Abstract

The objective of this study was to investigate the effects of sowing on hay yield and quality of oat genotypes. Sixteen oat genotypes were grown over the consecutive four growing seasons in Samsun, North of Turkey. Hay yield and quality were significantly different between genotypes and sowing dates. Hay yield, Crude Protein (CP), Acid Detergent Fibre (ADF), Neutral Detergent Fibre (NDF), Total Digestible Nutrients (TDN), Relative Feed Value (RFV), Ca, K, P and Mg contents of hay were determined. Hay yield of the oat genotypes in the autumn sowing was higher than in the spring sowing while hay quality (CP, ADF, NDF, TDN, RFV and some elements) in the autumn sowing was lower than in the spring sowing. The hay yield of late-maturing and tall genotypes like Yesilkoy-330, Yesilkoy-1779, Faikbey and Seydisehir (12.1, 12.2, 12.4 and 12.9 t ha^-1, respectively) were higher compared with the other genotypes in sowed in autumn. But quality of these genotypes in autumn sowing was lower than the other genotypes. In spring sowing, genotypes Samsun and Kupa had the highest hay yield and fairly high quality. Ca, K and P contents of hay were adequate for ruminants in both sowing dates but Mg content was not adequate. This study showed that sowing date had great effect on hay yield and quality potential of oat genotypes.

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INTRODUCTION

In Turkey, the capacity of natural grassland was lower as well as other forage crops production that are an important feed source was undeveloped and therefore, remains inadequate for present livestock. As alternative feed source, uses of small grain cereals forage could be partly solved for scarcity of available forage (Celik and Bulur, 1996). Small grain cereal forages are greatly adjusted highly multi-purpose forages used for pasture, green chop, silage and hay (Fohner, 2002). Cereal forages are a major crop both in Turkey and in many parts of world and their importance is increasing because of their significant economic and environmental benefits (Braunwart et al., 2001). Oat (Avena sativa L.) is used extensively as feed for livestock because of its high-quality as well as its high-forage yield (Moreira, 1989; Zhang et al., 1998). Oat varieties are sown either in the fall or in the spring in Turkey. Oat can be grown either at coastal regions in spring as well as in fall or inland regions of Turkey in spring due to frost damage. Oat genotypes can be generally grown for both grain and forage in Turkey. Several studies have evaluated grain oat genotypes for forage yield. Riveland et al. (1977) evaluated 12 genotypes and found that medium to late-maturing genotypes produced the greatest forage yield.

Anderson and Kaufmann (1963) evaluated 25 genotypes in Canada and concluded that breeding for forage yield was unnecessary because late-maturing genotypes were suitable for both seed and forage production. Kaufmann (1961) and Stuthman and Marten (1972) also reported that late-maturing genotypes had high forage yield but Stuthman and Marten (1972) found no relationship between forage yield and grain yield. Folkins and Kaufmann (1974) found that five oat genotypes ranked the same for forage and grain yield in 1 year but not in 2 other years. If a grain oat is to be used as a forage oat in dairy regions, it is important that the oat also have good forage quality (Cherney and Marten, 1982). Some researchers argued that the value of high quality forage for improving body weight gain on ruminant animals (Waldo and Jorgensen, 1981; Linn and Martin, 1989). Juskiw et al. (2000) stated that quality forage must have high intake, digestibility and efficiency of utilization. Plant cell walls, containing a digestible and an indigestible fraction are an important element fixing forage quality. ADF (acid detergent fiber) and NDF (neutral detergent fiber) are good indicators of fiber contents in forages. While Acid Detergent Fiber (ADF) content is a measure of the indigestible fraction, Neutral Detergent Fiber (NDF) content is a measure of the total cell wall fraction.

Oat genotypes that are low in NDF and ADF should have good forage quality because low NDF is associated with high forage intake and low ADF is associated with high digestibility. Protein content is an important feed factor per se, with high quality feed having high protein content. The chemical composition and nutritive value of green plant material can give useful information about the forage quality (Kjos, 1990). About 12 oat genotypes evaluated by Riveland et al. (1977) were similar in forage quality and nutritionally competitive with good-quality cool-season grass hay. Additionally, Stuthman and Marten (1972) found minimal variation for forage quality among 11 oat genotypes.

The differences regarding hay yield and quality of different oat genotypes sown in autumn and spring were investigated in this study.

