The present study aimed to determine the effect of administrating prostaglandin F2α (PGF2α) and GnRH at the time of artificial insemination (AI) on the pregnancy per artificial insemination (P/AI) and the pregnancy survival rate of dairy cows. A number of 830 lactating Holstein cows were randomly divided into four groups. Cows in group 1 (n=200) treated with 150 µg d-cloprostenol. In group 2 (n...

Sixty-four zebu cows, comprised mainly of Bunaji cattle aged between 3 and 7 years old, were involved in an intensive artificial insemination programme. The study was conducted during the breeding period (May-October), and cows were inseminated with freshly prepared Friesian semen when they stood to be mounted by the vasectomised bull or herdmates. Fertility was measured by serum progesterone (...

Many genetic markers related to health or production traits are not evaluated in populations independent of the discovery population or related to phenotype. Here we evaluated 68 single nucleotide polymorphisms (SNP) in candidate genes previously associated with genetic merit for fertility and production traits for association with phenotypic measurements of fertility in a population of Holstei...

Suckled Bos indicus  Bos taurus cows were used to compare a Select Synch/CIDR + timed artificial insemination (AI) protocol (SSC) vs a modified Co-Synch/CIDR protocol (COS). Five groups of suckled Bos indicus  Bos taurus cows were evaluated (n=659). Cows received GnRH and a CIDR on d 0. On d 7, SSC cows had their CIDR removed and received prostaglandin F2α (PGF2α), whereas COS cows had their ...

The objective of this study was to evaluate the associations among milk production, rectal temperature, and pregnancy maintenance in lactating recipient dairy cows. Data were collected during an 11-mo period from 463 Holstein cows (203 primiparous and 260 multiparous) assigned to a fixed-time embryo transfer (ET) protocol. Only cows detected with a visible corpus luteum immediately prior to ET ...

the present study was conducted to evaluate the effects of extruded linseed on milk production,dry matter intake and reproduction performance of 300 holstein lactating cows (35±15 days in milk;41±9/8 kg/day of milk production). cows were placed in a completely randomized design of 2treatments (concentrate containing 7 percent of extruded linseed vs. control), (150 cows pertreatment). cows were ...

The objective of this study was to evaluate effects of a daily oral drench of Propylene Glycol (PG) on fertility in dairy cows experiencing seasonal heat stress. In treatment group, cows (n=9) were treated with drenching 250 ml propylene glycol once daily from 3 to 15 days post-partum following the morning milking. Another group of cows (n=9) was selected as untreated control. The serum beta-hy...

In Exp. 1, 187 lactating beef cows were treated with injections of GnRH 7 d before and 48 h after prostaglandin F2alpha (PGF2alpha; Cosynch) or with Cosynch plus a 7-d treatment with an intravaginal progesterone (P4)-releasing insert (CIDR-B; Cosynch + CIDR). In Exp. 2, 183 lactating beef cows were treated with the Cosynch protocol or with Cosynch plus a 7-d treatment with norgestomet (Cosynch ...

Our objectives were to determine pregnancy rate, fetal loss, and number of calves born in beef cattle after a fixed-time transfer of an embryo 7 d after a fixed-time artificial insemination (TAI) of cows (Exp. 1) and after transfer of 2 demi-embryos into a single heifer recipient (Exp. 2). In Exp. 1 after synchronization of ovulation, during 2 yr, 297 suckled beef cows were assigned randomly to...

The objective of this study was to evaluate the effects dietary zeolite clinoptilolite on re- productive performance, serum progesterone and insulin-like growth factor 1 (IGF-1) concentra- tions in 78 Holstein Friesian (HF) cows during pregnancy lactation. were divided into two groups comprising 40 (control group; CON) 38 (CPL group) cows. To assess repro- ductive performance HF following varia...