Effects of age and live weight on the sexual development of gilts and boars fed two planes of nutrition

Prunier, Armelle; Bonneau, Michel; Etienne, Monique

doi:10.1051/rnd:19870508

Cited by 25 publications

(20 citation statements)

References 28 publications

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“…At slaughter, the mean uterine weight was the lowest in immature gilts compared to pubertal ones. Similar observations on the uterine weight of immature and pubertal gilts have been done by Kauffold et al [27] and Prunier et al [15] after examination of the genital tract at slaughter.…”

Section: Discussionsupporting

confidence: 84%

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Determination by echography of uterine changes around puberty in gilts and evaluationof a diagnosis of puberty

et al. 2003

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-Three experiments were carried out to evaluate the use of ultrasonography in assessing the onset of puberty in gilts. In experiment 1, gilts (n = 17) were scanned 3 times per week beginning at 133 and continuing until 187 days of age. The ultrasonic appearance of the uterus was described, quantified and compared with the reproductive status observed at slaughter. The quantification of the pictures showed a different correlation in time for infantile, impubertal, prepubertal and pubertal stages. For pubertal females, "uterine area" increased at around 180 days of age, well-defined sections of the uterine horns appeared 3 ± 0.5 days before puberty. In infantile and impubertal gilts during the same period of age, uterine images remained dark and homogeneous; no significant change in the "uterine area" was observed. This difference in images allowed an evaluation of the diagnosis of puberty. In experiment 2, the gilts (n = 123) were scanned, the result was verified at slaughter the day after by examination of the genital tract. The uterine weight of the gilts that had reached a prepubertal or pubertal stage was significantly greater (P = 0.0001) than that in impubertal gilts. The sensitivity and the specificity of the diagnosis were 91.9% and 96.5% respectively. Experiment 3 was performed on a farm and echographic examinations were carried out one and five days after gilts (n = 117) arrived at the piggery. Oestrus detection or blood sampling for progesterone determinations were used as tools to determine the reproductive status. The sensitivity and the specificity of the diagnosis were 98.9% and 100% respectively. This diagnosis of puberty is thus accurate.pig / puberty / detection / ultrasonography * Corresponding author: fbotte@tours.inra.fr Reprod. Nutr. Dev. 43 (2003) 225-236 225

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Section: Discussionsupporting

confidence: 84%

“…This period has been characterised by a decrease in LH and FSH secretions and an increase in ovarian secretions [11] which act on uterine development and the central nervous system [2,7,12,13]. The growth of the uterus has been observed during this period [14,15].…”

Section: Introductionmentioning

confidence: 99%

Determination by echography of uterine changes around puberty in gilts and evaluationof a diagnosis of puberty

et al. 2003

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“…However, a complete discrimination is not possible because as shown in the present study, the testes of one IC pig were heavier than those of four EMG pigs. Based on results of earlier studies, testes weight is highly correlated with BW in entire males (Prunier et al, 1987). Similarly, we report that testes of IC pigs are also heavier when slaughter weight increases.…”

Section: Discussionsupporting

confidence: 83%

Growth performance, carcass characteristics and meat quality of group-penned surgically castrated, immunocastrated (Improvac®) and entire male pigs and individually penned entire male pigs

