Browsing by Author "Gonzalez Martin, Juan Vicente"

Now showing 1 - 7 of 7

Effects of maternal factors during pregnancy on the birth weight of lambs in dairy sheep
(Wageningen Academic Publishers, 2018) Pesántez Pacheco, José Luis; Torres Rovira, Laura; Gonzalez Bulnes, Antonio; Astiz, Susana; Vazquez Gomez, Marta; Gonzalez Martin, Juan Vicente; Vazquez Gomez, Marta
The aim of the present study was to evaluate the influence of physiological and productive factors of ewes (age and type of pregnancy and level of milk production) during pregnancy on birth weight of lambs. The study was carried out in a single commercial farm on 334 Lacaune dairy sheep, classified by age (187 mature and 147 maiden ewes), pregnancy type (155 single vs 179 multiple pregnancies), milk production average milk yield per day (YDIM),from conception to drying off; 45 Low yielding, LYDIM, <1.37 l/d; 70 Average yielding, AYDIM, 1.37 to <1.8l/d; 72 High yielding, HYDIM, >1.8 l/d; and average milk yield per day during month of conception (Yc); 45 Low yielding, LYc, <0.91 l/d; 70 Average yielding, AYc, 0.91 to <1.3 l/d; and 72 High yielding, HYc, >1.3 l/d). Lambs body weight was recorded in 576 lambs (253 males, 323 females) at birth and at 18 days old. Differences among groups were evaluated with ANOVA and Kruskal-Wallis test when non-normal distributed. The lambs born to mature ewes were heavier than those from maiden ewes both at birth (4.2±0.8 vs 3.5±0.8 kg; P<0.0001) and at 18 d-old (8.8±2.0 vs 6.8±1.6 kg; P<0.0001). Newborns from single pregnancies were heavier at birth than those born from multiple pregnancies (4.3±0.9 vs 3.8±0.8 kg; P<0.0001), but no difference was found at 18 d-old (8.0±2.1 vs 7.9±2.1 kg; P>0.05). The birth weight of lambs was similar in the groups HYDIM and AYDIM and heavier in these both groups than lambs from the groups LYDIM (4.3±0.8; 4.3±0.8; 4.0±0.8 kg; P<0.05); there were no differences at 18 d-old. Concomitantly, lambs of the groups HYc and AYc were heavier than lambs in the group LYc at birth (4.4±0.8; 4.2±0.7; 4.1±0.8 kg; P>0.05), but values were similar among the three groups at 18 d-old. The present study suggests that, age, type of pregnancy and level of milk production during gestation in ewes are determinants of lamb birth weight.
Effects of maternal factors on the metabolic profile throughout pregnancy in dairy sheep
(WBC 2018 SPONSORS, 2018) Pesántez Pacheco, José Luis; Torres Rovira, Laura; Gonzalez Bulnes, Antonio; Astiz, Susana; Vazquez Gomez, Marta; Gonzalez Martin, Juan Vicente; Gonzalez Martin, Juan Vicente
Objectives: Physiological states as pregnancy and lactation modify metabolism in sheep. The aim of this study was to evaluate the influence of pregnancy features (parity and type of pregnancy) on the maternal metabolism in high yielding Lacaune dairy sheep. Material and methods: The study was carried out in a single commercial farm on 334 Lacaune dairy sheep, classified by age (187 mature and 147 maiden ewes), parity (145 multiparous vs. 42 primiparous) and type of pregnancy (161 single vs. 173 multiple). Fasting plasma samples were collected at two points during pregnancy mid and late-pregnancy (74±5 and 141±3 d, respectively) and postpartum (52±5 d after delivery). The following metabolic parameters were considered: plasma ß-hydroxybutyrate (ß-OHB), nonesterified fatty acids (NEFA), glucose, lactate, urea, cholesterol, triglycerides and fructosamine. Differences