P. Roldan-Santiago

Changes in blood constituents of swine transported for 8 or 16 h to an Abattoir

The effects of two transportation periods on physio- metabolic hemodynamic changes and gaseous exchange in commercial swine during transportation to the slaughterhouse was studied in 684 pigs, 357 barrows and 327 gilts, transported in 2 groups for 8 and 16 h. Transportation caused an increase of oxygen consumption and body temperature, a decrease in pH, lactic acid accumulation. Both transportation periods caused higher than normal plasma glucose levels, lactic acidosis and evidence of dehydration. The linear regression analysis for pigs transported for 8h indicates that the PO(2,) lactate and Ca(++) variables correlated negatively with the PCO(2.) Whilst the animals that were transported for 16 h had negative correlations between glucose, and calcium, hematocrit, lactate and potassium levels. It was concluded that regardless of transport time acidosis, hypocapnia, hypoxaemia, hypernatraemia, hypercalcaemia, hyperglycemia, lactacidemia and increased hematocrit levels occurred.

Effects of long distance transportation and CO2 stunning on critical blood values in pigs

The aim of the study was to evaluate the effect of two stressful stimuli, long transportation and 80% CO(2) stunning on metabolic-physiological variables, hemodynamic and gas exchange in slaughter pigs imported from the U.S. to Mexico City with a journey time of 27 h, with 8 h of lairage at the abattoir. A total of 589 pigs from three genders were monitored. Overall results show that both stimuli caused metabolic and physiological disturbance. Gilts were more efficient in controlling glycemia after a long transport journey (24h), than castrated males (P<0.05), whose glucose was increased above the 30 mg/dL basal level. Females on arrival had 23mg/dL more lactate compared to basal levels (P<0.05). Stunning caused more physiological effects compared to transportation. Regarding the gender factor, females and entire males were more susceptible to transport stress and stunning compared to the castrated pigs, and entire males showed more complications restoring the gas exchange compared to females and barrows.

Assessment of the vitality of the newborn: An overview

Four million newborns die in the world every year, and reports indicate that 98% of those deaths occur in developing countries. The infant mortality rate in children under 5 years of age in Mexico has decreased progressively, in contrast to the neonatal mortality rate, where the reduction was not significant. For this reason, it is necessary and important to have resources that make it possible to assess, rapidly and efficiently, the physiological status of newborns. The objective of this review is to identify the factors involved in the vigor of the newborn. This review will thus allow us to understand the relation that exists between the vitality scores and birth weight, the repercussions of the process of prenatal asphyxia, age of gestation and mortality. Once the factors involved in decreases in the vigor of the newborn have been reviewed, additional studies will be required to use animal models to test different pharmacological therapies that newborn humans have shown their value for early diagnosis and treatment, as a means of improving their physiological and hemodynamic condition during the first hours of extra uterine life, as this is a fundamental factor in their survival.

Physiological response to hypoxia in piglets of different birth weight

In the present study, we aimed to extend the characterization of the proposed naturalistic experimental model of piglets born with hypoxia by assessing the relationship between birth weight, intra partum asphyxia and gross indicators of neurophysiological alterations in newborn piglets. Three groups of 50 piglets each were classified according to their birth weight into normal (1000–1350 g), low (below 1000 g), and high (over 1350 g). In comparison to piglets within normal weight, those born with high birth weights showed acid-base imbalance as reflected by lower pH levels (7.03±0.01), hyper-capnia (88.50±13.20 mmHg), and lactic acidosis (lactate levels: 89.40±26.30). These piglets had lower viability scores (5.40±0.60) and longer periods of time to contact the udder (52.30±8.30) than piglets with normal birth weight. In conclusion, data show that piglets with birth weight over 1350 g are at a higher risk of gross neurophysiological deficits, probably secondary to neonatal hypoxia.

