2.C VALENCIA EN LA SEGUNDA MITAD DEL SIGLO

Annual herbage DM production ranged from 12.4 to 13.8 t DM/ha among grazing management treatments. In the first year, annual herbage DM production was greater in SL (14.0 ± 0.4 t DM/ha) and CG (13.7 ± 0.4 t DM/ha) than AL (12.4 ± 0.4 t DM/ha, P<0.05). This effect did not occur in the second year (Table 3.4). There were no significant differences in annual DM production between CG and SL, though a lenient grazing in autumn reduced (P=0.03) annual DM production by 1.2 t DM/ha. The lower annual DM production in AL is reflected by lower seasonal herbage DM production in both winters, spring 2015 and autumn 2015.

Annual herbage DM production was greater in DP (13.4 ± 0.3 t DM/ha, P<0.01) than DP+Ita (12.4 ± 0.3 t DM/ha) in the first year. Annual herbage DM production in the second year was not significantly different between DP and DP+Ita. Averaged over two years, annual herbage DM production was greater in DP (13.4 ± 0.2 t DM/ha) than DP+Ita (12.8 ± 0.2 t DM/ha, P=0.006). The effect appeared to be related to greater production in summer and autumn of year 1 in DP, where Italian ryegrass was not sown.

There was tendency for an interaction between grazing management and pasture mixture (GM x PM) for mean annual DM production, averaged across the two years of study (P=0.10). Within three of the eight seasons measured, significant grazing management x pasture mixture interactions were observed (Table 3.4). Herbage DM production was lower (P<0.05) in AL of spring 2015 than CG and SL. There was also an interaction between grazing management and pasture mixture for spring herbage DM (P=0.03). In spring 2015, differences in herbage DM production between pasture mixture was small in CG and SL, but in AL, herbage DM yield was 878 kg DM/ha greater in DP than DP+Ita (3043 versus 2165 kg DM/ha; Table 3.4). The result reflected the difference in annual herbage between DP and DP+Ita; difference in CG grazing (13929 versus 13806 kg DM/ha) was small

compared to the difference in SL grazing (14901 versus 12725 kg DM/ha) and AL grazing (13354 versus 11895 kg DM/ha) (Table 3.4).

Table 3.4 The effect of grazing management and pasture mixture on annual herbage DM production and seasonal DM production (kg DM/ha) from June 2015- May 2017 at the Lincoln University Research Dairy Farm, Canterbury, New Zealand.

P-values from ANOVA for main effects of grazing management and pasture mixture are shown. Means followed by a different letter within a row are significantly different (P<0.05).

Grazing management Pasture mixture SEM P-value

Season AL CG SL DP DP+Ita Management Mixture

Management

*Mixture Management Mixture

Management *Mixture Year 1 Winter 2015 1875a ₂₃₄₁b ₂₂₂₆b ₂₁₆₇ ₂₁₂₇ ₆₄ ₅₂ ₉₀ _<0.01 _0.60 _0.38 Spring 2015 2604a ₃₀₄₅b ₃₀₂₂b ₃₀₂₄ ₂₇₅₇ ₁₁₇ ₉₆ ₁₆₅ _0.04 _0.08 _0.03 Summer 2016 4608 4514 4708 5065 4154 312 254 441 0.91 0.03 0.43 Autumn 2016 3353a ₃₇₉₂a,b ₄₀₃₇b ₄₀₅₄ ₃₄₀₀ ₁₅₈ ₁₂₉ ₂₂₄ _0.04 _<0.01 _0.04 Year 2 Winter 2016 716a ₁₃₁₇b ₁₂₃₀b ₁₁₄₈ ₁₀₂₆ ₁₀₇ ₈₈ ₁₅₂ _<0.01 _0.35 _0.38 Spring 2016 2768 3478 3391 3211 3213 211 173 299 0.08 0.99 0.88 Summer 2017 5350 5208 5145 5271 5197 202 165 286 0.77 0.76 0.03 Autumn 2017 3977 4041 3869 4182 3742 381 311 539 0.95 0.34 0.99 Year 1 12439a ₁₃₆₉₂b ₁₃₉₉₂b ₁₃₃₇₄ ₁₂₄₃₉ ₃₈₉ ₃₁₇ ₅₅₀ _0.04 _<0.01 _0.21 Year 2 12811 14043 13634 13496 13178 581 474 822 0.35 0.37 0.47 Mean 12625a ₁₃₈₆₈b ₁₃₈₁₃b ₁₃₄₃₅ ₁₂₈₀₉ ₃₁₀ ₂₅₃ ₄₃₉ _0.03 _0.006 _0.10

*CG=conventional grazing, SL=spring lenient grazing, AL=autumn lenient grazing, DP=diverse pasture mixture, DP+Ita=diverse pasture mixture with Italian ryegrass **Significant interactions are shown in Table 3.5.

