Association between prepartum metabolic status and resumption of postpartum ovulation in dairy cows

Cows transitioning from late gestation to early lactation experience an increase in energy demands, which lead to a negative energy balance (NEB) because the greater energy requirement is not fully synchronized with the intake of dry matter. In this context, there is an increase in plasma NEFA and ghrelin concentrations and a decrease in plasma insulin and glucose-dependent insulinotropic polypeptide (GIP) concentrations. This situation could have a negative impact on the return to cyclicity because some of these variables have been associated with reduced GnRH and LH pulsatility (high NEFA and low insulin concentrations). However, there are no studies showing the relationship between ghrelin or GIP and reproductive performance. It is known that these hormones are related with lipolysis and NEB, with NEB being one of the main determinants of GnRH pulse generator activity. Thus, the objective of the present study was to evaluate the association between plasma NEFA concentration and metabolic hormones (insulin, ghrelin, and GIP) before parturition and their associations with the resumption of postpartum ovulations in dairy cows. A completely randomized block design was used in a commercial dairy herd with sampling day (visit to farm) as the blocking criteria. Holstein cows (n = 92) were screened for plasma NEFA concentration -5 d (+/-2 d) relative to the expected parturition day, and top and bottom quartiles were considered as high (H-NEFA) and low (L-NEFA) NEFA groups. Data were analyzed with correlation, linear regression, and proportional hazard regression models. Plasma NEFA concentration (H-NEFA mean ¼ 294 mM, SD ¼ 141.2; and L-NEFA mean ¼ 122 mM, SD ¼ 25.3) was correlated (P < 0.01) with plasma insulin (r2 = 0.374) and ghrelin (r2 = 0.346) concentrations but not with plasma GIP concentration (P = 0.64). The greater the concentration of insulin, the lesser the prepartum NEFA concentration (for each 1 mU/mL of plasma insulin increase, there is a decrease of 1.223 +/- 0.62 mM of NEFA). Plasma ghrelin and GIP concentrations were not associated with plasma NEFA concentration. Finally, H-NEFA prepartum cows were less likely to resume ovulation than L-NEFA cows (hazard ratio [HR] = 0.563, 95% confidence interval [CI] = 0.314–1.011), whereas high ghrelin cows were more likely to resume ovulation than low ghrelin cows (HR = 1.873, 95% CI = 0.846–4.145). Conversely, resumption of ovulation was not associated with prepartum insulin and GIP concentrations. Prepartum NEFA and possibly ghrelin are associated with the return to postpartum cyclicity; however, insulin and GIP are not related to the resumption of ovulation in dairy cows.Facultad de Ciencias Veterinaria

Toward assessing the role of dietary fatty acids in lamb's neurological and cognitive development

Understanding and measuring sheep cognition and behavior can provide us with measures to safeguard the welfare of these animals in production systems. Optimal neurological and cognitive development of lambs is important to equip individuals with the ability to better cope with environmental stressors. However, this development can be affected by nutrition with a special role from long-chain fatty acid supply from the dam to the fetus or in lamb's early life. Neurological development in lambs takes place primarily during the first two trimesters of gestation. Through late fetal and early postnatal life, the lamb brain has a high level of cholesterol synthesis. This rate declines rapidly at weaning and remains low throughout adulthood. The main polyunsaturated fatty acids (PUFA) in the brain are ω-6 arachidonic acid and ω-3 docosahexaenoic acid (DHA), which are elements of plasma membranes' phospholipids in neuronal cells. DHA is essential for keeping membrane integrity and is vital for normal development of the central nervous system (CNS), and its insufficiency can damage cerebral functions and the development of cognitive capacities. In sheep, there is evidence that supplying PUFA during gestation or after birth may be beneficial to lamb productive performance and expression of species-specific behaviors. The objective of this perspective is to discuss concepts of ruminant behavior and nutrition and reflect on future research directions that could help to improve our knowledge on how dietary fatty acids (FA) relate to optimal neurological and cognitive development in sheep

Effects of maternal calcium propionate supplementation on offspring productivity and meat metabolomic profile in sheep

