The effect of plant and animal-derived dietary oil supplementation on the reproduction performance of Dohne Merino ewes and the growth performance of their offspring

doi:10.21203/rs.3.rs-3415686/v1

Download PDF

Research Article

The effect of plant and animal-derived dietary oil supplementation on the reproduction performance of Dohne Merino ewes and the growth performance of their offspring

https://doi.org/10.21203/rs.3.rs-3415686/v1

This work is licensed under a CC BY 4.0 License

You are reading this latest preprint version

The effect of different dietary oils on ewe reproductive performance and lamb growth was investigated. Fifty-second parity Dohne Merino ewes (body condition score 3.5±0.4) were randomly divided into five groups of ten each. Ewes received 30 ml of sunflower- or olive- or fish- or palm oil. The control group received no oil. Ewes received oils before and after laparoscopic artificial insemination (LAI). Two weeks after LAI, follow-up rams were introduced. Mean conception and lambing rates were 88%. Ewes that received olive oil had the highest conception rate and lambing rate of 100% but did not differ (P>0.05) from other groups (sunflower- 90%, fish- 90%, palm- 70% and control group 90%). The control group had the shortest gestation length (150 days). The gestation lengths of sunflower-, olive-, fish- and palm oil were 153, 156, 155, and 156 days. Birth weights of female lambs from control, sunflower-, olive-, fish- and palm oil were 5.41 ± 0.87, 5.70 ± 0.61, 5.8 ± 0.70, 5.8 ± 0.74 and 4.9 ± 0.50 kg (no difference between groups). The birth weights of male lambs from control, sunflower-, olive-, fish- and palm oil were 5.6 ± 1.19, 4.85 ± 0.70, 5.6 ± 0.84, 5.5 ± 0.49 and 5.4 ± 0.33 (no difference between groups). Weaning weights for male lambs were (28.8 ± 4.93, 25.5 ± 8.13, 29.0 ± 4.88, 30.2 ± 4.59, 28.8 ± 5.03) and female lambs were (28.5 ± 4.58, 28.3 ± 3.81, 25.8 ± 6.93, 28.9 ± 4.51, 27.6 ± 2.46), no difference between groups.

Reproduction

Weaning

Additives

Gestation

The current state of small stock production

Small stock plays a significant role in human food security and income at the household level and an integral role in agriculture around the world. In 2019, the total sheep population was 1, 24 billion in the world, 408 million in Africa, and 25, 5 million in South Africa (FAOSTAT, 2021). There is a high disparity in the sheep population in various provinces of South Africa, but generally, many sheep are found in the Eastern Cape, followed by the Northern Cape and Free State (DAFF, 2020). Extensive small stock production occurs mostly in the drier western and north western parts of the country, with a low grazing capacity - below 12 ha per large stock unit (LSU) (Cloete and Olivier 2010). In addition, the population of extensively reared beef increases in the eastern and northern directions, as the average precipitation rises. Extensive beef production replaced a higher population of extensive small stock production in the Northern provinces (Cloete et al. 2014).

Only 16.5% of the approximately 86.2 million ha of commercial agricultural land can be considered arable (Cloete et al. 2014) and therefore it has become crucial to improve production efficiency on the farm level. Methods to improve production efficiency have been investigated by numerous researchers. One method is the use of feed additives. Feed additives have been used extensively in animal feed rations, especially in extensive animal production systems. Feed additives are included to enrich animal diets and enhance digestive and metabolic processes (Zaitsev et al. 2020) (to stimulate growth, health, and animal production performance). Feed additives include various spices, and herbs, as well as oils extracted from the plant (e.g. sunflower and palm oil), and animal (fish oil) products (Windisch et al. 2008).