Effects of subcutaneous administration of caffeine on the physiometabolic profile of low-birthweight neonate piglets

Caffeine administration has been used to stimulate respiration and reverse metabolic alterations in high-birthweight piglets that suffer neonatal asphyxia. However, its effect has not been evaluated on low-birthweight neonates. This study determined the effect of subcutaneously administering caffeine on the physiometabolic profile of neonate piglets with low birthweight and neonatal asphyxia. A 35-mg subcutaneous dose of caffeine, or an equivalent placebo, was randomly administered at 0 and 24 h to neonate piglets (n = 120) diagnosed with intrapartum asphyxia and classified as low-(LW) or high weight (HW) in a 2 by 2 experimental design. Blood samples were obtained at 0, 2 and 24 h postpartum. At 2 h, blood glucose concentrations diminished in the animals in both groups that were treated with caffeine (P < 0.005). Of those animals, only the ones in HW showed increased glucose concentrations by 24 h. At 0 h, group LW exhibited the highest levels of pCO2 (P < 0.005). In contrast, from 2 to 24 h only the neonates in group HW treated with caffeine reached the levels of pCO2 and pO2 characteristic of non-asphyxiated piglets. At the conclusion of the experiment, the weight of the piglets in group LW that were treated with caffeine was less than that of those that received the placebo. In contrast, the weight of the piglets in group HW that were treated with caffeine was 19% higher than that of those which received the placebo (P < 0.005). In this study, administering two doses of 35 mg of caffeine to LW neonate piglets significantly accelerated their energy expenditure, thus reducing their weight gain at 8 days of life; in contrast, the physiometabolic profile of the HW neonate piglets improved and they showed greater weight gain.

Outcomes of gestation length in relation to farrowing performance in sows and daily weight gain and metabolic profiles in piglets

The objectiveof this study was toevaluate uterineactivity at farrowing insows with differentgestation lengths (GL),anditseffectonthemetabolicprofile,bloodgasesanddailyweightgainofneonatepiglets.Theexperimentcovereda period of 25 weeks and involved 200 Yorkshire-Landrace sows. The animals were assigned to four groups of 50 sows each and distributed according to GL, as follows: GL1: 107-109 days; GL2: 110-113 days; GL3: 114-116 days; GL4: 117-119days.Theproductiveindicatorsofthesowswererecorded,aswerethesurvivaloutcomesoftheneonatalpigs.Fetal cardiac frequency and both intensity and frequency of myometrial contractions were monitored using a Corometrics Fetal monitor.Thebloodgases,electrolytesandglucoselevelsoftheneonateswereobtainedbymeansofanautomaticbloodgas and electrolyte analyser. The GL groups GL1 and GL2 had more prolonged births (>226.26 4.95 min) regardless of litter size(P <0.05).Ofthefourgroups,GL1presentedthelongestduration(P <0.05)oftheexpulsionphase(P <0.05),thehighest numberofuterinecontractions(P <0.05),andthehighestandlowestnumberofintra-partumdeaths(P <0.05)andlivebirths, respectively. The live birth piglets in this group had both the lowest birthweights (P < 0.05) and the highest incidences of hypercapnia, hyperlactatemia and hypercalcaemia (P < 0.05), which later resulted in lower rates of daily weight gain (P < 0.05). In conclusion, premature births increase the number of intra-partum deaths and result in lower birthweights, the presence of apnoea, and severe metabolic alterations in piglets.

Adaptation of ostriches to transport-induced stress: physiometabolic response.

This study assessed the effects of five different transport periods on physiometabolic responses and gas exchange in ostriches. It included 138 ostriches that were assigned to five experimental groups. G1 included 78 birds that were set aside as a reference group (RG). Each one of the four remaining experimental groups included 20 ostriches, which were transported in the following manner: G1 on one occasion for a period of 1 h; G2 on one occasion for 2 h; and G3 on one occasion for 3 h; G4a was made up of the ostriches from G1 but they were shipped on a second occasion, for 2 h (making a total of 3 h); finally, G4b was that same group, but after a third transport period, on this occasion during 3 h (for a total of 6 h). Groups G2 and G3 presented the most marked blood alterations (P < 0.05), including an increase in pH, hypocapnia (27.8 ± 0.80 mmHg), hypernatremia (171.75 ± 1.84 mmol/L), hypocalcemia (0.95 ± 0.03 mmol/L), and hyperglycemia (224.05 ± 3.94 mg/dL). Also, group G3 presented the lowest hematocrit values (26.5 ± 0.47 HTC%). Therefore, transporting ostriches with no prior experience for 3 h caused the most pronounced physiometabolic changes.

