The size and cost of the estimation error when using analysis of a sample of a dairy herd to assess the whole herd performance

Chamberlain, A. T.; Wassell, T. R.

doi:10.1016/0167-5877(94)00435-l

Cited by 3 publications

(1 citation statement)

References 2 publications

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“…Extracting a variety of estimates concerning the incidence of lameness and mastitis in dairy herds throughout the world, there does appear to be an increasing trend (although not statistically significant) in spite of many attempts at prevention (Figure 6; Bigras-Poulin et al , 1990; Grohn et al , 1990; Kaneene and Hurd, 1990; Tranter and Morris, 1991; Bartlett et al , 1992; Lam et al , 1993; Oltenacu and Ekesbo, 1994; Chamberlain and Wassell, 1995; Hemsworth et al , 1995; Clarkson et al , 1996; Esslemont and Kossaibati, 1996; Etherington et al , 1996; Enting et al , 1997; Frei et al , 1997; Judge et al , 1997; Beckett et al , 1998; Shpigel et al , 1998; Duffield et al , 1999; Loeffler et al , 1999; Galindo et al , 2000; Stevenson, 2000; Heuer et al , 2001; Leonard et al , 2001; Hultgren, 2002; Regula et al , 2004; Haskell et al , 2006). Within these studies, the average incidence ± s.e.…”

Section: Solutionsmentioning

confidence: 99%

Why is it getting more difficult to successfully artificially inseminate dairy cows?

Dobson

Walker

Morris

et al. 2008

Animal

133

101

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Successfully using artificial insemination (AI) is defined as getting cows pregnant when the farmer wants them in-calf and making the best use of appropriate genetic potential. Over the past 30 to 50 years, the percentage of animals in oestrus that stand-to-be-mounted (STBM) has declined from 80% to 50%, and the duration of STBM from 15 h to 5 h; both in parallel with a reduction in first-service-pregnancy-rate from 70% to 40%. Meanwhile, the incidence of lameness and mastitis has not decreased; and it takes more than an extra 40 and 18 days, respectively, to get a lame or mastitic cow in-calf compared to healthy herd-mates. The intensity of oestrus is 50% lower in severely lame cows, and fewer lame cows ovulate. Luteal phase milk progesterone concentrations are also 50% lower in lame cows, and follicular phase oestradiol is also lower in non-ovulating lame cows compared to ovulating animals. Furthermore, lame cows that do not ovulate do not have an LH surge, and the LH pulse frequency in their late follicular phase is lower (0.53 v. 0.76 pulses/h). Thus, we suggest that the stress of lameness reduces LH pulsatility required to drive oestradiol production by the dominant follicle. The consequent low oestradiol results in less-intense oestrus behaviour and failure to initiate an LH surge; hence there is no ovulation. A series of experimental studies substantiate our hypothesis that events activating the hypothalamus-pituitary-adrenal axis interfere at both the hypothalamus and the pituitary level to disrupt LH and oestradiol secretion, and thus the expression of oestrus behaviour. Our inability to keep stress at a minimum by appropriately feeding and housing high-production cows is leading to a failure to meet genetic potential for yield and fertility. We must provide realistic solutions soon, if we want to successfully use AI to maintain a sustainable dairy industry for the future.

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