among groups and interactions were evaluated with ANOVA and Kruskal-Wallis test when non-normal distributed. Results: ß-OHB was higher during gestation in mature than in maiden ewes (0.58±0.20 vs. 0.37±0.11 mmol/L; P< 0.0001) at mid pregnancy, (0.67±0.34 vs. 0.55±0.21 mmol/L; P< 0.0001) and late pregnancy, but did not differ with age at postpartum (0.78±0.25 vs. 0.74±0.23 mmol/L; P> 0.05). During gestation ß-OHB was not affected by type of pregnancy, although, postpartum ß-OHB was lower in ewes that had carried out single gestation than in those with multiple pregnancy (0.59±0.27 vs. 0.65±0.31 mmol/L; P< 0.01). At mid pregnancy NEFA were lower in mature than in maiden ewes (0.46±0.22 vs. 0.57±0.17 mmol/L; P< 0.0001); whereas NEFA were higher in mature at late pregnancy and postpartum (0.67±0.29 vs. 0.55± 0.18 mmol/L; P< 0.0001 for late pregnancy); (0.50±0.18 vs. 0.44±0.16 mmol/L; P=0.004 for postpartum). At late pregnancy, ewes carrying a single pregnancy showed lower NEFA than those with multiple foetuses (0.57±0.25 vs. 0.67±0.25 mmol/L; P< 0.0001). Glucose levels during gestation did not differ with age, however, at postpartum mature ewes had lower levels than maiden ewes (67.90±6.44 vs. 74.63±7.54 mg/dl P<0.0001). Glucose during gestation was higher in ewes carrying a single gestation at mid (65.45±15.48 vs. 60.44±8.82 mg/ dl; P< 0.004) and late pregnancy (71.84±14.62 vs. 67.37±12.53 mg/dl; P<0.003) but did not differ postpartum. Lactate was lower in mature ewes at mid pregnancy (16.34±8.73 vs. 18.85±10.13 mg/dl; P<0.003), and postpartum (11.13±6.90 vs. 12.07±5.64 mg/dl; P<0.01), but it was similar at late pregnancy and did not change by type of pregnancy. Urea was higher in mature ewes at mid pregnancy (57.44±11.23 vs. 39.95±7.86 mg/dl; P<0.0001) and postpartum (67.56±15.01 vs. 58.18±13.53 mg/dl; P<0.0001), but lower at late pregnancy (41.44±10.70 vs. 42.31±8.81; P<0.048). Urea was higher at late pregnancy in ewes carrying a single gestation (43.29±10.15 vs. 40.45±9.50 mg/dl; P<0.004). Cholesterol was higher during gestation in mature than in maiden ewes (P<0.0001). However, at postpartum cholesterol was higher in maiden ewes (108.79±21.76 vs. 100.44±21.74 mg/dl; P<0.001) and it was not affected by type of pregnancy. Triglycerides were higher in mature ewes (23.51±8.04 vs. 19.29±7.33 mg/dl; P< 0.001) at mid pregnancy. At postpartum, triglycerides were higher in maiden ewes (17.73±8.62 vs. 15.07±4.37mg/dl; P<0.001) and did not differ with type of pregnancy. Fructosamine was higher at mid gestation in mature ewes (310.77±31.63 vs. 275.47±30.58 umol/L; P<0.0001) and at the same time, it was affected by type of pregnancy (289.75±36.95 vs. 300.30±33.90 umol/L for single and multiple pregnancies respectively; P=0.013). The daily average milk yield during the lactation was not different between primiparous and multiparous (312.42±130.68 vs. 339.6±0.142.9 L; P>0.05); before getting pregnant, primiparous produced less than multiparous (1.71±0.62 vs. 2.07±0.67 L; P<0.05), and after conception primiparous produced the same as multiparous (1.11±0.38 vs. 1.07±0.46 L; P>0.05). Milk yield was not affected by type of pregnancy. Conclusions: The present data reveal interactions among maternal factors (age and type of pregnancy) physiological status (pregnancy and lactation) and time of pregnancy on the metabolism of dairy ewes, which be related to health and productivity.
