Reproductive management of dairy herds in New Zealand: Attitudes, priorities and constraints perceived by farmers managing seasonal-calving, pasture-based herds in four regions

Figures & data

Table 1. Summary statistics for biophysical variables from 133 seasonal-calving, pasture-based dairy herds from four regions in New Zealand, enrolled in the National Herd Fertility Study during 2009, presented for all herds in the study, and for herds in the study by region, compared with published industry means^a.

Biophysical variable of herd	All herds			Means for herds by region				P-value^b
	Mean	SD	Range	Waikato	Taranaki	North Canterbury	South Canterbury
Effective area of farm (ha)	164.4	72.6	50–350	126.6 (109)	114.5 (89)	221.5 (243)	195 (239)	<0.001
Size of herd	561	279	151–1,200	397 (313)	345 (237)	808 (723)	699 (743)	<0.001
Cows/ha	3.34	0.48	1.96–5.03	3.13 (2.93)	2.98 (2.68)	3.66 (3.35)	3.60 (3.14)	<0.001
Full-time staff equivalents (FTE)	3.3	1.3	1–7	2.7	2.3	4.4	3.8	<0.001
Cows/FTE	169	51	78–396	148	151	187	189	<0.001
Years dairy farming^c	18.9	10.0	1–50	22.8	19.3	16.3	16.9	0.03
^a Mean figures for regions are included in brackets, and were derived from New Zealand Dairy Statistics 2008–09 (Anonymous 2009)
^b Significance of effect of region as a covariate in linear regression models
^c Years the key decision maker interviewed for each farm had been dairy farming

Table 2. Summary statistics for demographic variables for farms and key decision makers (KDM) from 133 seasonal-calving, pasture-based dairy herds from four regions in New Zealand, enrolled in the National Herd Fertility Study during 2009, presented for all herds in the study, and for herds in the study by region.

Variable, and level	No. (%) all herds	Herds by region				P-value^a
		Waikato	Taranaki	North Canterbury	South Canterbury
Farm
Farm business structure						0.02
Family owned farm	104 (78%)	91%	88%	67%	66%
Non-family owned corporate farm	13 (10%)	9%	6%	9%	16%
Equity partnership	16 (12%)	0%	6%	24%	19%
Production system^b						<0.001
1	11 (8%)	11%	21%	0%	0%
2	14 (10%)	11%	24%	0%	6%
3	38 (29%)	49%	18%	24%	22%
4	38 (29%)	26%	15%	30%	44%
5	32 (24%)	3%	21%	46%	28%
Predominant breed						0.60
Friesian	51 (38%)	39%	36%	33%	47%
Friesian x Jersey	70 (53%)	58%	49%	58%	44%
Jersey	12 (9%)	3%	15%	9%	9%
KDM
Occupation						0.01
Owner-occupier	77 (57%)	69%	63%	64%	34%
Higher-order sharemilker^c	25 (19%)	20%	31%	6%	19%
Lower-order sharemilker^c	17 (13%)	6%	6%	12%	28%
Farm manager	4 (3%)	3%	0%	3%	6%
Other (manager of equity partnership)	10 (8%)	3%	0%	16%	13%
Age group (years)						0.02
20–29	12 (9%)	3%	13%	9%	13%
30–39	36 (27%)	17%	22%	21%	50%
40–49	56 (42%)	46%	41%	55%	28%
≥50	28 (20%)	34%	25%	15%	9%
^a Significance of differences between regions derived using χ^2 tests
^b Production systems were defined as: 1 = no imported feed fed to lactating or non-lactating (dry) cows; 2 = 4–14% imported feed fed to lactating cows, and dry cows grazed off-farm; 3 = 10–20% imported feed fed to dry cows and to lactating cows at the end of the season to extend lactation; 4 = 20–30% imported feed fed to dry cows and to lactating cows at both the beginning and end of the season to extend lactation; 5 = 25–30% imported feed used throughout the year
^c Higher-order sharemilkers were those that received >35% of farm income; lower-order sharemilkers were those that received ≤35% of farm income

Figure 1. Distribution of responses by key decision makers managing 133 seasonal-calving, pasture-based dairy herds from four regions in New Zealand, enrolled in the National Herd Fertility Study during 2009, asked to rate their attitude in relation to personality traits, using a Likert-type scale, where 1 = very low and 5 = very high.

