**3.3 Productivity**

The most important nutrients influencing milk and beef production in semiarid environments are protein, energy, and minerals [57]. Some studies have revealed that energy and minerals are not the limiting requirements for grazing cattle, but rather protein deficits are the cause of cattle productivity losses [58, 59]. Blezinger et al. [57, 60] however, reported that rangelands fail to supply energy and minerals in adequate quantity during the early to mid-wet season. The consequence is a retarded growth rate of cattle which turns out to be a main stumbling block to boosting body weight growth [61, 62] and, as a result, impacting semi-arid beef production In the semi-arid areas, rangeland energy and mineral supplies in the late wet and dry seasons are usually perceived as sufficient to support cattle production needs on pastoral systems [59, 60]. Thus, in community rangelands in semi-arid areas, cattle production efficiency is sometimes governed by nutrient availability, which is affected primarily by temperature and seasonal rainfall distribution [54]. The traditional cattle sector in Nigeria is characterized by low productivity due to seasonality of quantitative and qualitative feed shortages, which is arguably the most significant barrier to improving smallholder enterprise production and productivity [63, 64]. Permanent land damage is prevented through grazing on large expanse of land. The pastoralists use the approach to maximize spatial resource use by allowing soil rejuvenation. Negative consequences of seasonal fluctuations in feed supplies have not been adequately established on performance parameters of pasture cattle in the Guinea Savannah Zone of Nigeria. Such data is required for the development of effective feeding and disease prevention strategies. Cattle, for example, are susceptible to stomach discomfort due to a seasonal shift in food [64]. The changeover from a forage-based to a finishing diet strong in grain aids marbling in beef, but it also causes gastric distress. This may have a negative impact on their development. Similarly, seasonal variations in the quantity and quality of feed supplies have an impact on beef cattle performance and carcass quality [64, 65].

### **3.4 Assisted reproductive technologies in animal production**

Assisted reproductive technologies (ART) are widely used in humans and animals in many parts of the world to expand our understanding of reproductive processes and to improve reproductive efficiency. Oestrus synchronization, artificial insemination (AI), multipleovulation and embryo transfer (MOET), in vitro fertilization (IVF), sex determination, cloning, and genetic engineering are some of the technologies used in animal production [66]. These are powerful technologies capable of enhancing productivity, and when combined with bioinformatics will provide more impact in the future of animal production [66]. The cow is typically monotocous with an average gestation length of 40 weeks and therefore a relatively long generation interval. The rate at which a highly desirable cow can be used to enhance the genetic state of a herd is slow if no interference is made [67]. Hence ARTs are particularly useful in this species because of the low reproductive rates and long generation intervals. In the cattle industry, ARTs were initially developed to increase the production of calves from parent cattle with high genetic potentials, but now offer many opportunities for beef and dairy cattle production.

### *3.4.1 Oestrus synchronization*

Oestrous synchronization involves the application of pharmacologic means to control oestrus and ovulation in farm animals. As a result, female animals are forced to go through oestrus (ovulation) at a specified, opportune time rather than

### *Assisted Reproductive Technologies as Veritable Tools for Improving Production Efficiencies… DOI: http://dx.doi.org/10.5772/intechopen.100066*

when it would naturally occur. In general, the procedures rely on either artificially inducing premature luteolysis with luteolytic drugs (e.g. prostaglandin F2 alpha or its analogues) or temporarily suppressing ovarian function with progestagens.

Synchronization offers several advantages and facilitates the maximal and batch managements of AI and calving in cattle herds, thereby increasing productivity and decreasing costs in dairy and beef cattle production [68].

Synchronization may have some benefits in beef herds, such as decreasing the calving to conception gap, and hence the calving interval and possibly the calving season. Accurate detection of oestrus is critical to achieving high pregnancy rates particularly in large cattle herds. Hence oestrous synchronization offers another strategy to circumvent the critical problem of oestrus detection [69].

## *3.4.2 Artificial insemination (AI)*

Artificial insemination has been utilized worldwide for more than 50 years. It is still the predominant technology applied for the improvement of reproductive efficiency and productivity in cattle through progeny testing and genetic improvement [67]. AI is the introduction of live spermatozoa into the genital tract of the female to cause fertilization by means other than natural mating. Semen from bulls can be extended and preserved at 4–5°C for a few days or frozen in plastic straws in liquid nitrogen at −196°C for years or decades. Semen from a few high-performance bulls can then be used to breed large number of cows leading to rapid genetic improvement and dissemination of new breeds within cattle populations [65].

Movement of preserved semen instead of live bulls would also improve trade, reduce production cost and also decrease the spread of cattle diseases usually transmitted by direct contact between cattle. The use of AI also prevents the rearing of bulls that involve added cost along with the possibility of causing injury or death to farmers or staff. Controlling and recording the time of AI helps to avoid indiscriminate mating (often observed in natural mating), thereby facilitating proper farm recordkeeping and fertility management.