Factors affecting pregnancy loss in dairy cows
(WBC 2018 SPONSORS, 2018) Astiz Blanco, Susana; Pesántez Pacheco, José Luis; Gonzalez Martin, Juan Vicente; Lopez Helguera, Irene; Gonzalez Martin, Juan Vicente
Objectives: The objectives of this study were to examine possible relationships between pregnancy loss (described as the loss of pregnancy occurred after a positively diagnosed pregnancy -days 28-40- and before day 110 of pregnancy) and different factors such as synchronization protocol used, parity, number of Artificial Insemination (AI), days in milk at AI, age at AI (in the case of heifers) and the fact of having had a previous pregnancy, in dairy cows managed under intensive milk production systems. Material and methods: A total of 12978 AIs from seven different farms were included in the study. The number of AIs from each farm were 812/12978 from farm 1 (6.3%), 710/12978 from farm 2 (5.5%), 1865/12978 from farm 3 (14.4%), 4104/12978 from farm 4 (31.6%), 1530/12978 from farm 5 (11.8%), 589/12978 from farm 6 (4.5%) and 3368/12978 from farm 7 (26.0%). A total of 5119 were first AIs and 7859 were second or more AIs (from them 1729 were 5th or more AIs). The AIs were performed in animals with different lactation orders, with 1586 AIs having been in heifers (only from farms 4 and 7), 3983 in primiparous cows, and the rest in multiparous cows (with lactation order up to 9th). Synchronization protocols recorded were observed estrus, G6G, Double Ovsynch, Presynch, Ovsynch (with or without intravaginal dispositive), 5dCosynch (with or without intravaginal dispositive). A total of 10186 AIs was performed during the cool season (September to May) and 2792 during the hot season (June, July and August). Straightforward stepwise Wald logistic regression analysis was used to study the influence of the different factors, including the factor farm as covariable in the model. Results: Average conception rate for all AIs was 36.7%, and average pregnancy loss was 13.9% (664/4764). The range among farms oscillated from 9.5% (28/294) to 16% (194/1209), with the factor “farm” being a significant one affecting pregnancy loss (P<0.0001). When all AIs were included into the model (controlled including the factor “farm” in the model), significant factors affecting pregnancy loss were season with the hot season increasing the risk of pregnancy loss (11.6 vs. 14.5%; OR, 1.539; 95% CI, 1.215–1.949; P<0.0001); the number of AIs, with second or more inseminations showing an increased risk (14.2 vs. 10.5% for first and second or more AIs, respectively; OR, 0.696, 95% CI, 0.581–0.834; P<0.0001), the parity using the stage of heifer (nulliparous) as reference value, and both primiparous and multiparous increasing the loss risk when compared to the heifers (7.8 vs. 9.9 vs. 14.7% for heifers, primiparous and multiparous, respectively; OR, 1.854, 95% CI, 1.330–2.585; P<0.0001 for primiparous cows, and OR, 3.057, 95% CI, 2.248–4.157; P<0.0001 for multiparous cows). The fact of having had a pervious pregnancy loss was demonstrated as a “protective factor (OR, 0.445, 95% CI 0.278–0.713; P<0.0001). Synchronization protocol did not affect significantly pregnancy loss. When heifers were separately studied (n=1586 AIs), in order to explore the effect of age at insemination a significant effect of this factor was (OR, 1.026, 95% CI, 1.016– 1.035; P<0.0001), besides the significant effect of number of AI observed with second or more inseminations showing less rates of pregnancy loss (OR, 0.305, 95% CI, 0.120–0.774; P=0.012). In the case of primiparous cows separately analyzed (n=3982 AIs), besides farm (P<0.0001) and season (OR, 1.855, 95% CI, 1.252–2.747; P=0.002) no other factor was kept in the model as significant factor; and in the case of multiparous cows (n=7409AIs) season (OR, 1.647, 95% CI, 1.221–2.221; P=0.001), second or more insemination (OR, 0.640, 95% CI 0.513–0.799; P<0.0001) and having had a pervious pregnancy loss (OR, 0.340, 95% CI 0.189–0.610; P<0.0001) influenced significantly pregnancy loss. Synchronization protocol and days in milk at insemination did not significantly affect the risk of having pregnancy loss in adult cows (P>0.05). Conclusions: Our study suggests that the cool season, a higher number of insemination, a younger age of the dam in the case of heifers and having previously suffered pregnancy loss are protective factors for pregnancy loss. However, these factors seem to affect in a different way depending if the inseminations are performed on heifers, primiparous or multiparous cows, which highlights the different reproductive characteristics of the dairy cattle.
