Attenuation of luteolytic response following fish meal supplementation in dairy buffaloes (Bubalus bubalis)

Effects of dietary supplementation with omega-3 fatty acid-rich linseed on the reproductive performance of ewes in subtropical climates

The present study evaluated the effects of omega-3 (ω-3) fatty acid-rich linseed supplementation on the reproductive performance, endocrine profile, and biochemical profile of ewes reared in subtropical climates. Forty-eight acyclic and clinically healthy Marwari sheep, aged 1.5-2.5 years with no parity, were divided into four groups (n = n = 12 in each). Ewes in the control group (group I) were fed only a basal feed, whereas ewes in the treatment groups II, III, and IV were fed the basal diet along with 10%, 15%, and 20% linseed, respectively, daily on a dry matter basis. The experiment was conducted during the typical breeding season (October-November) of the sheep. The estrus induction rate was significantly higher (p < 0.05) in all treatment groups than in the control group. The estrus induction interval was significantly lower (p < 0.05) in group III. The conception rate in group I was significantly lower (p < 0.05). In addition, ewes in the control group had a significantly lower (p < 0.05) lambing rate than all treatment groups. Serum progesterone concentrations differed significantly (p < 0.05) between the control and the treatment groups on days 15, 30, 45, and 60 of supplementation. On treatment days 15 and 30, the serum estrogen concentrations were significantly higher (p < 0.05) in all treatment groups compared to that in group I. In all treatment groups, monounsaturated fatty acid (MUFA) decreased significantly (p < 0.05), whereas polyunsaturated fatty acid (PUFA) increased significantly (p < 0.05) from day 15 onward. In conclusion, by providing 15% dietary linseed supplementation to ewes, their reproductive performance can be improved in subtropical climates. Future studies are recommended to further elucidate the role of linseed supplementation in sheep reproduction in subtropical climates.

Effect of dietary supplementation of palm kernel cake on ovarian and hepatic function in buffalo (Bubalus bubalis)

To determine the optimal inclusion amount of palm kernel cake (PKC) in a buffalo diet, in the present study there was evaluation of the ovarian activity, metabolism and hepatic function of females that were treated to synchronize the time of ovulation. Twenty-four estrous-cyclic and non-lactating Murrah buffalo with a mean age of 5.7 years were supplemented with 0%, 0.25%, 0.5% and 1% of their body weight (BW) with PKC. Animals were subjected to the Ovsynch protocol (beginning of protocol = D0). The ovaries were examined and the blood was collected on D10 (follicular phase) and D17 (luteal phase). Follicular and luteal development and serum progesterone concentrations were not affected by diet (P > 0.05). Serum concentrations of cholesterol were greater in animals supplemented with PKC in amounts at 0.5% of BW or less with PKC, regardless of the phase of the estrous cycles when evaluations occurred (P < 0.05). Concentrations of HDL-cholesterol were similar (P > 0.05) during the follicular and luteal phases. Triglyceride concentrations increased linearly (P = 0.03) as percentage of PKC inclusion diets increased during the follicular phase, but were similar in the luteal phase (60.0 mg/dL; P = 0.51). Amount of PKC supplementation did not affect the concentrations of alanine aminotransferase, but there was a greater amount of aspartate aminotransferase (AST) and gamma glutamyl transferase (GGT) during both phases of the estrous cycle (P < 0.05). Animals supplemented at 1.0% of BW with PKC had greater AST and GGT concentrations than what is recommended for buffalo. The results of the present study indicate PKC supplementation of buffalo diets does not affect the development of the ovarian follicle and corpus luteum nor the peripheral concentration of progesterone, even though there are greater serum concentrations of total cholesterol and triglycerides. Because the amount of PKC supplementation in the present study does not result in hepatic dysfunction when fed at the 0.5% of BW amount, it is suggested that this agro-industrial byproduct of high nutritional value may be a new alternative for dietary supplementation of grazing buffalo.

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.

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.