Figure 2. Distribution of responses by key decision makers managing 133 seasonal-calving, pasture-based dairy herds from four regions in New Zealand, enrolled in the National Herd Fertility Study during 2009, asked to rate the importance of farm management practices or likelihood of them trying unproven ideas or technologies, using a Likert-type scale, where 1 = very low and 5 = very high.

Figure 3. Distribution of responses by key decision makers managing 133 seasonal-calving, pasture-based dairy herds from four regions in New Zealand, enrolled in the National Herd Fertility Study during 2009, asked to rate the current genetic quality, milksolids performance and reproductive performance of their herd, using a Likert-type scale, where 1 = very low and 5 = very high.

Figure 4. Distribution of responses by key decision makers managing 133 seasonal-calving, pasture-based dairy herds from four regions in New Zealand, enrolled in the National Herd Fertility Study during 2009, asked to rate their management priorities over the next 3 years, using a Likert-type scale, where 1 = very low and 5 = very high.

Figure 5. Distribution of responses by key decision makers managing 133 seasonal-calving, pasture-based dairy herds from four regions in New Zealand, enrolled in the National Herd Fertility Study during 2009, asked to rate the likelihood of factors being a constraint to the reproductive performance of their herd over the previous 2 years, using a Likert-type scale, where 1 = very low and 5 = very high.

Table 3. Odds ratios (and 95% CI) of significant predictors for rating attitudinal and management variables (using a Likert-type scale where 1 = very low and 5 = very high) by key decision makers (KDM) from 133 seasonal-calving, pasture-based dairy herds from four regions in New Zealand, enrolled in the National Herd Fertility Study during 2009.