MATERIALS AND METHODS

A field experiment was conducted for 4 years during the 2003-2007 growing seasons at the Experiment Farm of Ondokuz Mayis University in Samsun, Turkey. The altitude of experimental area was 195 m (41°21'N, 36°15'E). The experiment was established in a clay soil with pH 7.10, organic matter content 3.01%, available P content 25.40 ppm and K 305 ppm (0-30 cm depth). Climatic data during the four growing seasons of the experimentation were shown in Table 1. The genotypes were shown in a completely randomized block design with three replications. Names and origin of genotypes is used in the study were shown in Table 2. Each genotype was sown in 7.2 m² (1.2 by 6.0 m) plots consisting of 6 row with 20 cm row spacing at the beginning of November for the autumn sowing and at the beginning of March for the spring sowing in all years. Plots were fertilized with 60 kg N and 60 kg P ha^-1 at sowing. Harvest dates were shown in Table 2. Maturity at harvest was determined using Zadoks’s scale (Zadok et al., 1974). Harvest was done at late milk dough (Zadok scale 77).

A sub-sample (800-1000 g) was randomly selected from each harvested plot to estimate hay yield and provide samples for forage quality analysis. The samples were weighed and dried for 72 h by forced-air drying oven at 65°C. The dried samples were reassembled and ground to pass through a 1 mm screen. Crude protein, Acid Detergent Fibre (ADF), Neutral Ddetergent Fibre (NDF) and Ca, K, Mg and P contents of samples were determined using Near Infrared Reflectance Spectroscopy (NIRS) (Hoy et al., 2002; Poblaciones et al., 2008). NIRS was calibrated using software program coded IC-0904 FE.

Total Digestible Nutrients (TDN), Dry Matter Intake (DMI), digestible Dry Matter (DDM) and Relative Feed Value (RFV) were estimated according to the following equations adapted from:

TDN	=	(-1.291 x ADF) + 101.35
DMI	=	120/NDF% dry matter basis
DDM	=	88.9-(0.779 x ADF% dry matter basis)
RFV	=	DDM% x DMI% x 0.775

Data were analyzed with Analysis of Variance (ANOVA) procedures using the MSTAT-C statistical software. The mean separation among treatment means for years, sowing date and variety was obtained by using the Least Significant Difference (LSD) test (Steel and Torrie, 1980).

 

Table 1:	Monthly total rainfall and mean air temperature during the four growing seasons of experimentation at Samsun, Turkey

 

 

Table 2:	Origin, harvest date and plant height of investigated oat genotypes
*Means are averaged over four growing seasons (2003-2007) and three replicates

 

RESULTS AND DISCUSSION

Precipitations and temperatures for the years under study are shown in Table 1. Cumulative precipitation both in autumn and in spring of 1st, 2nd and 3rd growing seasons was more than the normal yearly average. However, cumulative precipitation in autumn and spring of fourth growing season was less than the normal yearly average. Mean temperatures over 30 years were similar for the four growing season years (Table 1).

Variance analysis of the 4 years data showed that significant effect of genotype, sowing date, year and their interaction on hay yield and hay quality. As shown in Table 3-5 hay yield for both sowing dates in the growing seasons 2003-04 (first year) and 2004-05 (second year) was higher than 2005-06 (third year) and 2006-07 (fourth year). This may result from the fact that the rainfall between March and May was much higher in the first and second year compared with the third and fourth year (Table 1).

Hay yield: Maturity period for hay among genotypes in the autumn sowing was shorter than that of the spring sowing. Maturity period of Checota and Karaman were earlier than that of the others both in the autumn and in the spring sowing (Table 2). Plant height of genotypes in autumn sowing had taller than in spring sowing. Hay yield of the genotypes in the autumn sowing was higher than in the spring sowing.

Comparison of hay yields by the sowing time indicated a clear advantage of autumn sowing. Based on 4 years data autumn sowed oat resulted in 56.4% higher hay yield than the spring sowed crop (Table 3). This result could be due primarily to air temperature, precipitation and other factors. Similar findings were indicated by Maloney et al. (1999).

The hay yield of genotypes Yesilkoy-330, Yesilkoy-1779, Faikbey and Seydisehir (12.1, 12.2, 12.4 and 12.9 t ha^-1, respectively) were higher compared with the other genotypes in sowed in autumn. Genotypes Sivas and Karaman had the lowest hay yield (5.21 and 5.87 t ha^-1, respectively) (Table 5). The highest hay yield in spring sowing was obtained from Samsun and Kupa genotypes (8.25 and 7.77 t ha^-1, respectively). This study in the autumn sowing, hay yield of genotypes which had tall and late-maturing were generally higher than the other genotypes (Table 1, 3). Chapko et al. (1991) showed that tall, late-maturing genotypes were associated with high forage yield.