This study determined the effect of dietary calcium propionate (CaPr) as a source of energy supplementation during the First Half of Gestation (FMG), the Second Half of Gestation (SMG), and during All Gestation (AG), on offspring post-weaning growth performance, meat quality, and meat metabolomic profile. Thirty-one pregnant ewes were assigned to one of four treatments: a) supplementation of 30 gd-1 of CaPr during the first half of gestation (day 1 to day 75, n = 8) (FMG); b) supplementation of 30 gd-1 of CaPr during the second half of gestation (day 76 to day 150, n = 8) (SMG); c) supplementation of 30 gd-1 of CaPr during all gestation (AG, n = 8); d) no CaPr supplementation (control; CS, n = 7). The ewes were ad libitum fed a basal diet based on oat hay and corn silage. Ewes were distributed in a completely randomized unbalanced design to four treatments. The FMG group had lower (P ≤ 0.05) birth weight and weaning weight than the CS group. However, the average daily gain was similar across all treatments. Empty body weight and FMG had lower values (P ≤ 0.05) than the other groups. Both FMG and AG had lower hot carcass weight (P ≤ 0.05) compared to CS, while CaPr treatments resulted in reduced hot carcass yield (P ≤ 0.05). Meat color and texture were similar among treatments. A principal component analysis between gestation stages showed a trend for separating CS and FMG from SMG and AG, and that was explained by 93.7% of the data variability (PC1 = 87.9% and PC2 = 5.8%). Regarding meat metabolomic profile, 23 compounds were positively correlated between all treatments. Only 2 were negatively correlated (eicosane and naphthalene 1,2,3); but tetradecanoic acid, hexadecane, undecane 5-methyl, (-)-alpha, hexadecenoic acid, octadecanoic acid, and octadecane had a highly significant correlation (P ≤ 0.05). Overall, dam supplementation with CaPr during different periods of gestation provoked changes in meat metabolites related to the biosynthesis of fatty acids in lambs without negative changes in lamb's growth performance and carcass quality

Ghrelin antagonist regulates metabolic hormone receptorsin the hypothalamus of ewes

This study evaluates the effects of ghrelin antagonist on mRNA abundance for metabolic hormone receptors in feed-restricted ewes. Ewes were randomly assigned to one of three treatments; Control (CO): feed above maintenance energy intake requirements and daily subcutaneous saline infusion; Feed restriction (FR): feed restricted and daily subcutaneous saline infusion; Ghrelin antagonist (GA): feed restricted and daily subcutaneous of 7.5 μg/kg of D-Lys3-GHRP-6. Blood was sampled on days 1, 4, 9, and 13, relative to the start of the experiment, to quantify plasma glucose, NEFA and ghrelin concentrations. At day 13, the hypothalamus was collected to evaluate relative mRNA expression. The CO ewes had lesser plasma NEFA concentration compared with FR and GA ewes. There was a treatment by time interaction for plasma glucose concentration, all treatment started with similar plasma glucose concentration, but at day 13 CO ewes had a greater plasma concentration than FR and GA. Relative mRNA expression for glucagon receptor in GA ewes tended to be lesser compared with CO and FR treated ewes. There were no differences in insulin receptor mRNA relative expression between the groups. Ghrelin receptor mRNA relative expression tended to be greater in the GA compared with the CO treated ewes. There was no effect of GA on leptin receptors. However, there was a tendency toward greater relative expression of leptin receptor mRNA in the FR compared with the CO ewes. Relative expression of adiponectin receptor mRNA was lesser in the GA compared with CO and FR ewes. Cortisol receptor relative mRNA expression was greater in the FR compared with the CO ewes. Restricting dietary intake of ewes change mRNA relative expression of cortisol and leptin receptors in the hypothalamus of ewes. These variations are countered with ghrelin antagonist. Ghrelin antagonist modifies the mRNA relative expression of ghrelin, glucagon and adiponectin receptors. These results suggest that ghrelin could regulates metabolic hormone activity by modifying the relative expression of their receptors mRNA.Fil: Carranza Martin, Ana Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentina. Department of Animal Sciences; Estados UnidosFil: Parker, Anthony J.. Department of Animal Sciences; Estados UnidosFil: Furnus, Cecilia Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Relling, Alejandro E.. Department of Animal Sciences; Estados Unidos. Ohio State University; Estados Unido

Prepartum dietary energy source fed to beef cows: II. Effects on progeny postnatal growth, glucose tolerance, and carcass composition