Attitude	Predictor, and level	OR (95%CI)	P-value^a
Self motivation for job	Herd size (per SD of herd size)^b	1.62 (1.15–2.32)	0.006
Appetite to learn	Region^c		0.007
	Waikato	3.01 (1.21–7.66)
	Taranaki	Ref
	North Canterbury	4.57 (1.78–12.14)
	South Canterbury	3.73 (1.47–9.76)
influence over other farmers	KDM age (years)		0.015
	20–29	Ref
	30–39	1.79 (0.51–6.34)
	40–49	1.76 (0.52–5.92)
	≥50	2.18 (0.58–8.19)
Importance of timeliness of seasonal tasks	Region^c		<0.001
	Waikato	6.11 (2.13–19.63)
	Taranaki	Ref
	North Canterbury	4.33 (1.6–12.57)
	South Canterbury	6.76 (2.25–23.61)
Importance of adherence to proven protocols	KDM occupation		0.008
	Owner-occupier	Ref
	Higher-order sharemilker^d	1.19 (0.49–2.90)
	Lower-order sharemilker^d	3.00 (1.00–9.68)
	Farm manager	7.57 (2.02–37.4)
	KDM age (years)		0.020
	20–29	Ref
	30–39	1.87 (0.51–7.00)
	40–49	2.01 (0.54–7.66)
	≥50	3.48 (0.87–14.45)
Likelihood of trying unproven ideas or technologies	Production system^e		0.008
	1	Ref
	2	3.47 (0.78–16.33)
	3	7.66 (2.02–30.95)
	4	6.15 (1.61–24.93)
	5	11.1 (2.78–47.3)
benefit of group learning with farmers	KDM age (years)		0.008
	20–29	2.04 (0.64–6.70)
	30–39	1.75 (0.78–3.94)
	40–49	Ref
	≥50	2.27 (0.95–5.54)
	Production system^e		0.03
	1	1.83 (0.53–6.39)
	2	1.67 (0.51–5.59)
	3	4.21 (1.73–10.58)
	4	Ref
	5	1.54 (0.61–3.95)
	Herd size (per SD of herd size)^b	1.62 (1.10–2.40)	0.01
Importance of farm machinery	KDM age (years)		<0.001
	20–29	3.27 (1.02–11.17)
	30–39	2.46 (1.11–5.56)
	40–49	Ref
	≥50	1.47 (0.62–3.5)
Importance of data recording	Region^c		0.01
	Waikato	4.48 (1.71–12.16)
	Taranaki	Ref
	North Canterbury	3.62 (1.41–9.63)
	South Canterbury	2.76 (1.02–7.63)
	KDM age (years)		0.02
	20–29	1.71 (0.53–5.84)
	30–39	1.55 (0.67–3.67)
	40–49	Ref
	≥50	1.50 (0.61–3.76)
Importance of staff training	KDM occupation		0.03
	Owner-occupier	1.38 (0.51–3.86)
	Higher-order sharemilker^d	Ref
	Lower-order sharemilker^d	3.40 (0.88–13.96)
	Farm manager	6.10 (1.49–29.02)
Importance of staff suggestions	KDM age (years)		0.03
	20–29	Ref
	30–39	5.40 (1.39–21.84)
	40–49	4.14 (1.14–15.57)
	≥50	5.73 (1.4–24.39)
Importance of delegation	KDM age (years)		0.03
	20–29	3.31 (0.62–18.82)
	30–39	3.40 (0.97–12.37)
	40–49	1.62 (0.6–4.38)
	≥50	Ref
	Years dairy farming^f	1.07 (1.02–1.12)	0.009
	Production system^e		0.04
	1	Ref
	2	4.63 (0.95–23.71)
	3	4.23 (1.13–16.53)
	4	4.25 (1.14–16.44)
	5	8.89 (2.28–36.61)
Importance of succession planning	KDM age (years)		0.003
	20–29	1.14 (0.35–3.92)
	30–39	1.94 (0.91–4.18)
	40–49	Ref
	≥50	1.58 (0.69–3.7)
^a Significance of the likelihood-ratio test indicating that a model including the variable improved the ft of the model significantly, with an alpha (type I) error equivalent to p
^b The odds of rating self motivation at any particular rating or higher increased by 1.62 for every increase in herd size of 279 cows (SD of size of herd in the study, from Table 1)
^c The predictor represented the effect of the four regions examined in the study
^d Higher-order sharemilkers were those that received >35% of farm income; lower-order sharemilkers were those that received ≤35% of farm income
^e Production systems were defined as: 1 = no imported feed fed to lactating or non-lactating (dry) cows; 2 = 4–14% imported feed fed to lactating cows, and dry cows grazed off-farm; 3 = 10–20% imported feed fed to dry cows and to lactating cows at the end of the season to extend lactation; 4 = 20–30% imported feed fed to dry cows and to lactating cows at both the beginning and end of the season to extend lactation; 5 = 25–30% imported feed used throughout the year
^f Odds of reporting any particular rating or higher for every extra year dairy farming
Ref = reference (for all variables, the level with the lowest odds was used as the reference category)

Table 4. Odds ratios (and 95% CI) of significant predictors for increased rating of perceived priorities (using a Likert-type scale, where 1 = very low and 5 = very high) by key decision makers (KDM) from 133 seasonal-calving, pasture-based dairy herds from four regions in New Zealand, enrolled in the National Herd Fertility Study during 2009.

