Milk production and reproductive performance of cows induced into lactation and treated with bovine somatotropin

2006 ◽  
Vol 82 (4) ◽  
pp. 555-559 ◽  
Author(s):  
M. Mellado ◽  
E. Nazarre ◽  
L. Olivares ◽  
F. Pastor ◽  
A. Estrada

AbstractMilk production and reproductive performance of pluriparous dairy cows was compared for cows whose lactations were induced by hormonal treatment or followed natural calving. The study was conducted on 179 high-yielding dairy cows in a large dairy operation in a hot arid environment of northern Mexico, where bovine somatotropin (bST) was routinely used in all cows. To induce lactation, 98 cows that had previously failed to become pregnant were treated with 500 mg bST on days 1, 8 and 21. From days 2 to 8, cows were treated with oestradiol cypionate (0·30 mg/kg live weight (LW) per day) and progesterone (0·28 mg/kg LW per day). From days 9 to 15, oestradiol cypionate alone was given. PGF2α was given on day 16. Nothing was administered on days 17 and 18, and 15 mg flumetasone was administered from days 19 to 21. Lactation was induced successfully in all 98 cows subjected to the hormone treatment. All cows received 500 mg bST every 14 days throughout lactation from 63±7 days after lactation had started. Cows with induced lactations produced less (P<0·01) milk per 305-day lactation (9599±1387 kg) than controls (12 302±1245 kg). Proportion of cows pregnant was similar in induced cows and non-treated cows (71 v. 75%). Induction of lactation was associated with increased numbers of services per pregnancy (5·8±4·0 v. 4·22±2·98; P<0·01) compared with controls; however, impaired reproduction might not necessarily have been related to the hormonal treatment to induce lactation, but due to the nature of the cows utilized for this treatment group. This protocol can be used on dairy farms where bST treatment and prolonged steroid administration of dairy cows is legally permitted.

Author(s):  
Jesús Mellado ◽  
Jessica Flores ◽  
Francisco G. Véliz ◽  
Ángeles de Santiago ◽  
José E. García ◽  
...  

The objective of this observational study was to determine the effect of two (2x) compared to three (3x) times a day milking in Holstein cows undergoing lactations ≥600 d on milk production and reproductive performance. Two large adjacent commercial dairy herds with similar size, facilities, and management in a hot area of northern Mexico (25° N) were used. Cows in one herd (n= 214) were milked two times a day (2x), the other herd was milked three times a day (3x; n=245) and both groups were milked for at least 600 days. For cows in first lactation, total milk yield did not differ between 3x and 2x cows (19796 ± 3354 vs. 19269 ± 3652 kg; p > 0.10) in lactations with an average of 696 and 650 days in milk (DIM), respectively. Multiparous 3x cows produced more total milk days than 2x cows (20942 ± 3920 vs. 18910 ± 2632 kg; p < 0.01) with greater (p < 0.01) DIM for 3x (685 ± 117 days) than 2x (631 ± 88 days) cows. Lactation persistence was greater (p < 0.05) in 2x (62 ± 9%) than 3x (60 ± 10%) cows. Overall conception rate (CR) did not differ between 2x and 3x cows (53.3% vs. 49.8%) but 3x cows required one more service (p < 0.01) to get pregnant than 2x animals.  Given that average milk yield throughout the complete lactation did not differ between 2x (29.8 ± 2.0 kg) and 3x (29.3 ± 2.9 kg) cows, it was concluded that two-times-a-day milking is equally effective as three-times-a-day milking to attain acceptable milk yield in lactations over 600 days. However, reproductive performance based on first-service CR and services per pregnancy was negatively affected by three-times-a-day milking.


1999 ◽  
Vol 52 (3) ◽  
pp. 481-496 ◽  
Author(s):  
L.J. Judge ◽  
P.C. Bartlett ◽  
J.W. Lloyd ◽  
R.J. Erskine

1989 ◽  
Vol 48 (2) ◽  
pp. 449-457 ◽  
Author(s):  
B. P. Mullan ◽  
I. H. Williams

ABSTRACTThe level of body reserves in first-litter sows was manipulated by giving gilts one of three levels (high (H), medium (M) or low (L)) of food from selection (44 kg live weight) to parturition. The aim of this experiment was either to maintain or to mobilize these reserves during lactation (31·4 days) by feeding sows to appetite (high (H)) or 2·0 kg/day (low (L)).When the level of body reserves was increased prior to farrowing (171 kg live weight, 32 mm backfat) sows had a lower voluntary food intake during lactation than those animals that farrowed with a low level of body reserves (126 kg live weight, 20 mm backfat) (H-H v. L-H, 3·4 v. 4·9 kg/day; P < 0·001). Both groups had a normal return to oestrous activity after weaning (mean interval between weaning and mating of 14 days) but the heavier animals mobilized more of their body reserves (H-H −30·7 kg live weight, -4·3 mm backfat; L-H -3·6 kg live weight +0·9 mm backfat; P < 0·001). When food intake during lactation was restricted to 2·0 kg/day the interval between weaning and mating was increased by 50% regardless of the level of body reserves present at farrowing. For the same animals, there were insufficient body reserves to support milk production at the same level as for those animals given food t o appetite.