Similar results were reported by other investigators (Anderson and Kaufmann, 1963; Stuthman and Marten, 1972). On the contrary, there is no such a relationship in the spring sowing. Maturity differences among the genotypes were much greater in autumn sowing than in spring sowing. These results agree with those of Smith (1974) and found that a change from warm to cool temperature delayed panicle emergence in oat while a change from cool to warm decreased time to reach this maturity stage.

Hay quality: Significant differences were found amongst years, the genotypes and sowing dates regarding crude protein, ADF, NDF, TDN, RFV and mineral contents of hay. Crude protein content of forage is one of the most important criteria for forage quality evaluation (Caballero et al., 1995; Assefa and Ledin, 2001). The highest CP content was obtained in autumn sowing in the third year and in the spring sowing in the second and third years (Table 4). CP concentrations for all oat genotypes were higher in spring sowing than in autumn sowing (104.0, 92.0 g kg^-1 DM, respectively) (Table 3). Among genotypes, CP concentrations were greater in Kupa, Peniart, Mugla than in the other genotypes in autumn sowing.

 

Table 3:	Effects of sowing date on the parameters investigated in the study as 4 year average
HY: Hay yield, CP: Crude protein, NDF: Neutral detergent fibers, ADF: Acid detergent fibers, TDN: Total digestible nutrients, RFV: Relative feed value, Ca: Calcium, K: Potassium, P: Phosphor, MG: Magnesium. Means within a column followed by the same lowercase letter are not significantly different (p<0.01)

 

 

Table 4:	Effects of sowing date on the parameters investigated in the study as 4 year average
HY: Hay yield, CP: Crude protein, NDF: Neutral detergent fibers, ADF: Acid detergent fibers, TDN: Total digestible nutrients, RFV: Relative feed value, Ca: Calcium, K: Potassium, P: Phosphor, MG: Magnesium. Means within a column followed by the same lowercase letter are not significantly different (p<0.01)

 

 

Table 5:	Hay yield (HY), some quality characters and mineral concentration of oat genotypes in the autumn and spring sowing
CP: Crude protein, NDF: Neutral detergent fibers, ADF: Acid detergent fibers, TDN: Total digestible nutrints, RFV: Relative feed value, Ca: Calcium, K: Potassium, P: Phosphor, MG: Magnesium. Means within a column followed by the same lowercase letter are not significantly different (p<0.01), Means are averaged over four growing seasons (2003-2007) and three replicates

 

But, in spring sowing, Baranja had greater CP concentration than the other genotypes (Table 5). Some researchers pointed out that crude protein content of hay changed among oat genotypes significantly (Ericson et al., 1977; Kim et al., 2006). Same researchers also showed that CP content of late-maturing oat varieties was higher than the early-maturating varieties. The results were consistent with the findings of Ericson et al. (1977) and Kim et al., 2006.

Other important quality characteristics for forages are the concentrations of ADF and NDF (Caballero et al., 1995; Assefa and Ledin, 2001). In this experiment, the values for ADF and NDF in spring sowing were lower than those in autumn sowing (Table 3). The values for ADF in the fourth year were greater than those in the first, second and third in autumn sowing. In spring sowing, however, these values in the first and fourth years were greater than those in the second and third (Table 4). The NDF values were in autumn sowing greater in the third and fourth years compared with the first and second year in spring sowing the NDF values were in the first, third and fourth years greater than second year (Table 4). The ADF and NDF values significantly differed with oat genotypes. Checota, Peniarth, Mugla, Kupa, Samsun-Kavak, Ordu and Bursa had lower the ADF and NDF values than those of the other genotypes in autumn sowing (Table 5). In spring sowing, much smaller differences were observed regarding the ADF and NDF values among genotypes and Mugla showed the lowest the ADF and NDF values (360.3 and 570.7 g kg ^-1 DM, respectively) (Table 5).

The TDN refers to the nutrients that are available for livestock and are related to the ADF concentration of the forage. As ADF increases there is a decline in TDN which means that animals are not able to utilize the nutrients that are present in the forage. TDN value was higher in spring sowing than in autumn sowing (530.1 and 516.8 g kg^-1 DM, respectively) (Table 3). The values for TDN in the 4th year were lower than those in the 1st, 2nd and 3rd in autumn sowing.

In spring sowing, however, these values in the first, third and fourth years were lower than those in the second. Genotypes Checota, Peniarth, Mugla, Kupa, Ordu and Bursa had the highest values for TDN during both season (Table 5). Additionally to these genotypes, the highest TDN values was obtained from the genotypes Samsun and Samsun-Kavak in autumn sowing and from the genotypes Yesilkoy-330, Seydisehir, Karaman and Baranja in spring sowing. Kim et al., 2006 showed that TDN value has significant differences among oat varieties (Table 5).

