final body weight, body weight gain, the weight of kidney fat, omental fat, tail fat, and fat tissue, the activity of fatty acid synthetase, acetyl-coa carboxylase, and malic dehydrogenase, and the relative abundance (RA) of unclassified_f_Peptostreptococcaceae and Intestinibacter were remarkably higher in the LNO treatment than in the HLS treatment, but the [Eubacterium]_coprostanoligenes_group RA showed the opposite result. The content of triglyceride, cholesterol, and low-density lipoprotein cholesterol were significantly higher in the CON and LNO treatments than in the HLS treatment, while the hormone-sensitive lipase activity and the non-esterified fatty acid content showed the opposite result. In conclusion, the flaxseed grain is more efficient than flaxseed oil in ameliorating the blood lipid profiles and it is a potential product for decreasing the lipid deposition of cashmere goats.

Effect of n-3 PUFA-rich fish oil supplementation during late gestation on kidding, uterine involution and resumption of follicular activity in goat

We have shown that dietary supplementation of n-3 polyunsaturated fatty acid (n-3 PUFA)-rich fish oil (FO) around the breeding time improved the utero-ovarian functions in the goat. Here, we investigated the effect of FO supplementation during the periparturient period on serum n-3 PUFA, prostaglandin F_2α metabolite (PGFM), placental expulsion, uterine involution, resumption of oestrus and neonatal vigour. Rohilkhandi goat in advanced gestation (n = 16) was divided into two equal groups. One group was supplemented with FO containing 26% n-3 long-chain PUFA at the rate of 156 mg per kg body weight, while the control group was fed isocaloric palm oil (PO) from -3 to +3 week of kidding. Dietary FO increased serum concentration of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) by 7.3- and 6.6-fold, respectively, after 6 weeks of supplementation. Goats in FO group expelled the foetal membranes 99.1 min earlier (p < .01) than those of PO group. Further, dietary FO significantly decreased the serum PGFM on day 7 post-partum. However, no difference was found on uterine involution, which was complete by day 20 post-partum in either group. Resumption of follicular activity by day 5 post-partum was 87.5% in the FO as compared to 25% in the PO group (p < .05). Similarly, occurrence of behavioural oestrus by day 90 post-partum was 57.1% in goats of the FO group while none of does was in the PO group (p < .01) expressed oestrus. It was concluded that feeding FO-rich diet during -3 to +3 weeks of kidding decreased the PGFM till day 7 post-partum, hastened the expulsion of foetal membranes and reduced the time from kidding to first post-partum oestrus in Rohilkhandi does.

Effects of nutrition and genetics on fertility in dairy cows

Optimal reproductive function in dairy cattle is mandatory to maximise profits. Dairy production has progressively improved milk yields, but, until recently, the trend in reproductive performance has been the opposite. Nutrition, genetics, and epigenetics are important aspects affecting the reproductive performance of dairy cows. In terms of nutrition, the field has commonly fed high-energy diets to dairy cows during the 3 weeks before calving in an attempt to minimise postpartum metabolic upsets. However, in the recent years it has become clear that feeding high-energy diets during the dry period, especially as calving approaches, may be detrimental to cow health, or at least unnecessary because cows, at that time, have low energy requirements and sufficient intake capacity. After calving, dairy cows commonly experience a period of negative energy balance (NEB) characterised by low blood glucose and high non-esterified fatty acid (NEFA) concentrations. This has both direct and indirect effects on oocyte quality and survival. When oocytes are forced to depend highly on the use of energy resources derived from body reserves, mainly NEFA, their development is compromised due to a modification in mitochondrial β-oxidation. Furthermore, the indirect effect of NEB on reproduction is mediated by a hormonal (both metabolic and reproductive) environment. Some authors have attempted to overcome the NEB by providing the oocyte with external sources of energy via dietary fat. Conversely, fertility is affected by a large number of genes, each with small individual effects, and thus it is unlikely that the decline in reproductive function has been directly caused by genetic selection for milk yield per se. It is more likely that the decline is the consequence of a combination of homeorhetic mechanisms (giving priority to milk over other functions) and increased metabolic pressure (due to a shortage of nutrients) with increasing milk yields. Nevertheless, genetics is an important component of reproductive efficiency, and the incorporation of genomic information is allowing the detection of genetic defects, degree of inbreeding and specific single nucleotide polymorphisms directly associated with reproduction, providing pivotal information for genetic selection programs. Furthermore, focusing on improving bull fertility in gene selection programs may represent an interesting opportunity. Conversely, the reproductive function of a given cow depends on the interaction between her genetic background and her environment, which ultimately modulates gene expression. Among the mechanisms modulating gene expression, microRNAs (miRNAs) and epigenetics seem to be most relevant. Several miRNAs have been described to play active roles in both ovarian and testicular function, and epigenetic effects have been described as a consequence of the nutrient supply and hormonal signals to which the offspring was exposed at specific stages during development. For example, there are differences in the epigenome of cows born to heifers and those born to cows, and this epigenome seems to be sensitive to the availability of methyl donor compounds of the dam. Lastly, recent studies in other species have shown the relevance of paternal epigenetic marks, but this aspect has been, until now, largely overlooked in dairy cattle.

