Stress during first gestation of ewes impairs memory and learning of male offspring.

This study aimed to investigate the influence of gestational stress induced by lipopolysaccharide (LPS, Escherichia coli) on the physiological changes of ewes, as well as on the subsequent behavioral interaction between ewes and lambs and on the memory and learning of 30-day-old offspring in a T-maze. Thirty-six nulliparous pregnant crossbred Santa Ines ewes with an initial live weight of 45 ± 6 kg, age of 12 ± 2 months, and body condition score between 3 and 3.5 (on a scale of 1 to 5) were divided into two treatments: LPS treatment (E. coli; 0.8 µg.kg-1) and Control (placebo/saline) administered in late pregnancy (day 120). Blood samples were collected before (0 h at 5:00 h) and 1 h, 2 h, 4 h, 8 h, 12 h, 24 h after the administration of LPS or placebo to determine the cortisol release curve. Rectal temperature was measured at the same time points. After birth, male lambs (N = 19) were used to evaluate the maternal-offspring behavioral interaction, weight, and cognitive ability in a T-maze. Blood cortisol and rectal temperature of ewes increased after LPS administration and returned to baseline levels after 24 h. The activities facilitating and stimulating suckling were higher on LPS group (P < 0.05). Lambs whose mothers were challenged with LPS during late pregnancy showed greater learning and memory disabilities including fear behavior and the inability to make decisions at 30 days of age in the T-maze. In sheep, the immunological stress induced by LPS in late pregnancy promotes an inflammatory response characterized by specific rectal temperature and cortisol release profiles, improving maternal care that can increase offspring survival; however, the exposure of sheep fetuses to maternal inflammation causes cognitive impairment in lambs at 30 days of age, which could not be reduced by the behavioral interaction between the mother and offspring.

Greenhouse gas balance and carbon footprint of pasture-based beef cattle production systems in the tropical region (Atlantic Forest biome).

The production of beef cattle in the Atlantic Forest biome mostly takes place in pastoral production systems. There are millions of hectares covered with pastures in this biome, including degraded pasture (DP), and only small area of the original Atlantic Forest has been preserved in tropics, implying that actions must be taken by the livestock sector to improve sustainability. Intensification makes it possible to produce the same amount, or more beef, in a smaller area; however, the environmental impacts must be assessed. Regarding climate change, the C dynamics is essential to define which beef cattle systems are sustainable. The objectives of this study were to investigate the C balance (t CO2e./ha per year), the intensity of C emission (kg CO2e./kg BW or carcass) and the C footprint (t CO2e./ha per year) of pasture-based beef cattle production systems, inside the farm gate and considering the inputs. The results were used to calculate the number of trees to be planted in beef cattle production systems to mitigate greenhouse gas (GHG) emissions. The GHG emission and C balance, for 2 years, were calculated based on the global warming potential (GWP) of AR4 and GWP of AR5. Forty-eight steers were allotted to four grazing systems: DP, irrigated high stocking rate pasture (IHS), rainfed high stocking rate pasture (RHS) and rainfed medium stocking rate pasture (RMS). The rainfed systems (RHS and RMS) presented the lowest C footprints (-1.22 and 0.45 t CO2e./ha per year, respectively), with C credits to RMS when using the GWP of AR4. The IHS system showed less favorable results for C footprint (-15.71 t CO2e./ha per year), but results were better when emissions were expressed in relation to the annual BW gain (-10.21 kg CO2e./kg BW) because of its higher yield. Although the DP system had an intermediate result for C footprint (-6.23 t CO2e./ha per year), the result was the worst (-30.21 CO2e./kg BW) when the index was expressed in relation to the annual BW gain, because in addition to GHG emissions from the animals in the system there were also losses in the annual rate of C sequestration. Notably, the intensification in pasture management had a land-saving effect (3.63 ha for IHS, 1.90 for RHS and 1.19 for RMS), contributing to the preservation of the tropical forest.