Cause Of Repeat Breeding Research Articles

Repeat breeding: prevalence and potential causes in dairy cows at different milk pocket areas of Bangladesh

The objective of this study was to figure out the prevalence and probable causes of repeat breeding (RB) in dairy cows. Hence, a cross-sectional study was conducted on randomly selected 265 dairy farms in Sirajganj, Bogura, Rangpur, Satkhira, and Munshiganj districts of Bangladesh from December 2018 to February 2019. Data were collected through a direct interview method using a survey questionnaire. The reproductive organs of repeat breeder cows were examined for pathological, infectious, and functional reasons, and genital tract abnormalities. Additionally, the influence of nutrition, season, and age on the frequency of RB was recorded. The prevalence of RB was 28% among the 3824 cows investigated. Among the total repeat breeder cases, 72.54% of RB cases were found in Holstein-Friesian crossbred, 23.90% in Jersey crossbred, 1.50% in Sahiwal crossbred, and 2.06% in indigenous cows. The prevalence of RB was significantly highest (P < 0.01) in Satkhira (44.35%) and lowest in the Munshiganj district (15.87%). Data indicated that a major proportion of cows significantly (P < 0.05) faced RB problems due to functional causes (34.18%), followed by pathological causes (28.01%), genital tract abnormalities (21.32%), and infectious causes (16.49%). Furthermore, the cows were remarkably (P < 0.001) affected in RB during the summer season and nutritional deficient diseases like milk fever (70%). Age (3-7years) had a significant (P < 0.001) effect on the RB occurrence (90%) in crossbred cows. However, particular focus should be given to systematic breeding, balanced nutrition, artificial inseminator efficiency, and hygienic inseminating tools to reduce RB incidence in high-yielding crossbred cows.

Embryo Transfer as an Option to Improve Fertility in Repeat Breeder Dairy Cows.

Repeat breeding is a serious reproductive disorder in dairy cattle. The causes of repeat breeding are multifactorial and there are two main mechanisms: failure of fertilisation or early embryo death, mainly due to poor quality of oocytes and an inadequate uterine environment. Many methods have been used to increase the pregnancy rate for repeat breeder cows, such as intrauterine infusion of antibacterial agents or antibiotics, hormonal treatments for oestrus synchronisation and induction of ovulation, and progesterone supplementation or induction of accessory corpus luteum; however, the results were inconsistent between studies. Embryo transfer (ET) has the capability to minimalise the effects of poor oocyte quality and unfavourable uterine environments on early embryo development during the first seven days after ovulation in repeat breeder cows, and several studies showed that ET significantly improved the pregnancy rate in this group of animals. Thus, ET can be considered an option to increase the conception rate in repeat breeder dairy cows.

Comparative economic analysis of dairy characteristics focused on repeat breeding losses in selected milk pocket areas of Bangladesh

Dairy farming is an important approach for farmers to increase their incomes and which has a significant contribution to the economy of Bangladesh. The present study describes the dairy characteristics and estimates the financial profitability of dairy farming in selected milk pocket districts of Bangladesh. Following study areas- Sirajganj, Bogura, Rangpur, Satkhira and Munshiganj districts were selected based on the fastest growing dairying, abundant number of dairy farms and contribution in national milk production. Two hundred and sixty-five (265) dairy farms were selected across the study areas and data were collected through direct interview method. The study revealed that dairy herd sizes from the surveyed farms varied from 5 to 19 per farm. Average milk productivity was found 7 to 10 L per cow per day, in which Satkhira district cow’s milk productivity per day (10 L/cow/d) and lactation (3,116 L/cow/lactation) was found the highest and Rangpur district was the lowest. On the contrary, significantly (p=0.000) highest milk production per farm per lactation was in the Rangpur district (33,697 L) and the lowest in the Bogura district (9,818 L). Results revealed that statistically (p=0.000) higher income generated in Munshiganj district in terms of per cow per year and/or per day compared to the other milk pocket districts. The study also indicated that repeat breeding cost and unavailable income per farm per year were higher in the Sirajganj district and lowers in the Bogura district. Repeat breeding problems increases the production cost of the animals significantly (p=0.000) and negatively affect the farm profitability of the milk pocket areas in Bangladesh. Annually gross margin and net return per cow were statistically (p=0.000) higher in Munshiganj district. Benefit-cost ratios were found more than one and indicated that benefit is much higher than the cost of production at Satkhira (annual BCR/farm=1.52) and Munshiganj districts (annual BCR/farm=1.50) compared to the other areas (0.27–0.35 units more). Dairy farming provides higher economic benefits to the farmers of Munshiganj and Satkhira districts compared to the other milk pocket districts. The research concludes that there is an ample scope and possibility for sustaining and developing dairy farming in the milk pocket districts of Bangladesh. Overall, it may be suggested that the causes of repeat breeding should be identified and corrected accordingly within the shortest possible time for the betterment of dairying. Also, milk prices should be similar across the milk pocket districts and essential inputs prices should be kept within the affordable purchase range of farmers for sustainable dairying.&#x0D; Bang. J. Anim. Sci. 2019. 48 (2): 145-154