The use of energy-protein supplement increases performance of high-yielding dairy cows and improves health-promoting properties of milk

Lipid additives are of particular importance in the diet of high-yielding dairy cows. The aim of this study was to determine the effects of a specially designed energy-protein supplement on dairy cows’ performance and milk composition. The experiment was conducted on 24 Polish Holstein-Friesian cows fed total mixed ration. Two kilograms of energy-protein supplement/cow.day were added to the ration for one group of cows whereas the other was fed solely the total mixed ration. The supplement consisted of whole flax seeds, wheat bran, flaxseed and fish oils, and rapeseed cake and its composition is protected by a patent. Feed intake and daily milk yield were recorded automatically for each cow. Gross milk composition and fatty acid profile of milk were determined. An ANOVA was performed to determine the influence of the supplement on performance traits and milk composition. Energy-protein supplement had a positive impact on dry matter intake and milk yield of cows. It had a little effect on the gross milk composition and somatic cell count. The effect of the additive on fatty acids in milk was beneficial, therefore its use in high-yielding dairy cows nutrition is recommended to improve health-promoting properties of milk.

Effects of supplementation with docosahexaenoic acid on reproduction of dairy cows

The objectives were to determine the effects of supplementing docosahexaenoic acid (DHA)-rich algae on reproduction of dairy cows. Holstein cows were assigned randomly to either a control (n = 373) or the same diet supplemented daily with 100 g/cow of an algae product containing 10% DHA (algae, n = 366) from 27 to 147 days postpartum. Measurements included yields of milk and milk components, fatty acids (FA) profiles in milk fat and plasma phospholipids, resumption of ovulation by 57 days postpartum, pregnancy per artificial insemination (AI) and expression of interferon-stimulated genes in leukocytes. Feeding algae increased resumption of estrous cyclicity (77.6 vs 65.9%) and pregnancy at first AI (47.6 vs 32.8%) in primiparous cows. Algae increased pregnancy per AI in all AI in both primiparous and multiparous cows (41.6 vs 30.7%), which reduced days to pregnancy by 22 days (102 vs 124 days) compared with control cows. Pregnant cows fed algae had greater expression of RTP4 in blood leukocytes compared with those in pregnant control cows. Feeding algae increased the incorporation of DHA, eicosapentaenoic acid, conjugated linoleic acid isomers cis-9 trans-11, trans-10 cis-12 and total n-3 FA in phospholipids in plasma and milk fat. Yields of milk and true protein increased by 1.1 kg/day and 30 g/day respectively, whereas fat yield decreased 40 g/day in algae compared with that in control. Supplementing DHA-rich algae altered the FA composition of lipid fractions and improved reproduction in dairy cows. The benefits on reproduction might be mediated by enhanced embryo development based on changes in interferon-stimulated gene expression.

Inclusion of various amounts of steam-flaked soybeans in lactating dairy cattle diets

Whereas most soybean feedstuffs have been extensively investigated for use in ruminant diets, a lack of information exists regarding steam-flaked soybeans (SFSB). This research evaluated various inclusion rates of SFSB in diets for lactating dairy cattle. Twelve multiparous Holstein cows (103 ± 39 d in milk) were used in a 4 × 4 Latin square experiment consisting of 28-d periods, 14 d for diet transitioning followed by a 14-d sampling period. Treatments were inclusion of SFSB at 0, 5, 10, and 15% of dietary dry matter (DM), replacing a mixture of soybean meal, soy hulls, calcium salts of fatty acids, and choice white grease. Animals were fed lactating dairy cow diets formulated to be isonitrogenous and isoenergetic, containing 60% of DM as forage and 40% of DM as concentrate. Dry matter intake (mean = 28.8 kg/d), milk production (42.2 kg/d), milk fat percentage (3.52%), and feed efficiency (1.43 kg of energy-corrected milk/kg of DM intake) were similar across all treatments. Milk protein (2.98%) and lactose (4.87%) were also unaffected by the amount of SFSB in the diet. Milk urea nitrogen concentration decreased linearly as the amount of SFSB in the diet increased. Unlike some other soybean supplements, feeding SFSB did not increase trans-11 C18:1 or cis-9,trans-11 conjugated linoleic acid, but instead resulted in increased cis-9,cis-12 C18:2 and α-C18:3. Body weights (752 kg) and body condition scores (3.17) were similar with all diets. This research demonstrated that SFSB can be substituted for soybean meal and commercial fat sources while maintaining milk and milk component production and decrease milk urea nitrogen concentration.

