The effect of zeranol implants on growth and pregnancy loss in beef heifers

1994 ◽  
Vol 74 (1) ◽  
pp. 73-76 ◽  
Author(s):  
B. D. King ◽  
R. N. Kirkwood ◽  
C. L. Guenther ◽  
R. D. H. Cohen ◽  
G. A. Bo ◽  
...  

Live weight, average daily gain (ADG) and reproductive performance were compared between heifers implanted with zeranol at birth, 100 and 200 d of age (n = 54) and those not implanted (n = 50). Zeranol implantation resulted in increased (P < 0.05) ADG from birth to weaning, weaning weight, ADG from weaning to breeding, breeding weight and calving weight but did not affect (P > 0.05) calf birth weights, incidence of dystocia, calf survival or gestation lengths. Zeranol implants did not affect (P > 0.05) the incidence or magnitude of the pre-ovulatory LH surge or the number of heifers that ovulated between 48 and 168 h after cloprostenol injection. Pregnancy rate 42 d after bull entry did not differ between the two groups (P > 0.10), tended toward a difference at 72 d (P < 0.10), and was different at 133 d (P < 0.05), with implanted heifers having a lower pregnancy rate than non-implanted heifers. Between day 72 and day 133 after bull entry there was a 10% embryonic or fetal mortality rate in zeranol-implanted heifers, which differed from the 0% loss in non-implanted heifers (P < 0.05). We conclude that serial implants of zeranol from birth reduced the pregnancy rate in heifers and that this effect was due to early fetal loss. Key words: Zeranol, embryonic/fetal mortality, bovine, pregnancy rate, ultrasonography

2017 ◽  
Vol 5 (2) ◽  
pp. 26
Author(s):  
Janice G. P. Bowman ◽  
Bok F. Sowell

One hundred-one crossbred beef heifers (average weight 256.1 kg) were used to evaluate the effects of diet during an 84-day period, on growth and reproductive performance. The four treatments were: 1) grass hay; 2) grass hay + 0.9 kg/day barley; 3) grass hay + 1.8 kg/day barley; and 4) alfalfa hay. Heifers were assigned randomly to 12 pens by weight (three pens/treatment). Prior to feeding, barley was cracked through a roller-mill. Heifers consuming alfalfa hay or grass hay + 1.8 kg barley gained 39% faster (0.68 and 0.74 kg/day, respectively; P = 0.01) than heifers consuming grass hay alone (0.51 kg/day). Heifers consuming grass hay + 0.9 kg barley were intermediate in average daily gain (ADG; 0.63 kg/day). Hay intake was 16% greater (P < 0.10) by heifers consuming alfalfa hay, grass hay, and grass hay + 0.9 kg barley compared with those consuming grass hay + 1.8 kg barley (average 8.1 vs 7.0 kg/day). Using costs (USD) of $0.066/kg, $0.099/kg, and $0.0935/kg for grass hay, alfalfa hay, and barley, respectively, feed cost/day was greatest (P < 0.01) for alfalfa hay ($0.81/day), intermediate for the grass hay + barley diets (average $0.63/day), and lowest for grass hay ($0.53/day). Cost/kg gain was less (P < 0.10) for grass hay + 1.8 kg barley compared with alfalfa hay. No diet differences (P > 0.70) were found in reproductive performance of the heifers. Feeding replacement heifers alfalfa hay resulted in performance equivalent to feeding grass hay + 1.8 kg barley, but the alfalfa hay diet had a higher cost.


2021 ◽  
Vol 73 (5) ◽  
pp. 1180-1186
Author(s):  
A.M. Oliveira ◽  
L.D.F. Silva ◽  
A.P.O. Souza ◽  
E.L.A. Ribeiro ◽  
C.C. Jobim ◽  
...  

ABSTRACT The aim of this study was to evaluate the effect of sorghum silage substitution with different proportions of triticale silage on the performance and carcass of Braford heifers. Twenty-four Braford heifers were randomly assigned to four diets where sorghum silage was replaced at 0%, 30%, 60%, and 100% for triticale silage in a feedlot system. During sixty-tree days of the experiment, the feed intake, feed ratio conversion, and average daily gain were measured. The heifers were slaughtered and the effects of the sorghum and triticale silage in carcass characteristics were evaluated. The replacement of sorghum silage with triticale silage did not affect the feed intake and average daily gain (P> 0.05). Feed gain ratio was higher for the heifers that received lower proportions of triticale silage (0% and 30%) in replace sorghum silage (P <0.05). Eye loin area and fat thickness were similar among treatments (P<0.05). Other carcass characteristics, such as slaughter live weight, dressing percentage, conformation and fat classification were similar among experimental treatments (P<0.005). Triticale silage can replace sorghum silage for finishing beef heifers in feedlot system and provides similar carcass characteristics.