Mature Angus-cross beef cows (n = 228) were used to evaluate effects of prepartum dietary energy source on postnatal growth and carcass composition of progeny in a 2-yr study. Starting at approximately 160 d of gestation, cows were fed diets consisting of 1 of 3 primary energy sources: grass hay (HY), corn (CN), or dried corn distillers grains with solubles (DG). The CN and DG diets were limit-fed to achieve similar energy intakes as cows fed HY. Following parturition, cows were fed a common diet and managed as a single group. Calves were weaned at an average of 185 ± 6 d of age and backgrounded for 28 d. A subset of progeny (n = 134) was individually fed a common finishing diet until slaughter, when each calf reached 1.2 ± 0.05 cm of backfat. A glucose tolerance test (GTT) was conducted in year 2 on 4 calves/treatment after 41 and 111 d on the finishing diet (DOF). Calf birth weights were greater (P = 0.002) in calves from cows fed CN and DG than calves from cows fed HY, and weaning BW (P = 0.08) was less for calves from cows fed HY vs. CN. Receiving BW, final BW, and HCW did not differ (P ≥ 0.16) among treatments. No difference (P ≥ 0.28) in ADG, morbidity, and mortality from birth to slaughter was observed among treatments. In response to a GTT, increased DOF resulted in greater (P ≤ 0.005) fasting insulin, faster glucose disappearance rate, and greater insulin:glucose area under the curve ratio. Glucose disappearance rate was greater (P = 0.01) in calves from cows fed CN than in calves from cows fed HY or DG. A greater initial insulin response (P = 0.005) was observed in calves from cows fed CN or DG than in calves from cows fed HY. Carcass traits used to measure yield grade did not differ (P ≥ 0.19) among treatments. Calves from dams fed CN had the lowest marbling score (P = 0.03) and intramuscular fat content (P = 0.07). These results indicate that prepartum maternal dietary energy source can alter fetal adipose tissue development and insulin sensitivity resulting in long-term effects on progeny's intramuscular fat deposition. Moreover, present findings suggest that increasing the number of days on a corn-based finishing diet increases insulin resistance in beef cattle.Fil: Radunz, A. E.. Ohio State University; Estados UnidosFil: Fluharty, F. L.. Ohio State University; Estados UnidosFil: Relling, Alejandro Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Felix, T. L.. University of Illinois. Urbana - Champaign; Estados UnidosFil: Shoup, L. M.. University of Illinois. Urbana - Champaign; Estados UnidosFil: Zerby, H.N.. Ohio State University; Estados UnidosFil: Loerch, S.C.. Ohio State University; Estados Unido

Toward assessing the role of dietary fatty acids in lamb's neurological and cognitive development

Understanding and measuring sheep cognition and behavior can provide us with measures to safeguard the welfare of these animals in production systems. Optimal neurological and cognitive development of lambs is important to equip individuals with the ability to better cope with environmental stressors. However, this development can be affected by nutrition with a special role from long-chain fatty acid supply from the dam to the fetus or in lamb's early life. Neurological development in lambs takes place primarily during the first two trimesters of gestation. Through late fetal and early postnatal life, the lamb brain has a high level of cholesterol synthesis. This rate declines rapidly at weaning and remains low throughout adulthood. The main polyunsaturated fatty acids (PUFA) in the brain are ω-6 arachidonic acid and ω-3 docosahexaenoic acid (DHA), which are elements of plasma membranes' phospholipids in neuronal cells. DHA is essential for keeping membrane integrity and is vital for normal development of the central nervous system (CNS), and its insufficiency can damage cerebral functions and the development of cognitive capacities. In sheep, there is evidence that supplying PUFA during gestation or after birth may be beneficial to lamb productive performance and expression of species-specific behaviors. The objective of this perspective is to discuss concepts of ruminant behavior and nutrition and reflect on future research directions that could help to improve our knowledge on how dietary fatty acids (FA) relate to optimal neurological and cognitive development in sheep

Role of Long Chain Fatty Acids in Developmental Programming in Ruminants

Nutrition plays a critical role in developmental programs. These effects can be during gametogenesis, gestation, or early life. Omega-3 polyunsaturated fatty acids (PUFA) are essential for normal physiological functioning and for the health of humans and all domestic species. Recent studies have demonstrated the importance of n-3 PUFA in ruminant diets during gestation and its effects on pre-and postnatal offspring growth and health indices. In addition, different types of fatty acids have different metabolic functions, which affects the developmental program differently depending on when they are supplemented. This review provides a broad perspective of the effect of fatty acid supplementation on the developmental program in ruminants, highlighting the areas of a developmental program that are better known and the areas that more research may be needed