Modulation of post-partum reproductive performance in dairy cows through supplementation of long- or short-chain fatty acids during transition period

Thirty-six cross-bred cows were used to study the effect of long-chain (flaxseed) or short-chain (butyric acid) fatty acid supplementation on metabolic status, ovarian function and reproduction performance during transition period. Control cows received a routine feed of transition diet, while the cows in two treatment groups were supplemented with either 750-g crushed flaxseed or 250 g butyric acid per cow per day. Ovarian activity was monitored by transrectal ultrasonography on 10th, 20th and 30th days post-partum. Blood samples were collected by jugular venipuncture into heparinized polystyrene tubes; plasma was prepared and stored under -20 °C until analysis. Results indicated that cows in flaxseed group were in positive energy balance as indicated by lower NEFA and Beta hydroxy Butyrate and higher glucose concentrations. Uterine involution was completed well within 30 days post-partum in all the cows in flaxseed fed group compared to 76.9% in butyric acid supplemented and 61.5% in control groups. The size of dominant follicle and corpus luteum was significantly higher (p < 0.05) for flaxseed group compared to control group, which in turn resulted in higher concentrations of plasma progesterone. Cows fed on diets supplemented with flaxseed exhibited post-partum heat earlier and bred sooner (p < 0.05) than control cows. It has been noticed that supplementation of flaxseed and butyric acid enhanced involution of uterus, early resumption of cyclicity and thereby early breeding. However, in view of the encouraging results obtained for flaxseed supplemented group, its organic nature and easier availability at farmer's gate, we concluded that flaxseed can be safely included in transition diet to modulate reproductive performance of dairy cattle.

Molecular structures and metabolic characteristics of protein in brown and yellow flaxseed with altered nutrient traits

The objectives of this study were to investigate the chemical profiles; crude protein (CP) subfractions; ruminal CP degradation characteristics and intestinal digestibility of rumen undegraded protein (RUP); and protein molecular structures using molecular spectroscopy of newly developed yellow-seeded flax (Linum usitatissimum L.). Seeds from two yellow flaxseed breeding lines and two brown flaxseed varieties were evaluated. The yellow-seeded lines had higher (P < 0.001) contents of oil (44.54 vs 41.42% dry matter (DM)) and CP (24.94 vs 20.91% DM) compared to those of the brown-seeded varieties. The CP in yellow seeds contained lower (P < 0.01) contents of true protein subfraction (81.31 vs 92.71% CP) and more (P < 0.001) extensively degraded (70.8 vs 64.9% CP) in rumen resulting in lower (P < 0.001) content of RUP (29.2 vs 35.1% CP) than that in the brown-seeded varieties. However, the total supply of digestible RUP was not significantly different between the two seed types. Regression equations based on protein molecular structural features gave relatively good estimation for the contents of CP (R(2) = 0.87), soluble CP (R(2) = 0.92), RUP (R(2) = 0.97), and intestinal digestibility of RUP (R(2) = 0.71). In conclusion, molecular spectroscopy can be used to rapidly characterize feed protein molecular structures and predict their nutritive value.

Milk production, milk composition, live weight change and milk Fatty Acid composition in lactating dairy cows in response to whole linseed supplementation

The objective of this study was to determine the effects of whole linseed supplementation on performances and milk fatty acid composition of dairy cows. Thirty six Holstein Friesian crossbred lactating dairy cows were blocked by milking days first and then stratified random balanced for milk yields and body weight into three groups of 12 cows each. The control group received 300 g of palm oil. The second group was supplemented with 344 g/d of top-dressed whole linseed plus 150 g of palm oil and the third group was supplemented with 688 g/d of top-dressed whole linseed. All cows also received ad libitum grass silage (Brachiaria ruziziensis), had free access to clean water and were individually housed in a free-stall unit and individually fed according to treatments. Residual feeds were collected on 2 consecutive days weekly and at the end of the experiment. Feed samples were pooled to make representative samples for proximate and detergent analyses. Daily milk yields were recorded. Milk samples were collected on 2 consecutive days weekly. Live weights were recorded at the start and at the end of the experiment. Milk samples were taken on d 56 of the experiment and subjected to milk fatty acid composition. The results showed no statistical significant differences in intakes, live weight change, milk yields and milk compositions, however, C18:1, C18:3 and unsaturated FAs were increased while saturated FAs were reduced by whole linseed supplementation. It is recommended that the addition of 300 g/d oil from whole linseed could be beneficial to lactating dairy cows in early lactation.

Protective effects of antioxidants on linoleic acid-treated bovine oocytes during maturation and subsequent embryo development

Linoleic acid (LA; n-6, 18:2) is the most abundant polyunsaturated fatty acid in the ovarian follicular fluid and is known to inhibit oocyte maturation and its subsequent development. In the present study, we investigated how its effects on cumulus cell expansion, oocyte nuclear maturation, and blastocyst development are altered by supplementation of the media with vitamin E (VE; 100 μM) and glutathione peroxidase (GPx; 1 μM) either alone or in combination, and whether it has any effect on the mRNA expression of GPx1, GPx4, or superoxide dismutase (SOD2) in the bovine cumulus oocyte complexes (COCs). LA supplementation of the culture media significantly (P ≤ 0.05) reduced the percentage of COCs exhibiting full cumulus cell expansion and the percentage of oocytes reaching metaphase II stage, and lowered the blastocyst rate compared with controls. And these inhibitory effects were associated with a reduction in the relative mRNA expression of GPx1 and SOD2 but not of GPx4 compared with controls. However, VE and GPx, both alone and in combination, completely abrogated the inhibitory effects of LA on nuclear maturation of oocytes and blastocyst rate but failed to do so for cumulus cell expansion. In conclusion, these data suggest that the detrimental effects of LA on oocyte developmental competence are mediated, at least in part, by a reduction in GPx1 and SOD2 mRNA expression. Moreover, VE and GPx may provide protection to most of the inhibitory effects of LA.