The RFV is an index that is used to predict the intake and energy value of the forages and it is derived from the DDM and Dry Matter Intake (DMI). Forages with an RFV value over 151, between 150-125, 124-103, 102-87, 86-75, and fewer than 75 are considered as prime, premium, good, fair, poor and reject, respectively. In the present experiment, the RFV value was higher in the spring sowing than in the autumn sowing. Genotypes Checota, Mugla and Bursa were higher in RFV value than the other oat genotypes in both autumn and spring sowing (Table 5). Since RFV value was calculated from ADF and NDF, the observed differences were reflective of previously described ADF and NDF differences. Thus, a more comprehensive assessment on forage quality should be done for the different oat varieties in the different regions and at different seasons. This conclusion is consistent with the findings of Kim et al., 2006 who studied yield and quality of oat varieties.

There were significant differences amongst genotypes and years regarding their mineral content. Differences in Ca contents were not significant between sowing dates. Ca contents of the genotypes varied from 4.20 (Samsun-Kavak) to 5.69 (Ordu) g kg^-1 DM in the autumn sowing, while Ca contents of the genotypes varied from 3.80 (Samsun-Kavak) to 5.85 g kg^-1 DM in the spring sowing (Table 5). Tajeda et al. (1985) reported that forage crops should contain at least 3.0 g kg^-1 of Ca for ruminants. The American National Research Council (NRC, 1984) recommended that forage crops should contain 3.1 g kg^-1 Ca concentration for beef cattle. Results obtained for Ca concentration in this study were more than these recommended values. In the autumn sowing, K contents of the genotypes varied from 15.80 (Faikbey) to 20.07 (Bursa) g kg^-1 DM while K contents of the genotypes changed between 14.37 (Mugla) and 19.73 (Rize) g kg^-1 DM in the spring sowing (Table 5). Differences in K contents of sowing date were not significant. This conclusion is consistent with the findings of Mut et al. (2006) who studied yield and quality of triticale, barley, rye and barley varieties. These results were higher than suggested values of 8.0 g kg^-1 by Tajeda et al. (1985). But high K concentration may cause Mg deficiency (Loreda et al., 1986).

P content was higher in spring sowing (3.37 g kg^-1) than in autumn sowing (3.20 g kg^-1). In the autumn 1.05 concentrations of 1.8-3.9 g kg^-1 for forage crops are recommended for ruminants (National Research Council, 2001). Results obtained for P concentration in this study were adequate for ruminants.

Mg content was higher in autumn sowing than in spring sowing and this difference was statistically significant. In both sowing dates, Mg concentration in the all genotypes was between 0.82 and 1.47 g kg^-1 (Table 5). Mg concentrations for forage crops are recommended as 2.0 g kg^-1 for ruminants by Tajeda et al. (1985) and 1 g kg^-1 for beef cattle by the NRC (1984). Grass tetany or hypomagnesemic tetany in cattle is caused by an imbalance of K, Ca and Mg in the diet. Mineral imbalances, deficiencies or excess and low bio-availability of essential minerals result in negative economic impacts when animal performance and health are compromised (Van Soest, 1982). Magnesium deficiency may lead to a reduction in weight gain, milk production and conception rate (Stuedemann et al., 1983).

Osman and Nersoyan (1986) pointed out that monocultures of common vetch or cereals do not provide satisfactory results for forage production. Similarly, Lithourgidis et al. (2006) indicated that forage quality of cereal hay is usually lower than that required to meet satisfactory production levels for many categories of livestock. On the other hand, Lawes and Jones (1971) showed that small grain cereals provide high yields in terms of dry weight.

CONCLUSION

The study showed that sowing date had great effect on hay yield and quality potential of oat genotypes. Comparison of hay yields by the sowing date indicated a clear advantage of autumn sowing. Based on 4 years data autumn sowed oat resulted in 56.4% higher hay yield than the spring sowed crop. However, in spring sowing, oat genotypes had higher quality values than in autumn sowing. This study also showed that late-maturing and tall genotypes like Yesilko-330, Yesilkoy-1779, Faikbey and Seydisehir performed better hay yield in autumn sowing but showed lower hay quality. On the contrary, there is no such a relationship in the spring sowing. With regard to low forage quality of cereals, forage yield and quality could be increased by growing suitable oat genotypes with legume forage crops.

How to cite this article:

Hanife Mut, Ilknur Ayan, Zeki Mut and Nevzat Aydin. Effect of Autumn and Spring Sowing Dates on Hay Yield and Quality of Oat (Avena sativa L.) Genotypes.
DOI: https://doi.org/10.36478/javaa.2010.1539.1545
URL: https://www.makhillpublications.co/view-article/1680-5593/javaa.2010.1539.1545