Priority	Predictor, and level	OR (95%CI)	P-value^a
Animal health	Region^b		0.028
	Waikato	Ref
	Taranaki	2.49 (0.9–7.16)
	North Canterbury	1.55 (0.57–4.31)
	South Canterbury	6.68 (1.77–31.14)
	KDM occupation		0.013
	Owner-occupier	Ref
	Higher-order sharemilker^c	1.57 (0.53–5.15)
	Lower-order sharemilker^c	28.63 (3.2–737.95)
	Farm manager	1.70 (0.44–7.54)
	KDM age (years)		0.015
	20–29	Ref
	30–39	8.16 (1.52–48.61)
	40–49	11.42 (2.07–70.7)
	≥50	8.02 (1.38–51.85)
Nutrition management	Region^b		0.001
	Waikato	Ref
	Taranaki	2.85 (1.15–7.25)
	North Canterbury	1.82 (0.72–4.65)
	South Canterbury	8.34 (2.9–25.62)
	KDM age (years)		0.003
	20–29	Ref
	30–39	2.53 (0.74–8.75)
	40–49	1.87 (0.59–5.97)
	≥50	3.61 (0.98–13.64)
Environmental sustainability	Region^b		<0.001
	Waikato	Ref
	Taranaki	4.79 (1.93–12.21)
	North Canterbury	1.22 (0.5–3.01)
	South Canterbury	9.50 (3.5–26.91)
	KDM age (years)		0.016
	20–29	Ref
	30–39	1.29 (0.37–4.61)
	40–49	1.71 (0.51–5.86)
	≥50	1.70 (0.46–6.47)
Herd genetics	Region^b		<0.001
	Waikato	Ref
	Taranaki	3.09 (1.26–7.72)
	North Canterbury	1.01 (0.41–2.47)
	South Canterbury	5.88 (2.21–16.22)
	KDM age (years)		0.004
	20–29	1.26 (0.36–4.44)
	30–39	Ref
	40–49	1.26 (0.55–2.86)
	≥50	1.52 (0.59–3.96)
	Further education^d	0.43 (0.21–0.87)	0.018
Milksolids performance	Region^b		0.004
	Waikato	Ref
	Taranaki	4.10 (1.56–11.17)
	North Canterbury	2.65 (1–7.23)
	South Canterbury	5.84 (2.05–17.53)
	KDM age (years)		<0.001
	20–29	Ref
	30–39	5.59 (1.58–20.66)
	40–49	10.62 (2.72–44.4)
	≥50	26.29 (4.65–166.77)
	Years dairy farming^e	0.92 (0.87–0.97)	0.002
Milk quality	Region		<0.001
	Waikato	1.51 (0.64–3.63)
	Taranaki	9.28 (3.44–26.66)
	North Canterbury	Ref
	South Canterbury	10.78 (3.85–32.34)
	KDM age (years)		<0.001
	20–29	Ref
	30–39	3.33 (0.93–11.93)
	40–49	6.01 (1.7–21.6)
	≥50	4.43 (1.13–17.61)
Pasture management	KDM occupation		0.036
	Owner-occupier	1.54 (0.62–3.73)
	Higher-order sharemilker^c	Ref
	Lower-order sharemilker^c	11.89 (1.97–230.09)
	Farm manager	2.30 (0.55–12.03)
Staff management	KDM occupation		<0.001
	Owner-occupier	Ref
	Higher-order sharemilker^c	2.38 (0.85–7.01)
	Lower-order sharemilker^c	18.03 (4.47–84.67)
	Farm manager	6.98 (1.96–27.83)
	KDM age (years)		0.001
	20–29	Ref
	30–39	1.54 (0.38–6.22)
	40–49	8.13 (1.78–38.42)
	≥50	2.93 (0.63–13.96)
^a Significance of the likelihood-ratio test indicating that a model including the variable improved the ft of the model significantly, with an alpha (type I) error equivalent to p
^b The predictor represented the effect of the four regions examined in the study
^c Higher-order sharemilkers were those that received >35% of farm income; lower-order sharemilkers were those that received ≤35% of farm income
^d The odds of increasing a ranking of a priority if the KDM had undertaken a form of further education
^e Odds of reporting any particular rating or higher for every extra year dairy farming
Ref = reference (for all variables, the level with the lowest odds was used as the reference category)

Table 5. Odds ratios (and 95% CI) of significant predictors for increased rating of the perceived likelihood of constraints affecting herd reproductive performance (using a Likert-type scale, where 1 = very unlikely and 5 = very likely) by key decision makers (KDM) from 133 seasonal-calving, pasture-based dairy herds from four regions in New Zealand, enrolled in the National Herd Fertility Study during 2009.