Effects of different polyunsaturated fatty acid supplementations during the postpartum periods of early lactating dairy cows on milk yield, metabolic responses, and reproductive performances

In spite of the difficulties in delivering PUFA to ruminants, studies have generally indicated that the PUFA of the omega-6 (linoleic acid) and omega-3 [α-linolenic acid; eicosapentaenoic (EPA), C20:5 omega-3; docosahexaenoic (DHA), C22:6 omega-3] families are the most beneficial to improving reproduction in cows. The objectives were to determine if a diet enriched in α-linolenic acid (omega-3) or linoleic acid (omega-6) would influence milk production and composition, metabolic status, and reproductive performance in lactating dairy cows. High-yielding multiparous Holstein dairy cows (n = 120) with no overt clinical illnesses were blocked according to calving date and parity. Cows were assigned randomly to be fed 1) soybean whole roast (Soy, omega-6, n = 40) or 2) linseed (Lin, omega-3, n = 40) or 3) palm oil as a source of SFA (PO, n = 40) from calving until first heat after 40 d postpartum (dpp), and then half of the cows in each treatment group were switched to receive either Lin or SFA (PO) from first heat after d 40 to 120 dpp. Blood was collected from a subsample of cows. Blood was collected at 14 d intervals for 12 wk, starting on the day of calving. Results showed milk yield and DMI were not affected. Milk compositions were similar (P > 0.08) among diets, except concentration and yield of milk fat percentage, which was less in cows fed Lin (P < 0.05). Uterine involution in cows fed Soy occurred earlier (P < 0.05). Diets affected day to first estrus and day to first insemination in cows (P < 0.05). There were no differences among treatments for percent heat detection, percent pregnancy per first insemination, and percent conception per AI at estrus. Also, there is a trend of pregnancy by 120 d, which is 66.7% for the Lin group vs. 50.91% for the PO group (P < 0.08). Of the 4 pregnancy losses, 2 occurred in PO-PO group and 2 occurred in Soy-PO group, and none occurred in the other 4 treatments. In conclusion, our study showed feeding omega-6 fatty acids during 40 dpp could be a good treatment for early postpartum periods, and a shift to omega-3 fatty acids until 40 d after AI can be considered as a strategy for improving fertility in lactating dairy cows.

Improvement of conception rate in postpartum flaxseed supplemented buffalo with Ovsynch+CIDR protocol

The present study was conducted on lactating Murrah buffalo to assess the effect of crushed flaxseed (a source of omega-3 fatty acids) supplementation (300g/100kg bwt/day for 60 days), over and above the routine feed, on luteolytic signal (PGF2α), luteal function (progesterone) and conception rate. In first experiment, on day 50 post-calving, six non-supplemented buffalo were treated to synchronize time of ovulation using an Ovsynch+Controlled Internal Drug Release (CIDR) protocol followed by intravenous oxytocin treatment (OT; 100IU) on day 15 post-ovulation. Blood samples were collected at 15min interval, 1h before to 4h after OT challenge. Thereafter, the same buffalo were supplemented with flaxseed, treated to synchronize time of ovulation starting on day 35 post-supplementation using the same protocol and subjected to OT treatment and blood sampling on day 15 post-ovulation. The PGF2α response was measured as the venous concentration of 13,14-dihydro-15-keto PGF2α (PGFM). The mean hourly concentration of PGFM subsequent to flaxseed supplemented was less (P<0.05) than in the pre-supplementation period at all the occasions. Flaxseed supplementation did not affect plasma fatty acids and other plasma metabolites except for an increase (P<0.05) in plasma cholesterol and plasma alanine transaminase. In the second experiment, 31 buffalo were randomly assigned to a control (n=16) and flaxseed supplemented (n=15) group. The latter group was supplemented with flaxseed starting from day 15 post-calving. On day 50-post-calving, buffalo of both groups were treated to synchronize time of ovulation among animals as described for the first experiment followed by artificial insemination (AI). Post-AI luteal phase plasma progesterone was greater (P<0.05) in the supplemented group compared to controls. Conception rate on day 63 post-AI was 66.7% in supplemented and 31.2% in controls (P<0.05). The present study indicated the beneficial impact of dietary supplementation of crushed flaxseed on conception rate through attenuation of luteolytic signal and improvement in post-breeding luteal profile.

Effect of dietary enrichment with either n-3 or n-6 fatty acids on systemic metabolite and hormone concentration and ovarian function in heifers

