Pregnancy Rates During Experimentation in Dairy Cows

Mann, G.E.

doi:10.1053/tvjl.2000.0522

Cited by 16 publications

(9 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…1 Not only, glucocorticoids suppress reproductive functions at the hypothalamic, pituitary, ovarian and also uterine level in mares ,2 but also in women, 3 rodents, 4 sheep 5 and cattle. 6 Therefore, stressful events may contribute to low reproductive efficiency due to glucocorticoid mediated inhibition of reproduction in a variety of species.…”

Section: Introductionmentioning

confidence: 99%

Stress and its effects on horses reproduction

AboEl-Maaty

2011

Vet Sci Develop

View full text Add to dashboard Cite

A total of 90 mares and horses were subjected to blood sampling for determining the effect of management (farm), reproductive condition, sex, age, breed and month of the year during breeding on circulating levels of cortisol and sex hormones. Blood samples were collected from December to the following June from four farms. Blood sera underwent testosterone, estradiol, progesterone and cortisol assaying using ELISA kits. Cortisol levels were significantly low in lactating mares during their foal heat but significantly high levels were recorded in both repeat breeder mares and horses used for racing. High and significant testosterone and estradiol levels were recorded in both stallions used for breeding especially after semen collection and early pregnant mares. Similar testosterone levels were recorded in both early pregnant mares and racing horses but high levels were recorded in stallions. Estradiol was high in both early pregnant and mares with endometritis but the highest levels were observed in stallions. Horses held in private farms had high cortisol levels compared to those of governmental farms. In contrast to mares, horses had low cortisol and high estradiol levels. Cortisol levels were high from April to June (Spring and early summer) compared to its levels from December to March (Winter). Arab horses had low cortisol compared to native and imported foreign breeds. In conclusion, environmental condition, exercise, breed, management and the purpose of raising horses all are affecting its cortisol levels.

show abstract

Section: Introductionmentioning

confidence: 99%

Stress and its effects on horses reproduction

AboEl-Maaty

2011

Vet Sci Develop

View full text Add to dashboard Cite

show abstract

“…The precise mechanisms involved remain however to be discovered. One hypothesis is that the usual practice where horses are given limited amounts of roughage in a limited time span is stress inducing discomfort [37] and that the resulting chronic stress may affect reproduction in horses as it does in pigs [18], sheep [3], [39] and cattle [5]. The effect of the stress on reproductive disorders has been reviewed by Dobson and Smith [13] and the adverse effects of stress on both oestrus expression and the maintenance of pregnancy in several species are clear.…”

Section: Discussionmentioning

confidence: 99%

“…Many field observations and induced-stress studies showed that at least acute stress events may impair reproduction efficiency in sheep [1], [2], [3], [4], cattle [5], rhesus monkey [6], [7], rodents [8], [9], [10] and human [11], [12]. In fact, activation of the hypothalamus–pituitary–adrenal axis by stressors reduces the pulsatility of GnRH/LH by actions at both the hypothalamus and pituitary gland, ultimately depriving the ovarian follicle of adequate LH support.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Temporal Feeding Pattern May Influence Reproduction Efficiency, the Example of Breeding Mares

Benhajali

Ezzaouïa²,

Lunel³

et al. 2013

PLoS ONE

View full text Add to dashboard Cite

Discomfort in farm animals may be induced by inappropriate types or timing of food supplies. Thus, time restriction of meals and lack of roughage have been shown to be one source of emergence of oral stereotypies and abnormal behaviour in horses which have evolved to eat high-fibre diets in small amounts over long periods of time. This feeding pattern is often altered in domestic environment where horses are often fed low fibre meals that can be rapidly consumed. This study aimed at determining the effect of the temporal pattern of feeding on reproductive efficiency of breeding mares, One hundred Arab breeding mares were divided into two groups that differed only in the temporal pattern of roughage availability: only at night for the standard feeding pattern group (SFP mares), night and day for the “continuous feeding” group (CF mares). The total amount of roughage provided was the same as the CF mares received half of the hay during the day while in paddock (haynets). Mares were tested for oestrus detection by teasing with one stallion and were then examined clinically by rectal palpations and ultrasound before being mated naturally or inseminated by fresh or frozen semen. Multivariate logistic regression was used to analyse data. The treatment affected significantly the reproductive efficiency of the mares with fewer oestrus abnormalities (p = 0.0002) and more fertility (p = 0.024) in CF mares (conception rate = 81% versus 55% in SFP mares). Ensuring semi-continous feeding by providing roughage may be a way of fulfilling the basic physiological needs of the horses' digestive system, reducing stress and associated inhibitors of reproduction. To our knowledge, this study provides the first evidence of an impact of temporal feeding patterns on reproductive success in a Mammal. Temporal patterns of feeding may be a major and underestimated factor in breeding.

show abstract

“…Cortisol also enhances the negative feedback of oestradiol and thus reduces the stimulatory effect of oestradiol on GnRH receptor expression (Macfarlane et al 2000, Tilbrook et al 2000. Also in female cattle, acute stress may prevent the preovulatory LH surge (Stoebel and Moberg 1982) and manipulations such as collection of blood samples and a new environment resulted in a per cycle pregnancy rate as low as 17% in cows (Mann 2001 …”

Section: Mechanisms Of Stress Induced Effects On Fertilitymentioning

confidence: 99%