ORIGINAL ARTICLE

Metabolic and reproductive state of Holstein cattle in the Carchi region, Ecuador

Estado metabólico y reproductivo del ganado Holstein en la región del Carchi, Ecuador

L. R. Balarezo,^I J. R. García-Díaz,^II M. A. Hernández-Barreto,^II R. García López,^III

ABSTRACT

In order to evaluate the metabolic and reproductive state of dairy Holstein herds and the main factors affecting their reproductive indicators in Carchi province, Ecuador, a total 150 cows were selected. The main biochemical variables of 73 animals in the rainy season and 77 in the dry season were studied, the main indicators of reproductive efficiency and their relation with the metabolic state were also studied. Factors affecting reproductive indicators were determined by means of a multifactorial analysis of variance, using the Bonferroni test to compare the means. In the rainy and dry season, increases in beta-hydroxybutyrate were diagnosed in 68.4 % and 71% of the samples in relation to critical limits and blood urea nitrogen in 30 % and 33 % of them, poor body condition in 56 % and 61% of the animals and low concentrations of albumin in 30 and 33 % and phosphorus in 63 and 64.3% of the samples in each period of the year. The 70% of the animals showed calcium deficiency in the dry season. Cows had in very bad condition the reproductive indicators and body condition influenced (P <0.001) at conception calving and intrapartum intervals and gestational services, as well as (P <0.01) at first-service calving and interestral intervals. The state of beta-hydroxybutyrate (P <0.01) and the three-month period in which the artificial insemination (P <0.05) was performed were also influenced on these reproductive parameters. It is concluded that in the studied herds are deficiencies of energy, protein and phosphorus with poor reproductive performance, in which beta-hydroxybutyrate, body condition and the trimester of the year in which artificial insemination is performed are significantly influenced.

RESUMEN

Para evaluar el estado metabólico y reproductivo de rebaños Holstein lecheros y los factores principales que inciden en sus indicadores reproductivos en la provincia del Carchi, Ecuador se seleccionaron 150 vacas. Se estudiaron las principales variables bioquímicas de 73 animales en el período lluvioso y 77 en el poco lluvioso, los principales indicadores de eficiencia reproductiva y su relación con el estado metabólico. Se determinaron los factores que inciden en los indicadores reproductivos mediante un análisis de varianza multifactorial, con la aplicación de la prueba de Bonferroni para comparar las medias. En el período lluvioso y poco lluvioso, se diagnosticaron aumentos del betahidroxibutirato en 68.4 y 71 % de las muestras en relación con los límites críticos y del nitrógeno ureico en sangre en 30 y 33 % de ellas, mala condición corporal en 56 y 61 % de los animales y bajas concentraciones de albúmina en 30 y 33 % y de fósforo en 63 y 64.3% de las muestras en cada período del año. El 70 % de los animales mostró deficiencia de calcio en la época poco lluviosa. Las vacas tenían deteriorados los indicadores reproductivos y la condición corporal influyó (P < 0.001) en los intervalos parto concepción e interpartal y los servicios por gestación, así como (P < 0.01) en los intervalos parto primer servicio e interestral. También influyeron en esos parámetros reproductivos el estado del betahidroxibutirato (P < 0.01) y el trimestre en que se efectuó la insemnación artificial (P < 0.05). Se concluye que en los rebaños estudiados existen deficiencias de energía, proteínas y fósforo con pobre comportamiento reproductivo, en el que influyen significativamente el betahidroxibutirato, la condición corporal y el trimestre del año en  que se realiza la inseminación artificial.

INTRODUCTION

The low reproductive efficiency negatively affects profitability (Hess et al.2005, Flamenbaum and Galon 2010) and is attributed to inadequate reproductive management practices, environmental factors, genotype and reproductive diseases, although the most important are the nutritional factors that cause disorder at the level of the hypothalamic-hypophysis -ovary axis, which cause anestrus or an-ovulatory cycles due to a failure in the synthesis or gonadotropins release, causing an ovarian hypo-function (Montaño and Ruiz 2005, Macrae et al. 2006, Llewellyn et al. 2007).

In Carchi province, Ecuador, the specialized dairy herds have production levels of 15-18 L / cow^-1 d^-1 (Balarezo et al. 2015), which together with the edaphic component and food base can favor the appearance of metabolic alterations associated with protein and energy nutrition. However, there are no scientific publications on the nutritional and metabolic state of these herds.

Metabolic state studies are a useful tool because they express, directly or indirectly, the level of each circulating metabolite in blood, plasma or serum, which allows characterizing the metabolic pathways, intake, egress or biotransformation of the ingredients of the intake ration by the animals (Villa et al. 1999, Álvarez 2001, Ceballos et al. 2002).