Sensory factors involved in mother-young bonding in sheep: a review

The aim of this review is to discuss sensory recognition (olfaction, vision, vocalisation, hearing and direct contact) in relation to the ewe-lamb bond, and the relevance of this information for animal management, considering that sensory recognition between ewes and their offspring is a key element of lamb welfare. In some parental care strategies, parents promote recognition of their own young in order to ensure their survival by providing them – and only them – with food, while the young simultaneously learn features of the environment. In the specific case of sheep, mother-young bonding is established during the sensitive period of the first 4 h after birth. The ewe prints a distinctive signal on her lambs that marks her as the legitimate mother, while stimulating the offspring’s learning processes through olfactory, visual and acoustic cues. However, the sensory basis for proximal recognition of lambs changes over time as they learn to recognise the signals emitted by the mother. After 4 h – or less – the ewe becomes maternally selective; this means that she accepts only her own lambs at the udder, while actively rejecting alien newborns. Likewise, newborn lambs develop a preference for their mothers in less than one day. This preference is regulated by the difference between the acceptance behaviour manifested by the lamb’s own mother and the aggressive rejecting behaviour shown by alien ewes. This early discriminative ability allows the lamb to avoid the aggressive actions of alien dams and maintain close contact with its own lactating mother. At around one week of age, lambs learn to develop the sensory cues that allow them to recognize their mother. These include olfactory, visual, acoustic and tactile information. Mutual ewe-lamb recognition at an early age also ensures that newborns will be fed and cared for by their own mother, which satisfies some of the requirements for their survival and welfare. For all these reasons, any disruption of ewe-lamb bonding during parturition is detrimental to lamb welfare and survival.

Physiological responses in horses, donkeys and mules sold at livestock markets

Abstract The horse welfare at markets includes fatigue, fear, fasting, dehydration and injuries. However, the scientific literature contains no readily-available information on the physiology responses of equids sold in livestock markets. The objective of the present study was to evaluate the effect of holding in livestock markets on gas exchange, the acid-base balance, energy metabolism, and the mineral and water balance in 4 types of horses (Equus caballus), donkeys (Equus asinus) and mules ((Equus asinus × Equus caballus). To this end, a total of 1,438 equine were utilized, after classification into six groups, as follows: mules, donkeys, culled horses, charrería horses (Mexican rodeo horses), foals, and ponies. The time intervals evaluated were 1 and 5 h. During the study, the animals received only water ad libitum. The physiological blood indicators assessed were: PvCO2 (mm Hg) and PvO2 (mm Hg) pressure, pH, glucose (mg/dL), lactate (mg/dL), bicarbonate levels (mmol/L), hematocrit (%), Na+, K+ and Ca2+ (mmol/L). The animals that presented the most marked physiological alterations were the mules and donkeys. The mules that remained in the corrals for 1 h presented increases (P < 0.0001) in the values for pO2, glucose, hematocrit and blood pH, compared to reference values (RV), while the donkeys had increases (P < 0.0001) in glucose and hematocrit values. By the end of the first hour at the exhibition corrals the equine were dehydrated, suffered fatigue, and suffered metabolic and compensatory problems, probably due to the combined effects of a series of factors that include transport and inadequate handling.

Metabolic changes during brief periods of ewe–lamb separation at different ages

The present study evaluated metabolic changes in lambs during three brief periods of ewe–lamb separation, namely 1 min (T1), 10 min (T10) and 60 min (T60). The lambs were divided by age into the following three groups: 15 days (G1 = 40 lambs), 30 days (G2 = 40 lambs) and 60 days (G3 = 40 lambs). The hypothesis to be tested was that breaking the ewe–lamb bond at different ages and for these brief time periods will cause significant metabolic changes in the lambs. To this end, blood samples were taken from the three test groups 24 h before separation to establish reference values (RVs), and again at the end of the three separation times. The following blood variables were analysed for all three study groups: glucose (mg/dL), lactate (mg/dL), calcium (Ca2+, mmol/L), sodium (Na+, mmol/L), potassium (K+, mmol/L), haematocrit (HTC, %), pCO2 (mmHg), pO2 (mmHg), HCO3– (mmol/L) and pH. Results showed that the G1 lambs suffered the greatest metabolic changes for the variables pO2, pCO2, glucose, lactate, pH, HCO3–, Ca2+, Na+, K+ and HCT. With respect to time, the first 10 min of separation from the mother induced marked metabolic changes in the 15-, 30- and 60-day-old lambs, but, at 60 min, the G2 and G3 lambs tended to recover their physiological RVs, while the G1 lambs did not. These findings showed that breaking the ewe–lamb bond immediately generated metabolic changes in the lambs even though they remained in a familiar, habitual environment. They also indicated that the age of the lambs at separation was a significant factor, as the older animals tended to re-establish their RVs after the metabolic changes, likely because their physiological compensating mechanisms are more efficient, or perhaps because the intensity of attachment to the mother decreases with greater age.