Effect of Human Somatotropin-Releasing Factor and Photoperiods on Carcass Parameters and Mammary Gland Development of Dairy Heifers

Ringuet, H.; Petitclerc, D.; Sørensen, Martin Tang; Gaudreau, Pierrette; Pelletier, G.; Morisset, Jean; Couture, Y.; Brazeau, Paul

doi:10.3168/jds.s0022-0302(89)79444-3

Cited by 9 publications

(15 citation statements)

References 23 publications

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“…A long-day photoperiod (16 v. 8 h of daylight) increased mammary parenchymal weight by 40% in peri-pubertal heifer and by 30% in post-pubertal heifer (Petitclerc et al, 1985). Such an exposure also increased lean growth (Petitclerc et al, 1985;Ringuet et al, 1989). Only one study reported the effect of pre-pubertal photoperiod on milk production.…”

Section: Nutritional Factorsmentioning

confidence: 98%

Rearing strategy and optimizing first-calving targets in dairy heifers: a review

Cozler

Lollivier

Lacasse

et al. 2008

Animal

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Much research has been carried out and published on dairy replacement management, in order to rear heifers as efficiently as possible, from both a technical and economical point of view. In most cases, the aim is to rear the heifers at the lowest cost possible without any deleterious effects on future performances. However, the importance of dairy heifer husbandry is not sufficiently well recognized and probably mishandled by most farmers. The present review aims to give an actual overview of rearing procedures in dairy heifers and possible ways to achieve optimal goals. For many years, it has been well known that rapid rearing lowers the age of sexual maturity and consequently may be an efficient way to reduce the non-producing period prior to conception. But this may impair mammary development and consequently future milk production, at least during first lactation. In addition, a growth rate that is too low may not only be costly but also result in animals that are too fat at first calving, creating problems such as calving difficulties, dystocia, etc. Genetic considerations must also be factored, i.e. frame, size, body weight, etc. have changed during the last 20 years and there are differences between breeds. As a result, some time-honoured recommendations may not be appropriate. The present paper reviews factors and management practices that may affect rearing and subsequent performance of dairy heifers.

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Section: Nutritional Factorsmentioning

confidence: 98%

Rearing strategy and optimizing first-calving targets in dairy heifers: a review

Cozler

Lollivier

Lacasse

et al. 2008

Animal

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“…Hence, milk production is a function of alveolar cell number and of the metabolic activity of these cells along with the metabolic support provided by other body tissues. Previously published results have reported either no change (Purup et al 1993) or an increase (Sandles et al 1987;Ringuet et al 1989) in mammary parenchyma of peripubertal heifers receiving GH or GRF. Increases in parenchymal protein (Purup et al 1993) and in total parenchymal DNA (Sandles et al 1987) have also been observed in GH-treated heifers.…”

Section: Farmer Et Al -Grf and Mammary Gland Development 337mentioning

confidence: 96%

“…This decrease was brought about by a diminished feed intake which was significant during the 4th wk of lactation in LACT and GEST-LACT sows (Farmer et al 1992). A decrease in extraparenchymal tissue was also reported in GH-treated (Sandles et al 1987;Purup et al 1993) and in GRF-injected prepubertal heifers (Ringuet et al 1989) and was said to be due to the lypolytic action of GH. For personal use only.…”

Section: Farmer Et Al -Grf and Mammary Gland Development 337mentioning

confidence: 98%

“…However, sows injected with GRF during lactation were able to maintain their milk production in spite of a significant reduction in feed intake (Farmer et al 1992). In dairy heifers, exogenous GH (Purup et al 1993) or GRF (Ringuet et al 1989) was found to affect development of the mammary gland. Yet, in swine, the effect of exogenous GH or GRF on mammary gland composition has never been investigated.…”

Section: Mots Clésmentioning

confidence: 99%

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Mammary gland development of sows injected with growth hormone-releasing factor during gestation and(or) lactation

Farmer¹,

Pelletier²,

Brazeau³

et al. 1997

Can. J. Anim. Sci.