In a dairy farm from Carchi province, calving first service intervals (CFSI), calving conception (CCI) and intrapartum (IPI) were 110, 167 and 434 d respectively, with 1.64 inseminations to achieve gestation (Revelo 2013) and for the province in general. The Holstein Friesian Association from Ecuador (HFAE) reports 187 and 470 d for the CCI and IPI respectively, with 2.14 services per gestation (S/G), which are equivalent to percentages of gestations at the first service and birthrate of 46.72 and 77.7%, respectively.

The above results show that the postpartum anestrus (PPA), the repetition of service or both reproductive problems coexist in the territory, although the data are imprecise and questionable. In Revelo (2013) studies, the indicators are estimated from 20 cows, a small and unrepresentative sample of bovine cattle from this scenario. The data provided by the HFAE are absolute values, which is unknown how they were determined.

The objective of this study is to evaluate the metabolic and reproductive state of dairy Holstein herds and the main factors that influence on their reproductive indicators in Carchi province, in the Andean region of Ecuador.

MATERIALS AND METHODS  

The study was carried out in three dairy herds from Tufiño parish, Tulcan canton, Carchi province, Ecuador, representative of the region livestock. This region is located between the 1º 12 and 43 "NL and the 78 º, 33, 12" 02 WL, to 2990 and 3450 m o.s.l. The sum of annual precipitations in the territory is 1000 mm; the rainy season is September-January and the dry season February-August. The average temperature is 12 °C, with minimums and maximums of 2 and 15 °C, respectively. In the farms irrigation of grasses is applied from natural sources (rivers) and fertilization with doses of 200-300 kg of N²/ha^-1/year^-1.

The three farms use a time-restricted rotational grazing system with an electric fence, with a global stocking rate of 2.5 ha^-1 animals grazing 24h a day the artificial grasses Kingston (Lolium perenne var.), One fifty (Lolium perenne var. ), Banquete (Lolium perenne var.), Bluegrass (Dactylus glomeratta), white clover (Trifolium repens) and naturalized, Kikuyo (Pennisetum clandestinum) and Holco (Holcus lannatus).

In the farms under study, it is not supplemented with concentrate and the mineral supplement is supplied to guarantee availability between 100 and 150 g/animal/ d. The supplement has a Ca: P ratio of 2.25: 1, ideal for dairy cows (McDowell and Arthington 2005). Cows were manually milked twice a day. The first milking took place between 4 and 6 a.m. and the second, between 3 and 4 p.m. The artificial rearing of the calf is applied from the third day of birth.

The detection of heat was performed from 5-9 a.m. and from 3-7 p.m. by a trained man, as well as the use of auxiliary methods, such as painting at the base of the cow's tail. The insemination was carried out using the deep cervical method by an experienced technician, with technical efficiency between 60 and 65 % in the last four years and the use of frozen semen in straws of proven fertility bulls.

Considering the nutritional requirements of dairy cows (NRC 2001), in the herds are covered the needs of crude protein, P, Mg and Mn in the rainy and dry periods, but not those of metabolizable energy, Ca, Cu and Zn ( Balarezo 2015, unpublished data). Of the three farms, 150 crossbred dairy Holstein cows were selected between second to fourth lactation, with average milk production between 15.37 and 15.388 L cow¹day^-1 and body condition (BC) at calving between 2.5 and 4 in the five points scale. The animals selection was performed according to the methodology described by Álvarez (2001).

In the rainy season (RS), 73 animals (29, 22 and 22 from farms 1, 2 and 3, respectively) were researched and 77 animals in the dry season (DS) (36, 17 and 24 from farms 1, 2 and 3, respectively). The main variables of the metabolic state were studied (table 1).

The blood was extracted by coccygeal venipuncture and deposited in IDEXX VetTube ™ tubes (IDEXX LABORATORIES VetLab® USA), previously sterilized and demineralized.

For the hematological analyzes, 5 mL were deposited with EDTA (1 mg / mL blood) and for biochemical indicators 10 mL, without anticoagulant. It was centrifuged at 3500 g for 15 minutes and the blood serum was obtained, which was frozen at -10 °C until their analysis.

The relation between the metabolic state of the animals and the reproductive performance was evaluated, for which the intervals calving first service of insemination (CFS), calving conception (CC), calving-calving (CC), birth rate (BR), percentage of gestations at first service, services per conception(S/C) and interestrual intervals (IEI) were determined from the individual records, according to the methodologies described by González (2001) and Soto (2001). Body condition (BC) was diagnosed by clinical examination and classified on the five-point scale (Parker 1989).

