Impact of diet deprivation and subsequent over-allowance during prepuberty. Part 1. Effects on growth performance, metabolite status, and mammary gland development in gilts1

Abstract

The impact of diet deprivation and subsequent over-allowance on the metabolite status, mammary development, and mammary gene expression in prepubertal gilts was determined. Forty-seven gilts were reared under a conventional (control, CTL; n = 23) or an experimental (treatment, TRT; n = 24) dietary regimen. The later regimen (consisting of diet deprivation and subsequent over-allowance) provided 70 (restriction diet, RES) and 115% (over-allowance diet, OVER) of the protein and DE contents provided by the CTL diet. Experimental diets were fed ad libitum starting at 27.7 ± 3.4 kg of BW as follows: 3 wk RES, 3 wk OVER, 4 wk RES, and 4 wk OVER. At each diet change, BW and individual feed intakes were measured, and blood samples for metabolite and IGF-I assays were obtained. Some gilts (11 CTL and 12 TRT) were slaughtered on d 235 (after reaching puberty) to collect mammary tissue for compositional analyses and measures of gene expression. Body weight gain (P < 0.01) and G:F (P < 0.05) of gilts were reduced during each period with the RES diet; however, there was no compensatory growth during the periods when the OVER diet was fed. Feeding the RES diet reduced concentrations of urea and IGF-I (P < 0.01) and feeding the OVER diet increased FFA (P < 0.01) and glucose (P < 0.10) in TRT gilts compared with CTL gilts. The TRT gilts had less parenchymal tissue (P < 0.05) and tended to have less total parenchymal fat and protein (P < 0.10) than CTL gilts. The mammary mRNA relative abundance of the signal transducers and activators of transduction 5B was decreased in TRT compared with CTL gilts (P < 0.05). In conclusion, the diet deprivation and over-allowance regimen used in the growing-finishing period did not have beneficial effects on mammary development after puberty. In fact, a detrimental effect was observed.

Impact of diet deprivation and subsequent over-allowance during prepuberty. Part 2. Effects on mammary gland development and lactation performance of sows1

“…This indicates that the physiological state (i.e., growth vs. gestation) or endocrine status of the animal at the time of imposition of such a feeding regimen affects the biological response. On the other hand, ingredients used in the diet formulation may have come into play because Crenshaw et al (1989) did see some compensatory growth at the end of the finishing period, whereas that was not observed with the present diets (Farmer et al, 2012). Sunflower hulls were used as a fiber source in Crenshaw et al (1989; J. D. Crenshaw, APC Inc., Ankeny, IA, personal communication), whereas soybean hulls and wheat middlings were used in the present study.…”

“…All these diets were fed ad libitum and are described by Farmer et al (2012). Representative feed samples were taken every 3 wk throughout the experiment for compositional analyses (Farmer et al, 2012). All gilts were bred via AI using a pool of semen from Duroc boars, and their backfat thickness was measured ultrasonically (Vetkoplus, Noveko, Lachine, Québec, Canada) at mating.…”

“…The RES diet was given for 3 wk starting at 67.9 ± 1.7 d of age (27.7 ± 3.4 kg of BW), followed by 3 wk of the OVER diet, 4 wk of the RES diet, and 4 wk of the OVER diet. All these diets were fed ad libitum and are described by Farmer et al (2012). Representative feed samples were taken every 3 wk throughout the experiment for compositional analyses (Farmer et al, 2012).…”

“…The relative mRNA abundance of studied genes (IGF1, PRLR-LF, STAT5A, STAT5B, WAP, CSN2, GGT1, and ODC1) was determined using real-time PCR amplifications. Primers (Farmer et al, 2012) were designed with a software (Primer Express software 3.0, PE Applied BioSystems, Foster City, CA). The PCR amplifications were performed in a 10-µL reaction volume consisting of 300 nM forward and 300 nM reverse (150 nM for STAT5A and ODC1) primers, 5 µL of 2 × Power SYBRGreen Master Mix (PE Applied BioSystems), 3 µL of 15 × diluted cDNA, and 0.05 µL of Uracil N-glycosylase AmpErase (PE Applied BioSystems).…”

Epigenetics and developmental programming of welfare and production traits in farm animals

“…There is evidence of both positive (Crenshaw et al 1989) and negative (Farmer et al 2012a) effects of 'stair-step' feeding on mammary gland development, but with little effect on piglet performance (Farmer et al 2012b). It is difficult to reconcile these mixed results in pigs with the more clear-cut findings in cattle, other than to observe that in the studies cited above there was no evidence of compensatory growth in restricted-overfed gilts, which, at the end of the experimental periods, were lighter than matched control-fed gilts.…”