Objective of the research

Oils extracted from plant and animal products have different fatty acid profiles and ratios of fatty acids (n3: n:6 n:9) with different effects on the reproduction and general health of an animal (Moallem 2018). Fish oil is rich in n3 fatty acids, sunflower is rich in n6 fatty acids, and palm oil and olive oil are both rich in n9 fatty acids (Moallem 2018; Mwangi et al. 2018). Therefore, using oils as a supplement to pregnant and lactating ewes may potentially increase the economic return through their weaned offspring. Literature on dietary oil supplementation in pregnant and lactating South African Dohne Merino has not been recorded yet. The impact of oils on the productivity of Dohne Merino sheep for a 120-day feeding trial was studied. Findings from this project will give farmers a guideline on which oil supplement (if any) to use to improve production efficiency.

This study was reviewed and approved by the Animal Research Ethics Committee of the University of the Free State (Ethics number UFS-AED2020/0020/63). The trial was carried out on fifty (50), second parity, South African Dohne Merino ewes ranging in age 2 to 4 years (4-6 tooth) weighing 46-55kg with mean body condition score (BCS) 3.5±0.4. The ewes were housed in a sheltered environment but had access to outside paddocks. The animals were quarantined for a period of 21 days and inspected for possible diseases and infections before the start of the trial.

Housing

All 50 ewes grazed together on a paddock of 5 hectares. The paddock consisted of a mixture of natural pasture and the ewes had unrestricted access to water in troughs that were connected to a permanent water supply (tanks) that were cleaned regularly. Each evening, the ewes were kept in an overnight sheltered kraal for protection from unfavorable weather conditions and predation.

Feeding of ewes

The ewes grazed daily from 9:00 am – 4:00 pm on the pastures and in addition, each ewe received 2kg of pellets per day. The pellets consisted of a ration of crushed yellow maize, Lucerne, and molasses. Ewes experiencing diarrhea were fed 1 kg bucket of pellets and 1 kg bucket full of crushed lucerne and water was provided ad libitum.

Health management

During the selection of ewes, inspections were conducted for any signs caused by diseases and infection. The experimental animals were dosed for internal parasites using propose orange, dipped with Prodip, and vaccinated against Ovine pasteurellosis at the beginning of the trial. Sick animals were separated from healthy animals after routine inspections that were done daily. Sick animals were kept in bays where they were fed enough hay and had access to water and treatment.

Experimental design

The 50 ewes were randomly divided into 5 groups of 10 each. The control group (n=10) received no oil, the SO group (n=10) received 30 ml sunflower oil per day, the OO group (n=10) received 30 ml olive oil per day, the FO group (n=10) received 30 ml fish oil per day and the PO group (n=10) received 30 ml palm oil per day. The animals were tagged on the right-hand side and the ear tag clearly indicated the animal number and its group.

Data analysis for this trial was subjected to analysis of variance (IBM SPSS statistics 27 programs) using General Linear Model (GLM) procedure for repeated measures and used Tukey’s model at an interval of 95% confidence interval

Drenching of ewes with dietary oils

The ewe’s head was slightly lifted in an upward position, holding it towards one’s hip to gain full control of the animal’s head. On the other hand, the drench gun was slowly inserted into Ewe’s mouth. Oils were gently drenched in the animal’s mouth and allowed to swallow before releasing. After drenching, the animals were taken to pasture camps for grazing and returned to the kraal at 16:30 where they were sheltered for overnight resting. The ewes received 30 ml oil for 120 days; 2 weeks prior to insemination, a rest period of 45 days after insemination to ensure embryo attachment, throughout gestation and parturition and ended when lambs were weaned from the ewes.

Synchronization of oestrus using CIDR^®

Oestrus was synchronized in all ewes using controlled internal drug-releasing device (CIDR) with 0.6 g progesterone to assist in the administering of exogenous progesterone (Plate 3.17). The CIDRs were in place for a period of 15 days. All ewes were checked daily to ensure that the CIDRs remained in place for the duration of the treatment period. At CIDR removal ewes were administered 20 IU/kg of pregnant mare serum gonadotropin (PMSG). The ewes were then allowed to rest for 48 hours and monitored for signs of oestrus behaviour every 2 hours before laparoscopic AI could take place.