Gestational toxemia in lactating sheep is associated with alterations in circulating inflammatory biomarkers
(WBC 2018 SPONSORS, 2018) Pesántez Pacheco, José Luis; Gonzalez Bulnes, Antonio; Astiz, Susana; Vazquez Gomez, Marta; Gonzalez Martin, Juan Vicente; Sanz Fernandez, María Victoria; Gonzalez Bulnes, Antonio; Astiz, Susana; Gonzalez Martin, Juan Vicente
Objectives: Gestational toxemia (GT) is a late pregnancy metabolic disease characterized by the disruption of glucose and lipid homeostasis. Metabolic dysregulation leads to hepatic failure and neurological disorders, which frequently result in the death of both the ewe and its lamb/s. The etiopathology of GT is poorly understood. Several risk factors have been identified (e.g. age, number of fetuses, nutritional status, etc.); however, the large individual variability in GT susceptibility suggests that other factors are likely involved. Recently, inflammation has been associated with metabolic diseases both in cows and sheep. Thus, the study objective was to evaluate changes in inflammatory biomarkers between toxemic and healthy sheep. Materials and methods: The current dataset was retrospectively obtained as a subset from a larger experiment (n=334) conducted at a Lacaune sheep high-yield dairy farm (“Granja Cerromonte”, Spain). Within individuals treated for GT (clinically diagnosed based on neurological symptoms), sheep with the highest β-hydroxybutyrate (BHB) blood concentrations were selected (n=9; TOX). Matching healthy controls (n=9; CON) were chosen based on lambing date, lactation number (4±3lactations), and number of carried lambs (2±1born lambs). Body condition parameters were recorded and a fasting blood sample (prior to morning feeding) was collected in late gestation (6±2 days before parturition). Results: There were no differences in body weight or body condition score between groups. As expected, TOX sheep had decreased glucose (58.8 vs. 69.4 mg/dl; P < 0.02), and increased non-esterified fatty acids (1.57 vs. 0.72 mM; P < 0.0004; NEFA) and BHB (2.00 vs. 0.84 mM; P < 0.0004) blood concentrations, compared to CON sheep. Circulating cholesterol was decreased in TOX sheep (83.8 vs. 98.4 mg/dl; P < 0.03); but fructosamine, lactate, triglycerides and urea concentrations did not differ between groups. Gestational toxemia increased circulating tumor necrosis factor α (8.4 vs. 5.9 pg/ml; P < 0.002) and decreased haptoglobin (2.4 vs. 7.1 mg/dl; P < 0.03), but did not change interleukin-6 concentrations. Haptoglobin concentrations were negatively correlated with both BHB (r = -0.62; P < 0.006) and NEFA (r = -0.60; P < 0.009) levels. Tumor necrosis factor α concentrations tended to be and were positively correlated with BHB (r = 0.42; P < 0.09) and NEFA (r = 0.82; P < 0.0001) levels. Conclusions: In summary, GT in sheep appears to be associated with alterations in biomarkers of inflammation.
Las explotaciones lecheras no tienen que asumir una mala eficiencia reproductiva
(2018) Arias Vaca, Milton Rafael; Torres Rovira, Laura; Hernandez, Fernando; Gonzalez Martin, Juan Vicente; Gonzalez Bulnes, Antonio; Pesántez Pacheco, José Luis
Sin lugar a dudas, la eficiencia reproductiva compromete la rentabilidad de los rebaños. Desde los años 60, hemos ido observando como los indices reproductivos, en especial la tasa de concepción, ha ido disminuyendo a medida que la producción por lactacion y vaca se eleva.
Observational study on a novel management system involving 10 lambings per year in one high-yield dairy ewe farm
(WBC 2018 SPONSORS, 2018) Pesántez Pacheco, José Luis; Torres Rovira, Laura; Gonzalez Bulnes, Antonio; Astiz, Susana; Vazquez Gomez, Marta; Gonzalez Martin, Juan Vicente; Heras Molina, Ana; Sanz Fernandez, María Victoria; Gonzalez Bulnes, Antonio
Objectives: In order to reduce non-productive days in dairy ewe production, the “accelerated sheep mating systems” can be used. One example is the STAR system, which involves up to 5 lambings/ewe in 3 years (1.2 to 1.4 lambing/ewe/year) through 5 successive annual breeding and lambing seasons (5LY). Despite its feasibility, a major disadvantage to this system is an irregular distribution of the workload throughout the year. For instance, the farm staff capacity is easily overwhelmed during the lambings periods, resulting in a deficient care of the newborns. In an attempt to distribute the workload more evenly, a high-yielding Lacaune farm transitioned from the 5LY system to a novel one consisting on 10 lambing periods per year (10LY). The present study examines the efficiency, productivity and workload concentration in this farm under both systems. Its goal was to determine the effects of a more intensive management system on the farm’s productivity, animal welfare and workload distribution. Material and methods: This observational