The objective of this experiment was to examine the effects of dietary n-3 or n-6 fatty acid (FA) supplementation on blood FA, metabolite and hormone concentrations, follicle size and dynamics and corpus luteum (CL) size. Reproductively normal heifers (n = 24) were individually fed diets of chopped straw and concentrate containing either (i) no added lipid (CON; n = 8); (ii) 2% added fat as whole raw soya beans (WSB, n-6; n = 8); or (iii) 2% added fat as fish oil (FO, n-3; n = 8). Following oestrous cycle synchronisation, blood samples were collected at appropriate times and intervals for the measurement of hormones, FAs and metabolites. On days 15 and 16 of the cycle, animals were subjected to an intravenous oxytocin challenge and prostaglandin F2α (PGF2α) response, measured as venous concentrations of 13,14-dihydro-15-keto PGF2α (PGFM). Dry matter intake and average daily gain were similar among treatments (P > 0.05). Plasma concentration of linoleic acid was highest on WSB (P < 0.05), while eicosapentaenoic (EPA, n-3; P < 0.0001) and docosahexaenoic acid (DHA, n-3; P < 0.0001) were greatest in the FO group. Plasma concentrations of arachidonic acid were higher on FO (P < 0.05) compared with CON and WSB. Plasma triglyceride concentrations increased, while β-hydroxybutyrate (BHBA) decreased with time on all diets (P < 0.05). There was a diet × time interaction (P < 0.01) for non-esterified fatty acid (NEFA) concentrations. Plasma cholesterol was higher on WSB and FO (P < 0.01) compared with CON. Progesterone (P4) and oestradiol (E2) concentrations, as well as follicle growth rate and CL diameter were similar across diets (P > 0.05). There was a diet × day interaction for PGFM (P < 0.01). When corrected for systemic E2 : P4 ratio, day 15 concentrations of PGFM were higher in the WSB group at 15 and 30 min (P < 0.01) post oxytocin administration compared with CON and FO, which were similar (P > 0.05). Concentrations of PGFM on day 16 were similar for WSB and FO and were greater than CON at 15 (P < 0.01) and 45 min (P < 0.05) post oxytocin administration, and at 30 min for FO (P < 0.05). With the exception of PGFM, dietary lipid source did not affect the reproductive variables measured.

Effect of supplementation with different fat sources on the mechanisms involved in reproductive performance in lactating dairy cattle

Supplementary fat positively influences reproductive performance in dairy cattle, although the mechanisms involved are not clearly defined. Our objective was to determine the effects of four different fat supplements on follicle development, plasma steroid hormone concentrations and prostaglandin (PG) synthesis in lactating dairy cattle. Forty-eight early lactation Holstein-Friesian cows (21 primiparous, 27 multiparous) were used in a completely randomized block design. Cows were fed the same basal TMR diet and received one of four fat supplements: (i) palmitic acid (18:0 fatty acid; Control), (ii) flaxseed (rich in 18:3 n-3 fatty acid; Flax), (iii) conjugated linoleic acid (a mixture of cis-9, trans-11 and trans-10, cis-12 isomers; CLA), and (iv) fish oil (rich in 20:5 and 22:6 n-3 fatty acids; FO). All lipid supplements were formulated to be isolipidic; palmitic acid was added as necessary to provide a total lipid supplement intake of 500 g/day. Cows were synchronized to be in estrus on Day 15 of dietary treatment. All antral follicles were counted, and dominant follicles, subordinate follicles and corpora lutea were measured daily via transrectal ovarian ultrasonography for one complete estrous cycle. Blood samples were collected daily, and selected samples were analyzed for progesterone, estradiol, insulin-like growth factor-1, insulin, cholesterol and non-esterified fatty acids. Estrus was synchronized a second time, and liver and endometrial biopsies were collected on Day 7 of the estrous cycle. Gene expression was evaluated for a number of genes involved in prostaglandin synthesis (endometrium) and fatty acid uptake and utilization (liver). Fat supplementation had little effect on follicle development. Cows receiving supplementary n-3 fatty acids had lesser plasma progesterone (P4) and smaller corpora lutea than cows receiving the CLA or Control supplements. Effects of fat supplementation on the endometrial expression of genes involved in PG synthesis were minor. Hepatic expression of SREBF1, ASCL1 and FABP1 was reduced by FO supplementation. Reduced plasma P4 in n-3 supplemented cows may lead to a suboptimal uterine environment for embryo development and hence reduced fertility compared to cows receiving the control or CLA supplements.

Effects of dietary fats differing in n-6:n-3 ratio fed to high-yielding dairy cows on fatty acid composition of ovarian compartments, follicular status, and oocyte quality