Laparoscopic artificial insemination (LAI)

Laparoscopy is an intrauterine technique of insemination, especially used in small species to go around their unique tortuous cervix (Sathe, 2018). The laparoscopic technique for AI is regarded as less dangerous than the traditional surgical approach (Evans et al. 2004; Anel et al. 2006). This technique is widely regarded by scientists as the one with improved results in conception rates and a highly effective method of semen administration at the point of reception compared to other surgical techniques (Stefani et al. 1990; Fantinati et al. 2005; Shipley et al. 2011).

Follow up rams until pregnancy

After laparoscopic artificial insemination, animals were not handled for a fortnight before follow-up rams were introduced to ewes. Rams were kept with ewes for a period of 15 days. The purpose of these rams was to cover or impregnate those that could not conceive during laparoscopy. There was no handling of ewes for a period of 45 days, this was to ensure a proper embryo attachment and also to avoid stress to the ewes. Drenching of animals resumed after 45 days of resting and continued for 196 days.

Pregnancy diagnosis

The importance of pregnancy diagnosis is to detect ewes that are pregnant and also that are not pregnant on time. The procedure of pregnancy diagnosis was done using a sonar scanner.

Measurements

The following data was generated: Conception rate and pregnancy rate of the Dohne Merino ewes, lambs born alive, singletons vs. multiple birth rate, lamb birth weight, lamb mortality rate, lamb average weight gain (weekly), average daily gain of lambs, time taken until weaning, which is determined by date, weight of the lambs at weaning.

Data collected and statistical analysis

Lambs were separated from the flock and placed in smaller holding pens. Lambs were then weighed using a hanging scale (A 50 kg mechanical hanging scale was used).

Parameters and statistical analysis

Lambing percentage = (number of females lambing/ total number of mated females) x 100 (Smith, 2011).

Fecundity rate = (number of lambs born/ number of females lambed) x 100

Mortality rate = (number of lambs dying before 10 days/ Total number of lambs born alive) x100 (Smith, 2011).

Weaning percentage = (Number of lambs weaned/number of lambs born) x 100 (Smith, 2011).

Conception and lambing rate

The fertility evaluation was an important tool to verify in vivo results of the various oil treatments. All ewes showed oestrus behavior within 48 hours post CIDRwithdrawal indicating the effectiveness of oestrus synchronization. In total 44 of the 50 ewes conceived and lambed. CIDRsaccompanied by PMSG have been extensively used in many countries for oestrus synchronization of small ruminants to improve ovulation rate (Najafi et al. 2014). The reproductive performance in the present study demonstrated that a good ovarian and conception response could be achieved by using CIDR plus PMSG in Dohne Merino sheep, though not showing difference (P>0.05) between the treatment groups. The average conception and lambing rates of the Dohne merino ewes in this study were both 88%. This is found to be in the same range with the previous findings of Jainudeem et al. (2000) who found an average conception rate of 85% in matured sheep.

Gestation length of ewes supplemented with different dietary oils

The gestation length in the current study ranged between 150 and 155 days with an overall mean of 153 ± 6.13 days, with no difference (P>0.05) between the groups (table 1). The length of gestation in sheep is generally variable. Alshdaifat (2017) found that ewes that received additional fish oil and palm oil had shorter gestation length in Awassi ewes (palm oil 145 days and fish oil 149 days). Forgaty et al. (2005) found a gestation length that ranged between 147.1 (Finnsheep cross lambs) and 150.3 days (Corridale sired lambs). A review by Cardoso and Padmanabha (2019) reported a mean gestation period of ewes at 147 days, ranging from 142 to 155 days. De Carolis et al. (2020) noticed an average gestation period of 149 days in Sarda and Lacaune sheep.

