Management of photoperiod to control caprine reproduction in the subtropics

Delgadillo, J.A.; Duarte, Gerardo; Véliz, Francisco Gerardo; Carrillo, Evaristo; Flores, Jerónimo Landeros; Vielma, Jesús; Hernández, H.; Malpaux, Benoît

doi:10.1071/rd04030

Cited by 48 publications

(26 citation statements)

References 32 publications

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“…Increases in milk yields from 5% to 15.8%, with an average reported increase of 8% to 10% or 1.2 to 2.0 kg of milk per cow per day, have been reported (Peters et al, 1978;Barash et al, 2001;Crill and Hancher, 2001;Erickson, 2001). Goats and sheep are seasonal breeding species; at northern latitudes, they exhibit sexual activity during the fall of the year when light to dark ratios are decreasing (Cheminau et al, 1992;Delgadillo et al, 2004). In Assaf dairy sheep (Pollott and Gootwine, 2004) day length is a major environmental variable influencing milk yield.…”

Section: Introductionmentioning

confidence: 99%

Effect of photoperiod on milk yield and quality, and reproduction in dairy goats

et al. 2007

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Section: Introductionmentioning

confidence: 99%

Effect of photoperiod on milk yield and quality, and reproduction in dairy goats

et al. 2007

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“…2000; Duarte et al. 2008), Delgadillo et al. (2004) recommended that bucks should be previously stimulated with a long days light regimen to obtain maximum responses in anoestrous does.…”

Section: Introductionmentioning

confidence: 99%

“…In goats, Flores et al (2000) proposed that the buck physiological status is the main limitation to obtain ovulations in an important percentage of does in a flock. As when does are in seasonal anoestrous, bucks are in their lower reproductive condition (Delgadillo et al1999;Flores et al 2000;Duarte et al 2008), Delgadillo et al (2004) recommended that bucks should be previously stimulated with a long days light regimen to obtain maximum responses in anoestrous does. Even if most does (>80%) exposed to male goats rendered sexually active by a photoperiod treatment responded (Flores et al 2000;Rivas-Mun˜oz et al 2007), the response assessed by oestrous behaviour or ovulations appeared in the first 5 days after male exposure (Flores et al 2000;Delgadillo et al 2002;Fitz-Rodrı´guez et al 2009).…”

Section: Introductionmentioning

confidence: 99%

The Ovulatory Response of Anoestrous Goats Exposed to the Male Effect in the Subtropics is Unrelated to their Follicular Diameter at Male Exposure

Delgadillo

Ungerfeld

Flores

et al. 2010

Reprod Domestic Animals

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This study was designed to determine whether the follicular diameter at the introduction of the bucks influences the ovarian response in does exposed to males during the anoestrous season in the subtropics. Bucks (n = 4) were subjected to 2.5 months of long days from November 1st to stimulate their sexual activity. On 29th March, one of the four treated males was joined with the females (n = 13), being exchanged with other males every 12 h, during 10 days. Oestrous behaviour was recorded twice daily. Ultrasound examinations of the ovaries were performed once daily from Day -7 to -1 and twice daily from Day 0 to 6. Follicles that ovulate were categorized according to the diameter at the moment when females were joined with males, as Small (<3.9 mm), Medium (4.0-5.9 mm) or Large (>6.0 mm). All females ovulated (13/13) and 12 came into oestrus during the first 5 days after exposure to males. The growth rate of the follicles increased after the introduction of the bucks from 1.1 ± 0.1 mm per day to 1.5 ± 0.1 mm per day (p < 0.05). The percentage of follicles from each category that ovulated did not differ (p > 0.05; Small 47.8%; Medium 34.8% and Large 17.4%). From follicles that ovulated, the growth rate of those that were Small at the moment of the introduction of the bucks was greater (2.1 ± 0.1 mm per day; p < 0.05) than that observed in those that were Medium (1.3 ± 0.1 mm per day) and Large follicles (1.1 ± 0.1 mm per day). In 12 does, the largest follicle present in the ovaries was growing when bucks were introduced. From these follicles, five finally ovulated and seven finally regressed. In conclusion, the follicular diameter at the introduction of the bucks is not related to the oestrous behaviour and ovulatory responding patterns in female goats exposed to sexually active bucks in the subtropics.

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“…It is well established that, under experimental conditions, artificial LDs inhibit and artificial short days stimulate reproductive activity in caprine species (Bissonnette 1941; Chemineau et al. 1992b; Delgadillo et al. 2004).…”

Section: Introductionmentioning

confidence: 99%

Evidence that Refractoriness to Long and Short Daylengths Regulates Seasonal Reproductive Transitions in Mediterranean Goats

Gómez-Brunet

Santiago-Moreno

Toledano-Dı́az

2010

Reprod Domestic Animals

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Two experiments were performed to assess the role of refractoriness to long and short daylengths in the timing of seasonal reproductive transitions in Mediterranean Malagueña goats. In the first experiment, intact adult does were either maintained under natural photoperiod conditions (NP; n = 5) or exposed to a constant long day photoperiod (LD - 16 h light/day; n = 5) from June to December 2005. In the second experiment, does were maintained either under NP conditions (n = 5) or received a series of subcutaneous melatonin implants (MI) from December 2005 to June 2006 to mimic a short day signal (n = 5). In both experiments, ovulatory activity was assayed by determining progesterone concentrations in blood samples collected twice per week. The onset of seasonal ovulatory activity did not differ (p > 0.05) between the LD and NP does (3 October ±5 days and 23 September ±3 days respectively). The simulated short days did not modify (p > 0.05) the timing of the end of ovulatory activity. The MI does become anoestrus at the same time (1 March ±9 days) as their NP counterparts (23 February ±8 days). These results indicate that, in Malagueña does, the onset and offset of anoestrus are not driven by photoperiod changes but appear to be the result of long and short day refractoriness respectively. An endogenous circannual rhythm may therefore be involved in regulating seasonal reproductive changes in these animals.

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Management of photoperiod to control caprine reproduction in the subtropics

Cited by 48 publications

References 32 publications

Effect of photoperiod on milk yield and quality, and reproduction in dairy goats

Effect of photoperiod on milk yield and quality, and reproduction in dairy goats

The Ovulatory Response of Anoestrous Goats Exposed to the Male Effect in the Subtropics is Unrelated to their Follicular Diameter at Male Exposure

Evidence that Refractoriness to Long and Short Daylengths Regulates Seasonal Reproductive Transitions in Mediterranean Goats

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