Reproductive Performance of Ewes, Fed Flushing Diet at Different Management Feeding Program

MATERIALS AND METHODS

Animal experimental setup: The study was conducted at the Department of Nutrition and Feed Technology, Faculty of Animal Science, IPB University, Indonesia for 8 months, since October, 2020 until May, 2021. The experimental procedure was approved by The Animal Care and Use Committee of IPB University with number 120-2020/IPB. Twenty multiparous garut ewes, with initial body weight of 30.06±6.20 kg (av. BCS less than 2.40) were kept in individual cage equipped with feeding and drinking water facilities. The animals were divided into four treatments with five ewes of each group. The treatments were: Without flushing (F0 as concentrate control), flushing at the beginning of mating (F1 = 2 weeks pre-mating until 2 weeks just after-mating), two times flushing (F2 = F1 plus 4 weeks flushing during mid gestation) and three times flushing (F3 = F2 plus 2 weeks flushing at the end of gestation and another 2 weeks just after parturition).

Feeding management: During the study, the ration was given 3.5% BW of DM, consist of concentrate control and forage as Pennisetum purpureum with a ratio of 70:30 based on dry matter. Daily feeding management was three times a day at 07.00 am, 11.00 am and 03.00 pm and water served ad libitum. The flushing concentrate was given according to management program treatments. The concentrate made by soybean meal, pollard, dried cassava, coconut oil, lemuru fish oil, molasses, CaCO₃, NaCl and premix, which the composition of macro nutrients and minerals, as mention in Table 1 and 2. The differences between concentrate control and concentrate flushing is only in the presence of lemuru fish oil. Proximate analysis was done according to Horwitz and Latimer¹⁷, while minerals were analyzed by using Atomic Absorption Spectrophotometer (AAS) and TDN was calculated following¹⁸. The feeding management program of flushing was mention in Fig. 1.

Fig. 1:

Flushing management program during experiment

Estrus synchronization and detection of pregnancy: Synchronization of estrus was conducted by injecting PGF₂α (Noroprost^®, Norbrook Laboratories Limited) hormone at a dose 2 mg (b/v) per ewe intramuscularly, twice with 11 days apart before mating. Natural mating was done with ratio ewe to rams 4:1 in colony pen for around 5 days and their behavior was observed¹⁴. Determine of pregnancy and number of embryo was conducted at day 28th after mating by using detector transrectal ultrasound with 7.5 MHZ (ALOKA model SSD-500, SN MO7265, ALOKA Co. Ltd., Tokyo, Japan) described by Viñoles et al.¹⁹. The percentage of pregnancy and embryo lose calculated by using the formula:

Nutritional intake and body condition score: Consumption of feed and nutrients were measured daily by the difference between feed offered and its remaining for the duration of the observation. Assessment of BCS is carried out every month during pregnancy. Determination of the BCS value through observation and palpation of the spine (backbone), loin and hip (rump) to evaluate fat deposits. The BCS range from 1 to 5, starting from very thin (score 1), thin (score 2), moderate/moderate (score 3.0), obese (score 4) to very fat (score 5)²⁰.

Reproductive performance: Reproductive performance was measured including percentage of pregnancy, pregnant period, number of embryos, litter size (single, twin or triplet) and sex ratio. The percentage of pregnancy was obtained by counting the number of pregnant ewes from each treatment. The definition of pregnant period is the duration of pregnancy length, which is start from implant follicle on the uterus until the embryo ready to be partus. Ewe weight and lamb birth weight at partus were done after partus within 24 hrs. Type of birth and sex ratio were expressed in percent.

Statistical analysis: The study was designed by a Randomized Completely Block Design (RCBD) and all data obtained were analyzed statistically with ANOVA using IBM SPSS Statistics version 20.0 (2011). The comparation among the different mean treatment was done by Duncan’s multiple range test.

Data of pregnancy parameters and type of birth was analyzed descriptively. Model of statistical RCBD is mentioned:

where, Y_ij is observed data, μ is overall mean, P_i is effect of treatment, β_j is effect of block and €_ij is random residual error.