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. 1997. Mammary gland development of sows injected with growth hormone-releasing factor during gestation and(or) lactation. Can. J. Anim. Sci. 77: 335-338. Twenty-four gilts received s.c. injections of saline or growth hormone-releasing factor (GRF) in late gestation and(or) lactation. Sows were sacrificed on day 30 of lactation and functional mammary glands were excised for chemical analyses. Weight of parenchymal (P = 0.004) and extraparenchymal tissues (P = 0.002) were decreased with GRF injections during lactation. Parenchymal mass per milligram of DNA also decreased (P = 0.025) with GRF in lactation while parenchymal DNA concentration increased (P = 0.03). Exogenous GRF given to sows during lactation therefore decreased total parenchymal mass, increased cell density and decreased mammary cell size.Key words: Sow, mammary gland, growth hormone-releasing factor Farmer, C., Pelletier, G., Brazeau, P. et Petitclerc, D. 1997. L'effect d'un apport de somatocrinine en gestation et(ou) en lactation sur le développement mammaire des truies. Can. J. Anim. Sci. 77: 335-338. Vingt-quatre cochettes ont reçu des injections s.c. de saline ou de somatocrinine en fin de gestation et(ou) en lactation. Les truies ont été sacrifiées au jour 30 de lactation et les glandes mammaires ont été recueillies pour analyses biochimiques. Les poids des tissus parenchymateux (P = 0.004) et extraparenchymateux (P = 0.002) ont diminué suite au traitement en lactation. Le rapport de tissu parenchymateux sur l'ADN total a aussi diminué (P = 0.025) avec le traitement en lactation, mais la concentration d'ADN dans le parenchyme a augmenté (P = 0.03). Un apport de somatocrinine en lactation a donc diminué la masse totale de tissu parenchymateux, augmenté la densité cellulaire et diminué la taille des cellules mammaires.

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“…In cattle, most early work with exogenous GRF showed no effect on growth (Plouzek et al, 1988;Ringuet et al, 1989;Lapierre et al, 1991), feed intake (Plouzek et al, 1988;Lapierre et al, 1991), feed efficiency (Lapierre et al, 1991) or diet digestibility (Moseley et al, 1987;Plouzek et al, 1988). However, improvements in nitrogen (N) retention (Moseley et al, 1987;Lapierre et al, 1991) and apparent digestibility of dry matter (DM) and N (Lapierre et al, 1991) were reported and subsequently confirmed by Lapierre et al (1992) using a higher dose of GRF.…”

Section: Introductionmentioning

confidence: 92%

Growth, Feed Digestibility and Carcass Characteristics of Male Dairy Calves Infused with Growth Hormone-releasing Factor and/or Actively Immunized against Somatostatin

Roy¹,

Pelletier²,

Bernier³

et al. 1999

Acta Agriculturae Scandinavica, Section A - Animal Science

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4M1). Growth, feed digestibility and carcass characteristics of male dairy calves infused with growth hormone-releasing factor and/or actively immunized against somatostatin.One week after weaning, 16 animals were immunized (IMM) against human-globulin (hG-IMM) and 16 against SRIF conjugated to hG (SRIF-IMM) in Freund's complete adjuvant. Subsequent boosters in Freund's incomplete adjuvant were made on days 14, 28, 56 and 73 of the experimental period. On day 79, half of the animals within each immunization treatment were infused continuously with human GRF(1-29)NH 2 (3.33 ng min −1 kg −1 BW) and the other half with saline over a 32-day period. GRF increased (P= 0.01) body weight gain by 12%, whereas SRIF immunization decreased (P= 0.01) weight gain by 7.5% during the infusion period (days 79-111). However, the effect of SRIF immunization on growth rate was not significant (P\0.10) when considered over the entire duration of the experiment (days 0-111). Feed intake, feed efficiency, carcass characteristics, nutrient digestibility, nitrogen retention and metabolizability of energy were not affected (P \ 0.10) by SRIF immunization or GRF infusion. However, GRF infusion increased pancreatic activity of amylase (PB 0.05). In conclusion, GRF, unlike SRIF immunization, could be used to improve growth performance of fast-growing corn-fed bull calves.

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Effect of Human Somatotropin-Releasing Factor and Photoperiods on Carcass Parameters and Mammary Gland Development of Dairy Heifers

Cited by 9 publications

References 23 publications

Rearing strategy and optimizing first-calving targets in dairy heifers: a review

Rearing strategy and optimizing first-calving targets in dairy heifers: a review

Mammary gland development of sows injected with growth hormone-releasing factor during gestation and(or) lactation

Growth, Feed Digestibility and Carcass Characteristics of Male Dairy Calves Infused with Growth Hormone-releasing Factor and/or Actively Immunized against Somatostatin

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