Table 1 Mean ±SD gestation length (days) of ewes supplemented with 30 ml sunflower- or olive- or fish- or palm oil

Treatment groups	Gestation period (days)
Control group	150 ± 1.36
Sunflower oil	155 ± 7.78
Olive oil	154 ± 8.22
Fish oil	154 ± 6.56
Palm oil	154 ± 6.75

Fecundity rate (FR)

Fecundity rates of different treatment groups ranged from 100% to 133% with control at 122%, sunflower treatment at 133%, olive and fish oils both at 100% and palm oil at 114%. No difference (P> 0.05) was found within different oil treatment groups.

Litter size

Type of birth (single or twin) of ewes used in this experimental study was single and twins, there were no triplet births. There were 38 single, six twin lambing and six ewes didn’t lamb. Treatment groups had no effect (P>0.05) on the type of birth. Marais (2011) conducted a study supplementing 144 ewes with dietary oils and 77 (1.26 ± 0.64) gave birth to single lambs and 67 (1.45 ± 0.58) gave birth to twins. The experimental study also indicated that 60% of ewes that gave birth to twins were older than 43 months and 60% of ewes that gave birth to single lambs were under the age of 43 months (Marais, 2011).

Levy et al. (2020) conducted a study using 22 lle de France ewes fed with sunflower meal and the control group. Nine ewes that were fed sunflower gave birth to fifteen lambs and they were four singles, eight twins and three triplets. The thirteen ewes from control group gave birth to fifteen lambs and they were eleven singles and four twins.

Growth performance of lambs

Table 2 indicates the weight of lambs that were born from ewes supplemented with different dietary oils. Previous research in sheep, negated lamb birth weight as not being affected by prepartum supplementation of protected saturated fatty acids (SFA) or PUFA (Palmquist et al. 1977), or fish oil supplementation (Capper et al. 2006). However, dairy calves born from multiparous dams fed rumen-inert SFA or essential PUFA during the last 8 weeks of pregnancy had a significant birth weight compared to calves born to multiparous dams fed no fatty acids (Garcia et al. 2014). Supplementing pregnant and lactating ewes with diets containing PUFA in this study had no effect on post lambing performance and was similar to the performance of the control group. Previous studies found that during later stages of gestation intake in pregnant dams is due to reduced ruminal capacity, on the other hand nutrient requirements increase for fetal growth, udder development, and lactogenesis (Vicente-Perez et al. 2015).

Table 2 Mean ± SD weight of lambs from ewes supplemented with different dietary oils (No oil, sunflower oil, olive oil, fish oil, and palm oil)

	Experimental dietary oils
	Control group	Sunflower oil	Olive oil	Fish oil	Palm oil	Difference
Initial body weight (Birth)	5.49±0.94	5.27±0.77	5.74±0.77	5.74±0.65	5.24±0.45	NS
Body weight ( 0 to 7 days)	7.20±1.62	7.83±0.78	8.10±1.30	7.35±0.80	7.66±1.00	NS
Body weight (7 to 28)	18.40±2.70	16.20±5.33	17.75±4.35	17.78±4.39	17.46±4.10	NS
Body weight (28 to 56 days)	21.90±3.68	20.45±4.90	21.70±5.56	22.12±3.36	21.64±3.64	NS
Body weight (56 to 84 days)	26.68±4.08	25.12±5.73	26.15±5.13	27.31±4.06	26.35±3.76	NS
Body weight (Weaning)	28.63±4.46	26.91±6.23	28.10±5.38	29.50±4.23	28.35±3.89	NS

Group 1: No oils (control group), Group 2: Sunflower oil, Group 3: Olive oil, Group 4: Fish oil, Group 5: Palm oil, NS: No significance

The aim of this study was to investigate the effect of various dietary oils (sunflower oil, olive oil, fish oil, palm oil and a control group) on the reproductive efficiency and lamb growth performance in Dohne Merino ewes. All ewes showed oestrus within 48 hours after implants were removed which indicated that oestrus synchronization was succesful. The findings in this study suggest that CIDR plus OMSG to be a satisfactory tool in achieving a good ovarian and conception response in Dohne Merino. However, dietary oils made no difference in shortening or extending the gestation length of Dohne Merino ewes. Gestation length was not affected by birth status (single vs twins), sex of the lambs, and age of ewes, management or nutrition. Irrespective of type of dietary oil used, it did not effectively improve the fecundity, litter size, lamb sex and ratio of male to female lambs born in this study. Furthermore, the dietary oils used in this study did not have a positive attribution on birth weight, ADG, weaning weight and mortality rate of lambs born. The general findings that can be made based on the results of this study is: the four following dietary oils namely sunflower, olive oil, fish oil and palm oil failed to enhance all parameters that were investigated in the present study.