The objectives were to determine the incorporation of dietary encapsulated fats differing in n-6:n-3 ratio into milk fat, plasma, and various ovarian compartments and to examine the effects on ovarian follicular status, preovulatory follicle characteristics, and oocyte quality. Twenty-four multiparous Israeli Holstein cows, averaging 114 d in milk, were assigned to 1 of 3 treatment groups: 1) control (n=7), in which cows were fed a lactating cow diet; 2) E-FLAX (n=8), in which cows were fed a lactating cow diet that consisted of 1kg/d of encapsulated fat (3.8% of dry matter) containing 40.8% flaxseed oil, providing 242.2g of C18:3n-3 (low n-6:n-3 ratio); or 3) E-SUN (n=9), in which cows were fed a lactating cow diet that consisted of 1kg/d of encapsulated fat (3.8% of dry matter) containing 40.8% sunflower oil, providing 260.0g of C18:2n-6 (high n-6:n-3 ratio). Ovaries were monitored by ultrasonography for follicular status, and after synchronization, follicles >7mm were aspirated and evaluated. Ovum pickup was performed (19 sessions for the control and E-FLAX groups and 11 for the E-SUN group), and in vitro maturation and oocyte fertilization were conducted. The E-FLAX treatment increased the proportions of C18:3n-3 (5.8 fold), C20:5n-3, and C22:5n-3 (approximately 4-fold) in milk fat as compared with the other 2 treatments. The proportion of C18:3n-3 fatty acid in plasma increased dramatically with the E-FLAX treatment, from 1.43 and 1.49% in the control and E-SUN groups, respectively, to 7.98% in the E-FLAX group. Consequently, the n-6:n-3 ratio in plasma was reduced from approximately 42 in the control and E-SUN groups to 6.74 in the E-FLAX group. Proportions of C18:3n-3 in follicular fluid and granulosa cells were approximately 5-fold higher in the E-FLAX group than in the other 2 groups. The percentage of C18:2n-6 in cumulus-oocyte complexes of cows in the E-SUN group was 54% higher than that in the E-FLAX group and was 2.4-fold higher than that in the control group; the proportion of C18:3n-3 in the E-FLAX group was 4.73% and was not detected in the other groups. The average numbers of 2- to 5-mm follicles on d 5 and 9 of the cycle were higher in the E-FLAX group than in the E-SUN group, whereas the average numbers of follicles > or =10mm on d 5, 9, and 13 were higher in the E-SUN group than in the other 2 groups. The estrous cycles of the cows were synchronized and PGF(2alpha) was injected on d 16 to 17 of the cycle. The interval from PGF(2alpha) injection to behavioral estrus was longer in the E-FLAX group than in the E-SUN group, and the beginning of the luteal phase of the subsequent cycle was delayed. Concentrations of estradiol in follicular fluid of the preovulatory follicles were higher in the E-SUN group than in the E-FLAX group. The number of follicles aspirated by ovum pickup was higher in the E-FLAX group than in the control group, and the cleavage rate in the E-FLAX group was higher than in the control group, but not the E-SUN group. In conclusion, dietary n-3 fatty acids influenced the follicular status and increased the cleavage rate of oocytes as compared with those of control cows. These findings could be related to modifications of the fatty acid composition in plasma and ovarian compartments in response to dietary supplementation.

Impact of linoleic acid on bovine oocyte maturation and embryo development

Linoleic acid (LA; 18:2 n-6) is the most abundant fatty acid in bovine follicular fluid, and it was previously reported that LA concentration significantly decreases when follicle size increases. This suggests that LA may have a role in the regulation of oocyte maturation. The present study investigated the effect of LA supplementation on bovine oocyte maturation and early embryo development in vitro. Treatment of cumulus-oocyte complexes (COCs) with LA significantly inhibited cumulus cell expansion and retarded development of the oocytes to the metaphase II (MII) stage in a dose-dependent manner. This effect was reversible, and the oocytes developed to the MII stage after extended culture in the absence of LA. Treatment of COCs with LA also resulted in a significantly lower percentage of cleaved embryos and blastocyst yield. Furthermore, COCs treated with LA had significant effects compared with controls in i) increasing prostaglandin E(2) concentration in the medium, ii) decreasing intracellular cAMP at 6 and 24 h of maturation and iii) decreasing phosphorylation of the MAPK1 and 3 at 24 h, and AKT at 6 h of maturation. In conclusion, LA supplementation to bovine oocytes during maturation altered the molecular mechanisms regulating oocyte maturation and resulted in decreased percentage of oocytes at MII stage and inhibition of the subsequent early embryo development. These data provide evidence for adverse effects of LA on oocyte development, which can be associated with dietary increased level of LA in the follicular fluid and the decline in fertility in farm animals and human.

Estradiol-17beta and linseed meal interact to alter visceral organ mass and hormone concentrations from ovariectomized ewes

To evaluate the estrogenic potential of secoisolariciresinol diglycoside (SDG) found in linseed meal (LSM) on visceral organ mass, IGF-I, and thyroid hormone (T(3) and T(4)) concentrations, 48 multiparous, ovariectomized ewes (54.6 +/- 1.1 kg) were used in a 3 x 4 factorial arrangement. Main effects were length of LSM feeding (0, 1, 7, or 14 d) and length of exposure to estradiol-17beta (E(2)) implant (0, 6, or 24 h prior to tissue collection). Implanting ewes with E(2) for 24h increased liver mass relative to empty body weight (EBW; g/kg EBW) compared with ewes implanted for 0 or 6 h (P <or= 0.03), whereas feeding LSM for 14 d decreased liver mass compared with ewes fed LSM for 1 or 7 d (P <or= 0.02). There was an LSM x E(2) interaction (P = 0.01) for duodenal mass (g/kg EBW), LSM, and E(2) tended (P = 0.07) to influence the stomach complex mass; however, ileal mass was not affected. Neither LSM nor E(2) affected (P >or= 0.12) CYP2C or CYP3A mRNA expression or cellularity of the liver. Exogenous E(2) influenced circulating concentrations of IGF-I, T(3), and T(4). The estrogenic or anti-estrogenic potential of LSM is dependent upon the tissue, exposure to E(2), and the duration of LSM feeding. Feeding LSM during gestation, lactation, or during the grow-finish phase warrants further investigation.