RESULTS

The following average consumption of reproductive garut ewes presented in Table 3. The results showed that there was no significant effect between all treatments on the consumption of dry matter, crude protein, crude fiber and NFE, but significantly increased the crude fat consumption (p<0.01) and significantly different for TDN (p<0.05). Dry matter consumption in the study was not significantly different, this indicates that the addition of lemuru fish oil to the flushing ration did not reduce palatability. According to NRC²¹, reproductive ewes with an average body weight of 30-50 kg need around 2.13-2.81% body weight (BW) of dry matter intake. Energy consumption in TDN unit in this study significantly higher in the treatment given flushing ration (635.87-676.14 g/day) than the control treatment (578.25 g/day), however this result was suitable and adequate for reproductive ewes based on²¹ for reproduction with an average body weight of 30-50 kg. Fat consumption in this study was significantly increased in different flushing management treatments (p<0.01). Fat consumption in flushing treatments was higher compared to control. This doe to the presence of lemuru fish oil in flushing ration. The unsaturated fatty acids consumption increased significantly (p<0.05) in all flushing treatments compared to control. The increasing of unsaturated fatty acids consumption was higher than saturated fatty acids (Table 3). This condition is very good, especially for reproduction system.

Body condition score: The BCS values of the ewes before flushing treatment ranged from 1.88-2.13 (Table 4). This condition illustrated that the ewes have not in ideal conditions for reproduction yet.

The flushing program at different periods and different age of gestation did not affect the BCS value of the garut ewes, however changes of BCS value that received flushing treatment in F3 with three times flushing were significantly higher than controls (p<0.05), but not significantly different from F1 and F2 treatments. The highest percentage of BSC change value was in F3 treatment.

This condition indicated that the flushing ration which was given in start from beginning, middle and end of gestation (F3) had an impact on changes in BCS and the condition of the ewe before giving birth. There was no significant difference in body weight gain for all ewes, both those that were treated with flushing and those that did not receive flushing rations. Body weight at birth in ewes that received a 3-period flushing ration (F3), was significantly higher than the control, but there was no difference with (F1) and (F2).

Ewes reproductive performance: Reproductive performance of garut ewes with different flushing periods, presented in Table 5. Total embryo with different management flushing treatment did not give significance difference in all treatments. Statistically, there was no significance difference of litter size among the treatments, but especially in treatment F3 with three times flushing there was tendency had higher litter size. Meanwhile, there were no significance difference of sex ratio, length of gestation and birth weight (Table 5).

The percentage of rate pregnancy of ewes fed flushing with difference management were 25% higher than control, even though there were no effect to the total embryo, litter size and birth weight. The higher embryo lost was done in control (10%) and F1 treatments than in F2 and F3 treatments. The total embryo were same in all treatments were doe to they have same BCS when they were matting, so the ovulation rate and fertilization rate were same. The male lambs were more happen in flushing treatment compare to control one.

DISCUSSION

The nutrients consumption in all treatments are same means that the palatability of flushing diet containing lemuru fish oil is quite good and same with control. Different flushing management did not affect to the dry matter, protein, fiber and NFE intakes. According to NRC²¹ recommendation, pregnant ewes with around 35-40 kg b.wt. and have more than one embryo need 2.50-2.80% DM intake of b.wt. Data of protein and TDN intake for those pregnant ewes also had been enough asrecommendation²¹. Lemuru fish oil could increase the density of energy in the flushing diet, so the total TDN intake start from beginning (670 g/hr/day) until end of pregnancy (1120 g/hr/day) could support energy for reproduction processes of those ewes during pregnancy. This condition shows that ewes obtain excessive energy intake that can support the ewes for reproductive preparation²². It was reported by Astuti et al.²³ that pregnant small ruminant especially does have average feed intake around 672-932 g/hr/day. Increased consumption of fat is used in the formation of cholesterol which functions as a precursor of steroid hormones, so that it has a positive effect on reproductive hormone status²⁴. Fat source from lemuru fish oil could increase of reproduction hormone biosynthesis which is very importance during fertilization until parturition²⁵. This statement was in line with stated that fat has special function for increasing milk quality and reproduction performance²⁶, meanwhile another researcher reported that fat with specific Polyunsaturated Fatty Acids (PUFA) has very strong correlation with reproduction²⁷. Supplementation with PUFA in the flushing diet could stimulate steroid hormone and follicle development²⁸, increasing of fertilization and embryo development^29,30 and also progesterone concentration³¹. At the end of pregnancy, ewe need high energy diet in order to support the fastest growing embryo³². Lemuru fish oil contains n-3 Polyunsaturated Fatty Acids (PUFA), namely eicosapentaenoic acid 13.70% (EPA) and docosahexaenoic acid (DHA) of 22.47% from total fatty acid.

