Induced Lactation in Dairy Ewes by Various Brief Hormone Treatments

Alifakiotis, T.; Katanos, I.; Hatjiminaoglou, I.; Zervas, N. P.; Zerfiridis, Gregory K.

doi:10.3168/jds.s0022-0302(80)83003-7

Cited by 8 publications

(5 citation statements)

References 18 publications

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“…As in this study, lactation induction has been used to assess mammary gland specific transgene performance in cattle (Van Berkel et al 2002 ;Brophy et al 2003), goats (Ebert et al 1994;Baguisi et al 1999;Cammuso et al 2000) and even in pigs (Shamay et al 1992). The efficiency of what has become the standard oestrogen/progesterone/dexamethasone regime was 89 % (8 out of 9 heifers on the first attempt, 100% ultimately) in this study and is similar to the efficiencies of 70-100% reported by others for prepubertal heifers (Smith & Schanbacher, 1973;Fulkerson & McDowell, 1975 ;Field et al 1979), sheep (Alifakiotis et al 1980) and goats (Cammuso et al 2000). Furthermore, in the current study there was no evidence that the presence of the transgene influenced the responsiveness of the heifer calves to the induction protocol.…”

Section: Induction Success In Heiferssupporting

confidence: 88%

Lactation induction as a predictor of post-parturition transgene expression in bovine milk

Powell

Kerr

Guthrie

et al. 2007

Journal of Dairy Research

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The bovine's long generation interval results in a delay of several years when evaluating mammary specific transgenes in genetically engineered animals. This experiment was conducted to evaluate the feasibility of reducing that waiting period. Lactation was induced in prepubertal bull and heifer calves as a means of predicting transgene behaviour during subsequent post-parturient lactations in the heifers themselves, and in daughters sired by the bulls. The animals carry a lactation-specific transgene encoding lysostaphin, an antimicrobial protein that kills Staphlococcus aureus, a mastitis-causing pathogen. Oestrogen, progesterone and dexamethasone were administered as previously described (Ball et al. 2000) to nine heifers (five transgenics) ranging in weight from 80 to 145 kg. Eight bull calves (seven transgenics) weighing 81-178 kg received additional oestrogen and progesterone injection prior to dexamethasone treatment. All nine heifers responded to the milk induction scheme yielding between 19 ml and 4.5 l over 5 d. Milk volume from the four responding males (30 microl to 2.5 ml) was significantly less than that harvested from females (P=0.025). Only bull calves >117 kg had a positive response. Lysostaphin was detected in all transgenic prepubertal heifers and in two transgenic prepubertal bull calves induced. A positive relationship was observed between lysostaphin's stapholytic activity in the two types of lactations (r2=0.907, P<0.001) thus providing a useful means of predicting subsequent lysostaphin production in post-partum milk.

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Section: Induction Success In Heiferssupporting

confidence: 88%

Lactation induction as a predictor of post-parturition transgene expression in bovine milk

Powell

Kerr

Guthrie

et al. 2007

Journal of Dairy Research

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“…Most studies of lactation induction in sheep have been conducted with Prealpes du Sud ewes (Kann, 1997;Kann et al, 1999;Head et al, 1980), which is a dual-purpose local French breed and not a true dairy sheep, or with local dairy ewes of a nonspecified breed (Alifakiotis et al, 1980). Kann (1997) and Kann et al (1999) concluded that the inclusion of growth hormone in the induction protocol is necessary to improve milk yield in ewes.…”

Section: Introductionmentioning

confidence: 99%

Response to Lactation Induction Differs by Season of Year and Breed of Dairy Ewes