Effect of feeding flax or linseed meal on progesterone clearance rate in ovariectomized ewes

Ovariectomized ewes (n=22; 68.76+/-2.34 kg initial body weight; 2.9+/-0.1 initial body condition score) were individually fed one of three diets: (1) control (phytoestrogen-free; n=7), (2) flax containing diet (n=8), or (3) linseed meal (LSM) containing diet (n=7) to investigate the rate of progesterone (P4) clearance. On day 20 of feeding (day 0=initiation of treatment), a P4 releasing device (CIDR) was placed in the vagina and jugular blood samples were obtained prior to CIDR insertion and 15, 30, 60, and 120 min following CIDR insertion. Further, blood samples were obtained daily between days 21 and 24. On day 25, blood samples were retrieved prior to CIDR removal and 2, 5, 10, 15, 30, 60, 120, and 360 min following CIDR removal. There was no difference in initial or final body weight or body condition score and there were no time by diet interactions on P4 clearance. The fractional rate of P4 uptake measured prior to CIDR insertion through day 4 following insertion tended to be greater (P=0.07) in LSM fed ewes (508.75+/-71.37%/min) compared to flax (295.39+/-66.76%/min) and control fed (287.54+/-71.37%/min) ewes. Diet tended (P=0.10) to influence P4 clearance rate when measured from prior to CIDR removal through 120 min following CIDR removal with LSM fed ewes having a greater (1.26+/-0.2) fractional rate constant than flax (0.929+/-0.09) and control fed (0.922+/-0.09) ewes. Flax fed ewes also had more (P<0.01) omega-3 fatty acids and total fatty acids in plasma. Reports of increased pregnancy rates in dairy cows fed flax may relate to P4 metabolism.

An inventory of the ethnoveterinary practices for reproductive disorders in cattle and buffaloes, Sargodha district of Pakistan

AIM OF THE STUDY

This study was conducted to document the ethnoveterinary practices (EVPs) used for the treatment and/or management of reproductive disorders of cattle and buffaloes.

MATERIALS AND METHODS

The information was collected using rapid and participatory rural appraisal techniques through interviews and focused group discussions with 217 traditional veterinary healers (TVHs) over a period of 16 months.

RESULTS

The use of 66 plant species was documented for the treatment of reproductive disorders in the two dairy species. Most frequently reported (>or=20 times) plants represented Apiaceae, Poaceae, Pedaliaceae, Linaceae, Arecaceae, Brassicaceae, Malvaceae, Zingiberaceae, Rosaceae, Cannabaceae, Fabaceae, Moraceae, Rubiaceae and Mimosaceae families. All the documented plant species were indigenous to the study area. Genital prolapse, retention of fetal membranes, silent estrous/delayed puberty, anestrous, dystokia associated with incomplete cervical dilatation and retention of lochial discharge were the frequently reported reproductive disorders. Some of the plants were reported to be used in more than one condition. Materials other than plants used for the treatment of these disorders included camel milk, butter and butter fat, minerals, eggs, organic matters, chemical substances and meat preparations. These materials were used either alone or as adjunctive therapy.

CONCLUSION

Richness of EVPs in the study area and extensive variation in the doses, methods of preparation, indications, and claims regarding efficacy of plants for various disorders merit controlled studies for their validation.

Diets enriched in unsaturated fatty acids enhance early embryonic development in lactating Holstein cows

We hypothesized that a diet enriched in alpha-linolenic acid would enhance embryonic development relative to diets enriched in linoleic or saturated fatty acids. Twenty-four lactating Holstein cows (86+/-22 d postpartum) were assigned to one of three diets containing saturated fatty acids (SAT; high in palmitic and stearic acids), whole flaxseed (FLX; high in alpha-linolenic acid) or sunflower seed (SUN; high in linoleic acid). Rations were formulated to provide 750 g supplemental fat/cow/d in all dietary groups. Ovulation (Day 0) was synchronized approximately 20 d after diets began. Ultrasound-guided follicular ablation of all follicles >8 mm was performed 5 d after ovulation; super stimulatory treatments began 2 d after follicular ablation, and embryos were collected non-surgically 7 d after AI. Fertilization rate, numbers of follicles and ovulations, and total and transferable embryos did not differ (P>0.05) among dietary groups. Sixty-one transferable embryos were stained and total blastomere number determined. Blastomere number was affected by diet (P<0.01); without regard to stage of development, embryos collected from cows fed SAT had lower (P<0.01) blastomere numbers (mean+/-S.E.M.; 77.1+/-3.9) than those from cows fed FLX (93.4+/-3.3) or SUN (97.2+/-3.5). Differences were most evident in the expanded blastocyst stage; at this stage, embryos of cows fed FLX and SUN diets had more blastomeres (P<0.02) than those of cows fed SAT (115.4+/-6.3, 132.3+/-8.3, and 89.3+/-9.6 cells, respectively). Although our hypothesis was only partially supported, embryonic development was enhanced in Holstein cows fed unsaturated fatty acids compared to those fed saturated fatty acids.