Table 3.5 The interactions of grazing management (AL, CG, SL) and pasture mixture (DP, DP+Ita) on mean annual herbage DM production and seasonal DM production (kg DM/ha) from June 2015-May 2017 at the Lincoln University Research Dairy Farm, Canterbury, New Zealand.

P-values from ANOVA for main effects of grazing management and pasture mixture are shown. Means followed by a different letter within a row are significantly different (P<0.05).

AL CG SL SEM P-value

Season DP DP+Ita DP DP+Ita DP DP+Ita Grazing

management Mixture Grazing management *Mixture Grazing management Mixture Grazing management *Mixture Spring 2015 3043a ₂₁₆₅b ₂₉₇₅a ₃₁₁₅a ₃₀₅₄a ₂₉₉₀a ₁₁₇ ₉₆ ₁₆₅ _0.04 _0.08 _0.03 Autumn 2016 3411b,c ₃₂₉₄c ₄₀₁₇b ₃₅₆₇b,c ₄₇₃₃a ₃₃₄₀b,c ₁₅₈ ₁₂₉ ₂₂₄ _0.04 _0.01 _0.04

Summer 2017 5550a,b ₅₁₅₀a,b ₄₇₂₄b ₅₆₉₂a ₅₅₃₉a,b ₄₇₅₀b ₂₀₂ ₁₆₅ ₂₈₆ _0.77 _0.76 _0.03

Mean of annual herbage DM production

13354c ₁₁₈₉₅e₁₃₉₂₉b₁₃₈₀₆b₁₄₉₀₁a₁₂₇₂₅d ₃₁₀ ₂₅₃ ₄₃₉ _0.03 _0.0006 _0.10

3.5.3 Seasonal herbage DM production

Grazing management was significant (P<0.05) on seasonal herbage DM production in winter 2015, spring 2015, autumn 2016 and winter 2016 (Table 3.4). Pasture mixture was significant (P<0.05) on seasonal herbage DM production in summer 2016 and autumn 2016.

Herbage DM production was not different between CG and SL (Table 3.4). There appeared to be no carry over effects of early (SL) and late (AL) season grazing management on herbage production in the summer. However, in the cooler months of winter and spring, there were evident DM production benefits of seasonal lenient grazing, as both AL and SL improved DM production compared with CG. In the first year, lenient spring grazing had more pronounced benefits on DM production in autumn than autumn lenient grazing.

In the first winter, Italian ryegrass in DP+Ita had the same DM production as DP and not statistically significant (P>0.05; Table 3.4). Beyond winter year one, there was a net reduction in seasonal DM yield in plots where Italian ryegrass had been sown. However, in the second year, more than two years after establishment (October 2014), there was no longer an effect of Italian ryegrass on herbage yield (P>0.05). There was an interaction between grazing management and pasture mixture for autumn 2016 DM yield (P=0.03). This interaction reflected that the greatest herbage DM yield (4733 kg DM/ha) occurred in DP pastures that were grazed by the SL treatment (Table 3.5). Though pasture mixture was not statistically significant, the difference in seasonal herbage between DP and DP+Ita in CG (4017 versus 3567 kg DM/ha) and AL (3411 versus 3294 kg DM/ha) was small compared to the difference in SL grazing (4733 versus 3340 kg DM/ha; Table 3.5).

There was no significant effect on grazing management or pasture mixture on herbage DM production in summer 2017. Though there was an interaction between grazing management and pasture mixture for summer 2017 DM yield (P=0.03). This interaction reflected a significant difference between DP and DP+Ita in herbage DM yield in CG (4724 versus 5692 kg DM/ha) but not in SL (5539 versus 4750 kg DM/ha) and AL (5550 versus 5150 kg DM/ha; Table 3.5).

In document La asistencia sanitaria, los cuidados y la profesión enfermera en Valencia, durante la segunda mitad del siglo XIX / tesis doctoral presentada por Estefanía del Rey Corado ; dirigida por [la] Dra Esperanza Ferrer Ferrándiz [y el] Dr Juan José Tirado Dar (página 97-101)