2019 ◽  
Vol 17 (1) ◽  
pp. e0403 ◽  
Author(s):  
Jessica Flores ◽  
José E. García ◽  
Jesús Mellado ◽  
Leticia Gaytán ◽  
Ángeles De Santiago ◽  
...  

The objective of this study was to determine the effects of the administration of recombinant bovine somatotropin (rbST) throughout lactation to high-yielding subfertile (conception > 270 days postpartum) Holstein cows undergoing extended lactations (≥480 d) on milk production and reproductive performance. The study used two large adjacent commercial herds with similar management in a hot area of northern Mexico (25° N). Cows in one herd (n=2341) received a 500-mg dose of rbST every 14 d until dried off, starting 60 days postpartum. The other herd served as control (n=984). Across parity, rbST-treated cows produced 20% greater milk yield than control cows in 305-d lactations. Across parities, milk yield from 305 d postpartum to the end of lactation was 2734 kg higher in rbST-treated cows than control cows. Across parities rbST-treated cows produced 4777 more kg of milk during the entire lactation (mean 605 d) than the control group (mean 572 d). Conception rates (CR) at first service were only 3.2% and 5.9% (p<0.05) for control and rbST-treated cows, respectively. Overall CR was 43.5% and 61.6% (p<0.05) for control and treated cows, respectively. Control cows required 2.4 more (p<0.01) services per conception than rbST-treated cows. It was concluded that in this hot environment, the use of rbST suits dairy producers because it substantially improves both milk yield and reproductive performance in subfertile high-yielding Holstein cows. By markedly increasing lactation length and lactation persistency farm efficiency is greatly improved due to extended herd life.


2004 ◽  
Vol 78 (2) ◽  
pp. 345-354 ◽  
Author(s):  
H. C. F. Wicks ◽  
A. F. Carson ◽  
M. A. McCoy ◽  
C. S. Mayne

AbstractTwenty-nine Holstein-Friesian and 20 Norwegian dairy herd replacements were used to investigate the effect of habituating heifers to the milking parlour environment prior to calving on subsequent lactational performance. The heifers commenced the study at 3 weeks prior to calving when they were allocated on the basis of breed, genetic merit and live weight to either a habituation or no habituation (control) treatment. Heifers were housed together in cubicle accommodation with grass silage offered ad libitum along with 1 kg of concentrates per head per day offered in the feeding passage (control treatment) or in the food managers in the milking parlour (habituation treatment). Animals in the habituation treatment were exposed to the full milking parlour routine once daily (afternoon milking) in a 20-point rotary herringbone parlour. Holstein-Friesian heifers averaged 2.6 kg/day more milk than the Norwegian replacements. Holstein-Friesian heifers also had higher fat and protein yields than Norwegian heifers, however they also lost more body condition during the first 3 months of lactation. Habituated heifers yielded on average 1.3 kg/day more milk (P < 0.001) than the control group of heifers over the first 100 days of lactation (26.7 v. 25.4 (s.e.d. 0.38) kg/day), with the difference being greatest in the first 2 to 3 weeks of lactation. In early lactation, animals on the habituation treatment lost more live weight (0.16 v. 0.02 (s.e.d. 0.061) kg/day) (P < 0.05) and body condition than those on the control treatment. Duration of milking was longer (P < 0.001) (378.4 v. 340.5 (s.e.d. 6.53) s) and milk flow rate slower (P < 0.001) (2.20 v. 2.46 (s.e.d. 0.041) kg/min) respectively for the habituation compared with control group. Somatic cell counts (SCC) were lower (P < 0.001) for habituation group (1.66 v. 1.79 (s.e.d. 0.037) log10SCC per ml), but there was no significant treatment effect on locomotion scores. Reproductive performance was lower for habituated heifers, with increased intervals to conception (P < 0.05) (102 v. 83 (s.e.d. 9.22) days). Habituating heifers to the milking parlour environment prior to calving increased milk production but appeared to have some detrimental effects on reproductive performance.


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