1994 ◽  
Vol 74 (2) ◽  
pp. 203-208 ◽  
Author(s):  
L. M. Rutter ◽  
P. A. Day

A field trial was conducted to determine the effects of a growth implant on growth, pregnancy rate, calving difficulty and calf weaning weight in replacement beef heifers. Heifers were assigned equally to either a control (n = 43; no implant), Ralgro (n = 43) or Synovex-C (n = 42) treatment group based on age of dam and age and weight at the start of the trial (implantation at 45–90 d of age). Neither Ralgro nor Synovex-C enhanced heifer weight or average daily gain (ADG) from the start of the trial to weaning (approximately 7 mo of age), breeding, or pregnancy determination. At breeding, Synovex-C implanted heifers had greater pelvic area than controls while Ralgro implanted heifers were intermediate (control = 149.7, Ralgro = 154.7 and Synovex-C = 157.4 pooled SE of 2.2 cm2; P = 0.05). Pelvic dimensions were similar among treatments at pregnancy determination and there were no treatment effects on calving difficulty. Age of dam affected heifer weight (P = 0.0005) and ADG (P = 0.001) to weaning, with heifers from mature cows weighing more at weaning and having a higher ADG from the start of the study to weaning than heifers from either first- or second-calf cows. Post-weaning performance of heifers from first-calf cows was similar to heifers from mature cows while heifers from second-calf cows were lighter at breeding (P = 0.04) and had a lower ADG from weaning to breeding (P = 0.04). Age of dam did not influence pregnancy rate (P = 0.10), but more heifers from second-calf cows calved late in the calving season (≥ 64 d) compared with heifers from either first-calf or mature cows (P = 0.04). It appears from this field trial that use of a growth implant between 45 and 90 d of age neither enhanced growth nor impaired fertility in beef heifers bred as yearlings. It also appears that second-calf 3-yr-olds may need to be managed separately from the mature cow herd in order to optimize replacement heifer development. Key words: Bovine, replacement heifers, growth implant, age of dam, weight, pregnancy rate


1994 ◽  
Vol 74 (1) ◽  
pp. 77-82 ◽  
Author(s):  
L. M. Rode ◽  
T. J. Lysyk ◽  
K. A. Beauchemin

A 2-yr grazing study was conducted to determine the effect of lasalocid (BOVATEC) supplement, to yearling beef heifers, on growth rate, reproductive performance and survival of horn fly larvae in feces. Lasalocid was supplemented via a commercially prepared mineral mix offered free-choice. Average daily mineral intake was 83.2 and 89.1, and 140.3 and 147.2 g head−1, for BOVATEC and CONTROL animals, in years 1 and 2, respectively. Mineral intake was unaffected by treatment. The variability in mineral intake was high, as indicated by the large coefficients of variation: 32.1 and 29.1% in year 1 and 29.0 and 38.8% in year 2, for BOVATEC and CONTROL treated animals, respectively. Average daily gain for BOVATEC heifers was 14.5% greater (P = 0.04) than for CONTROL heifers in year 1 even though lasalocid intake was less than the expected level, but only 3% greater (P = 0.51) in year 2. Lasalocid had no significant effect on reproductive performance of heifers or on horn fly larval survival in cattle feces. Horn fly larval survival showed a weak (R = 0.21) and negative relationship with manure nitrogen content. Key words: Mineral consumption, lasalocid, ionophore, pasture, cattle


2020 ◽  
Author(s):  
Lidiane R. Eloy ◽  
Carolina Bremm ◽  
José F. P. Lobato ◽  
Luciana Pötter ◽  
Emilio A. Laca