Effect of dietary n-3 polyunsaturated rich fish oil supplementation on ovarian function and interferon stimulated genes in the repeat breeding cow

Dietary n-3 polyunsaturated fatty acids (n-3 PUFA) improve utero-ovarian functions and embryonic survival in postpartum dairy cows. Because early embryonic mortality is the major cause of repeat breeding (RB) in cows, there was investigation of the effect of dietary supplementation of n-3 PUFA [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] rich fish oil (FO) from −2 to +2 weeks of artificial insemination on the size of preovulatory follicle (POF), serum progesterone (P4) and relative abundance of the mRNA of interferon stimulated genes (ISG) that encode for these proteins in the peripheral blood leukocytes (PBL) in the RB cow (n = 12). The diet of control group was supplemented with palm oil (PO). The results indicated serum concentrations of EPA and DHA were greater by 4.6- and 3.5-fold, respectively at the end of feeding study in the RB cows of the FO group. The diameter of POF was larger by 2.2 mm in FO group; however, serum P4 did not vary from day 14–20 post-artificial insemination. Greater abundance of ISG mRNA transcripts such as ISG15, RTP4, Mx2 and OAS1 in the PBL of pregnant cows of FO group indicates day 20 conceptuses produced more IFN-τ. It is concluded that supplementation of FO during the breeding period increased the size of POF and enhanced the abundance of ISG mRNA transcripts in RB cows that became pregnant.

Study on the hormonal profile in crossbred dairy cows in relation to repeat breeding at Baghabari milk shed areas, Bangladesh

Repeat breeding (RP) is a one of the most significant problem in dairy cattle because it increased production cost of insemination, treatment, feed, labor and management and also increased calving interval with decreased milk production. This study was conducted at the different Bathan areas of Shahjadpur Upazila under Sirajgonj district. The total of 30 repeat breeder cows was selected randomly to determine their reproductive hormonal profile before and after synchronization at the selected areas and repeat breeder cows were marked by ear tag and collected breeding history of each individual cow. All experimental RP were synchronized by the administration of GnRH (day- 0), PGF2α (day-7) and Artificial Insemination (AI) with GnRH (day-9). Blood samples were collected before and after synchronization during standing heat period of estrous cycle of each cow. The total experiment was done and analyzed in the laboratory by using endocrine detection kits (Mono LelacR USA). This present study revealed that the level of luteinizing hormone (LH), follicle stimulating hormone (FSH), progesterone (P4) were significantly differed between repeat breeder cows and synchronized repeat breeder cows. These findings clearly indicated that reproductive hormonal aberrations might be one of the major causes of repeat breeding in Baghabari milk shed areas.&#x0D; Asian Australas. J. Biosci. Biotechnol. 2018, 3 (3), 237-240

Identification of possible causes of repeat breeding in dairy cows at Baghabari milk shed areas, Sirajgonj, Bangladesh

The present study was conducted at milk pocket areas Sahjadpur Upazila under Sirajgonj district and Shathia and Bera Upazila under the Pabna district, respectively. A total number of one hundred ninety (190) dairy farmers were surveyed randomly selecting twenty farmers from each village. All data collected were statistically analyzed using Univariate General Linear Model (GLM) procedure of SPSS computer program. Lack of balanced feed was the highest cause of repeat breeding claimed by about sixty (60%) percent farmers in this study. The highest incidence of RB was obtained in Local´Holstein Friesian crosses (69%) and lowest in Local´Sahiwal crosses (8%). From the study of present findings; it can be concluded that genotype, nutrient of feed, quality of semen, frequency of insemination and reproductive problems are the main possible causes for RB in the studied areas.Asian J. Med. Biol. Res. June 2017, 3(2): 186-190