Flushing treatments with different periods did not affect to the BCS, but delta of BCS is affected by flushing management. The highest BCS with 3.81 was happen in F3 treatment with three times flushing. It is therefore recommended to maintain the BCS of ewes at mating in the range of 3-3.5, to optimize the profitability of flocks in this breed³³. Al-Sabbagh et al.³⁴ stated that animal with 2.50-3.50 BCS condition is ready to do reproduction and they have high immunity so that can depress mortality. High energy intake from flushing treatment will support nutrient for matting, embryo development and partus³⁵. Furthermore it was reported that flushing by using sunflower oil for ewe could decrease lost weight after parturition³⁶. Body condition Score can be used for detection of dietary management tool after partus, a good quality diet is required to meet milk production requirement, especially for low BCS ewes³⁵. The BCS value in this study were higher compared to study before by flushing using different kinds of plant and animal fat¹⁴. A better BCS during mating will result a better conception rate. The low of BCS ewes value will lead to reduce GnRH production in undernourished ewes³³. This study proved that three times flushing management at pre, in the middle and late of gestation, especially for ewes with under BCS standard will improve BCS condition and reproduction performance. This result supported by previous study which was flushing before and after matting could increase BCS, estrus percentage, calving rate, milk production, birth weight and shorten the postpartum estrus and calving interval^2,9,10.

Data showed that flushing program could gave positive response to the pregnancy percentage. Flushing treatment before and after matting is aimed to make sure that follicle can implant well in the uterus without any problem with reabsorption by hormone status²⁴ and also stated that with this flushing management could increase embryo survival¹⁹. Data from research resulted of flushing ewes with linoleic acid from sunflower oil had higher percentage pregnancy than control¹², while another researcher reported that flushing with high soybean meal on does resulted 100% pregnancy rate¹³. Flushing diet with high quality nutrient will give effect to hypothalamus to stimulate anterior pituitary gland than secret Follicle Stimulating Hormone (FSH) for follicle maturation and activate Luteinizing Hormone (LH) for ovulation¹⁵. The more follicle ovulation, the high possibility of percentage pregnancy increasing. This study showed ewe without flushing treatment has lower percentage of pregnancy doe to not enough nutrient to support implantation of follicle, so that those embryo re-absorbed by physiological system. The increasing of embryo survival in the flushing treatment of this study proved by the higher litter size. Supplementation of omega-3 from fish oil can increase prolific expression and total embryo^37,38. Supplementation of omega-3 will increase progesterone which important to maintain pregnancy, reduce PGF2α release from uterus and prevent embryo death³⁹.

Treatment with different flushing management containing lemuru fish oil with high PUFA (omega-3) resulted higher litter size. This study supported by Meteab et al.⁴⁰, who stated that omega-3 supplementation will result high litter size performance in doe due to survival embryo in the uterus during gestation. In general, this study with two and three times flushing resulted same ratio of female and male lambs. Flushing once at the beginning of gestation, containing lemuru fish oil with high linoleic acid in thus study resulted more female kids. This data supported by previous study²⁷ and another study flushing with diet containing high omega-6 during pre-matting resulted female kids⁴. The higher female birth with omega-6 diet rat is due to the higher lost male embryo during gestation⁴². The higher ratio omega-3 to omega-6 in the ewe diet will result more male kids. Flushing management did not affect to length of pregnancy. This result supported by previous flushing study by using different kinds of fat at does¹⁴. The length of gestation in this study (141-144 days) shorter than data (148-151) reported by Celik et al.⁴³. The gestational length is affected by litter size, where higher litter size will have shorter gestational length compare to singlet one. Total birth weight is relate to the gestational length too. The high litter size in F2 and F3 treatment resulted the high total birth weight. The earlier researcher⁴⁴ stated that total birth weight is expression of hormonal system especially progesterone and the complexity of growth factor in the body. The higher progesterone concentration, will result higher birth weight⁴⁴. On the other hand it was reported that calf birth weight was in line with the gestational length and not affected by fatty acid treatment⁴⁵.

CONCLUSION

Three times flushing feeding program, before and after mating, in the middle and at the end of gestation low BCS ewes could improve reproductive performance such weight at partus, pregnancy percentage and type of twin birth and also could decrease loose of embryo. However, the three times flushing program did not affect to the pregnant period, total birth weight of lamb, litter size and sex ratio offspring.

SIGNIFICANCE STATEMENT

This research evaluated the implementation of flushing diet program containing lemuru fish oil with time difference management for understanding the reproductive performance indicators of local garut ewes. Results shows that three times flushing for very low BCS ewes will increase reproduction performance as percent of pregnancy and twin birth and also decrease loose embryo.

ACKNOWLEDGMENTS

We would like to say thank you to the Indonesian Ministry of Research Technology and Higher Education for funded our study through International Collaboration Project in 2020 with nomor 2492/IT3.L1/PN/2020 and IPB University Research Institute program nomor 264 tahun 2021.