Andrade

Salama

Caja

et al. 2008

Journal of Dairy Science

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Lactation artificially induced (ART) by steroid hormones and natural lactation (NAT) after lambing were compared in 2 dairy sheep breeds (Manchega and Lacaune) in 2 experiments conducted during winter and spring. In experiment 1, ART ewes (14 Manchega and 9 Lacaune) were induced into lactation in winter by the standard protocol, which consisted of s.c. injections of estradiol and progesterone administered in 2 portions daily from d 1 to 7. Hydrocortisone acetate was injected s.c. daily on d 18 to 20. Milking was initiated on d 21 and continued for 13 wk. A similar group of NAT ewes was selected for the contemporary comparison of NAT vs. ART lactation. All Lacaune ewes, but only 3 of the 14 Manchega ewes (21%), were successfully induced into lactation. Despite the successful induction of lactation in Lacaune ewes, milk yield was much lower than that obtained in NAT lactation (1.23 +/- 0.14 vs. 2.51 +/- 0.15 L/ d). Milk composition from wk 5 to 13 did not differ between groups, except for whey protein, which was greater in ART than in NAT ewes (1.47 vs. 1.25%). In experiment 2, 19 Manchega ewes were divided into 2 groups and induced into lactation in spring by using the standard induction protocol, similar to that used in experiment 1 (control, n = 9), or the standard protocol modified with bovine somatotropin (bST, 250 mg/ewe on d 11; n = 10). Manchega ewes had an improved response to the standard protocol of lactation induction in spring compared with winter. Milk yield in bST-treated Manchega ewes was 98% greater than that in control ewes (402 +/- 85 vs. 203 +/- 86 mL/d). The use of bST during mammogenesis did not affect milk composition. In conclusion, marked differences between Manchega and Lacaune dairy ewes were observed in their response to lactation induction when using the standard protocol during different photoperiod conditions. The Manchega ewes were unable to establish lactation in winter but were able to do so in spring. The response to lactation induction in dairy ewes seems to be related to their endogenous levels of prolactin and growth hormone, the use of which should be explored more deeply in future research.

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“…Although milk yields increased rapidly, they were still less than those of ewes lactating after lambing, and the number of ewes which lactated after treatment was variable. The ewes were also induced to lactate after injections of estradiol-17(3 (E 2 -(3) and P 4 at doses (0.5 and 1.25 mg/kg body weight/day, respectively) similar to (D'Amico et al, 1976 ;Alifakiotis et al, 1980) or five-fold higher (Head et al, 1980) than those used to induce cows into lactation (Smith and Schanbacher, 1973 ;Erb et al, 1976 ;Chakriyarat et al, 1978 ;Delouis et al, 1978). In these studies, the milk yields of induced ewes were less than after lambing, and the number of animals responding to the treatment varied.…”

Section: Introductionmentioning

confidence: 99%

Hormone levels in plasma of ewes induced into lactation

Head¹,

Delouis²,

Fevre³

et al. 1982

Reprod. Nutr. Dévelop.

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Summary. A short-term treatment with estradiol-17(3 and progesterone induced mammary gland growth and lactogenesis in non-pregnant ewes. These events normally occur during the second half of pregnancy. In order to compare the hormonal environment during the treatment to that during pregnancy, the concentrations of total estrogens (TE), progesterone (P 4 ), glucocorticoids (G) and prolactin (Prl) Average pretreatment concentrations of plasma TE and P 4 were 3.1 + 0.8 and 2.1 ± 0.4 ng/ml, respectively ; these increased to 10.2 + 1.3 and 5.6 ± 0.6 ng/ml during the week of the E 2 -/3 and P 4 injections. Peak concentrations occurred on days 7 and 6, respectively, and the plasma levels had returned to pretreatment values by days 18 to 20. Concentrations of G in plasma were higher (13.0 ± 1.0 ng/ml) during E 2 -0 and P 4 injections than during pre-or post-injection (7.4 ± 1.4 and 8.2 ± 0.7 ng/ml, respectively). Plasma Prl showed biphasic two to six-fold increases on days 4 and 7 during E 2 -0 and P 4 injections and thereafter declined to lower average daily concentrations on days 10 to 13. Plasma Prl began to increase, and its average concentration was 579 + 56 ng/ml by days 18 to 20.These results suggest that the amount of the P 4 injections should be increased and that the treatment with E Z -[3 and P Q should last long enough to insure the induction of an endocrine balance which would correspond more accurately to the hormonal events occurring during the second half of pregnancy in the ewe.(1) Florida Agr.

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Induced Lactation in Dairy Ewes by Various Brief Hormone Treatments

Cited by 8 publications

References 18 publications

Lactation induction as a predictor of post-parturition transgene expression in bovine milk

Lactation induction as a predictor of post-parturition transgene expression in bovine milk

Response to Lactation Induction Differs by Season of Year and Breed of Dairy Ewes

Hormone levels in plasma of ewes induced into lactation

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