Combined effects of once-daily milking and feeding level in the first three weeks of lactation on milk production and enzyme activities, and nutritional status, in Holstein cows

Abstract

-Twenty-four multiparous cows were divided into 4 groups immediately after calving according to a 2 × 2 factorial design: 2 milking frequencies (1 daily [morning only] milking for the first three weeks of lactation, then 2 daily milkings vs. 2 daily milkings throughout) under two diet energy concentrations (normal or low). The trial lasted 30 weeks, on average, and ended in the pasture on 28 May 2000. During the winter period, the cows were housed together in a free-stall barn, and were given complete rations ad libitum. The cows that were not milked were significantly more vocal than the controls, close to the omitted milking, and in a large number of them, milk leaked from the udder. Once-daily milking gradually reduced the amount of milk secreted in relation to that produced by cows milked twice a day, with differences of 8.5 kg·d -1 (P < 0.01) at week 3. As early as the first week of resumption of twice-daily milking, that difference ceased to be statistically significant but amounted to 1.3 kg·d -1 (P > 0.10) throughout the rest of the trial. Once-daily milking did not affect the contents of milk fat, true protein, serum albumin and lactose contents or somatic cell count, plasmin activity and plasminogen-derived activity. That treatment also increased the G1 immunoglobulin concentration (P = 0.02; measured at week 3) and reduced milk lipoprotein lipase activity. Once-daily milking improved the nutritional status at the beginning of lactation (reduced live weight and body condition losses, and increased the computed energy balance) and had no effect on the ration intake. The normal-energy diet produced expected results, in relation to the low-energy diet: a significant increase in intake (1.2 kg DM·d -1 ), milk yield (3.1 kg·d -1 ), milk protein content (2.0 g·kg -1 ), and nutritional indices, in particular. The decrease in milk yield induced by once-daily milking during the (0)4 73 98 13 80; e-mail: remond@gentiane.enitac.fr first three weeks of lactation was 5.5 kg·d -1 in the low-energy group and 8.5 kg·d -1 for the normal energy group (non-significant interaction; P > 0.10). once-daily milking / level of feeding / milk production / enzyme activities / nutritional status Résumé -Effets de la traite une fois par jour combinée au niveau d'alimentation pendant les trois premières semaines de la lactation sur la production et les activités enzymatiques du lait, et l'état nutritionnel, chez des vaches Holstein. Vingt-quatre vaches multipares ont été réparties dès le vêlage en 4 lots, selon un schéma factoriel 2 × 2 : 2 fréquences de traite (1 traite par jour pendant les 3 premières semaines de lactation, puis 2 traites par jour vs. 2 traites par jour en permanence) × 2 concentrations énergétiques de la ration (normale ou basse). L'essai a duré en moyenne 30 semaines et s'est terminé au pâturage, le 28 mai 2000. Pendant la période hivernale, les vaches étaient logées ensemble dans une stabulation libre à logettes et recevaient à volonté une ration complète. La traite omise était celle du soir. Les vac...

Once-a-day milking of Holstein and Montbéliarde cows for 7 weeks in mid-lactation

“…This fall is consistent with earlier observations of a reduction of lipolysis with increased interval between milkings (Chilliard and Lamberet, 1984;Klei et al, 1997) and with a lowered LPL activity in OAD (Ré mond et al, 2002 and (and here), although we observed no individual correlation between these parameters. The relative fall in FFA, which was much more marked than that of the LPL activity (267% v. 227%), suggests that other mechanisms are brought into play.…”

“…The OAD cows demonstrated their discomfort (vocalisations) for a shorter time than in an earlier trial conducted in early lactation where they were separated from the TAD cows every evening at the time of milking (Ré mond et al, 2002), suggesting that it was the separation of the group rather than the skipped milking that caused these effects. This confirms the conclusion of a recent study (Tucker et al, 2007) that behavioural indices do not suggest that cow welfare is impaired by OAD milking.…”

“…However, certain authors (Stelwagen et al, 1998a;Brulé et al, 2003;Keane et al, 2006) have found that the plasma cortisol level (a potential stress marker) in the OAD cows is higher (sometimes not significantly) than in cows milked twice or thrice daily. Milk leakage from the udders of OAD cows was observed for a shorter time than in other trials (Ré mond et al, 2002;Brulé et al, 2003), probably because the cows were grazing at a more advanced stage of lactation.…”

The decrease in milk yield during once daily milking is due to regulation of synthetic activity rather than apoptosis of mammary epithelial cells in goats

“…However, the variation in milk fat content observed over the different weeks of the ODM period can explain the contradictory effects reported in various studies. Some studies reported an increase in milk fat content (Stelwagen et al, 1994;Lacy-Hulbert et al, 1999;O'Brien et al, 2002) but others reported no variation (Ré mond et al, 2002;Marnet and Komara, 2008) or a decrease (Ben Chedly et al, 2011) in milk fat content during ODM. Our finding suggests that the inhibition of milk fat synthesis by ODM may gradually disappear beginning in the second week of treatment.…”

Towards an agroecological assessment of dairy systems: proposal for a set of criteria suited to mountain farming

“…Criterion 6: As grass is the main production in mountain areas, not competing with human feeding, farmers may also choose breeds with a lower milk yield than Holstein cows that can be fed with grass forages only. In the case of highyielding cows, farmers may also shorten the periods when the animals have high needs by milking the cows only once a day from calving, to reduce the lactation peak (Rémond et al, 2002) or by extending the interval between calving (Auldist et al, 2007). In addition, grouping the calving in spring allows the production of most milk at pasture, which requires less concentrate for a similar milk yield, as the feeding value of grazed swards is always higher than that of the corresponding preserved forage.…”