The descriptive statisticians of each metabolic or reproductive variable were obtained. The main factors affecting reproductive indicators were determined using multifactorial analysis of variance (multifactorial ANOVA),using as explanatory factors the classification of BOH and BUN, body condition, farm and trimesters of calving and Artificial Insemination (AI) and as dependent variables to CFSI, CCI, IPI, S/C and IEI. The Bonferroni test was used to compare the means. The statistical package Statgraphis Centurion Ver. XV.II (StatPoint Technologies 2010) was used in all processing.

RESULTS AND DISCUSSION

The alanine amino transferase (ALAT), aspartate amino transferase (ASAT) and alkaline phosphatase (ALP) (Table 2) are among the physiological parameters for the species (Kaneko et al. 1997), and are similar to that reported for some bovine breeds belonging to B. taurus species under tropical conditions (Villa et al. 1999, Campos et al. 2007). The ALAT was high in 38% of the animals, which may be due to hepatic Fasciola infestation or to a liver damage caused by the crude protein excess in the diet intake by the animals (Fajardo 2009).

There were slight deficiencies of albumin, hemoglobin, hematocrit and poor body condition, with variable percentages of samples with deficient values. Increases in BUN and BOH were found (table 2), which show alterations related to protein and energy nutrition. The nitrogen and energy compounds act in the Central Nervous System (CNS), their deficiencies suppress or diminish the amplitude and frequency of GnRH discharges from the hypothalamus and pituitary gonadotropins, thus diminishing reproductive capacity (Deiros et al. 2004).

More than 60 % of blood serum samples were deficient in P, Cu and Zn, and Mg (table 2). Nutrient balances for the researched herds show that the requirements of P and Mg of these macroelements are covered, suggesting that hypophosphoremia and hypomagnesemia diagnosed may be due to antagonistic relations in the absorption and assimilation of both minerals (McDowell and Arthington 2005).

In Ecuador, there are no publications on macroelements levels in blood serum of dairy cows, but P deficiency is the most frequent mineral deficiency in grazing cattle (McDowell and Arthington 2005). In Cuba, P and Mg deficiencies have been found in several researchers in the soil-plant-animal system (Fajardo 2009, Viamonte 2010, García et al. 2011, Noval et al. 2014).

The hypocupremia was diagnosed in 66.67 and 60% of the samples in the rainy and dry seasons, respectively, and the hypocinemia in 73.33 and 65.71% in the same order. The Cu and Zn deficiencies diagnosed are primary, and are due to the fact that the contents of these microelements in the grasses do not cover the requirements of the researched animals.

The calving first service interval (CFSI) should not exceed the voluntary waiting period by more than 18 d (González 2001). In this study, CFSI was 45 d, but only 5.32 % of the cows showed CFSI lower than 65 d. Otherwise, in 48.9 % of cows, this indicator exceeds 150 d, showing that there is a too long period of postpartum anestrus, probably due to phosphorus deficiency, low body condition, BOH and BUN increase (table 2), associated with energy deficiencies and excess of degradable proteins in rumen or N₂.

The CCI is too long, the average value is higher than 270 d in all herds (table 3), and in farm 2 it exceeds 340 d. Only 6.5 % of the cows had CCI lower than 90 d and in contrast, 65.2 % of them had it higher to 180 d. A CCI higher than 120 d shows absence of cyclic ovarian activity or errors in heat detection, that is to say, a pre-service anestrus of a functional or management type (González 2002). In Cuba, it was proven that between 45 and 80% of reproductive disorders of cattle raised on grazing were associated with deficiencies and food imbalances (Fajardo 2009, Viamonte 2010, García et al. 2011).

González (2002) and Bahonar et al. (2009) point out that other factors may affect the CCI, such as lactation, parity, development of uterine involution, type of calving and postpartum infections. For each additional day above 120 d of CCI, are lost between 3.19 and 5.41 USD (De Vries 2006). The average values of this indicator in the 92 cows selected in this study exceed 177 d this value, and generate an additional total loss of 16 299 production days, which would represent a negative economic impact, fluctuating between 51 993.81 and 88 177.59 USD in the studied period.

The average IPI ranged between 554 and 622 d and the birthrate between 58 and 65 %. Both indicators can be classified as bad (González 2001). Only 8.7 % of the females had a IPI lower than 405 d, 44.6 % between 406 and 599 d, and, even more serious, 44.5 % of the cows above 600 d. Due to the metabolic state of cows, indicating nutritional imbalances, regardless of whether there is adequate technological discipline in reproductive management in the farms (Balarezo et al. 2015), the extension of CCI and IPI can be attributed to pre-service anestrus of functional type.