Low Incidence of an Altered Endometrial Epidermal Growth Factor (EGF) Profile in Repeat Breeder Holstein Heifers and Differential Effect of Parity on the EGF Profile Between Fertile Holstein (Dairy) and Japanese Black (Beef) Cattle

A high incidence (about 70%) of alteration in endometrial epidermal growth factor (EGF) profile, i.e., loss of 2 peaks on days 2–4 and 13–14, has been linked to a reduced fertility in multiparous repeat breeder Holstein cows. However, the EGF profile in Holstein heifers and other breeds (types) of cattle has not been investigated. In study 1, EGF concentrations were determined using endometrial tissues obtained by biopsy on days 3, 7 and 14 from 84 fertile Holstein heifers to obtain a normal range and 53 repeat breeder Holstein heifers to estimate incidence of alterations in the EGF profile. In repeat breeder heifers, EGF concentrations were similar to fertile controls on 3 days and five animals (9.4%) had an altered EGF profile with EGF concentrations below the normal range on days 3 and 14. In study 2, EGF concentrations on day 3 were repeatedly examined from the nulliparous period to the third postpartum period in 28 Holstein (dairy) and 47 Japanese Black (beef) cattle. The effect of parity on EGF concentrations on day 3 was different between Holstein and Japanese Black cattle. In Japanese Black cows, the EGF concentrations were consistently high throughout the study period, while in Holstein cows, the EGF concentrations decreased after the second calving. In conclusion, unlike multiparous repeat breeder Holstein cows, an altered EGF profile may not be a major cause of repeat breeding in Holstein heifers, and the peak EGF concentrations around day 3 may decrease even in fertile populations of multiparous dairy cows, but not in beef cows.

Prostaglandins vis-à-vis bovine embryonic mortality: a review

Decline in fertility in bovines is attributed to various reproductive problems viz. anoestrus, repeat breeding, abortions and post parturient disorders. Among these, repeat breeding has been an important cause for reducing the animals' fertility and life-time productivity. Many researchers have reported embryonic mortality as a major cause of repeat breeding arising due to premature corpus luteum lysis. Prostaglandin F2 α released from the uterus causes alterations in luteal blood flow, induces luteal lysis, and hence reduces progesterone secretion from the bovine corpus luteum. Therefore various strategies have been tried to modulate prostaglandin F2 α synthesis and secretion in order to prolong the lifespan of CL. Administration of cyclooxygenase inhibitors which include non-steroidal anti-inflammatory drugs acting by competitive inhibition of key enzymes of prostaglandin synthesis is one such method. Feeding of diet rich in polyunsaturated fatty acids during critical period significantly reduces prostaglandin synthesis. Other drugs, which are potential candidates for reducing prostaglandin synthesis, include oxytocin receptor antagonist, recombinant bovine somatotropin, lysophosphatidic acid and prostaglandin F synthase inhibitors. To conclude, there is much scope of using various compounds to reduce prostaglandins synthesis during the critical period of pregnancy for improving the embryo survival rate.

Morphological Quality of Oocytes and Blood Plasma Metabolites in Repeat Breeding and Early Lactation Dairy Cows