study was performed in a high-yielding Lacaune dairy ewe farm (“Granja Cerromonte”, Spain). The 5LY system was performed from 2010 to 2012, and the 10LY system from 2014 to 2015. Years 2009 and 2013 were considered transition years. During this period, 27,415 lactations were recorded from an average of 3,746 ewes/year. Results: Daily production (1.70 ± 0.62 l/d vs 1.73 ± 1.66; P = 0.038), interlambing period (302 ± 44 vs 283 ± 50 d; P < 0.0001) and lambings/ewe/year (1.30 ± 0.01 vs1.42 ± 0.01; P < 0.05) slightly worsened in the 10LY system compared to the 5LY one. In contrast, milk yield/lactation (370 ± 156 vs. 349 ± 185 L), lactation length (218±75 vs 192 ± 75 d) and dry period length (53.5 ± 38.3 vs 69.1 ± 34.8 d) (all P < 0.0001) were better in the 10LY system. Most importantly, the workload distribution improved by the 10LY system implementation. During 2010–2012, an average of 889.19 ± 158.47 lambings/lambing period (range, 664 to 1 291) was recorded, resulting in an average of 1,502.73 ± 267.82 live newborn lambs/lambing period and 20.80±18.73 lambings/day (range, 1 to 110). There were 500.6 lambs and 296.6 lambings per worker during lambings periods. Extra work hours were necessary at peak lambings/ day. However, during 2014–2015, an average of 443.66 ± 253.18 lambings/lambing period (range, 85 to 937) was recorded, resulting in 709.85 ± 405.10 live newborn lambs/lambing period and 15.16±7.83 lambings/day (range, 1 to 51). There were 354.5 lambs and 221.5 lambings per worker during lambing periods. Since the lambing and lamb related workload was better distributed in the 10LY-period, the workload/worker fell by 50%, needing only two workers/lambing season to take care of the lambings and lamb pens in the 10LY system (354.5 lambs and 221.5 lambing per worker), compared to the three necessary in the 5LY one (500.6 lambs and 296.6 lambing per worker). Further, culling rate decreased (35.39 ± 0.53 vs 42.51 ± 7.51 % P=0.294) and higher-order lactations increased (24.17 vs 16,08%, P<0.0001) which could be the result of better ewe and lamb management. Another possible benefit could be the increase in the worker’s welfare, since the workload does not concentrate so drastically in certain days. Conclusions: Our study suggests that a 10LY herd management system can be compatible with good profitability and productivity and, more importantly, better animal welfare due to lack of animal overcrowding and better care of lambs and ewes during lambing. Furthermore, it could also mean better working conditions for the farm staff, since the workload is more uniformly distributed throughout the year.
Ten years evolution of dairy cattle herds: fertility, production and management
(Scientific Committee, 2018) Pesántez Pacheco, José Luis; Hernandez, Fernando; Gonzalez Bulnes, Antonio; Astiz, Susana; Gonzalez Martin, Juan Vicente; Vazquez Gomez, Marta; Vazquez Gomez, Marta
This study described the productive data evolution from 71 dairy herds over ten years (2008 to 2017). During this period, two global management strategies changed: timed Artificial Insemination (AI) programs since 2011 onwards and composting bedding systems since 2014. The results showed an increase of total cows/ herd (293±299 in 2008 vs 498±558 cattle in 2017), and maximal herd size (980 in 2008 vs 2,505 cattle in 2017). The percentage of heifers (based on the total of animals) was 69.0% without a tendency of change over the years. Regarding production, average daily milk yield per lactating cow increased with time (30.3±2.5 in 2008 vs 33.5±2.2 l/cow in 2017). While calving to first AI interval and estrous detection rate remained stable (91 days and 51.2%, respectively), average days in milk decreased with time (204±14d in 2008 vs 195±16d in 2017). Similarly, the total of AIs per pregnancy decreased from 4.4±1.2 in 2008 to 3.6±1.1 AI/P in 2017. Accordingly to these data, conception and pregnancy rates increased (CR=28.7±5.0% and PR=15.0±3.5% in 2008 vs CR=32.0±5.6% and PR=16.4±4.3 in 2017). Age at first AI decreased from 16.1±1.4 m of age in 2008 to 14.8±51.5 m in 2017, with a reduced age at first calving from 26±1.7 m to 25.1±1.6 m of age in 2017. Neonatal mortality was 8.5%/year during the whole period, with a minimum of 7.2% in 2013 and a maximum of 13.4% in 2008. The annual percentage of culled cows remained stable (29.1±6.8 in 2008 vs 29.8±7.2% in 2017). Dry period length decreased from 64±10 in 2008 to 62±9d in 2017, without an apparent decreasing tendency over the period. In conclusion, the increase in the size of farms is confirmed during this ‘after milk quota period’. The historically impaired fertility with an increasing individual production could not be observed. Moreover, cow’s fertility and heifers reproductive efficiency (age at first calving) improved during this period.