Acknowledgement

The authors thank the University of the Free State, Bloemfontein by availing their experimental farm and animals for the study.

Funding

The authors did not receive support from any organization for the submitted work

Declaration of conflicting interests

The author declared no potential conflicts of interest with respect to the research, authorship, and / or publication of this article.

Author contributions

Original idea, O.B. Einkamerer, H.A. O’Neill; literature search T. Sedupane, H.A. O’Neill, T. Sedumedi, P. Fourie, H.A. O’Neill; draft and critical revision by T. Sedupane, H.A. O’Neill.

Data availability

Not applicable

Alshdaifat, M. M. M., 2017. Effect of fish oil supplementation during gestation on maternal and offspring performance in Awasi sheep. Institute of natural and applied science. PhD thesis, Department of animal science.
Anel, L., Alvarez, M., Martinez‐Pastor, F., Garcia‐Macias, V., Anel, E. and De Paz, P., 2006. Improvement strategies in ovine artificial insemination. Reproduction in Domestic Animals, 41, 30--42.
Capper, J.L., Wilkinson, R.G., Mackenzie, A.M. and Sinclair, L.A., 2006. Polyunsaturated fatty acid supplementation during pregnancy alters neonatal behavior in sheep. The Journal of Nutrition, 136(2), 397--403.
Cloete, S.W.P. and Olivier, J.J., 2010. South African sheep and wool industries. International sheep and wool Handbook, 95--104.
Cloete, S.W.P., Olivier, J.J., Sandenbergh, L. and Snyman, M.A., 2014. The adaption of the South Africa sheep industry to new trends in animal breeding and genetics: A review. South African Journal of Animal Science, 44(4), 307--321.
DAFF (Department of Agriculture, Forestry and Fishery). 2020. Newsletter: National Livestock Statistics.
De Carolis, M., Barba, O., Acuti G., Trubalza-Marinucci, M., de Sausa, N.M., Cnali, C. and Moscati, L., 2020. Plasmatic profile of pregnancy-associated glycoprotein (PAG) during gestation and postpartum in Sarda and Lacaune Sheep determined with two Radioimmunoassay system. Department of Veterinary Medicine, University of Perugia, 06126 Perugia, Italy.
Evans, G., Hollinshead, F.K. and Maxwell, W.M.C., 2004. Preservation and artificial insemination of sexed semen in sheep. Reproduction, Fertility and Development, 16(4), 455--464.
Fantinati, P., Zannoni, A., Bernardini, C., Webster, N., Lavitrano, M., Forni, M., Seren, E. and Bacci, M.L., 2005. Laparoscopic insemination technique with low numbers of spermatozoa in superovulated prepuberal gilts for biotechnological application. Theriogenology, 63(3), 806--817.
FAOSTAT (Food Agriculture Organization of the United Nations Statistics). 2021.
Fogarty, N.M., Ingham, V.M., Gilmour, A.R., Cummins, L.J., Gaunt, G.M., Stafford, J., Edwards, J.H. and Banks, R.G., 2005. Genetic evaluation of crossbred lamb production. 1. Breed and fixed effects for birth and weaning weight of first-cross lambs, gestation length, and reproduction of base ewes. Australian Journal of Agricultural Research, 56(5), 443--453.
Garcia, M., Greco, L.F., Favoreto, M.G., Marsola, R.S., Wang, D., Shin, J.H., Block, E., Thatcher, W.W., Santos, J.E.P. and Staples, C.R., 2014. Effect of supplementing essential fatty acids to pregnant nonlactating Holstein cows and their preweaned calves on calf performance, immune response, and health. Journal of dairy science, 97(8), 5045--5064.