The objectives of the study were to evaluate the morphological quality of oocytes in repeat breeder and early lactation cows and to determine the possible associations between the quality of oocytes and a range of blood metabolites. Oocyte quality and a range of metabolites were compared between 29 repeat breeder and 13 early lactation cows. The yield of oocytes from the repeat breeders was lower than that from the early lactation cows (4.4 ± 0.2 vs 5.4 ± 0.6, p < 0.05). Percentages of abnormal oocytes for the repeat breeders and the early lactation cows were 52.5% and 37.9%, respectively (p < 0.001). An excess of abnormal oocytes to normal was found in 55.2% of the studied repeat breeders (65.8% vs 34.2%, p < 0.05). Total protein, glucose and aspartate aminotransferase did not differ (p > 0.05) between the repeat breeders with an excess of abnormal oocytes (81 ± 1.0 g/l, 3.5 ± 1.0 mmol/l and 68.5 ± 3.7 U/l), those with the prevalence of normal oocytes (84 ± 1.0 g/l, 3.6 ± 0.1 mmol/l and 73.2 ± 3.5 U/l) and the early lactation cows (83 ± 2.0 g/l, 3.7 ± 0.1 mmol/l and 74.5 ± 3.6 U/I). The repeat breeders with an excess of abnormal oocytes had higher (p < 0.05) urea (5.2 ± 0.2 mmol/l) level than in those with the prevalence of normal oocytes (4.8 ± 0.2 mmol/l) and the early lactation cows (4.7 ± 0.2 mmol/l). A trend for higher total cholesterol and lactate dehydrogenase activity was found in the repeat breeders with an excess of abnormal oocytes. In conclusion, it is suggested that possible causes of repeat breeding in dairy cows may include impaired oocytes. An excess of abnormal oocytes in the repeat breeder cows was associated with elevated blood plasma levels of urea.

Influence of perioestrous suprabasal progesterone levels on cycle length, oestrous behaviour and ovulation in heifers

In order to induce suprabasal plasma concentrations of progesterone after luteolysis and to determine their effect on oestrous behaviour and ovulation, heifers subcutaneously received silicone implants containing 2.5 ( n = 4), 5 ( n = 4), 6 ( n = 3), 7.5 ( n = 3) or 10 ( n = 4) g of progesterone, or an empty implant (controls, n = 5) between days 8 and 25 of the cycle (ovulation designated Day 0). Growth of dominant follicles and time of ovulation were determined by ultrasound, and signs of oestrus were recorded and scored. Blood was collected at 2–4 h intervals from Days 15 to 27 and assayed for progesterone concentration. In all heifers, plasma concentrations of progesterone sharply decreased during Days 16–18. Control heifers had their lowest progesterone levels on Days 20.5 and 21, standing oestrus on Day 19.5 ± 0.4 (mean ± SEM), and ovulated on Day 20.7 ± 0.4. A similar pattern was observed in heifers treated with 2.5 and 5 g progesterone. Heifers treated with 6, 7.5 and 10 g of progesterone showed an extended ( P < 0.05) interovulatory interval. Onset of prooestrus and time of maximum expression of signs of oestrus were not significantly different from those in controls. However, there was an absence of standing oestrus in most of the cases, signs of oestrus lasted longer ( P < 0.05) and were weaker in intensity when doses increased. In these groups, the lowest progesterone concentrations were attained shortly after implant removal. Some heifers treated with 6 and 7.5 g of progesterone had standing oestrus and post oestrous bleeding as seen in the controls but ovulation occurred from Days 24.5 to 27. When plasma progesterone concentrations were over 1 nmol 1 −1 , disturbed oestrus and delayed ovulation occurred. The extended period of prooestrus and oestrus and delayed ovulation were similar to that described in cases of repeat breeding. It is suggested that suprabasal plasma concentrations of progesterone, after luteolysis, may lead to asynchrony between onset of oestrus and ovulation and consequently be a cause of repeat breeding in cattle.

Luteal phase deficiency as a possible cause of repeat breeding in dairy cows

The incidence of luteal phase dysfunction as indicated by milk progesterone profiles after artificial insemination (AI) and ovulation was investigated in 21 repeat-breeding dairy cows. Eight (38%) cows had a normal progesterone profile; progesterone levels in skim milk rose to 1·0 ng/ml or higher within five days after insemination (0 dayday of AI) and, thereafter, steadily increased to 2·0 ng/ml or higher at mid-luteal phase. Another 13 (62%) cows had an abnormal pattern of milk progesterone levels which indicated luteal phase defects after AI; seven (54%) of the 13 cows showed a delayed rise of the progesterone level until 6–11 days after AI, two (15%) had a comparatively low level of milk progesterone below 2·0 ng/ml through most of the luteal phase, and four (31%) had a combined pattern of a delayed rise and a low level of milk progesterone during luteal phase. After the AI, five (63%) of the eight cows with a normal progesterone profile conceived, while none of the 13 cows which had insufficient luteal function conceived. It is suggested that delayed formation of the corpus luteum, either combined or not combined with lowered secretion of progesterone during luteal phase is one of the causes of repeat breeding in dairy cows.