Effects of dietary energy source on energy balance, metabolites and reproduction variables in dairy cows in early lactation

This paper summarizes three recent studies by the same authors with the objective to study the effect of dietary energy source on the energy balance (EB) and risk for metabolic and reproductive disorders in dairy cows in early lactation. The first study, a literature survey, illustrated that feeding extra glucogenic nutrients relative to lipogenic nutrients, decreased milk fat and seems to decrease plasma non-esterified fatty acid (NEFA) and beta-hydroxybutyrate (BHBA) concentration. However studies are scarce and mostly confound the effect of energy source with level of energy intake, compromising eventual effects on EB and fertility. Therefore, in the second study, 16 dairy cows were either fed a glucogenic or a lipogenic diet (isocaloric) and EB was determined in climate-controlled respiration chambers from week 2 until 9 of lactation. Glucogenic diet decreased milk fat yield and milk energy and tended to decrease body fat mobilization compared with lipogenic diet. The objective of the third study was to study the effect of dietary energy source on EB, metabolites and reproduction variables. Dairy cows (n=111) were fed glucogenic, lipogenic or mixed diet from week 3 until week 9 relative to calving. Multiparous cows fed glucogenic diet had lower milk fat yield, higher calculated EB, and lower plasma NEFA, BHBA and liver triacylglyceride concentration and tended to have fewer days to first postpartum ovulation. In conclusion, increasing the glucogenic nutrient availability improved the EB and had potential to reduce the risk for metabolic disorders and to improve reproductive performance in dairy cows.

Conception rate and reproductive function of dairy cows fed different fat sources

The objective of the experiment was to determine the effects of fat supplementation on cyclicity, progesterone concentration, follicular development, conception rate, embryo mortality, and plasma concentrations of prostalglandin F metabolite (PGFM) in cattle. The hypothesis of this experiment was that feeding flaxseed, which is a source rich in C18:3, would increase conception rate of dairy cows due to decreased plasma PGFM concentrations. A total of 138 lactating Holstein cows were allotted at calving to three groups of 46 cows, blocked for similar calving dates. Cows within each block were assigned to one of three isonitrogenous, isoenergetic, and isolipidic supplements based on either whole flaxseed (FLA), Megalac (MEG) or micronized soybeans (SOY). The diets were fed from calving to Day 50 of pregnancy for pregnant cows, or 120 day postpartum for those not diagnosed pregnant after AI. Detailed measurements of PGFM and follicle dynamics were only made on four cows for FLA and five cows for both MEG and SOY. The response in PGFM concentration following the oxytocin challenge administered around Week 11 of lactation was similar over time among treatments. Plasma progesterone concentrations from Days 17 to 21 of the estrous cycle starting around Week 9 of lactation and determined on a subsample of cows (n=for FLA and n=5 for both MEG and SOY) were higher for cows fed FLA than for those fed SOY (P=0.04) or MEG (P=0.06). Conception rates were similar among treatments. Total embryo mortality was lower (P=0.07) for cows fed FLA (0%) compared to those fed either MEG (15.4%) or SOY (8.0%). The mean size of the CL measured during a complete estrous cycle from Week 9 of lactation was smaller for cows fed SOY (16.3 mm) compared to those fed either FLA (19.1 mm) or MEG (18.3 mm). We inferred that pregnancy losses could be reduced by feeding whole flaxseed as a result of its effects on different factors such as modulation in concentration of progesterone and size of the CL.

Lower Pregnancy Losses in Lactating Dairy Cows Fed a Diet Enriched in α-Linolenic Acid

The objectives were to determine if a diet enriched in alpha-linolenic acid (ALA) would influence ovarian function, early embryo survival, conception rates, and pregnancy losses in lactating dairy cows. Beginning 28 d before breeding, Holstein cows (55 +/- 22 d postpartum; mean +/- SD) were assigned to diets supplemented with either rolled flaxseed (FLAX; 56.7% ALA, n = 62) or rolled sunflower seed (SUNF; 0.1% ALA, n = 59) to provide approximately 750 g of oil/d. Diets continued for 32 d after timed artificial insemination (TAI, d 0) following a Presynch/Ovsynch protocol. Barley silage- and barley grain-based TMR were formulated to meet or exceed National Research Council requirements. Metabolizable protein and net energy for lactation concentrations were similar in the 2 diets. Based upon a mean dry matter intake of 22 kg/d, cows fed FLAX or SUNF consumed > 410 g or < 1 g of ALA, respectively. Pregnancy was confirmed by ultrasound 32 d after TAI. Nonpregnant cows were placed on a second Ovsynch regimen and reinseminated 42 d after first TAI, and received oilseeds for 32 d after second TAI. Relative to prediet levels, FLAX increased the ALA content of milk by 187%. Ovarian ultrasonography was performed in 8 cows per diet; the mean diameter of ovulatory follicles was larger in cows fed FLAX compared with SUNF (16.9 +/- 0.9 vs. 14.1 +/- 0.9 mm), but follicle number, corpus luteum size, and plasma progesterone concentrations remained unaffected. Presumptive conception (progesterone < 1 ng/mL on d 0 and > 1 ng/mL on d 21) rates to first TAI were greater in FLAX than in SUNF (72.6 vs. 47.5%). Pregnancy losses were lower in cows fed FLAX (9.8%) compared with those fed SUNF (27.3%). Including flaxseed in the ration of dairy cows increased the size of the ovulatory follicle and reduced pregnancy losses.