Jainudeen, M.R., Wahid, H. and Hafez, E, S, E., 2000. Reproduction in farm animals, 7th edition, 172--181.
Lévy, F., Badonnel, K., Bertin, A., Cornilleau, F., Durieux, D., Meurisse, M., Nowak, R., Parias, C., Persuy, M.A. and Baly, C., 2020. Artificial milk preference of newborn lambs is prenatally influenced by transfer of the flavor from the maternal diet to the amniotic fluid. Physiology & behavior, 227, 113166.
Marais, W.J., 2011. The influence of the flush feeding with different nitrogen sources on ovulation and conception rates in Dohne Merino ewes. Nutrition science in the faculty of Natural and Agricultural Sciences, University of Pretoria.
Moallem, U., 2018. Invited review: Roles of dietary n-3 fatty acids in performance, milk fat composition, and reproductive and immune systems in dairy cattle. Journal of dairy science, 101(10), 8641--8661.
Mwangi, P.J.M., Bázár, G. and Tóth, T., 2018. Effect of polyunsaturated fatty acid supplementation on milk production–review on health effects and cow milk characteristics. Acta Agraria Kaposváriensis, 22(1), 9--21.
Najafi, G., Cedden, F., Mojtahedi, S. and Aliverdinasab, R., 2014. Estrus synchronization and twinning rate of ghezel ewes treated with CIDR and PMSG during the breeding season. Online J. Anim. Feed Res, 4(6), 144--149.
Palmquist, D.L., 2010, February. Essential fatty acids in ruminant diets. In Proceedings of the 21nd Annual Ruminant Nutrition Symposium (2--3).
Sathe, S.R., 2018. Laparoscopic Artificial Insemination Technique in Small Ruminants—A Procedure Review. Frontiers in veterinary science, 5, 266.
Shipley, C.F., 2011. Equipment And Techniques For Transcervical Artificial Insemination And Laparoscopic Insemination In Small Ruminants. Clinical Theriogenology, 2(4), 525--529.
Stefani, J.S., Palha, M.D.C., Christmann, L., Rosa, J.M., Silveira, M.C. and Rodrioues, J.L., 1990. Laparoscopic versus surgical transfer of ovine embryos. Theriogenology, 33(1), 330.
Vicente-Pérez, R., Avendaño-Reyes, L., Álvarez, F.D., Correa-Calderón, A., Meza-Herrera, C.A., Mellado, M., Quintero, J.A. and Macías-Cruz, U., 2015. Comportamiento productivo, consumo de nutrientes y productividad al parto de ovejas de pelo suplementadas con energía en el preparto durante verano e invierno. Archivos de medicina veterinaria, 47(3), 301--309.
Windisch, W., Schedle, K., Plitzner, C. and Kroismayr, A., 2008. Use of phytogenic products as feed additives for swine and poultry. Journal of animal science, 86(suppl_14), E140--E148.
Zaitsev, S.Y., Savina, A.A., Volnin, A.A., Voronina, O.A. and Bogolyubova, N.V., 2020. Comparative study of the water-soluble antioxidants in fodder additives and sheep blood serum by amperometric and biochemical methods. Animals, 10(7), 1186.

Download PDF

Reviewers agreed at journal
22 Nov, 2023
Reviewers invited by journal
24 Oct, 2023
Editor assigned by journal
11 Oct, 2023
First submitted to journal
09 Oct, 2023

You are reading this latest preprint version

The effect of plant and animal-derived dietary oil supplementation on the reproduction performance of Dohne Merino ewes and the growth performance of their offspring

Status:

Version 1

Abstract

Introduction

The current state of small stock production

Objective of the research

Methodology

Study results

Conclusion

Declarations

References

Status:

Version 1