Factor affecting reproduction	Predictor, and level	OR (95%CI)	P-value^a
Anoestrous cows in the herd
	KDM age (years)		0.018
	20–29	2.49 (0.8–7.93)
	30–39	Ref
	40–49	1.38 (0.66–2.88)
	≥50	1.12 (0.43–2.90)
Low body condition score of herd	KDM age (years)		0.031
	20–29	1.08 (0.32–3.58)
	30–39	1.20 (0.49–2.96)
	40–49	1.41 (0.63–3.18)
	≥50	Ref
Management of bulls	Farm business type		0.031
	Family owned	Ref
	Non-family owned	2.81 (0.99–8.15)
	Equity partnership	2.82 (1.04–7.69)
	KDM age (years)		0.006
	20–29	1.11 (0.31–3.89)
	30–39	Ref
	40–49 ≥50	1.21 (0.56–2.62) 1.92 (0.75–4.99)
Protracted	KDM age (years)		0.002
calving spread	20–29	2.83 (0.76–10.6	9)
	30–39	2.02 (0.81–5.05)
	40–49	2.39 (1.03–5.61)
	≥50	Ref
Endometritis	KDM age (years)		0.003
	20–29	5.39 (1.44–20.84)
	30–39	2.04 (0.70–6.00)
	40–49	3.14 (1.19–8.58)
	≥50	Ref
	Further education^b	3.30 (1.57–7.15)	0.002
	Production system^c		0.042
	1	1.83 (0.45–7.41)
	2	2.57 (0.65–9.87)
	3	3.66 (1.52–9.02)
	4	Ref
	5	1.04 (0.41–2.67)
	Herd size (per SD of herd size)^d	1.93 (1.29–2.92)	0.001
Heat detection	KDM age (years)		0.006
	20–29	2.87 (0.91–9.15)
	30–39	1.26 (0.59–2.70)
	40–49	Ref
	≥50	1.57 (0.66–3.76)
Heifer size at calving	Region^e		0.033
	Waikato	3.57 (1.38–9.5)
	Taranaki	1.18 (0.45–3.14)
	North Canterbury	1.85 (0.74–4.7)
	South Canterbury	Ref
	KDM age (years)		<0.001
	20–29	6.57 (1.83–24.59)
	30–39	3.64 (1.27–10.92)
	40–49	4.03 (1.58–10.82)
	≥50	Ref
Genetic quality of herd	KDM age (years)		0.031
	20–29	1.28 (0.38–4.26)
	30–39	1.55 (0.61–3.98)
	40–49	1.40 (0.59–3.34)
	≥50	Ref
^a Significance of the likelihood-ratio test indicating that a model including the variable improved the ft of the model significantly, with an alpha (type I) error equivalent to p
^b The odds of increasing a ranking of a priority if the KDM had undertaken a form of further education
^c Production systems were defined as: 1 = no imported feed fed to lactating or non-lactating (dry) cows; 2 = 4–14% imported feed fed to lactating cows, and dry cows grazed off-farm; 3 = 10–20% imported feed fed to dry cows and to lactating cows at the end of the season to extend lactation; 4 = 20–30% imported feed fed to dry cows and to lactating cows at both the beginning and end of the season to extend lactation; 5 = 25–30% imported feed used throughout the year
^d The odds of rating self motivation at any particular rating or higher increased by 1.62 for every increase in herd size of 279 cows (SD of size of herd in the study, from Table 1)
^e The predictor represented the effect of the four regions examined in the study