AbstractPregnancy rate is a major determinant of population dynamics of wild ungulates and of productivity of livestock systems. Allocation of feeding resources, including stocking rates, prior to and during the breeding season is a crucial determinant of this vital rate. Thus, quantification of effects and interaction among multiple factors that affect pregnancy rate is essential for management and conservation of pasture-based systems. Pregnancy rate of 2982 heifers and primiparous cows was studied as a function of animal category, average daily gain during the breeding season, stocking rate, pasture type and body weight at the beginning of the breeding season. Data were obtained from 43 experiments conducted in commercial ranches and research stations in the Pampas region between 1976 and 2015. Stocking rate ranged from 200 to 464 kg live weight/ha, which brackets values for most of the grazinglands in similar regions. Age at breeding was 14-36 months (24.6 ± 7.5 months); initial breeding weights were 129-506 kg and 194-570 kg for heifers and primiparous cows. Pregnancy rate was modeled with an apriori set of explanatory variables where proximate variables (breed, body weight at start of breeding, weight gain during breeding and category) were included first and subsequently modeled as functions of other variables (pasture type, supplementation and stocking rate). This modeling approach allowed detection of direct and indirect effects (through nutrition and body weight) of factors that affect pregnancy rate. Taurine (Bos taurus breeds, N = 1058) had higher pregnancy rate than B. Taurus x B. indicus crossbreed (N = 1924) females. Pregnancy rate of heifers and primiparous cows grazing in natural grasslands decreased with increasing stocking rate, but no effect of stocking rate was detected in cultivated and improved pastures. Pregnancy rate increased with increasing average daily gain during the breeding season. Use of cultivated or improved natural pastures promotes higher pregnancy rate, as well as allows higher in stocking rate at the regional level. Body weight at the start of the breeding season is the primary determinant of pregnancy rates in heifer and primiparous cows.


Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 986 ◽  
Author(s):  
Ion Pérez-Baena ◽  
Marta Jarque-Durán ◽  
Ernesto A. Gómez ◽  
José-Ramón Díaz ◽  
Cristòfol Peris

The aim of this work was to improve the growth characteristics of Murciano-Granadina (MG) kids through terminal crossbreeding of MG goats to Boer bucks. Four experiments were carried out, using a total of 354 MG goats, half of which were mated with MG bucks (n = 12) and the other half with Boer bucks (n = 12). The kids were raised in artificial rearing until slaughter weight (9 kg). The birth weight and average daily gain were recorded in crossed kids (n = 197 and 145, respectively) and purebred kids (n = 257 and 169, respectively). Crossed kids presented significant differences (p < 0.001) compared to MG purebred kids in birth weight (+ 24%), mortality in artificial rearing (−37%), average daily gain (+32%) and milk powder conversion rate (−16%). However, the reproductive performance rates of MG goats mated with Boer bucks were slightly worse (pregnancy rate: 78.5% vs. 86.6%, p < 0.05; kidding rate: 62.0% vs. 75.7%; p < 0.01; prolificacy: 1.9 vs. 2.1 kids/parturition), especially when the matings took place in non-breeding season (experiments conducted at latitude 38–39° N). It is concluded that the terminal crossbreeding of MG goats to Boer bucks (those not used to produce replacement kids) could be an interesting option for ethical goat production.


2016 ◽  
Vol 52 ◽  
pp. 58-63
Author(s):  
L. V. Onishchenko ◽  
M. I. Danilchuk

The most perspective genotype in our region is Red White-belted breed, which has high performance both under pure breeding and under crossing with other breeds. The results of complex evaluation of Red White-belted swine of the herd bred in SE "RF Zoryane" breeding farm are presented. It was revealed that animals of the farm comply with elite class and the first class. The main breeding boars used at the farm belong to such genealogical lines: Deviz, Division, Dantist, Debut, and Dobryak. In the structure of the herd, the most numerous was Dobryak line, which part was 58.8%, Division, Debut, Devis lines – 11.8% per line, Dantist line – 5.8%. The herd sows belong to 7 families: Drabowka, Dekada, Dyktsiya, Doina, Dylema, Delta, Dogma. Average prolificacy of the sows was 10.0 piglets. Litter weight at 60 days’ age was 181.0 kg, and live weight of piglet – 19.0 kg. The performance of sows as prolificacy increased by 0.6 head on average. The complex appraisal index for the herd was 104.1 points. The average daily gain of the replacement pigs was 570 g. The highest daily gain was from five to six months – 611.2 g, and the figure of compactness index characterized a certain elongation of animals, increasing meat traits. Further work with Red White-belted breed aims at preserving and expanding the breeding base and genealogical structure, as well as increasing the reproductive, fattening and meat traits.