In the studied herds, more than 3.4 S/C are needed (table 3). When this indicator is higher than 2.5 it constitutes a severe fertility problem and is equivalent to less than 40% of pregnancies at the first insemination service (González 2001). Only 29.3 % of the cows needed 1 or 2 S/C, 70.7 % required three or four inseminations to be gestating, that is, lower than 33.3 % of gestation to the first service. The 3.6 % of the females needed more than five inseminations to achieve gestation. The results show that in the studied herds more than 70 % of the females are repetitive.

The interestral intervals (IEI) averaged 27 d in the three herds (table 3). In 30.6 % of cows, the IEI was equal to or lower than 21 d; 10.2 % between 21 and 24 d; 4.5 % between 25 and 27 d and 11.3 % between 28 and 30 d. In 43 %, it is higher than 30 d, indicating post-service anestrus (Soto 2001) or fertilization disorders and/or late embryonic deaths, which may be due to failures in maternal recognition of gestation, due to insufficient production of bovine trophoblastic protein (bTP^-1) (Thatcher et al. 1989). The latter may be due to energy deficit in animals (Inskeep 2004, Lucy 2007) and insufficient progesterone (Raheem 2015).

Table 4 shows the influence of some factors on the main reproductive indicators evaluated. The state of the BOH, body condition and artificial insemination trimester significantly influence on the CFSI, CCI and IPI. In addition, the BOH and BC affected the S/C and BC and the trimester from AI to IEI.

Energy and protein were related to the reproductive process (Viamonte 2010). The results of this study confirmed the observations, in the sense that infertility and subfertility constitute a multifactorial phenomenon, in which feeding is of great influence (Pedroso et al. 2003).

Table 5 shows the values of the main reproductive indicators in the different studied factors. These results coincide with studies that showed that cows submitted during the prep and post calving at a low energy level had a longer post-partum anestrus than animals submitted to a high energy input (Revilla et al. 2001). Pérez et al. (2001) observed that it is not only important to achieve adequate BC at calving, but it is necessary to maintain it during the first 20-30 postpartum.

The cattle have the capacity to compensate the energy deficit in the ration by mobilizing body fat (Wettemann et al. 2003), which leads to an increase in BOH (Roche 2007) as occurred in this research. It is possible to find a combined effect of BC on lactation days and energy balance in follicular development and, therefore, on the first postpartum ovulation (Galvis et al. 2007). With respect to the influence of protein on the reproduction of the bovine female, it is admitted that its low ingestion affects its reproductive performance (Ciccioli et al. 2003). In contrast, high protein intakes may affect reproduction in dairy cows and heifers (Butler et al. 1996), as well as pituitary and ovarian functions (Kane et al. 2004).

The lack, as excess of nitrogen inputs in feed ration, can lead to reproductive problems (Deiros et al. 2004). The plasma urea is related to energy balance and reproductive parameters in dairy cattle. In animals in which the BC decreased from calving to the first artificial insemination, significantly higher values of plasma urea were diagnosed than in those cows that maintained or increased their reserves (Deiros et al. 2004).The urea had a direct effect on the beginning of ovarian activity and the first luteal activity, at 90 d postpartum, which is related to the loss of BC (Viamonte 2010).

When there is lack of energy or when the crude protein in the diet is excessive, not all the NH₃ produced in rumen can be converted to microbial protein, when it over-passes the rumen wall and is transported to the liver, where it is converted to urea which is released into the blood (Correa and Cuéllar 2004). As plasma urea and NH3 concentrations increase, the pH of the uterine lumen is reduced and the secretion of the endometrial glands is affected during the early luteal phase (Razz and Clavero 2004).

The excess of urea at 60 to 90 d postpartum had negative effects on the conception rate at the first service of cows and acted in synergy with milk production and lactation number in the open days to the first service (Guo et al.2004). These results suggest that the negative effect of urea on reproduction may be related to the individual state of cows, which may be the cause that the BUN blood concentrations did not significantly influence on the reproductive indicators of cows, which had different lactations, lactation d and production levels at the time of sampling.

It is concluded that in the studied herds there are metabolic imbalances, mainly deficiency of protein, energy, phosphorus and Mg, with a marked deterioration of reproductive indicators, in which significantly influence the beta-hydroxybutyrate state, body condition and the trimester of the year in which the artificial insemination is performed.

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Received: 28/1/2016
Accepted: 28/10/2016

L. R. Balarezo, Escuela de Desarrollo Integral Agropecuario, Facultad de Industrias Agropecuarias y Ciencias Ambientales, Universidad Politécnica del Carchi. Calle Antisana y Av. Universitaria Tulcán, Carchi, Ecuador . Email: luis.balarezo@upec.edu.ec