Pauly

Spring

O’Doherty

et al. 2009

Animal

167

111

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The objective of the study was to compare growth performance, carcass characteristics, meat quality and fatty acid composition of the adipose tissue of group-penned barrows, immunocastrated boars and entire males. Furthermore, the effect of housing of entire males on the aforementioned parameters was evaluated. At 55.2 days of age, 52 Swiss Large White pigs were blocked by litter and assigned by BW to four experimental groups: barrows (C), immunocastrated boars (IC), entire males (EMG) reared in group pens and entire males (EMP) reared in individual pens. In experiment 1, the effects of the method of castration were investigated (experimental groups C, IC and EMG). In experiment 2, the effects of housing on entire male pigs were evaluated (experimental groups EMG and EMP). All pigs had ad libitum access to standard diets from weaning to 107 kg BW. The two vaccinations (Improvac R ) were applied to the IC pigs at an average BW of 22.6 and 73.0 kg. In experiment 1, average daily gain (ADG) did not ( P . 0.05) differ among the experimental groups. However, EMG consumed less feed and had a better feed-conversion ratio than C ( P , 0.001 for each). For IC, intermediate values were observed, which differed ( P , 0.001) from EMG and C. Lean meat percentage decreased ( P , 0.05) from EMG to IC, and from IC to C. The androstenone and skatole levels were higher ( P , 0.05) in the adipose tissue of EMG than IC and C. Shear force values were higher ( P , 0.01) in the longissimus muscle of C and EMG, compared to IC. The concentration of saturated fatty acid in the adipose tissue increased ( P , 0.001) from EMG to IC, and from IC to C pigs, and that of polyunsaturated fatty acid decreased ( P , 0.001). In experiment 2, ADG did not ( P . 0.05) differ between EMP and EMG. However, EMP pigs consumed more feed than EMG pigs and had a poorer feed efficiency ( P , 0.01 for each). In conclusion, EMG pigs had a better feed efficiency than IC pigs and their carcasses were leaner, but the risk of boar tainted pork was elevated. Group-housing negatively affected average daily feed intake but not ADG of entire males. At the moment, immunocastration offers a good approach to avoid castration and minimize the risk of boar taint.

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“…Moreover, in the present study we have also observed a 59% decrease in 3b-HSD protein expression in heavyweight males (92 kg mean carcass weight) when compared with conventional-weight males (70 kg mean carcass weight). The onset of puberty is thought to be linked to the weight and the age of the pigs (Einarsson et al, 1979;Schinckel et al, 1984;Prunier et al, 1987). Generally, the pubertal development of boars occurs around the age of 5 to 6 months (Claus et al, 1994).…”

Section: Discussionmentioning

confidence: 99%

Relationship between carcass weight, adipose tissue androstenone level and expression of the hepatic 3β-hydroxysteroid dehydrogenase in entire commercial pigs

Nicolau-Solano

Whittington

Wood

et al. 2007

Animal

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Boar taint is a major meat-quality defect in pigs and is due to excessive accumulation of skatole and androstenone in adipose tissue. The present work investigated the relationship between carcass weight, levels of skatole and androstenone in adipose tissue, and expression of the hepatic androstenone-metabolising enzyme 3b-hydroxysteroid dehydrogenase (3b-HSD), in 22 entire male and 22 entire female crossbred pigs (Large White (40%) 3 Landrace (40%) 3 Duroc (20%)). Animals of each gender were divided into two subgroups (11 pigs in each subgroup): (i) conventional weight (carcass weight 59 to 77 kg) and (ii) heavy weight (carcass weight 84 to 95 kg). No relationship between carcass weight and adipose tissue skatole level was found for entire male pigs (r 2 5 0.013, P > 0.05). There was a significant negative relationship between carcass weight and expression of the hepatic 3b-HSD protein (r 2 5 0.502, P , 0.001) and a significant negative relationship between 3b-HSD protein expression and androstenone level in adipose tissue (r 2 5 0.24, P , 0.05) in entire males. No relationship was found between carcass weight and 3b-HSD protein expression in female pigs (r 2 5 0.001, P > 0.05). 3b-HSD expression was 59% higher in conventional-weight male pigs when compared with heavy-weight animals (P , 0.05) and 36% higher in heavy-weight females when compared with heavy-weight males (P , 0.05). It is concluded that an increase in slaughter weight of entire commercial crossbred Large White pigs is accompanied by inhibition of expression of the hepatic 3b-HSD protein, which might result in a reduced rate of hepatic androstenone clearance with its subsequent accumulation in adipose tissue. It is suggested that regulation of pig hepatic 3b-HSD expression is under the control of sex hormones.

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Effects of age and live weight on the sexual development of gilts and boars fed two planes of nutrition

Cited by 25 publications

References 28 publications

Determination by echography of uterine changes around puberty in gilts and evaluationof a diagnosis of puberty

Determination by echography of uterine changes around puberty in gilts and evaluationof a diagnosis of puberty

Growth performance, carcass characteristics and meat quality of group-penned surgically castrated, immunocastrated (Improvac®) and entire male pigs and individually penned entire male pigs

Relationship between carcass weight, adipose tissue androstenone level and expression of the hepatic 3β-hydroxysteroid dehydrogenase in entire commercial pigs

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