1992 ◽  
Vol 55 (3) ◽  
pp. 425-430 ◽  
Author(s):  
S. Beers ◽  
A. W. Jongbloed

AbstractA total of 384 piglets from a three-way cross Yorkshire ♂ × (Finnish Landrace ♂ × Dutch Landrace♀) ♀ in the live-weight range of 11 to 25 kg were used in a feeding trial. The effect of supplementary microbial phytase from Aspergillus niger var. Van Tieghem on performance (average daily gain (ADG), average daily food intake (ADFI) and food conversion ratio (FCR)) and apparent digestibility of total phosphorus (P), in comparison with a non-supplemented basal diet or a diet supplemented with one or two levels of monocalcium phosphate (MCP), were studied.The piglets were allotted to 12 blocks. Within each block, four experimental diets were offered ad libitum for a period of 4 weeks i.e. (1) basal diet; (2) basal diet + 1·0 g P, from MCP per kg diet; (3) basal diet + 1·9 g P, from MCP per kg diet; and (4) basal diet + 1450 phytase units (PTU) per kg diet. The diets, with added chromium III oxide as a marker, were cold pelleted without steam at a temperature not above 60°C to avoid a possible inactivation of the phytase. In all diets the ratio calcium: digestible P was intended to be constant.Adding 1450 PTU of Aspergillus niger phytase enhanced the apparent digestibility of P by proportionately 0·216 when compared with diet 1 and by proportionately 0·100 compared with diet 3. In addition, significantly higher ADG and ADFI and better FCR were noted in pigs receiving supplementary microbial phytase than in pigs on any other treatment. The content of digestible P of the diet with added phytase, however, zvas between the two levels of the diets with added MCP.


1964 ◽  
Vol 6 (3) ◽  
pp. 301-308 ◽  
Author(s):  
Henning E. Nielsen

Sixteen blocks of eight littermate pigs were weaned at 3 weeks of age and each divided into four groups. Various levels of nutrition were applied to the pigs so that the four groups reached 20 kg. at 59, 68, 80 and 91 days of age, respectively.Only small differences were observed between groups in feed conversion ratio to 20 kg.; however, Group 4 required more feed per kg. gain than the three other groups.During the second period (20–90 kg.) the pigs in each group were divided into two sub-groups, which were on a high and a low plane of nutrition respectively. In both sub-groups the type of feeding before 20 kg. influenced the average daily gain and feed conversion ratio. The older the pigs were at 20 kg. the higher the daily gain and the lower the feed conversion ratio in the following period. There was an increase in daily feed intake with increased age at 20 kg. for pigs fed ad lib. during the second period.An increase in age at 20 kg. caused a significant decrease in thickness of backfat, a greater area of eye muscle and a smaller area of fat overlying muscle. For pigs fed ad lib. the area of eye muscle was significantly increased by a higher age at 20 kg. live-weight.


Author(s):  
A. A. Balnikov ◽  
Yu. S. Kazutova ◽  
N. M. Kostomakhin ◽  
I. F. Gridyushko ◽  
E. S. Gridyushko

The purpose of the work was a comprehensive evaluation of the productive and reproductive traits of sows of Yorkshire and Landrace breeds and their offspring under the conditions of a breeding enterprise in the Republic of Belarus. During the studies of reproductive traits, it has been revealed that the highest rate of prolificacy among the evaluated breeds was distinguished by Yorkshire sows 14,0 heads for farrowing. In terms of milk content, Landrace sows were 2,5 kg or 4,57 % higher than Yorkshire sows. In terms of weight and socket weight per piglet at weaning at the age of 28 days sows Landrace piglets surpassed herdmates Yorkshire breed in the weight of the litter by 6,8 %, and the weight of one pig by 0,9 %. It has been found by the results of the evaluation of fattening and meat qualities of purebred young pigs that the best parameters were different gilts of Landrace breeds, whose age achieve the live weight of 100 kg was 163,1 days, and average daily gain of live weight – 864,8 g, which was higher than in young pigs of Yorkshire breed by 1,8 day or 1,09 %, and 28,9 g or by 3,46 %. The young pigs of Landrace breed has been characterized by the best values of the area of the “eye of loin” – 73,8 cm² and the highest yield and amount of meat – 68,5 % and 24 kg, which was 11,4 cm² or 18,2 % and 0,4 kg or 3,5 abs.%, respectively, higher than the herdmates of Yorkshire breed. The results obtained indicate the possibility of using boars and sows of Landrace and Yorkshire breeds not only in breeding, but also in industrial pig breeding.


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